Cardiology — MCQs

Q: 274. A young athlete was found to have hypertrophic cardiomyopathy during testing for a competitive sport. Which of the following maneuvers will increase the murmur?

Valsalva maneuver. **Valsalva maneuver** - The **Valsalva maneuver** reduces **preload** by decreasing venous return to the heart. - A decrease in preload reduces the left ventricular chamber size, which in turn exacerbates the **left ventricular outflow tract (LVOT) obstruction** characteristic of hypertrophic cardiomyopathy (HCM), thereby **increasing the intensity of the murmur**. *Handgrip* - **Handgrip** is an isometric exercise that leads to an increase in **afterload** and **peripheral vascular resistance**. - Increased afterload causes the left ventricle to eject blood against higher pressure, which **enlarges the left ventricular chamber** and **reduces the LVOT obstruction**, thus **decreasing the intensity of the murmur** in HCM. *Squatting* - **Squatting** increases both **preload** (due to increased venous return) and **afterload** (due to increased peripheral vascular resistance). - The increased preload and afterload lead to an **increased left ventricular volume**, which **reduces the LVOT obstruction** and therefore **decreases the intensity of the murmur** in HCM. *Passive leg raise* - **Passive leg raise** increases **preload** by increasing venous return to the heart from the lower extremities. - The increased preload leads to an **increased left ventricular chamber size**, which **reduces the LVOT obstruction** and therefore **decreases the intensity of the murmur** in HCM. *Leaning forward* - Leaning forward during auscultation is typically used to better hear **aortic regurgitation murmurs**, as it brings the aorta closer to the chest wall. - This maneuver does not significantly alter **cardiac preload or afterload** in a way that would consistently increase the murmur of hypertrophic cardiomyopathy.

Q: A patient presents with features of heart failure. On examination, an irregularly irregular pulse is noted, and the patient has a loud diastolic sound. The jugular venous pressure (JVP) shows a rapid Y descent. What is the most likely diagnosis?

Mitral stenosis. ***Mitral stenosis*** - An **irregularly irregular pulse** suggests **atrial fibrillation**, a common complication of mitral stenosis due to left atrial enlargement. - A **loud diastolic sound**, also known as an **opening snap**, is characteristic of a stenotic mitral valve as it opens, occurring early in diastole. - The **rapid Y descent** on JVP can occur due to elevated right-sided pressures from pulmonary hypertension secondary to mitral stenosis. *Constrictive pericarditis* - While it can cause heart failure and an elevated JVP with a rapid Y descent (**Friedreich's sign**), the description of an "irregularly irregular pulse" and a "loud diastolic sound" (opening snap) is not typical. - The loud diastolic sound in constrictive pericarditis would be a **pericardial knock**, which is usually later than an opening snap and less distinct. *Cardiac tamponade* - Characterized by **Beck's triad** (hypotension, muffled heart sounds, elevated JVP) and often presents with **pulsus paradoxus**. - The JVP in tamponade typically shows an **absent or diminished Y descent**, due to impaired ventricular filling from external compression. *Aortic regurgitation* - Causes a **diastolic murmur**, but not a loud diastolic sound or opening snap. - The pulse is often a **collapsing pulse** or **water-hammer pulse**, and it is not typically irregularly irregular unless atrial fibrillation or another arrhythmia is co-existent. *Mitral regurgitation* - Can cause heart failure and atrial fibrillation, but the characteristic finding is a **pansystolic murmur**, not a loud diastolic sound. - There is no opening snap in mitral regurgitation; instead, there may be an **S3 gallop** in severe cases. - The rapid Y descent is less prominent compared to mitral stenosis.

Q: A patient presents with large sweaty hands, macroglossia, and frontal bossing. What is the best test for confirmation of the diagnosis?

IGF-1. ***IGF-1*** - Elevated **IGF-1 (Insulin-like Growth Factor 1)** is the most reliable screening test for acromegaly, reflecting integrated GH secretion over time. - The clinical signs of **large sweaty hands**, **macroglossia**, and **frontal bossing** are classic symptoms of acromegaly, caused by excessive growth hormone (GH) production, which then stimulates IGF-1. *GHRH levels* - **Growth hormone-releasing hormone (GHRH)** levels are typically only measured when investigating ectopic GHRH production as a rare cause of acromegaly, which is not the primary diagnostic step. - While GHRH stimulates GH, its direct measurement is not the standard initial diagnostic test for suspected pituitary-driven acromegaly. *IGF-2* - **IGF-2 (Insulin-like Growth Factor 2)** plays a role in fetal growth and certain tumor-related syndromes, but it is not the primary mediator or diagnostic marker for acromegaly in adults. - IGF-1, not IGF-2, is the main growth factor responsible for the anabolic effects of growth hormone. *GH levels after glucose suppression* - Measuring **GH levels after glucose suppression** (oral glucose tolerance test with 75g glucose) is a confirmatory test for acromegaly, used when IGF-1 levels are equivocal or borderline. - In healthy individuals, glucose suppresses GH secretion to <1 ng/mL, but in acromegaly, GH levels remain elevated (failure to suppress), confirming autonomous GH hypersecretion. *Random GH level* - **Random GH levels** are unreliable for diagnosing acromegaly due to the pulsatile nature of GH secretion, with significant variation throughout the day. - A single normal GH level does not exclude acromegaly, and a single elevated level can occur in healthy individuals during normal secretory peaks, making it inadequate as a diagnostic test.

Q: What is the most common cause of death in idiopathic pulmonary fibrosis (IPF)?

Respiratory failure. ***Respiratory failure*** - **Progressive fibrosis** of the lung tissue in idiopathic pulmonary fibrosis (IPF) directly impairs gas exchange, leading to **hypoxemia** and hypercapnia. - This deterioration ultimately culminates in **respiratory failure**, which is the primary cause of mortality in most IPF patients. *Pulmonary edema* - While pulmonary edema can occur in systemic conditions, it is not the **primary or most common cause of death** specifically in IPF. - IPF is characterized by **fibrotic remodeling**, not primarily fluid overload in the alveoli. *Cancer* - Patients with IPF have an **increased risk of lung cancer**, but it is not the most common cause of death compared to respiratory failure. - The development of cancer is a **complication**, not the direct mechanism by which most IPF patients succumb to the disease. *Pulmonary arterial hypertension (PAH)* - PAH can be a significant complication of IPF, contributing to increased morbidity and mortality, but it is typically a **secondary contributor to death**, often by worsening respiratory mechanics. - Its presence usually **compounds respiratory failure**, rather than being the standalone, most common cause of death. *Acute exacerbation of IPF* - Acute exacerbations represent episodes of **rapid clinical deterioration** with worsening dyspnea and hypoxemia, often idiopathic or triggered by infections. - While they are a **significant cause of mortality** (accounting for a substantial proportion of IPF deaths), the underlying mechanism still relates to respiratory failure, making chronic progressive respiratory failure the most common overall cause of death.

Q: In Type 1 Diabetes Mellitus (DM) stage 3 beta cell destruction, which of the following is the most likely presentation?

Hyperglycemia symptomatic. ***Hyperglycemia symptomatic*** - **Type 1 DM stage 3** is characterized by sufficient **beta-cell destruction** to cause overt hyperglycemia. - This level of hyperglycemia typically leads to classic symptoms such as **polyuria, polydipsia, and weight loss**. *Dysglycemic symptomatic* - **Dysglycemic** refers to abnormal blood sugar levels, but this term is too broad and doesn't specify the degree or symptomatic nature as precisely as **hyperglycemia symptomatic**. - While patients are symptomatic, the primary issue is **hyperglycemia**, making that a more specific and accurate description. *Normoglycemic symptomatic* - **Normoglycemic** implies normal blood sugar levels, which is inconsistent with **Type 1 DM stage 3** where significant beta-cell destruction has occurred. - This stage is defined by definite hyperglycemia, so a patient cannot be symptomatic while having normal glucose levels due to the disease. *Dysglycemic asymptomatic* - While there is **dysglycemia**, **asymptomatic presentation** is more characteristic of earlier stages (Type 1 DM stage 2), where hyperglycemia is present but not yet severe enough to cause overt symptoms. - In **stage 3**, beta-cell destruction is substantial, leading to glucose levels that are high enough to cause noticeable symptoms. *Normoglycemic asymptomatic* - **Normoglycemic asymptomatic** describes **Type 1 DM stage 1**, where autoimmunity is present but beta-cell destruction has not yet progressed enough to affect glucose levels. - This is the earliest stage of Type 1 DM, well before the overt hyperglycemia seen in stage 3.

Q: A young patient in an endemic area presents with pleural fluid showing LDH level greater than 0.6 times the serum LDH, protein level greater than 0.5 times the serum protein, and lymphocytic predominance. What is the most likely diagnosis?

Tuberculosis. ***Tuberculosis*** - The patient's presentation with **exudative pleural fluid** (LDH > 0.6 times serum LDH, protein > 0.5 times serum protein) in an **endemic area** strongly suggests tuberculosis. - The **lymphocytic predominance** in the pleural fluid is a hallmark characteristic of tuberculous pleurisy. - **Young age** and **endemic area** further support TB as the most likely diagnosis. *Heart failure* - Pleural effusions due to heart failure are typically **transudative**, meaning they have low protein and LDH levels. - While heart failure can lead to pleural effusions, the fluid characteristics (exudative, lymphocytic predominance) do not fit this diagnosis. *Hepatic failure* - Pleural effusions in hepatic failure (e.g., due to cirrhosis) are usually **transudative** and result from fluid shifting from the abdomen (hepatic hydrothorax). - The fluid analysis in this scenario (exudative, lymphocytic predominance) is inconsistent with hepatic failure. *Renal failure* - Pleural effusions associated with renal failure (e.g., uremic pleurisy) can be exudative, but they often present with a **neutrophilic predominance** or may be hemorrhagic. - The specific lymphocytic predominance points away from typical renal failure-associated effusions. *Malignancy* - While malignant pleural effusions (lymphoma, metastatic carcinoma) can present with **lymphocytic predominance** and exudative characteristics, the clinical context is crucial. - The patient's **young age** and presentation in an **endemic area for tuberculosis** makes TB far more likely than malignancy. - In endemic areas, TB should be ruled out first before considering malignancy in young patients with lymphocytic pleural effusions.

Q: A patient presents with hypotension, hyponatremia, and blackening of the palmar creases. Which of the following conditions is most likely associated with these symptoms?

Addison disease. ***Addison disease*** - **Hypotension**, **hyponatremia**, and **hyperpigmentation** (blackening of palmar creases) are classic symptoms of **primary adrenal insufficiency** or Addison disease, due to deficient cortisol and aldosterone. - The lack of **cortisol** leads to hypotension and fatigue, while the absence of **aldosterone** causes hyponatremia and hyperkalemia. *Conn syndrome* - This condition involves **primary hyperaldosteronism**, typically leading to **hypertension** and **hypokalemia**, which contradicts the patient's symptoms of hypotension and hyponatremia. - Pigmentation changes are not a feature of Conn syndrome. *Cushing's syndrome* - Characterized by **excess cortisol**, leading to symptoms like **hypertension**, **hyperglycemia**, and central obesity, not hypotension or hyperpigmentation. - **Hyponatremia** is also not typical in Cushing's syndrome. *Primary ACTH deficiency* - Also known as **secondary adrenal insufficiency**, this condition results in low cortisol but typically spares aldosterone production, meaning **hyponatremia** and **hyperkalemia** are less common. - **Hyperpigmentation** does not occur in primary ACTH deficiency because ACTH levels are low. *Sheehan syndrome* - This is **postpartum pituitary necrosis** causing panhypopituitarism, which can lead to secondary adrenal insufficiency with hypotension and hyponatremia. - However, **hyperpigmentation does not occur** in Sheehan syndrome because ACTH levels are low (secondary insufficiency), not elevated as in Addison disease. - The clinical context would typically include a history of postpartum hemorrhage and failure to lactate.

Q: A patient presents with wheezing that improves with as-needed use of albuterol. Spirometry shows FEV1 ranging from 70 % to 83 %, and the patient experiences nighttime chest tightening twice a week. What is the most appropriate treatment?

Add an inhaled corticosteroid. ***Add an inhaled corticosteroid*** * The patient has persistent asthma as evidenced by symptoms occurring twice a week (nighttime chest tightening), and **FEV1 variability** despite current albuterol use. * Adding a **low-dose inhaled corticosteroid** is the recommended *first-line controller treatment* for persistent asthma to reduce inflammation and prevent exacerbations per **GINA guidelines**. *Continue with albuterol* * Continuing albuterol alone is insufficient for persistent asthma, as it only provides **symptomatic relief** and does not address the underlying inflammation. * This approach would lead to continued symptoms and potential **asthma exacerbations**. *Replace with salmeterol twice daily* * Salmeterol is a **long-acting beta-agonist (LABA)**, and while it provides prolonged bronchodilation, it should never be used as monotherapy in asthma due to the risk of severe exacerbations. * LABAs should always be prescribed in combination with an **inhaled corticosteroid**. *Start Tab prednisolone* * **Oral prednisolone** is a systemic corticosteroid typically reserved for **severe asthma exacerbations** or for patients whose symptoms are not controlled by high-dose inhaled corticosteroids and other controller medications. * It carries more significant **side effects** with long-term use compared to inhaled corticosteroids. *Add a leukotriene modifier* * While **leukotriene receptor antagonists** (e.g., montelukast) can be used as alternative controller therapy for mild persistent asthma, they are considered **less effective** than inhaled corticosteroids. * They are typically reserved as an alternative for patients who cannot use or tolerate inhaled corticosteroids, or as **add-on therapy** in more severe cases.

A 32-year-old female presents with a 2-month history of progressive, painless swelling in the left side of her neck. She also reports low-grade fever, night sweats, and unintentional weight loss. Physical examination reveals a firm, non-tender, immobile mass in the left cervical region, and multiple smaller lymph nodes in the supraclavicular area. Chest X-ray shows mediastinal widening, and a lymph node biopsy confirms the presence of Reed-Sternberg cells. What is the most appropriate management for this patient?

A patient presents with large sweaty hands, macroglossia, and frontal bossing. What is the best test for confirmation of the diagnosis?

What is the most common cause of death in idiopathic pulmonary fibrosis (IPF)?

In Type 1 Diabetes Mellitus (DM) stage 3 beta cell destruction, which of the following is the most likely presentation?

A young patient in an endemic area presents with pleural fluid showing LDH level greater than 0.6 times the serum LDH, protein level greater than 0.5 times the serum protein, and lymphocytic predominance. What is the most likely diagnosis?

A patient presents with hypotension, hyponatremia, and blackening of the palmar creases. Which of the following conditions is most likely associated with these symptoms?

A patient presents with wheezing that improves with as-needed use of albuterol. Spirometry shows FEV1 ranging from 70 % to 83 %, and the patient experiences nighttime chest tightening twice a week. What is the most appropriate treatment?

Q10

A 60-year-old lady presents with shortness of breath (SOB) and episodes of angina pectoris. Work-up reveals aortic stenosis. Which of the following is the most likely reason behind these chest pain episodes?

Cardiology US Medical PG Practice Questions and MCQs

Question 1: 274. A young athlete was found to have hypertrophic cardiomyopathy during testing for a competitive sport. Which of the following maneuvers will increase the murmur?

A. Handgrip
B. Valsalva maneuver (Correct Answer)
C. Squatting
D. Leaning forward
E. Passive leg raise

Explanation: **Valsalva maneuver** - The **Valsalva maneuver** reduces **preload** by decreasing venous return to the heart. - A decrease in preload reduces the left ventricular chamber size, which in turn exacerbates the **left ventricular outflow tract (LVOT) obstruction** characteristic of hypertrophic cardiomyopathy (HCM), thereby **increasing the intensity of the murmur**. *Handgrip* - **Handgrip** is an isometric exercise that leads to an increase in **afterload** and **peripheral vascular resistance**. - Increased afterload causes the left ventricle to eject blood against higher pressure, which **enlarges the left ventricular chamber** and **reduces the LVOT obstruction**, thus **decreasing the intensity of the murmur** in HCM. *Squatting* - **Squatting** increases both **preload** (due to increased venous return) and **afterload** (due to increased peripheral vascular resistance). - The increased preload and afterload lead to an **increased left ventricular volume**, which **reduces the LVOT obstruction** and therefore **decreases the intensity of the murmur** in HCM. *Passive leg raise* - **Passive leg raise** increases **preload** by increasing venous return to the heart from the lower extremities. - The increased preload leads to an **increased left ventricular chamber size**, which **reduces the LVOT obstruction** and therefore **decreases the intensity of the murmur** in HCM. *Leaning forward* - Leaning forward during auscultation is typically used to better hear **aortic regurgitation murmurs**, as it brings the aorta closer to the chest wall. - This maneuver does not significantly alter **cardiac preload or afterload** in a way that would consistently increase the murmur of hypertrophic cardiomyopathy.

Question 2: A patient presents with features of heart failure. On examination, an irregularly irregular pulse is noted, and the patient has a loud diastolic sound. The jugular venous pressure (JVP) shows a rapid Y descent. What is the most likely diagnosis?

A. Constrictive pericarditis
B. Cardiac tamponade
C. Mitral stenosis (Correct Answer)
D. Aortic regurgitation
E. Mitral regurgitation

Explanation: ***Mitral stenosis*** - An **irregularly irregular pulse** suggests **atrial fibrillation**, a common complication of mitral stenosis due to left atrial enlargement. - A **loud diastolic sound**, also known as an **opening snap**, is characteristic of a stenotic mitral valve as it opens, occurring early in diastole. - The **rapid Y descent** on JVP can occur due to elevated right-sided pressures from pulmonary hypertension secondary to mitral stenosis. *Constrictive pericarditis* - While it can cause heart failure and an elevated JVP with a rapid Y descent (**Friedreich's sign**), the description of an "irregularly irregular pulse" and a "loud diastolic sound" (opening snap) is not typical. - The loud diastolic sound in constrictive pericarditis would be a **pericardial knock**, which is usually later than an opening snap and less distinct. *Cardiac tamponade* - Characterized by **Beck's triad** (hypotension, muffled heart sounds, elevated JVP) and often presents with **pulsus paradoxus**. - The JVP in tamponade typically shows an **absent or diminished Y descent**, due to impaired ventricular filling from external compression. *Aortic regurgitation* - Causes a **diastolic murmur**, but not a loud diastolic sound or opening snap. - The pulse is often a **collapsing pulse** or **water-hammer pulse**, and it is not typically irregularly irregular unless atrial fibrillation or another arrhythmia is co-existent. *Mitral regurgitation* - Can cause heart failure and atrial fibrillation, but the characteristic finding is a **pansystolic murmur**, not a loud diastolic sound. - There is no opening snap in mitral regurgitation; instead, there may be an **S3 gallop** in severe cases. - The rapid Y descent is less prominent compared to mitral stenosis.

Question 3: A 32-year-old female presents with a 2-month history of progressive, painless swelling in the left side of her neck. She also reports low-grade fever, night sweats, and unintentional weight loss. Physical examination reveals a firm, non-tender, immobile mass in the left cervical region, and multiple smaller lymph nodes in the supraclavicular area. Chest X-ray shows mediastinal widening, and a lymph node biopsy confirms the presence of Reed-Sternberg cells. What is the most appropriate management for this patient?

A. NHL with a highly aggressive chemotherapy regimen
B. Hodgkin Lymphoma with the ABVD regimen (Correct Answer)
C. NHL with Rituximab
D. Hodgkin Lymphoma with surgical excision only
E. Hodgkin Lymphoma with radiation therapy only

Explanation: ***Hodgkin Lymphoma with the ABVD regimen*** - The presence of **Reed-Sternberg cells** in a lymph node biopsy, along with **painless lymphadenopathy**, **mediastinal widening**, and **B symptoms** (fever, night sweats, weight loss), is characteristic of **Hodgkin Lymphoma**. - **ABVD chemotherapy** (Adriamycin, Bleomycin, Vinblastine, Dacarbazine) is the standard frontline treatment regimen for Hodgkin Lymphoma, especially in advanced stages or with B symptoms. *NHL with a highly aggressive chemotherapy regimen* - This patient's symptoms and especially the presence of **Reed-Sternberg cells** are pathognomonic for **Hodgkin Lymphoma**, not Non-Hodgkin Lymphoma (NHL). - While some NHLs require aggressive chemotherapy, the specific findings in this case point away from an NHL diagnosis. *NHL with Rituximab* - **Rituximab** is a monoclonal antibody targeting the **CD20 antigen** found on B-cells and is primarily used in the treatment of **B-cell Non-Hodgkin Lymphomas**. - Since the diagnosis here is Hodgkin Lymphoma, characterized by Reed-Sternberg cells (which are atypical B cells that typically lack CD20), rituximab is not an appropriate primary treatment. *Hodgkin Lymphoma with surgical excision only* - **Hodgkin Lymphoma** is a systemic disease, as evidenced by mediastinal widening and B symptoms, indicating spread beyond a localized area. - **Surgical excision alone** is not curative for Hodgkin Lymphoma; systemic chemotherapy, often combined with radiation therapy, is essential for effective treatment. *Hodgkin Lymphoma with radiation therapy only* - While **radiation therapy** plays a role in Hodgkin Lymphoma treatment, it is typically used in **combination with chemotherapy** (combined modality therapy) or reserved for **early-stage, favorable-risk disease without B symptoms**. - This patient presents with **advanced disease** (mediastinal involvement, B symptoms, multiple lymph node regions), which requires **systemic chemotherapy** as the primary treatment modality. - Radiation alone would be inadequate for achieving optimal disease control and cure in this clinical scenario.

Question 4: A patient presents with large sweaty hands, macroglossia, and frontal bossing. What is the best test for confirmation of the diagnosis?

A. GHRH levels
B. IGF-1 (Correct Answer)
C. IGF-2
D. GH levels after glucose suppression
E. Random GH level

Explanation: ***IGF-1*** - Elevated **IGF-1 (Insulin-like Growth Factor 1)** is the most reliable screening test for acromegaly, reflecting integrated GH secretion over time. - The clinical signs of **large sweaty hands**, **macroglossia**, and **frontal bossing** are classic symptoms of acromegaly, caused by excessive growth hormone (GH) production, which then stimulates IGF-1. *GHRH levels* - **Growth hormone-releasing hormone (GHRH)** levels are typically only measured when investigating ectopic GHRH production as a rare cause of acromegaly, which is not the primary diagnostic step. - While GHRH stimulates GH, its direct measurement is not the standard initial diagnostic test for suspected pituitary-driven acromegaly. *IGF-2* - **IGF-2 (Insulin-like Growth Factor 2)** plays a role in fetal growth and certain tumor-related syndromes, but it is not the primary mediator or diagnostic marker for acromegaly in adults. - IGF-1, not IGF-2, is the main growth factor responsible for the anabolic effects of growth hormone. *GH levels after glucose suppression* - Measuring **GH levels after glucose suppression** (oral glucose tolerance test with 75g glucose) is a confirmatory test for acromegaly, used when IGF-1 levels are equivocal or borderline. - In healthy individuals, glucose suppresses GH secretion to <1 ng/mL, but in acromegaly, GH levels remain elevated (failure to suppress), confirming autonomous GH hypersecretion. *Random GH level* - **Random GH levels** are unreliable for diagnosing acromegaly due to the pulsatile nature of GH secretion, with significant variation throughout the day. - A single normal GH level does not exclude acromegaly, and a single elevated level can occur in healthy individuals during normal secretory peaks, making it inadequate as a diagnostic test.

Question 5: What is the most common cause of death in idiopathic pulmonary fibrosis (IPF)?

A. Respiratory failure (Correct Answer)
B. Pulmonary edema
C. Cancer
D. Pulmonary arterial hypertension (PAH)
E. Acute exacerbation of IPF

Explanation: ***Respiratory failure*** - **Progressive fibrosis** of the lung tissue in idiopathic pulmonary fibrosis (IPF) directly impairs gas exchange, leading to **hypoxemia** and hypercapnia. - This deterioration ultimately culminates in **respiratory failure**, which is the primary cause of mortality in most IPF patients. *Pulmonary edema* - While pulmonary edema can occur in systemic conditions, it is not the **primary or most common cause of death** specifically in IPF. - IPF is characterized by **fibrotic remodeling**, not primarily fluid overload in the alveoli. *Cancer* - Patients with IPF have an **increased risk of lung cancer**, but it is not the most common cause of death compared to respiratory failure. - The development of cancer is a **complication**, not the direct mechanism by which most IPF patients succumb to the disease. *Pulmonary arterial hypertension (PAH)* - PAH can be a significant complication of IPF, contributing to increased morbidity and mortality, but it is typically a **secondary contributor to death**, often by worsening respiratory mechanics. - Its presence usually **compounds respiratory failure**, rather than being the standalone, most common cause of death. *Acute exacerbation of IPF* - Acute exacerbations represent episodes of **rapid clinical deterioration** with worsening dyspnea and hypoxemia, often idiopathic or triggered by infections. - While they are a **significant cause of mortality** (accounting for a substantial proportion of IPF deaths), the underlying mechanism still relates to respiratory failure, making chronic progressive respiratory failure the most common overall cause of death.

Question 6: In Type 1 Diabetes Mellitus (DM) stage 3 beta cell destruction, which of the following is the most likely presentation?

A. Dysglycemic symptomatic
B. Normoglycemic symptomatic
C. Dysglycemic asymptomatic
D. Hyperglycemia symptomatic (Correct Answer)
E. Normoglycemic asymptomatic

Explanation: ***Hyperglycemia symptomatic*** - **Type 1 DM stage 3** is characterized by sufficient **beta-cell destruction** to cause overt hyperglycemia. - This level of hyperglycemia typically leads to classic symptoms such as **polyuria, polydipsia, and weight loss**. *Dysglycemic symptomatic* - **Dysglycemic** refers to abnormal blood sugar levels, but this term is too broad and doesn't specify the degree or symptomatic nature as precisely as **hyperglycemia symptomatic**. - While patients are symptomatic, the primary issue is **hyperglycemia**, making that a more specific and accurate description. *Normoglycemic symptomatic* - **Normoglycemic** implies normal blood sugar levels, which is inconsistent with **Type 1 DM stage 3** where significant beta-cell destruction has occurred. - This stage is defined by definite hyperglycemia, so a patient cannot be symptomatic while having normal glucose levels due to the disease. *Dysglycemic asymptomatic* - While there is **dysglycemia**, **asymptomatic presentation** is more characteristic of earlier stages (Type 1 DM stage 2), where hyperglycemia is present but not yet severe enough to cause overt symptoms. - In **stage 3**, beta-cell destruction is substantial, leading to glucose levels that are high enough to cause noticeable symptoms. *Normoglycemic asymptomatic* - **Normoglycemic asymptomatic** describes **Type 1 DM stage 1**, where autoimmunity is present but beta-cell destruction has not yet progressed enough to affect glucose levels. - This is the earliest stage of Type 1 DM, well before the overt hyperglycemia seen in stage 3.

Question 7: A young patient in an endemic area presents with pleural fluid showing LDH level greater than 0.6 times the serum LDH, protein level greater than 0.5 times the serum protein, and lymphocytic predominance. What is the most likely diagnosis?

A. Tuberculosis (Correct Answer)
B. Heart failure
C. Hepatic failure
D. Renal failure
E. Malignancy

Explanation: ***Tuberculosis*** - The patient's presentation with **exudative pleural fluid** (LDH > 0.6 times serum LDH, protein > 0.5 times serum protein) in an **endemic area** strongly suggests tuberculosis. - The **lymphocytic predominance** in the pleural fluid is a hallmark characteristic of tuberculous pleurisy. - **Young age** and **endemic area** further support TB as the most likely diagnosis. *Heart failure* - Pleural effusions due to heart failure are typically **transudative**, meaning they have low protein and LDH levels. - While heart failure can lead to pleural effusions, the fluid characteristics (exudative, lymphocytic predominance) do not fit this diagnosis. *Hepatic failure* - Pleural effusions in hepatic failure (e.g., due to cirrhosis) are usually **transudative** and result from fluid shifting from the abdomen (hepatic hydrothorax). - The fluid analysis in this scenario (exudative, lymphocytic predominance) is inconsistent with hepatic failure. *Renal failure* - Pleural effusions associated with renal failure (e.g., uremic pleurisy) can be exudative, but they often present with a **neutrophilic predominance** or may be hemorrhagic. - The specific lymphocytic predominance points away from typical renal failure-associated effusions. *Malignancy* - While malignant pleural effusions (lymphoma, metastatic carcinoma) can present with **lymphocytic predominance** and exudative characteristics, the clinical context is crucial. - The patient's **young age** and presentation in an **endemic area for tuberculosis** makes TB far more likely than malignancy. - In endemic areas, TB should be ruled out first before considering malignancy in young patients with lymphocytic pleural effusions.

Question 8: A patient presents with hypotension, hyponatremia, and blackening of the palmar creases. Which of the following conditions is most likely associated with these symptoms?

A. Conn syndrome
B. Cushing's syndrome
C. Primary ACTH deficiency
D. Addison disease (Correct Answer)
E. Sheehan syndrome

Explanation: ***Addison disease*** - **Hypotension**, **hyponatremia**, and **hyperpigmentation** (blackening of palmar creases) are classic symptoms of **primary adrenal insufficiency** or Addison disease, due to deficient cortisol and aldosterone. - The lack of **cortisol** leads to hypotension and fatigue, while the absence of **aldosterone** causes hyponatremia and hyperkalemia. *Conn syndrome* - This condition involves **primary hyperaldosteronism**, typically leading to **hypertension** and **hypokalemia**, which contradicts the patient's symptoms of hypotension and hyponatremia. - Pigmentation changes are not a feature of Conn syndrome. *Cushing's syndrome* - Characterized by **excess cortisol**, leading to symptoms like **hypertension**, **hyperglycemia**, and central obesity, not hypotension or hyperpigmentation. - **Hyponatremia** is also not typical in Cushing's syndrome. *Primary ACTH deficiency* - Also known as **secondary adrenal insufficiency**, this condition results in low cortisol but typically spares aldosterone production, meaning **hyponatremia** and **hyperkalemia** are less common. - **Hyperpigmentation** does not occur in primary ACTH deficiency because ACTH levels are low. *Sheehan syndrome* - This is **postpartum pituitary necrosis** causing panhypopituitarism, which can lead to secondary adrenal insufficiency with hypotension and hyponatremia. - However, **hyperpigmentation does not occur** in Sheehan syndrome because ACTH levels are low (secondary insufficiency), not elevated as in Addison disease. - The clinical context would typically include a history of postpartum hemorrhage and failure to lactate.

Question 9: A patient presents with wheezing that improves with as-needed use of albuterol. Spirometry shows FEV1 ranging from 70 % to 83 %, and the patient experiences nighttime chest tightening twice a week. What is the most appropriate treatment?

A. Continue with albuterol
B. Replace with salmeterol twice daily
C. Start Tab prednisolone
D. Add an inhaled corticosteroid (Correct Answer)
E. Add a leukotriene modifier

Explanation: ***Add an inhaled corticosteroid*** * The patient has persistent asthma as evidenced by symptoms occurring twice a week (nighttime chest tightening), and **FEV1 variability** despite current albuterol use. * Adding a **low-dose inhaled corticosteroid** is the recommended *first-line controller treatment* for persistent asthma to reduce inflammation and prevent exacerbations per **GINA guidelines**. *Continue with albuterol* * Continuing albuterol alone is insufficient for persistent asthma, as it only provides **symptomatic relief** and does not address the underlying inflammation. * This approach would lead to continued symptoms and potential **asthma exacerbations**. *Replace with salmeterol twice daily* * Salmeterol is a **long-acting beta-agonist (LABA)**, and while it provides prolonged bronchodilation, it should never be used as monotherapy in asthma due to the risk of severe exacerbations. * LABAs should always be prescribed in combination with an **inhaled corticosteroid**. *Start Tab prednisolone* * **Oral prednisolone** is a systemic corticosteroid typically reserved for **severe asthma exacerbations** or for patients whose symptoms are not controlled by high-dose inhaled corticosteroids and other controller medications. * It carries more significant **side effects** with long-term use compared to inhaled corticosteroids. *Add a leukotriene modifier* * While **leukotriene receptor antagonists** (e.g., montelukast) can be used as alternative controller therapy for mild persistent asthma, they are considered **less effective** than inhaled corticosteroids. * They are typically reserved as an alternative for patients who cannot use or tolerate inhaled corticosteroids, or as **add-on therapy** in more severe cases.

Question 10: A 60-year-old lady presents with shortness of breath (SOB) and episodes of angina pectoris. Work-up reveals aortic stenosis. Which of the following is the most likely reason behind these chest pain episodes?

A. Increased pressure in aorta
B. Decreased pressure in aorta
C. Increased oxygen consumption in the heart (Correct Answer)
D. Increase in volume overload of the heart
E. Decreased coronary blood flow

Explanation: ***Increased oxygen consumption in the heart*** - In **aortic stenosis**, the left ventricle must generate significantly higher pressures to eject blood through the narrowed aortic valve, leading to **left ventricular hypertrophy**. This increased workload significantly raises the **myocardial oxygen demand**. - Angina pectoris occurs when this increased oxygen demand surpasses the oxygen supply, leading to **myocardial ischemia**. - This is the **primary mechanism** of angina in aortic stenosis. *Increased pressure in aorta* - While there is **increased pressure within the left ventricle** to overcome the stenotic valve, the pressure in the aorta *distal* to the stenosis is often normal or even slightly reduced due to the obstruction. - Increased aortic pressure itself is not the primary direct cause of angina in aortic stenosis; rather, it's the compensatory ventricular workload. *Decreased pressure in aorta* - A **decreased pressure in the aorta** could actually worsen coronary perfusion, but the primary reason for angina in aortic stenosis is the vastly **increased myocardial demand**, not necessarily a critical drop in aortic pressure. - The elevated left ventricular pressure required to overcome the stenosis is the key factor driving the angina. *Increase in volume overload of the heart* - **Aortic stenosis primarily causes pressure overload**, not volume overload, on the left ventricle due to the obstruction to outflow. - Volume overload typically occurs in conditions like **aortic regurgitation** or **mitral regurgitation**, which have different pathophysiological mechanisms for angina. *Decreased coronary blood flow* - While **decreased coronary perfusion** can be a contributing factor in aortic stenosis (due to reduced aortic pressure and shortened diastolic filling time), it is a **secondary mechanism**. - The **primary cause** of angina in aortic stenosis is the markedly **increased myocardial oxygen demand** from left ventricular hypertrophy and increased workload, rather than a primary reduction in coronary blood flow.

Question 11: A hypertensive patient presents with an irregularly irregular pulse and a loud P2 on auscultation. Which JVP finding is likely to be seen in this patient?

A. Absent a wave (Correct Answer)
B. Cannon a wave
C. Rapid $x$ descent
D. Rapid $y$ descent
E. Prominent v wave

Explanation: ***Absent a wave*** - An **irregularly irregular pulse** and **loud P2** suggest **atrial fibrillation** with **pulmonary hypertension**. In atrial fibrillation, there is chaotic atrial activity, meaning the atria do not contract in a coordinated fashion. - The **"a" wave** on the JVP tracing represents **atrial contraction**. Since the atria are fibrillating and not contracting effectively, the normal "a" wave will be absent. *Cannon a wave* - **Cannon a waves** occur when the **right atrium contracts against a closed tricuspid valve**, such as during **ventricular tachycardia** or **complete heart block** (AV dissociation). - This patient's irregularly irregular pulse suggests **atrial fibrillation**, not a condition typically associated with cannon a waves. *Rapid $x$ descent* - A **rapid x descent** primarily reflects **atrial relaxation** and **right ventricular systole**, which pulls the tricuspid annulus downwards. - While a rapid x descent can be seen in various conditions, it is not the most specific JVP finding for the described clinical picture, which points strongly to absent atrial contraction. *Rapid $y$ descent* - A **rapid y descent** signifies rapid filling of the right ventricle during early diastole, often associated with a **compliant right ventricle** and unobstructed tricuspid inflow. It can be prominent in conditions like **constrictive pericarditis** or **restrictive cardiomyopathy**. - This finding is not directly or specifically linked to the irregularly irregular pulse and absent atrial contraction seen in atrial fibrillation. *Prominent v wave* - A **prominent v wave** occurs with **tricuspid regurgitation**, where blood regurgitates back into the right atrium during ventricular systole, causing venous distension. - While pulmonary hypertension can eventually lead to right ventricular dysfunction and tricuspid regurgitation, the most characteristic JVP finding for **atrial fibrillation itself** is the **absence of the "a" wave** due to lack of coordinated atrial contraction.

Question 12: 30-year-old male, weighing 70 kg , presents with a serum sodium level of $120 \mathrm{mEq} / \mathrm{L}$. Calculate the total sodium deficit.

A. 630 mEq
B. 280 mEq
C. 420 mEq
D. 840 mEq (Correct Answer)
E. 1260 mEq

Explanation: ***840 mEq*** - The formula for calculating **total sodium deficit** is: **(Desired Na - Actual Na) × Total Body Water (TBW)**. - In a male, TBW is approximately **60% of body weight**. For a 70 kg male, **TBW = 0.6 × 70 kg = 42 L**. - With a desired sodium of **140 mEq/L** (normal) and actual sodium of **120 mEq/L**, the total deficit is: - **(140 - 120) × 42 = 20 × 42 = 840 mEq** - This represents the **complete calculated sodium deficit** needed to restore serum sodium to normal levels. - **Note:** In clinical practice, this entire deficit is NOT replaced rapidly. Typically, only **6-12 mEq/L increase per 24 hours** is recommended to prevent **osmotic demyelination syndrome**, but the question asks for the total calculated deficit. *630 mEq* - This value represents a **partial correction target**, corresponding to raising serum sodium to approximately **135 mEq/L** instead of 140 mEq/L: (135 - 120) × 42 = 630 mEq. - Alternatively, it equals about **75% of the total deficit** (840 × 0.75 = 630). - While this may reflect a practical clinical target, it does not answer the question which asks for the **total deficit**. *420 mEq* - This corresponds to raising serum sodium by **10 mEq/L** (10 × 42 = 420 mEq). - This represents the **maximum recommended increase in the first 24 hours** to prevent complications. - It is a safe initial correction amount but not the total calculated deficit. *280 mEq* - This represents an even smaller increment, roughly equivalent to raising serum sodium by **6-7 mEq/L**. - This would be an **ultra-conservative initial correction** for chronic hyponatremia. - It significantly underestimates the total sodium deficit. *1260 mEq* - This is an **overestimation** that might result from incorrectly using 100% body weight as TBW instead of 60%: (140 - 120) × 70 = 1400 mEq (close to this range). - Or from miscalculation using wrong formula components. - This exceeds the actual total sodium deficit.

Question 13: A patient presents with confusion, altered mental status, and unusual behavior. On examination, CNS features such as disorientation and lethargy are noted. Laboratory results reveal a urine osmolality of 1000 mOsm/kg and a plasma osmolality of 250 mOsm/kg. What is the most likely electrolyte imbalance?

A. Hypokalemia
B. Hyperkalemia
C. Hyponatremia (Correct Answer)
D. Hypernatremia
E. Hypercalcemia

Explanation: ***Hyponatremia*** - The **low plasma osmolality** (250 mOsm/kg) combined with a **high urine osmolality** (1000 mOsm/kg) indicates that the kidneys are inappropriately concentrating urine despite diluted plasma, a hallmark finding in euvolemic hyponatremia. - **Confusion**, **altered mental status**, and **unusual behavior** are classic neurological symptoms associated with hyponatremia, particularly when it develops acutely or severely. *Hypokalemia* - **Hypokalemia** is characterized by low serum potassium and can cause muscle weakness, arrhythmias, and fatigue, but it does not directly explain the given plasma and urine osmolality findings. - The neurological symptoms described are not typical primary manifestations of hypokalemia. *Hyperkalemia* - **Hyperkalemia** involves high serum potassium, commonly leading to cardiac arrhythmias and muscle weakness. - The provided **osmolality values** are not consistent with a primary diagnosis of hyperkalemia. *Hypernatremia* - **Hypernatremia** is defined by high serum sodium and would present with **high plasma osmolality**, which contradicts the given plasma osmolality of 250 mOsm/kg. - While it can cause neurological symptoms, the osmolality findings rule it out. *Hypercalcemia* - **Hypercalcemia** can present with neurological symptoms including confusion and lethargy ("stones, bones, groans, and psychiatric overtones"). - However, hypercalcemia does not produce the characteristic **low plasma osmolality with high urine osmolality** pattern seen in this case.

Question 14: A patient presents with breathing difficulty and generalized weakness. On auscultation, a middiastolic murmur with a prominent "a" wave is observed. What is the most likely diagnosis?

A. Mitral Regurgitation (MR)
B. Mitral Stenosis (MS)
C. Tricuspid Regurgitation (TR)
D. Tricuspid Stenosis (TS) (Correct Answer)
E. Pulmonary Stenosis (PS)

Explanation: ***Tricuspid Stenosis (TS)*** - A **middiastolic murmur** in the tricuspid area (usually left lower sternal border) along with a **prominent "a" wave** (due to increased right atrial pressure against a stenotic tricuspid valve) is pathognomonic for tricuspid stenosis. - The symptoms of **breathing difficulty** and **generalized weakness** can arise from reduced cardiac output and venous congestion characteristic of TS. *Mitral Regurgitation (MR)* - MR typically presents with a **holosystolic murmur** best heard at the apex and radiating to the axilla. - It does not characteristically produce a middiastolic murmur or a prominent "a" wave. *Mitral Stenosis (MS)* - MS causes a **diastolic rumble** with an **opening snap**, best heard at the apex, but it is not typically associated with a pronounced "a" wave in the jugular venous pulse unless there's associated pulmonary hypertension and right heart strain. - The murmur is usually localized to the apex, whereas tricuspid murmurs are typically heard from the lower left sternal border. *Tricuspid Regurgitation (TR)* - TR is characterized by a **holosystolic murmur** that increases with inspiration, heard at the left lower sternal border. - It typically causes a prominent **"v" wave** in the jugular venous pulse due to regurgitant flow into the right atrium, not a prominent "a" wave. *Pulmonary Stenosis (PS)* - PS presents with a **systolic ejection murmur** at the left upper sternal border (pulmonic area), not a diastolic murmur. - While it can cause right heart strain, it does not produce the characteristic middiastolic murmur or prominent "a" wave seen in tricuspid stenosis.

Question 15: A patient presents with breathlessness and wheezing. Absolute eosinophil count is 500 cells/ $\mu \mathrm{L}$. Chest X-ray shows a miliary pattern. What is the most likely diagnosis?

A. Tropical pulmonary eosinophilia (Correct Answer)
B. Bronchial asthma
C. Miliary Tuberculosis (TB)
D. Hypersensitivity pneumonitis
E. Allergic bronchopulmonary aspergillosis (ABPA)

Explanation: ***Tropical pulmonary eosinophilia*** - This condition is characterized by **eosinophilia** (absolute eosinophil count >500 cells/µL), **respiratory symptoms** such as breathlessness and wheezing, and a **miliary pattern** on chest X-ray, all consistent with the patient's presentation. - It results from a **hypersensitivity reaction** to microfilariae from Wuchereria bancrofti or Brugia malayi in individuals living in endemic regions. *Bronchial asthma* - While bronchial asthma can cause **breathlessness** and **wheezing**, a miliary pattern on chest X-ray is **not typical**, nor is an eosinophil count of 500 cells/µL, though eosinophilia can occur. - Asthma is primarily a disease of reversible airway obstruction, often triggered by **allergens** or irritants. *Miliary Tuberculosis (TB)* - **Miliary TB** would present with a miliary pattern on chest X-ray and breathlessness, but it is typically associated with **low or normal eosinophil counts**, and wheezing is less common. - Fever, night sweats, and weight loss are also common symptoms of Miliary TB. *Hypersensitivity pneumonitis* - This condition involves inflammation of the lung alveoli due to inhalation of organic dusts or chemicals, causing **breathlessness** and, occasionally, wheezing, but **eosinophilia is not a primary feature**. - Chest X-ray findings can be diverse, but a **miliary pattern** is less specific than for tropical pulmonary eosinophilia. *Allergic bronchopulmonary aspergillosis (ABPA)* - ABPA can present with **eosinophilia**, **wheezing**, and respiratory symptoms, but chest X-ray typically shows **central bronchiectasis** and **fleeting infiltrates** rather than a miliary pattern. - It occurs in patients with asthma or cystic fibrosis and is characterized by **hypersensitivity to Aspergillus fumigatus**.

Question 16: A 68-year-old male presents with cough, sputum production, bronchial breath sounds, respiratory rate of 20/min, urea of 44 mg/dl, and BP of 110/70 mmHg. What is the next step in management?

A. Admit in ICU without mechanical ventilation (MV)
B. Home treatment (Rx)
C. Admit in ICU with mechanical ventilation (MV)
D. Room admission (Correct Answer)
E. Observation in emergency department

Explanation: ***Room admission*** - The patient's **CURB-65 score** is **2** (one point for urea >7 mmol/L [44 mg/dL = 15.7 mmol/L] and one point for age ≥65 years), indicating **moderate mortality risk** and clear need for **hospital admission**. - **CURB-65 score of 2** mandates inpatient admission for monitoring, IV antibiotics if needed, and supportive care in a general medical ward. - While showing signs of respiratory infection, the vital signs are stable and do not meet criteria for ICU admission. *Admit in ICU without mechanical ventilation (MV)* - **ICU criteria** for pneumonia typically include severe respiratory failure, hemodynamic instability (shock requiring vasopressors), or impending organ dysfunction, which are not met. - The patient's respiratory rate (20/min) and blood pressure (110/70 mmHg) are within acceptable limits for a non-ICU setting. - CURB-65 score of 3-5 or presence of major severity criteria would warrant ICU consideration. *Home treatment (Rx)* - **CURB-65 score of 2** precludes outpatient management and requires hospital admission. - Outpatient treatment is only appropriate for CURB-65 scores of 0-1 in patients without other comorbidities. - Given the patient's age (68 years), elevated urea, and presence of **bronchial breath sounds** consistent with consolidative pneumonia, **hospital admission** is mandatory. *Admit in ICU with mechanical ventilation (MV)* - There is no indication of **severe respiratory distress** (e.g., severe hypoxemia with SpO2 <90% on high-flow oxygen, hypercapnia, or respiratory acidosis) that would necessitate immediate mechanical ventilation. - The respiratory rate of 20/min is normal, and there is no mention of altered mental status, severe tachypnea, or increased work of breathing. *Observation in emergency department* - While brief observation may be appropriate for borderline cases, a **CURB-65 score of 2** indicates the patient requires formal hospital admission rather than just ED observation. - The presence of consolidation (bronchial breath sounds) and elevated urea support the need for inpatient ward admission with monitoring and treatment.

Question 17: A known case of HIV presents with cough, sputum production, and fever. Examination reveals consolidation in the right infrascapular area, and an X-ray shows right lower lobe consolidation. The patient's CD4 count is 55. What is the common cause of this presentation?

A. Pneumocystis jiroveci
B. Streptococcus pneumoniae (Correct Answer)
C. Staphylococcus aureus
D. Mycoplasma pneumoniae
E. Mycobacterium tuberculosis

Explanation: ***Streptococcus pneumoniae*** * Despite a low **CD4 count** in an HIV patient, **_Streptococcus pneumoniae_** remains the most common cause of **community-acquired pneumonia (CAP)**, even in immunocompromised individuals. * The clinical presentation of **fever**, **cough**, **sputum production**, and **lobar consolidation** on X-ray is classic for bacterial pneumonia caused by this organism. *Pneumocystis jiroveci* * **_Pneumocystis jiroveci_ pneumonia (PCP)** typically presents with **diffuse interstitial infiltrates** on chest X-ray and severe **hypoxemia**, which is different from the lobar consolidation described. * It is more common when the **CD4 count is below 200**, but classic presentation differs. *Staphylococcus aureus* * **_Staphylococcus aureus_ pneumonia** is often associated with **nosocomial infections**, **influenza co-infection**, or **intravenous drug use**, which are not indicated here. * It frequently causes **necrotizing pneumonia** with **cavitation** or **abscess formation**, not typically simple lobar consolidation. *Mycoplasma pneumoniae* * **_Mycoplasma pneumoniae_** causes "**atypical pneumonia**" with a more **insidious onset** and symptoms like **headache** and **sore throat**, with **patchy infiltrates** on X-ray. * It is less likely to present with distinct lobar consolidation and significant sputum production. *Mycobacterium tuberculosis* * While **tuberculosis** is an important opportunistic infection in HIV patients with CD4 < 200, it typically presents with a more **chronic course** (weeks to months) with **night sweats**, **weight loss**, and **upper lobe involvement** or **miliary pattern**. * The **acute presentation** with **right lower lobe consolidation** is more consistent with acute bacterial pneumonia rather than TB.

Question 18: A known case of AIDS with a productive cough and fever is found to have consolidation in the right infrascapular area. Chest X-ray shows right lower lobe consolidation, and the CD4 count is 55 per microlitre. What is the most common cause of this presentation?

A. Staphylococcus aureus
B. Pneumocystis jirovecii
C. Streptococcus pneumoniae (Correct Answer)
D. Mycoplasma pneumoniae
E. Mycobacterium tuberculosis

Explanation: ***Streptococcus pneumoniae*** - Despite severe immunocompromise (CD4 count 55), **bacterial pneumonia**, especially **Streptococcus pneumoniae**, remains the most common cause of pneumonia in patients with AIDS. - The presentation of productive cough, fever, and focal consolidation on chest X-ray (**right lower lobe consolidation**) is typical for bacterial pneumonia. *Staphylococcus aureus* - While *Staphylococcus aureus* can cause pneumonia in AIDS patients, particularly those with IV drug use or recent hospitalization, it is **less common** than *Streptococcus pneumoniae*. - *S. aureus* pneumonia often presents with **abscess formation** or **necrotizing pneumonia**, which is not explicitly mentioned. *Pneumocystis jirovecii* - *Pneumocystis jirovecii* pneumonia (PJP) is a common opportunistic infection in AIDS patients with **CD4 counts below 200**, but it typically presents with **diffuse interstitial infiltrates** or **no consolidation** on chest X-ray. - The classic presentation is **dry cough**, progressive dyspnea, and hypoxia, rather than focal consolidation and productive sputum. *Mycoplasma pneumoniae* - *Mycoplasma pneumoniae* causes **"walking pneumonia"** and is characterized by a less severe cough, **fewer systemic symptoms**, and usually **interstitial or patchy infiltrates**, not frank consolidation. - It is also **less common** in immunocompromised patients with such a low CD4 count compared to typical bacterial pathogens. *Mycobacterium tuberculosis* - While tuberculosis is an important opportunistic infection in AIDS patients with **CD4 counts below 100**, it typically presents with **chronic symptoms** (weeks to months), night sweats, weight loss, and often **upper lobe cavitary disease** or **miliary pattern** on chest X-ray. - The **acute presentation** with productive cough and **focal lobar consolidation** is more consistent with bacterial pneumonia than TB.

Question 19: A patient presents with generalized and easy fatigability. He reports weakness while working in a factory with exposure to benzene. Which of the following conditions should be suspected in this patient?

A. Hepatocellular Carcinoma
B. Leukemia (Correct Answer)
C. Carcinoma Gall Bladder
D. Urinary Bladder Cancer
E. Aplastic Anemia

Explanation: ***Leukemia*** - **Benzene exposure** is a well-established risk factor for developing **leukemia**, particularly acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). - **Generalized fatigue** and **easy fatigability** are common symptoms of leukemia, resulting from anemia, bone marrow infiltration, and systemic effects of the disease. - Benzene is classified as a **Group 1 carcinogen** by IARC with strong evidence for leukemogenesis. *Aplastic Anemia* - While benzene exposure can cause **aplastic anemia** (bone marrow failure), this condition typically presents with **pancytopenia** and more severe symptoms including bleeding and infections. - However, given the occupational exposure and symptoms, **leukemia** remains the primary concern as it is more commonly associated with chronic benzene exposure. - Aplastic anemia from benzene is less common than benzene-induced leukemia. *Hepatocellular Carcinoma* - While benzene exposure can be **hepatotoxic**, it is not primarily associated with an increased risk of **Hepatocellular Carcinoma**. - Risk factors for hepatocellular carcinoma include **chronic viral hepatitis** (HBV, HCV) and **alcoholism**. *Carcinoma Gall Bladder* - There is **no significant association** between benzene exposure and the development of **gallbladder cancer**. - Risk factors for gallbladder cancer include **gallstones**, porcelain gallbladder, and chronic inflammation. *Urinary Bladder Cancer* - **Aromatic amines** and **anilines** (often found in dye, rubber, and chemical industries) are established causes of bladder cancer, not typically benzene itself. - While benzene is a carcinogen, **bladder cancer** is not considered a primary or strong association with its exposure.

Question 20: A patient presents with cold skin, fatigue, shortness of breath on exertion, and an enlarged liver. Upon examination, his jugular venous pressure (JVP) reveals a prominent "a" wave. What is the most likely cause of the elevated "a" wave in this patient?

A. Tricuspid Stenosis (Correct Answer)
B. Mitral Stenosis
C. Tricuspid Regurgitation
D. Mitral Regurgitation
E. Pulmonary Stenosis

Explanation: ***Tricuspid Stenosis*** - A prominent "a" wave in the **JVP** indicates increased **right atrial pressure** during atrial contraction, which is characteristic of **tricuspid stenosis** due to resistance to blood flow from the right atrium to the right ventricle. - The symptoms of **cold skin**, **fatigue**, **shortness of breath on exertion**, and an **enlarged liver** are consistent with **right-sided heart failure** caused by tricuspid stenosis. - Among the valvular causes, tricuspid stenosis most directly causes a prominent "a" wave with associated right heart failure symptoms. *Mitral Stenosis* - **Mitral stenosis** primarily affects the **left atrium** and left ventricle, leading to pulmonary symptoms and, if severe, right heart failure. - It would typically cause a prominent "a" wave in the **pulmonary veins**, not directly in the JVP, although severe pulmonary hypertension could eventually lead to right ventricular overload. *Tricuspid Regurgitation* - **Tricuspid regurgitation** causes a large, prominent, and often **pulsatile "c-v" wave** in the JVP due to the reflux of blood into the right atrium during ventricular systole. - While it can cause right heart failure symptoms, it does not typically present with an isolated prominent "a" wave. *Mitral Regurgitation* - **Mitral regurgitation** primarily affects the **left side of the heart**, leading to symptoms related to left heart failure (e.g., pulmonary edema). - It does not directly cause an elevated "a" wave in the **JVP** unless there is severe, longstanding left-sided heart failure leading to secondary pulmonary hypertension and right heart failure. *Pulmonary Stenosis* - **Pulmonary stenosis** causes obstruction to right ventricular outflow, which can lead to a prominent "a" wave due to increased right atrial pressure. - However, pulmonary stenosis typically presents with a **systolic ejection murmur** at the left upper sternal border and may have signs of **RV hypertrophy** rather than the predominantly congestive symptoms seen here. - The clinical picture of hepatomegaly and signs of backward failure is more consistent with tricuspid stenosis than pulmonary stenosis.

Question 21: A 45-year-old male with a 15-year history of diabetes mellitus presents to his primary care provider for a routine checkup. His doctor is concerned about his renal function and would like to order a test to detect renal impairment. Which of the following is the most sensitive test for detecting renal impairment in diabetic patients?

A. Urinalysis
B. Cystatin C levels
C. Hemoglobin A1C
D. Urine microalbumin to creatinine ratio (Correct Answer)
E. Urine protein dipstick

Explanation: ***Urine microalbumin to creatinine ratio*** - This is the **most sensitive early indicator** of diabetic nephropathy, detecting small amounts of **albumin** in the urine before overt proteinuria. - An elevated ratio indicates **early renal damage** due to diabetes, allowing for timely intervention to slow disease progression. *Urinalysis* - A routine urinalysis can detect significant proteinuria, hematuria, or casts, but it is **less sensitive** than the microalbumin-to-creatinine ratio for early diabetic nephropathy. - It may miss **microalbuminuria**, which is the earliest sign of diabetic kidney disease. *Cystatin C levels* - **Cystatin C** is an alternative marker for estimating **glomerular filtration rate (GFR)**, especially when creatinine measurements are unreliable. - While it can detect renal impairment, it's generally considered less sensitive than microalbuminuria for the **earliest stages** of diabetic kidney disease. *Hemoglobin A1C* - **Hemoglobin A1C** measures **average blood glucose levels** over the past 2-3 months and is used to monitor diabetes control. - It does **not directly assess renal function** or detect kidney damage. *Urine protein dipstick* - A urine protein dipstick primarily detects **macroalbuminuria** (significant protein in the urine). - It is **not sensitive enough** to detect the lower levels of protein (microalbuminuria) that characterize early diabetic nephropathy.

Question 22: A 61-year-old man presents to his primary care provider with fatigue, weight loss, and muscle aches. He has experienced these symptoms for the past year but initially attributed them to stress at his work as an attorney. However, over the past month, he has developed intermittent fevers associated with a skin rash that prompted him to seek medical evaluation. He denies any recent history of asthma, rhinitis, hematuria, or difficulty breathing. He is otherwise healthy and takes no medications. He has a distant history of cocaine abuse but has not used any drugs in 30 years. His family history is notable for pancreatic cancer in his father and inflammatory bowel disease in his sister. His temperature is 99.3°F (37.4°C), blood pressure is 130/75 mmHg, pulse is 90/min, and respirations are 18/min. On examination, rales are heard at the bilateral lung bases. S1 and S2 are normal. Strength is 5/5 in the bilateral upper and lower extremities and his gait is normal. Palpable purpura are noted on his trunk and bilateral upper and lower extremities. Erythrocyte sedimentation rate and C-reactive protein are both elevated. This patient’s condition is associated with antibodies directed against which of the following enzymes?

A. Topoisomerase-1
B. Myeloperoxidase (Correct Answer)
C. Type IV collagen
D. Complement component 1q
E. Tissue transglutaminase

Explanation: ***Myeloperoxidase*** - The patient's presentation of **palpable purpura**, **pulmonary involvement (rales)**, constitutional symptoms (fatigue, weight loss, fevers), and elevated inflammatory markers is highly suggestive of **ANCA-associated vasculitis**, specifically **microscopic polyangiitis (MPA)**. - **Myeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA or p-ANCA)** are the hallmark of MPA, which causes **necrotizing small-vessel vasculitis** affecting skin (palpable purpura) and lungs (pulmonary capillaritis causing rales). - While MPA commonly involves the kidneys, renal manifestations may not be present at initial evaluation, as in this case. *Topoisomerase-1* - Antibodies against **topoisomerase-1 (Scl-70)** are characteristic of **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form. - Scleroderma presents with skin thickening, Raynaud's phenomenon, and organ fibrosis, which are not described in this patient. *Type IV collagen* - Antibodies to **type IV collagen** (anti-GBM antibodies) are associated with **Goodpasture syndrome** (anti-glomerular basement membrane disease). - While Goodpasture syndrome causes pulmonary hemorrhage and glomerulonephritis, it does not typically present with **palpable purpura** or the systemic vasculitic features seen here. *Complement component 1q* - Autoantibodies against **complement component 1q (C1q)** are seen in **hypocomplementemic urticarial vasculitis** and some cases of systemic lupus erythematosus (SLE). - This patient's clinical picture with palpable purpura and pulmonary involvement is most consistent with ANCA-associated vasculitis (MPA), not conditions associated with anti-C1q antibodies. *Tissue transglutaminase* - Antibodies against **tissue transglutaminase (tTG)** are the primary serological marker for **celiac disease**. - Celiac disease is an autoimmune enteropathy affecting the small intestine and does not manifest with palpable purpura, pulmonary involvement, or systemic vasculitic features.

Question 23: A 25-year-old man presents to his physician for new-onset palpitations and tremors in his right hand. He also feels more active than usual, but with that, he is increasingly feeling fatigued. He lost about 3 kg (6.6 lb) in the last 2 months and feels very anxious about his symptoms. He survived neuroblastoma 15 years ago and is aware of the potential complications. On examination, a nodule around the size of 2 cm is palpated in the right thyroid lobule; the gland is firm and nontender. There is no lymphadenopathy. His blood pressure is 118/75 mm Hg, respirations are 17/min, pulse is 87/min, and temperature is 37.5°C (99.5°F). Which of the following is the best next step in the management of this patient?

A. Ultrasound examination
B. Radionuclide thyroid scan
C. Life-long monitoring
D. Thyroid hormone replacement therapy
E. Fine needle aspiration with cytology (Correct Answer)

Explanation: ***Fine needle aspiration with cytology*** - The presence of a **thyroid nodule** along with a history of **neuroblastoma** (a childhood cancer that can rarely predispose to other malignancies or be a component of syndromes associated with endocrine tumors) and new onset hyperthyroid-like symptoms (palpitations, tremors, weight loss, anxiety) indicate a strong suspicion for **thyroid malignancy**, necessitating prompt cytological evaluation. - While hyperthyroid symptoms could suggest a toxic nodule, the concern for malignancy (especially given the medical history and nodule characteristics) makes direct cytological assessment the most appropriate and urgent next step to guide definitive management. *Ultrasound examination* - An **ultrasound** is typically the initial imaging modality to characterize thyroid nodules (size, number, features) and guide FNA, but the question implies the nodule has already been palpated. - While often done before FNA, obtaining an ultrasound alone without proceeding to FNA would delay the definitive diagnosis when there's a high suspicion of malignancy based on clinical presentation. *Radionuclide thyroid scan* - A **radionuclide thyroid scan** helps determine if a nodule is "hot" (hormonally active) or "cold" (non-functional), which can differentiate between toxic adenoma and other nodules. - However, **cold nodules** have a higher risk of malignancy, and even hot nodules can rarely be malignant; thus, a scan should not delay FNA, especially with suspicious clinical findings. *Life-long monitoring* - **Life-long monitoring** is not appropriate for a newly discovered, potentially suspicious thyroid nodule, especially in a patient with a history of childhood cancer and new symptoms. - This approach would delay diagnosis and potential treatment for a condition that could be malignant. *Thyroid hormone replacement therapy* - **Thyroid hormone replacement therapy** is used for hypothyroidism or to suppress TSH in certain thyroid conditions, but it is not indicated for a patient presenting with symptoms suggestive of hyperthyroidism and a palpable thyroid nodule. - It would be inappropriate and potentially harmful given the patient's symptoms.

Question 24: A 28-year-old man presents to the emergency department after being rescued from his home. He was working at home alone on some renovations when 1 of his house's walls collapsed on him. His legs were trapped under the debris for about 30 hours before a neighbor came by, found him, and called an ambulance. He is very mildly confused and reports pain throughout both legs. The physical examination is notable for dry mucous membranes and tenderness to palpation throughout both legs with many superficial abrasions, but no active hemorrhage. The full-body computed tomography (CT) scan shows small fractures in both tibias, but no hematomas. He is admitted to the trauma service for observation. On hospital day 1, his urine appears very dark. Urine output over the preceding 24 hours is 200 mL. The laboratory studies show a creatinine of 2.7 mg/dL and serum creatine kinase (CK) of 29,700 IU/L. Which of the following is the next best step in the management of this patient?

A. Order anti-streptolysin O titers
B. Start dialysis
C. Order anti-nuclear antibody (ANA) titers
D. Start IV fluids (Correct Answer)
E. Order anti-glomerular basement membrane (GBM) titers

Explanation: ***Start IV fluids*** - This patient presents with signs of **rhabdomyolysis** (crush injury, dark urine, elevated CK) and **acute kidney injury** (elevated creatinine, oliguria). Aggressive intravenous fluid administration is crucial to prevent and treat acute kidney injury by flushing myoglobin from the renal tubules. - **Hydration** helps maintain renal blood flow and dilutes the myoglobin, reducing its nephrotoxic effects. *Order anti-streptolysin O titers* - **Anti-streptolysin O (ASO) titers** are used to diagnose **post-streptococcal glomerulonephritis**, a condition not suggested by the patient's presentation of trauma and rhabdomyolysis. - This test would be irrelevant in the context of acute crush injury and muscle breakdown. *Start dialysis* - While the patient has **acute kidney injury** and **oliguria**, dialysis is generally reserved for severe cases with electrolyte imbalances (like refractory hyperkalemia), fluid overload unresponsive to diuretics, or severe uremia. - The immediate priority is to address the underlying cause of the AKI through aggressive hydration to prevent worsening kidney function. *Order anti-nuclear antibody (ANA) titers* - **Anti-nuclear antibody (ANA) titers** are used to screen for **systemic autoimmune diseases** like lupus, which are unrelated to the current presentation of crush injury, rhabdomyolysis, and acute kidney injury. - This test would not aid in the immediate management of this patient's acute condition. *Order anti-glomerular basement membrane (GBM) titers* - **Anti-glomerular basement membrane (GBM) titers** are used to diagnose conditions like **Goodpasture syndrome**, an autoimmune disease causing rapidly progressive glomerulonephritis, which is not indicated by the patient's history or symptoms. - This test is inappropriate for the acute management of rhabdomyolysis-induced kidney injury.

Question 25: A 42-year-old woman comes to the physician because of frequent episodes of headaches and tinnitus over the past 3 months. One week ago, she had a brief episode of left arm weakness and numbness that lasted for 2 minutes before spontaneously resolving. She is otherwise healthy and takes no medications. She has smoked one-half pack of cigarettes daily for 22 years. Her pulse is 84/min and blood pressure is 155/105 mm Hg. Abdominal examination shows no masses or tenderness. A bruit is heard on auscultation of the abdomen. Abdominal ultrasonography shows a small right kidney. CT angiography shows stenosis of the distal right renal artery. Which of the following is the most likely underlying cause of the patient's condition?

A. Fibromuscular dysplasia (Correct Answer)
B. Congenital renal hypoplasia
C. Systemic lupus erythematosus
D. Atherosclerotic plaques
E. Polyarteritis nodosa

Explanation: ***Fibromuscular dysplasia*** - This condition is characterized by **abnormal cell growth in artery walls**, leading to narrowed vessels, most commonly affecting renal and carotid arteries. - The patient's age (42 years old), female gender, hypertension, and the renal artery stenosis found on CT angiography are all highly suggestive of fibromuscular dysplasia. The transient ischemic attack symptoms (left arm weakness and numbness) and headaches with tinnitus could be due to carotid artery involvement, another common site for FMD. *Congenital renal hypoplasia* - This is a condition where the **kidney is underdeveloped at birth**, leading to a permanently small kidney. - While it can cause hypertension, it doesn't typically present with an abdominal bruit or arterial stenosis in adulthood, and it's less likely to cause transient ischemic symptoms. *Systemic lupus erythematosus* - SLE is a **systemic autoimmune disease** that can affect multiple organs, including the kidneys (lupus nephritis). - Although it can cause hypertension and strokes, the specific presentation of renal artery stenosis with a bruit in a relatively healthy patient is not typical primary manifestation of SLE. *Atherosclerotic plaques* - **Atherosclerotic renal artery stenosis** usually occurs in older individuals (over 50-60 years old) with risk factors like hyperlipidemia, diabetes, and long-standing smoking, which are not explicitly mentioned as severe in this 42-year-old. - While smoking is a risk factor, the patient's age and the specific presentation of headaches and tinnitus point away from atherosclerosis as the primary cause. *Polyarteritis nodosa* - This is a **systemic necrotizing vasculitis** that can affect medium-sized arteries, often leading to renal involvement and hypertension. - It usually presents with more systemic symptoms like fever, weight loss, and muscle pain, which are absent in this patient. It also often affects multiple organ systems, and the isolated renal artery stenosis with potential carotid involvement is less characteristic of PAN.

Question 26: A 55-year-old Caucasian woman visits her family physician for a checkup and to discuss her laboratory results from a previous visit. The medical history is significant for obesity, hypothyroidism, and chronic venous insufficiency. The medications include thyroxine and a multivitamin. In her previous visit, she complained about being hungry all the time, urinating multiple times a day, and craving water for most of the day. Blood and urine samples were obtained. Today her blood pressure is 120/70 mm Hg, the pulse is 80/min, the respiratory rate is 18/min, and the body temperature is 36.4°C (97.5°F). The physical examination reveals clear lungs with regular heart sounds and no abdominal tenderness. There is mild pitting edema of the bilateral lower extremities. The laboratory results are as follows: Elevated SCr for an eGFR of 60 mL/min/1.73 m² Spot urine albumin-to-creatinine ratio 250 mg/g Urinalysis Specific gravity 1.070 Proteins (++) Glucose (+++) Nitrites (-) Microscopy Red blood cells none White blood cells none Hyaline casts few A bedside renal ultrasound revealed enlarged kidneys bilaterally without hydronephrosis. Which of the following kidney-related test should be ordered next?

A. Renal computed tomography
B. No further renal tests are required
C. Urine protein electrophoresis (Correct Answer)
D. Renal arteriography
E. Renal biopsy

Explanation: ***Urine protein electrophoresis*** - The patient's symptoms (polyuria, polydipsia, hunger) along with **significant proteinuria** (++ on urinalysis, **albumin-to-creatinine ratio of 250 mg/g**) and **glucosuria** (+++) suggest possible **diabetes mellitus** and associated **diabetic nephropathy**. - While diabetic nephropathy is likely, other proteinuric kidney diseases, such as **monoclonal gammopathy** (e.g., related to multiple myeloma), can also present with proteinuria and enlarged kidneys. Urine protein electrophoresis helps to **differentiate albuminuria from other proteinurias**, such as light chains, which is crucial for diagnosis and treatment. *Renal computed tomography* - This imaging study would be considered if there was suspicion of **renal masses**, stones, or other structural abnormalities not clearly defined by ultrasound, or if **hydronephrosis** was present, which is not the case here. - Given the primary concern is proteinuria with symptoms suggestive of diabetes, a CT scan is not the most immediate next step for characterizing the type of proteinuria. *No further renal tests are required* - This is incorrect because the patient has significant proteinuria and symptoms suggesting a systemic disease that involves the kidneys, requiring further investigation to **confirm the etiology of the kidney damage** and guide management. - The elevated specific gravity, proteinuria, and glucosuria, along with enlarged kidneys, warrant **further diagnostic workup** beyond an eGFR and ACR. *Renal arteriography* - This invasive procedure is used to visualize the **renal arteries** and assess for conditions like **renal artery stenosis** or vasculitis. - There is no clinical indication (e.g., uncontrolled hypertension despite medication, abdominal bruits, flash pulmonary edema) to suggest renal artery stenosis, and the current presentation points toward a primary glomerular issue. *Renal biopsy* - While a **renal biopsy** might eventually be necessary, it is an **invasive procedure** and usually performed after less invasive tests (like urine protein electrophoresis) have been conducted and if the diagnosis remains unclear or if there's a need for precise histological classification, especially if non-diabetic kidney disease is suspected. - In this case, characterizing the type of proteinuria is important first, as **diabetic nephropathy** can often be diagnosed clinically without a biopsy if typical features are present and other causes are ruled out.

Question 27: A 44-year-old woman presents to her primary care physician’s office with episodes of pain in her right hand. She says that the pain is most significant at night and awakens her from sleep numerous times. When she experiences this pain, she immediately puts her hand under warm running water or shakes her hand. She has also experienced episodes of numbness in the affected hand. Driving and extending the right arm also provoke her symptoms. She denies any trauma to the hand or associated weakness. Medical history is notable for hypothyroidism treated with levothyroxine. She works as a secretary for a law firm. On physical exam, when the patient hyperflexes her wrist, pain and paresthesia affect the first 3 digits of the right hand. Which of the following is the confirmatory diagnostic test for this patient?

A. Magnetic resonance imaging
B. Needle electromyography
C. Nerve conduction studies (Correct Answer)
D. Nerve biopsy
E. Tinel test

Explanation: ***Nerve conduction studies*** - **Nerve conduction studies (NCS)** are the most sensitive and specific diagnostic test for **carpal tunnel syndrome**, definitively confirming median nerve compression. - They measure the speed and amplitude of electrical signals through the **median nerve** at the wrist, identifying slowed conduction across the carpal tunnel. *Magnetic resonance imaging* - While MRI can visualize soft tissues and nerve pathology, it is not typically the **first-line confirmatory test** for carpal tunnel syndrome due to its lower sensitivity compared to NCS. - MRI is more useful for identifying **structural abnormalities** like tumors or synovitis, which might cause secondary nerve compression. *Needle electromyography* - **Electromyography (EMG)** involves inserting a needle into muscles to assess their electrical activity; it helps evaluate for **axonopathy** and muscle denervation. - While EMG is often performed alongside NCS, it primarily assesses muscle function and nerve damage severity, rather than directly confirming nerve compression itself, which is best done by NCS. *Nerve biopsy* - **Nerve biopsy** is an invasive procedure generally reserved for diagnosing demyelinating or infiltrative neuropathies when less invasive tests are inconclusive. - It carries risks and is **unnecessary** and inappropriate for diagnosing a common compressive neuropathy like carpal tunnel syndrome. *Tinel test* - The **Tinel test** is a clinical provocative maneuver where percussion over the median nerve at the wrist elicits tingling or pain. - It is a **screening tool** and part of the physical exam for carpal tunnel syndrome, but it is not a confirmatory diagnostic test due to its variable sensitivity and specificity.

Question 28: A 31-year-old woman presents to the physician for a routine health maintenance examination. She feels well and has no current complaints. She has no history of serious illness and takes no medications. The vital signs include: blood pressure 185/110 mm Hg, pulse 75/min, and respiration rate 12/min. Her high blood pressure is confirmed during a 2nd visit. Neurologic examination shows no abnormalities. Careful auscultation of the abdomen reveals bruits in both upper quadrants near the midline. The remainder of the physical exam is unremarkable. The results of a complete blood count (CBC), renal function panel, and urinalysis showed no abnormalities. Conventional angiography confirms bilateral disease involvement. To control this patient’s hypertension, it is most appropriate to recommend which of the following?

A. Percutaneous transluminal angioplasty (Correct Answer)
B. Dietary salt restriction
C. Long-term captopril
D. Surgical revascularization
E. Calorie restriction and weight loss

Explanation: ***Percutaneous transluminal angioplasty*** - The presence of **bilateral abdominal bruits** and **resistant hypertension** in a young woman strongly suggests **fibromuscular dysplasia** leading to renal artery stenosis. - Percutaneous transluminal angioplasty (PTA) is the **definitive treatment** for fibromuscular dysplasia, by dilating the narrowed renal arteries and restoring blood flow. *Dietary salt restriction* - While salt restriction is a general recommendation for hypertension, it is **insufficient** to control severe hypertension caused by renovascular disease such as **fibromuscular dysplasia**. - This approach does not address the **underlying anatomical obstruction** in the renal arteries. *Long-term captopril* - **Angiotensin-converting enzyme (ACE) inhibitors** like captopril are generally **contraindicated** or should be used with extreme caution in patients with **bilateral renal artery stenosis**. - These drugs can paradoxically **worsen renal function** and even induce **acute kidney injury** by reducing glomerular filtration pressure due to efferent arteriolar vasodilation. *Surgical revascularization* - Surgical revascularization (bypass grafting) is a more **invasive procedure** typically reserved for **atherosclerotic renal artery stenosis** with significant occlusions or when PTA has failed. - It is **less commonly indicated** for fibromuscular dysplasia, which usually responds well to less invasive angioplasty. *Calorie restriction and weight loss* - Calorie restriction and weight loss are lifestyle modifications that can help manage **primary (essential) hypertension**, particularly in overweight or obese individuals. - However, they are **ineffective** in treating **secondary hypertension** caused by a structural renal artery issue like fibromuscular dysplasia.

Question 29: A 65-year-old woman presents to the clinic for a routine checkup. She has unintentionally lost 4.5 kg (9.9 lb) in the past month but denies any other complaints. Her pulse rate is 90/min, respiratory rate is 18/min, temperature is 37.0°C (98.6°F), and blood pressure is 150/70 mm Hg. An irregularly irregular rhythm is heard on auscultation of the heart. Neck examination shows a markedly enlarged thyroid with no lymphadenopathy or bruit. Laboratory tests show low serum thyroid-stimulating hormone level, high T4 level, absent thyroid-stimulating immunoglobulin, and absent anti-thyroid peroxidase antibody. Nuclear scintigraphy shows patchy uptake with multiple hot and cold areas. Which of the following is the most likely diagnosis?

A. Toxic multinodular goiter (Correct Answer)
B. Hashimoto’s thyroiditis
C. Graves’ disease
D. Subacute granulomatous thyroiditis
E. Toxic adenoma

Explanation: ***Toxic multinodular goiter*** - The patient's presentation with **unexplained weight loss**, **irregularly irregular rhythm** (suggesting atrial fibrillation), and an **enlarged thyroid** points towards hyperthyroidism. - **Low TSH, high T4**, absent thyroid-stimulating immunoglobulin, and **patchy uptake with multiple hot and cold areas on scintigraphy** are all characteristic features of toxic multinodular goiter. *Hashimoto’s thyroiditis* - This is an **autoimmune condition** that typically causes **hypothyroidism** due to thyroid destruction, leading to high TSH and low thyroid hormone levels. - It is characterized by the presence of **anti-thyroid peroxidase antibodies**, which are absent in this case. *Graves’ disease* - While it causes hyperthyroidism with **low TSH and high T4**, it is characterized by the presence of **thyroid-stimulating immunoglobulins** and **diffuse uptake on scintigraphy**. - This patient has absent thyroid-stimulating immunoglobulins and patchy uptake, ruling out Graves' disease. *Subacute granulomatous thyroiditis* - This condition, often preceded by a **viral infection**, typically presents with **thyroid pain** and tenderness, which are absent in this case. - Scintigraphy would show **decreased or absent iodine uptake** during the initial hyperthyroid phase, not patchy uptake. *Toxic adenoma* - A toxic adenoma would present with a **solitary hot nodule** on nuclear scintigraphy, which is a single area of increased uptake, unlike the multiple hot and cold areas seen in this patient. - While it can cause hyperthyroidism, the scintigraphy findings are inconsistent with a single toxic adenoma.

Question 30: A 66-year old man comes to the physician because of fatigue for 6 months. He says that he wakes up every morning feeling tired. Most days of the week he feels sleepy during the day and often takes an afternoon nap for an hour. His wife says he snores in the middle of the night. He has a history of heart failure and atrial fibrillation. His medications include aspirin, atorvastatin, lisinopril, metoprolol, and warfarin. He drinks 1–2 glasses of wine daily with dinner; he does not smoke. He is 175 cm (5 ft 9 in) tall and weighs 96 kg (212 lb); BMI is 31.3 kg/m2. His blood pressure is 142/88 mm Hg, pulse is 98/min, and respirations are 22/min. Examination of the oral cavity shows a low-lying palate. Cardiac examination shows an irregularly irregular rhythm and no murmurs. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?

A. Echocardiography
B. Home sleep apnea testing
C. ENT evaluation
D. In-laboratory polysomnography (Correct Answer)
E. Overnight pulse oximetry

Explanation: ***In-laboratory polysomnography*** - The patient presents with classic symptoms of **obstructive sleep apnea (OSA)**, including chronic fatigue, daytime sleepiness, and snoring, along with risk factors such as **obesity (BMI 31.3)** and a **low-lying palate**. His medical history of **heart failure** and **atrial fibrillation** are also associated with OSA. - While **portable home sleep apnea testing** can be used to diagnose OSA, in-laboratory polysomnography is indicated when there is a **strong suspicion of sleep apnea** and **comorbid conditions** (like heart failure and atrial fibrillation in this case) that might require more comprehensive monitoring of sleep stages, respiratory effort, and cardiac rhythm during sleep. *Echocardiography* - This patient has a history of heart failure and atrial fibrillation, for which an echocardiogram would typically be part of routine management, but there are no new acute cardiac symptoms or signs to suggest a need for immediate re-evaluation. - Addressing the **sleep-related symptoms** that significantly impact his quality of life and potentially exacerbate his cardiac conditions takes precedence at this moment. *ENT evaluation* - An ENT evaluation might be considered later if **in-laboratory polysomnography** confirms severe OSA and surgical intervention, such as uvulopalatopharyngoplasty, is being considered. - However, immediate ENT consultation is not the most appropriate first step in diagnosing or managing the sleep disorder. *Home sleep apnea testing* - While home sleep apnea testing (HSAT) is a convenient and cost-effective option for diagnosing OSA in patients with a high pretest probability and no significant comorbidities, it is **less comprehensive** than in-laboratory polysomnography. - Given the patient's **comorbid heart failure and atrial fibrillation**, in-laboratory polysomnography is preferred to allow for more detailed physiological monitoring during sleep, including continuous EEG to determine sleep stages, which is crucial for distinguishing between central and obstructive events. *Overnight pulse oximetry* - **Overnight pulse oximetry** can screen for nocturnal hypoxemia but is **insufficient for diagnosing sleep apnea**. - It does not provide information on sleep stages, respiratory effort, or arousals, which are critical for characterizing the type and severity of sleep-disordered breathing.

Question 31: A 73-year-old male is brought into the ED unconscious with cold, clammy skin. His blood pressure is 65 over palpable. There are no signs of blood loss. You recognize the patient is in acute shock and blood is drawn for investigation as resuscitation is initiated. Which of the following might you expect in your laboratory investigation for this patient?

A. Increased serum bicarbonate
B. Increased arterial pH
C. Decreased hemoglobin
D. Increased serum ketones
E. Increased blood lactate (Correct Answer)

Explanation: ***Increased blood lactate*** - In **shock**, inadequate tissue perfusion leads to **anaerobic metabolism**, which produces **lactic acid** as a byproduct. - This accumulation of **lactate** is a key indicator of tissue hypoperfusion and is characteristic of various forms of shock. *Increased serum bicarbonate* - **Metabolic acidosis** is common in shock due to lactic acid accumulation, which would lead to a *decrease* in serum bicarbonate as the body tries to **buffer the acid**. - An increased bicarbonate level would suggest **metabolic alkalosis**, which is not expected in this context. *Increased arterial pH* - The elevated lactic acid levels from **anaerobic metabolism** in shock cause **metabolic acidosis**, leading to a *decreased* arterial pH. - An increased pH would indicate **alkalosis**, which is contrary to the expected physiological response in shock. *Decreased hemoglobin* - While a **decreased hemoglobin** could be a cause of shock (hemorrhagic shock), the question explicitly states there are **no signs of blood loss**. - Additionally, other forms of shock (e.g., cardiogenic, septic) would not necessarily present with decreased hemoglobin. *Increased serum ketones* - **Ketone bodies** are elevated in conditions involving increased **fat metabolism** due to **insulin deficiency** (e.g., diabetic ketoacidosis) or prolonged starvation. - While a patient in shock might have metabolic derangements, significant ketosis is not a primary or direct result of the **hypoperfusion** itself in the absence of other underlying conditions.

Question 32: A 14-year-old boy is brought to the emergency department from school after falling in gym class. He was unable to stand after the accident and has a painful and swollen knee. On presentation he says that he has never had an incident like this before; however, he does suffer from hard to control nosebleeds and prolonged bleeding after minor cuts. Based on his presentation a panel of bleeding tests is obtained with the following results: Bleeding time: Prolonged Prothrombin time: Normal Partial thromboplastin time: Prolonged Which of the following describes the function of the component that is defective in the most likely cause of this patient's symptoms?

A. Binds to a nucleotide derivative
B. Binds to fibrinogen
C. Binds to subendothelial collagen (Correct Answer)
D. It is a cofactor for an epoxide reductase
E. Catalyzes the conversion of factor X

Explanation: ***Binds to subendothelial collagen*** - The patient's history of **nosebleeds**, **prolonged bleeding**, and a knee injury suggests a **primary hemostasis** defect. The lab results (prolonged bleeding time, normal PT, prolonged PTT) point to **von Willebrand disease** (vWD). - The most important function of **von Willebrand factor** (vWF), which is deficient or dysfunctional in vWD, is to mediate platelet adhesion to the **subendothelial collagen** at sites of vascular injury. *Binds to a nucleotide derivative* - This option refers to the function of **P2Y12 receptors** on platelets, which bind to ADP (a nucleotide derivative) to promote platelet aggregation. - While important for platelet function, this is not the primary defect in von Willebrand disease, which is an issue with **platelet adhesion**. *Binds to fibrinogen* - **Glycoprotein IIb/IIIa receptors** on platelets bind to **fibrinogen** to mediate platelet aggregation and form a platelet plug. - This is a secondary step in hemostasis, and while affected by vWF's indirect role in stabilizing FVIII, it's not the direct primary defect. *It is a cofactor for an epoxide reductase* - This describes the role of **Vitamin K** in the carboxylation of clotting factors; specifically, its role as a cofactor for **gamma-glutamyl carboxylase**, which is then reduced by **epoxide reductase**. - Deficiencies in Vitamin K activity affect the **extrinsic** and **common pathways** (factors II, VII, IX, X), which would typically present with a **prolonged PT** in addition to PTT, unlike this patient. *Catalyzes the conversion of factor X* - This describes the function of **Factor IXa** (in complex with Factor VIIIa) and **Factor VIIa** (with Tissue Factor), which activate Factor X to Factor Xa. - While vWF stabilizes **Factor VIII**, leading to prolonged PTT, the direct catalytic conversion of Factor X is not the primary function of vWF itself.

Question 33: A 66-year-old man is brought to the emergency department because of fever, chills, and altered mental status for 3 days. According to his daughter, he has had a productive cough during this period. He has type 2 diabetes, hypertension, hypercholesterolemia, peripheral neuropathic pain, and a history of deep vein thromboses. Current medications include insulin, lisinopril, atorvastatin, warfarin, and carbamazepine. He is oriented only to self. His temperature is 39.3°C (102.7°F), pulse is 110/min, respirations are 26/min, and blood pressure is 86/50 mm Hg. Physical examination shows ecchymoses on both lower extremities. Crackles are heard at the right lung base. Laboratory studies show: Hemoglobin 11.1 g/dL Leukocyte count 18,000/mm3 Platelet count 45,000/mm3 Prothrombin time 45 sec Partial thromboplastin time 75 sec Serum Na+ 135 mEq/L K+ 5.4 mEq/L Cl- 98 mEq/L Urea nitrogen 46 mg/dL Glucose 222 mg/dL Creatinine 3.3 mg/dL Which of the following is the most likely cause of this patient's ecchymoses?

A. Adverse effect of warfarin
B. Immune thrombocytopenic purpura
C. Hemolytic uremic syndrome
D. Disseminated intravascular coagulation (Correct Answer)
E. Thrombotic thrombocytopenic purpura

Explanation: ***Disseminated intravascular coagulation*** - The patient presents with **sepsis** (fever, altered mental status, productive cough, crackles, hypotension, leukocytosis), **thrombocytopenia** (platelet count 45,000/mm3), and **prolonged PT and PTT** (45 sec and 75 sec, respectively). These findings, in the setting of severe infection, are highly suggestive of **DIC**. - **Ecchymoses** are a common manifestation of DIC due to widespread microthrombi consuming clotting factors and platelets, leading to subsequent bleeding. *Adverse effect of warfarin* - While the patient is on warfarin, his **severe thrombocytopenia** (45,000/mm3) and **markedly prolonged PTT** are not typical findings for isolated warfarin overdose; warfarin primarily prolongs PT and sometimes PTT, but usually doesn't cause such a severe drop in platelet count. - Furthermore, isolated warfarin toxicity would not explain the patient's profound **sepsis** and multi-organ dysfunction. *Immune thrombocytopenic purpura* - ITP is characterized by **isolated thrombocytopenia** without other coagulation abnormalities or systemic illness like sepsis. - This patient has signs of **severe infection**, coagulation factor consumption (prolonged PT/PTT), and renal dysfunction, which are not features of ITP. *Hemolytic uremic syndrome* - HUS involves **microangiopathic hemolytic anemia** (MAHA), **thrombocytopenia**, and **acute kidney injury** (AKI), often preceded by a diarrheal illness. - While this patient has thrombocytopenia and AKI, there is no mention of hemolytic anemia (e.g., schistocytes, elevated LDH, decreased haptoglobin), and the prolonged PT/PTT are not characteristic of HUS alone. *Thrombotic thrombocytopenic purpura* - TTP classically presents with the **pentad** of fever, neurological symptoms, renal dysfunction, thrombocytopenia, and microangiopathic hemolytic anemia (MAHA). - Similar to HUS, TTP is not associated with prolonged PT and PTT, which are prominent features in this patient and point towards a consumptive coagulopathy like DIC.

Question 34: A 27-year-old man is brought to the emergency department with his family because of abdominal pain, excessive urination and drowsiness since the day before. He has had type 1 diabetes mellitus for 2 years. He ran out of insulin 2 days ago. His vital signs at admission include a temperature of 36.8°C (98.24°F), a blood pressure of 102/69 mmHg, and a pulse of 121/min. On physical examination, he is lethargic and his breathing is rapid and deep. There is a mild generalized abdominal tenderness without rebound tenderness or guarding. His serum glucose is 480 mg/dL. The patient is admitted to the intensive care unit and management is started. Which of the following is considered a resolution criterion for this patient's condition?

A. Anion gap < 10 (Correct Answer)
B. Bicarbonate < 10 mEq/L
C. Increased blood urea nitrogen
D. Disappearance of serum acetone
E. Hyperkalemia

Explanation: ***Anion gap < 10*** - Resolution of **diabetic ketoacidosis (DKA)** is indicated by the closure of the **anion gap**, typically defined as an anion gap less than 10-12 mEq/L, signifying the correction of metabolic acidosis. - This criterion, along with serum bicarbonate ≥ 15 mEq/L and blood pH > 7.3, confirms that the excess ketoacids have been cleared. *Bicarbonate < 10 mEq/L* - A bicarbonate level less than 10 mEq/L indicates severe **metabolic acidosis**, which is characteristic of DKA, not a sign of its resolution. - As DKA resolves, **bicarbonate levels should increase** towards the normal range (typically ≥ 15 mEq/L for resolution). *Increased blood urea nitrogen* - **Increased BUN** reflects changes in kidney function, often due to dehydration in DKA, but it is not a direct measure of DKA resolution. - While hydration therapy will improve renal function, BUN levels may not normalize immediately and their elevation does not directly track the resolution of the **ketoacidotic state**. *Disappearance of serum acetone* - While the disappearance of serum acetone (a **ketone body**) indicates a reduction in ketosis, it is not the primary or sole resolution criterion. - **Beta-hydroxybutyrate** is the predominant ketone in DKA, and its levels returning to normal are more indicative; however, blood pH and anion gap are more robust indicators for overall resolution. *Hyperkalemia* - **Hyperkalemia** can occur in DKA due to acidosis, but paradoxically, total body **potassium is deficient**. - As insulin therapy is initiated and acidosis corrects, potassium shifts back into cells, often leading to **hypokalemia**, necessitating careful potassium monitoring and replacement; it is not a resolution criterion but a potential complication of treatment or the underlying condition.

Question 35: A 25-year-old man comes to the physician because of a severe headache for 1 hour. Every day of the past week, he has experienced 3–4 episodes of severe pain over his left forehead. Each episode lasts around 30–45 minutes, and he reports pacing around restlessly during these episodes. He has been using acetaminophen for these episodes, but it has provided only minimal relief. He works as a financial analyst and says his job is very stressful. He had experienced similar symptoms 4 months ago but did not seek treatment at that time. He has no history of serious illness and takes no other medications. He has smoked one pack of cigarettes daily for 7 years. He appears anxious. Vital signs are within normal limits. There is conjunctival injection and tearing of the left eye. The remainder of the physical examination is unremarkable. Which of the following measures is most likely to provide acute relief of this patient's headaches?

A. Oxygen therapy (Correct Answer)
B. Naproxen
C. Oxycodone
D. Amitriptyline
E. Carbamazepine

Explanation: ***Oxygen therapy*** - This patient's symptoms (unilateral severe headache, conjunctival injection, tearing, restlessness, short duration, and recurrent episodes) are characteristic of **cluster headaches**. - **High-flow oxygen (100% at 12-15 L/min)** delivered via a non-rebreather mask is a highly effective and safe acute treatment for cluster headaches, often providing relief within 15-20 minutes. *Naproxen* - **Naproxen**, an NSAID, is a common acute treatment for **mild to moderate tension-type headaches** or in conjunction with other abortive medications for migraine. - It is generally **ineffective** for the severe pain and distinct autonomic features of cluster headaches. *Oxycodone* - **Opioids like oxycodone** are not recommended for acute treatment of cluster headaches due to the risk of **medication overuse headache**, dependence, and their lack of specific efficacy for this condition. - They tend to be less effective than specific cluster headache treatments and can **aggravate the condition** with long-term use. *Amitriptyline* - **Amitriptyline** is a tricyclic antidepressant primarily used for the **prophylactic treatment** of **chronic tension-type headaches or migraines**. - It is **not effective** for the acute termination of a cluster headache attack. *Carbamazepine* - **Carbamazepine** is an anticonvulsant primarily used to treat **trigeminal neuralgia** due to its efficacy in neuropathic pain. - While sometimes used second-line in other headache disorders, it is **not a first-line acute treatment** for cluster headaches and its effectiveness in this context is limited.

Question 36: A 57-year-old man is sent to the emergency department by his primary care physician for hypertension. He was at a general health maintenance appointment when his blood pressure was found to be 180/115 mmHg; thus, prompting his primary doctor to send him to the emergency room. The patient is otherwise currently asymptomatic and states that he feels well. The patient has no other medical problems other than his hypertension and his labs that were drawn last week were within normal limits. His temperature is 98.3°F (36.8°C), blood pressure is 197/105 mmHg, pulse is 88/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is unremarkable. Laboratory values are redrawn at this visit and shown below. Hemoglobin: 15 g/dL Hematocrit: 46% Leukocyte count: 3,400/mm^3 with normal differential Platelet count: 177,000/mm^3 Serum: Na+: 139 mEq/L Cl-: 102 mEq/L K+: 4.0 mEq/L HCO3-: 24 mEq/L BUN: 29 mg/dL Glucose: 139 mg/dL Creatinine: 2.3 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most likely diagnosis?

A. Pheochromocytoma
B. Cushing syndrome
C. Hypertension
D. Hypertensive emergency (Correct Answer)
E. Hypertensive urgency

Explanation: ***Hypertensive emergency*** - This patient presents with **severe hypertension** (BP 197/105 mmHg) accompanied by evidence of **acute end-organ damage**, specifically a new elevation in **creatinine to 2.3 mg/dL** and **BUN to 29 mg/dL**, suggestive of acute kidney injury. - An asymptomatic presentation does not rule out hypertensive emergency; the key is the presence of **acute, severe elevation in blood pressure with new or worsening end-organ damage**. *Pheochromocytoma* - While it causes episodic or sustained hypertension, it typically presents with classic symptoms like **palpitations, headaches, and sweating**, which are absent in this patient. - Diagnosis involves elevated plasma or urinary metanephrines, not just elevated BP with acute kidney injury. *Cushing syndrome* - Characterized by hypertension, but also includes other features like **central obesity, moon facies, striae, and muscle weakness**, none of which are described. - Diagnosis is based on cortisol excess, confirmed by specific tests such as dexamethasone suppression tests. *Hypertension* - This is a general term for elevated blood pressure. While the patient certainly has hypertension, the presence of **acute end-organ damage (elevated creatinine/BUN)** elevates it beyond simple hypertension. - The definition of hypertension alone does not encompass the acute, severe nature and organ damage seen here. *Hypertensive urgency* - Defined as **severe elevation in blood pressure without evidence of acute end-organ damage**. - This patient has a new elevation in creatinine and BUN, indicating **acute kidney injury**, which constitutes end-organ damage, thus moving it beyond urgency to an emergency.

Question 37: A 45-year-old man with type 1 diabetes mellitus comes to the physician for a health maintenance examination. He has a 10-month history of tingling of his feet at night and has had two recent falls. Three years ago, he underwent retinal laser photocoagulation in both eyes. Current medications include insulin and lisinopril, but he admits not adhering to his insulin regimen. He does not smoke or drink alcohol. His blood pressure is 130/85 mm Hg while sitting and 118/70 mm Hg while standing. Examination shows decreased sense of vibration and proprioception in his toes and ankles bilaterally. His serum hemoglobin A1C is 10.1%. Urine dipstick shows 2+ protein. Which of the following additional findings is most likely in this patient?

A. Dilated pupils
B. Hyperreflexia
C. Increased lower esophageal sphincter pressure
D. Incomplete bladder emptying (Correct Answer)
E. Premature ejaculation

Explanation: ***Incomplete bladder emptying*** - This patient has signs of **diabetic neuropathy**, including peripheral neuropathy (tingling, sensory deficits) and likely **autonomic neuropathy** given the orthostatic hypotension. Autonomic neuropathy can affect the bladder, leading to **detrusor underactivity** and incomplete bladder emptying. - **Poor glycemic control** (HbA1c 10.1%) significantly increases the risk and progression of both peripheral and autonomic neuropathies. *Dilated pupils* - Diabetic autonomic neuropathy can affect pupillary function, but typically causes **miosis** (constricted pupils) and **poor pupillary light reflex**, rather than dilation. - Dilated pupils are more characteristic of other neurological conditions or medication side effects. *Hyperreflexia* - **Peripheral neuropathy** due to diabetes typically causes **hyporeflexia** or areflexia, especially in the lower extremities, due to damage to the peripheral nerves. - Hyperreflexia suggests an upper motor neuron lesion, which is not indicated by the patient's symptoms or diabetes. *Increased lower esophageal sphincter pressure* - Diabetic autonomic neuropathy can affect the gastrointestinal tract, leading to conditions like **gastroparesis**, but it tends to cause **reduced lower esophageal sphincter (LES) pressure**, contributing to **gastroesophageal reflux**, rather than increased pressure. - Increased LES pressure is typically seen in disorders like achalasia. *Premature ejaculation* - While diabetic neuropathy can cause **sexual dysfunction** in men, it more commonly leads to **erectile dysfunction** or **retrograde ejaculation** due to autonomic nerve damage. - Premature ejaculation is less directly associated with diabetic autonomic neuropathy compared to other forms of sexual dysfunction.

Question 38: A 65-year-old man comes to the physician because of shortness of breath, chest pain, and a cough for 2 days. The pain is exacerbated by deep inspiration. He has a history of congestive heart failure, hypertension, type 2 diabetes mellitus, and hyperlipidemia. Current medications include metoprolol, lisinopril, spironolactone, metformin, and simvastatin. He has smoked half a pack of cigarettes daily for the past 25 years. His temperature is 38.5°C (101.3°F), pulse is 95/min, respirations are 18/min, and blood pressure is 120/84 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 93%. Examination shows dullness to percussion and an increased tactile fremitus in the right lower lung field. Auscultation over this area shows bronchial breath sounds and whispered pectoriloquy. The remainder of the examination shows no abnormalities. Which of the following is the most likely cause of these findings?

A. Pleural fluid accumulation
B. Ruptured pulmonary blebs
C. Parenchymal consolidation (Correct Answer)
D. Alveolar transudate
E. Pulmonary infarction

Explanation: ***Parenchymal consolidation*** - The combination of **fever**, **cough**, **shortness of breath**, and pleuritic chest pain in a patient with risk factors like smoking, followed by examination findings of **dullness to percussion**, **increased tactile fremitus**, **bronchial breath sounds**, and **whispered pectoriloquy**, is highly indicative of **pneumonia** leading to **parenchymal consolidation**. - **Consolidation** occurs when alveoli fill with inflammatory exudate (e.g., in pneumonia), increasing the density of lung tissue and enhancing sound transmission. *Pleural fluid accumulation* - **Pleural effusion** would typically present with **dullness to percussion** but would cause **decreased tactile fremitus** and **decreased or absent breath sounds** over the affected area, as fluid dampens sound transmission. - While pleuritic pain can be present, the specific collection of physical exam findings points away from fluid accumulation. *Ruptured pulmonary blebs* - A **ruptured pulmonary bleb** can lead to **pneumothorax**, which would typically manifest with sudden chest pain, shortness of breath, and physical exam findings of **hyperresonance to percussion** and **decreased or absent breath sounds**. - There would also be **decreased tactile fremitus**, which contradicts the patient's presentation. *Alveolar transudate* - **Alveolar transudate** (e.g., in **pulmonary edema** due to CHF exacerbation) would lead to widespread **crackles** or rales bilaterally, not localized dullness and increased tactile fremitus. - While the patient has CHF, the localized findings are more suggestive of an infectious process. *Pulmonary infarction* - **Pulmonary infarction**, often due to **pulmonary embolism**, typically presents with sudden onset of pleuritic chest pain, dyspnea, and sometimes a cough with hemoptysis. - While it can cause some localized findings on auscultation, it does not typically produce the classic consolidation signs like **increased tactile fremitus**, **bronchial breath sounds**, and **whispered pectoriloquy**.

Question 39: A 14-year-old male presents to his primary care physician with complaints of shortness of breath and easy fatigability when exercising for extended periods of time. He also reports that, when he exercises, his lower legs and feet turn a bluish-gray color. He cannot remember visiting a doctor since he was in elementary school. His vital signs are as follows: HR 72, BP 148/65, RR 14, and SpO2 97%. Which of the following murmurs and/or findings would be expected on auscultation of the precordium?

A. Continuous, machine-like murmur at the left infraclavicular area
B. Mid-systolic murmur loudest at the right second intercostal space, with radiation to the right neck
C. Right supraclavicular continuous murmur which disappears with pressure on the internal jugular vein
D. Left infraclavicular systolic ejection murmur with decreased blood pressure in the lower extremities (Correct Answer)
E. Holodiastolic murmur loudest at the apex, with an opening snap following the S2 heart sound

Explanation: ***Left infraclavicular systolic ejection murmur with decreased blood pressure in the lower extremities*** - The combination of **hypertension (BP 148/65 mmHg)**, **exercise-induced dyspnea and fatigability**, and **cyanosis of the lower extremities** (blue-gray color) strongly suggests **coarctation of the aorta**. - A **systolic ejection murmur** over the left infraclavicular area and **decreased blood pressure in the lower extremities** are classic auscultatory and physical findings in coarctation. *Continuous, machine-like murmur at the left infraclavicular area* - This description is characteristic of a **patent ductus arteriosus (PDA)**, which typically presents with a **continuous murmur** throughout systole and diastole. - While PDA can cause pulmonary hypertension and heart failure, the specific finding of **differential cyanosis in the lower limbs** (indicating right-to-left shunting) is more indicative of coarctation with PDA, or severe coarctation alone, rather than an isolated PDA. *Mid-systolic murmur loudest at the right second intercostal space, with radiation to the right neck* - This murmur description is typical of **aortic stenosis**, particularly in adults. - While aortic stenosis can cause exertional dyspnea and fatigue, it does not typically cause **differential cyanosis of the lower extremities** or the specific blood pressure discrepancy seen in coarctation. *Right supraclavicular continuous murmur which disappears with pressure on the internal jugular vein* - This describes a **venous hum**, a benign finding that is common in children and usually disappears with position changes or compression of the jugular vein. - It is not associated with the patient's symptoms of **dyspnea, fatigue, or differential cyanosis**. *Holodiastolic murmur loudest at the apex, with an opening snap following the S2 heart sound* - This sign is indicative of **mitral stenosis**, an abnormality of the mitral valve that obstructs blood flow from the left atrium to the left ventricle. - Mitral stenosis would not explain the **hypertension in the upper extremities** or the **cyanosis localized to the lower extremities**.

Question 40: A 52-year-old man comes to the physician for a routine medical check-up. The patient feels well. He has hypertension, type 2 diabetes mellitus, and recurrent panic attacks. He had a myocardial infarction 3 years ago. He underwent a left inguinal hernia repair at the age of 25 years. A colonoscopy 2 years ago was normal. He works as a nurse at a local hospital. He is married and has two children. His father died of prostate cancer at the age of 70 years. He had smoked one pack of cigarettes daily for 25 years but quit following his myocardial infarction. He drinks one to two beers on the weekends. He has never used illicit drugs. Current medications include aspirin, atorvastatin, lisinopril, metoprolol, fluoxetine, metformin, and a multivitamin. He appears well-nourished. Temperature is 36.8°C (98.2°F), pulse is 70/min, and blood pressure is 125/75 mm Hg. Lungs are clear to auscultation. Cardiac examination shows a high-frequency, mid-to-late systolic murmur that is best heard at the apex. The abdomen is soft and nontender. The remainder of the physical examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Pulmonary valve regurgitation
B. Mitral valve stenosis
C. Tricuspid valve stenosis
D. Mitral valve prolapse (Correct Answer)
E. Pulmonary valve stenosis

Explanation: ***Mitral valve prolapse*** - A **mid-to-late systolic murmur** heard best at the apex is the characteristic finding of mitral valve prolapse, often accompanied by a **mid-systolic click** (though not mentioned here). - The **high-frequency** nature of the murmur is consistent with MVP. - Important association: **Panic attacks/anxiety disorders** are strongly linked with MVP, likely due to underlying connective tissue abnormalities and autonomic dysfunction. - This patient's history of recurrent panic attacks further supports the diagnosis. *Pulmonary valve regurgitation* - This typically causes a **diastolic murmur** (Graham Steell murmur), not a systolic murmur as described. - It is usually heard best at the **left upper sternal border**, not at the apex. *Mitral valve stenosis* - Mitral stenosis presents with a **low-pitched diastolic rumble** (mid-diastolic murmur) and often an **opening snap**, not a systolic murmur. - Most commonly caused by **rheumatic fever**. - Heard best at the apex but timing is diastolic, not systolic. *Tricuspid valve stenosis* - Tricuspid stenosis produces a **diastolic murmur**, usually accentuated with inspiration (Carvallo's sign). - Heard best at the **lower left sternal border**. *Pulmonary valve stenosis* - Presents with a **systolic ejection murmur** heard best at the **left upper sternal border** (pulmonic area), often with a preceding ejection click. - The murmur described is a mid-to-late systolic murmur at the apex, not an ejection murmur at the LUSB.

Question 41: A 68-year-old man presents to his primary care physician for a routine checkup. He currently has no complaints. During routine blood work, he is found to have a slightly elevated calcium (10.4 mg/dL) and some findings of plasma cells in his peripheral blood smear (less than 10%). His physician orders a serum protein electrophoresis which demonstrates a slight increase in gamma protein that is found to be light chain predominate. What is the most likely complication for this patient as this disease progresses if left untreated?

A. Peripheral neuropathy
B. Hepatomegaly
C. Kidney damage (Correct Answer)
D. Raynaud's phenomenon
E. Splenomegaly

Explanation: ***Kidney damage*** - The patient's presentation with **elevated calcium**, **plasma cells** in the peripheral blood (though <10%), and an **M-spike** (light chain predominance) on serum protein electrophoresis strongly suggests **Multiple Myeloma** or a precursor condition. - One of the most common and serious complications of multiple myeloma is **kidney damage** due to the deposition of **light chains** (Bence Jones proteins) in the renal tubules, leading to casts and renal failure, or hypercalcemia-induced nephropathy. *Peripheral neuropathy* - While peripheral neuropathy can occur in plasma cell dyscrasias, it is more characteristic of **POEMS syndrome** (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, Skin changes) or amyloidosis, which are not directly indicated here. - It is not the most likely primary complication of early multiple myeloma. *Hepatomegaly* - **Hepatomegaly** is not a common or direct complication of multiple myeloma, although liver involvement can occur in rare cases or with extensive amyloidosis. - The primary symptoms and lab findings provided do not point towards significant liver involvement. *Raynaud's phenomenon* - **Raynaud's phenomenon** is an episodic vasospastic disorder, often associated with connective tissue diseases or cryoglobulinemia. - It is not a typical direct complication of multiple myeloma based on the given presentation. *Splenomegaly* - **Splenomegaly** is uncommon in multiple myeloma. It can be seen in other hematologic malignancies or storage diseases, but not as a characteristic feature of this patient's likely condition. - The presented symptoms do not suggest splenic involvement.

Question 42: A 67-year-old woman presents to her primary care physician because she has been feeling increasingly fatigued over the last month. She has noticed that she gets winded halfway through her favorite walk in the park even though she was able to complete the entire walk without difficulty for years. She recently moved to an old house and started a new Mediterranean diet. Her past medical history is significant for hypertension and osteoarthritis for which she underwent a right hip replacement 2 years ago. Physical exam reveals conjunctival pallor as well as splenomegaly. Labs are obtained and the results are shown below: Hemoglobin: 9.7 g/dL (normal: 12-15.5 g/dL) Mean corpuscular volume: 91 µm^3 (normal: 80-100 µm^3) Direct Coombs test: positive Indirect Coombs test: positive Peripheral blood smear reveals spherical red blood cells. The disorder that is most likely responsible for this patient's symptoms should be treated in which of the following ways?

A. Avoidance of fava beans
B. Chelation therapy
C. Glucocorticoid administration (Correct Answer)
D. Vitamin supplementation
E. Chronic blood transfusions

Explanation: ***Glucocorticoid administration*** - This patient presents with signs of **anemia** (fatigue, dyspnea, conjunctival pallor) along with **splenomegaly**, a **positive Direct Coombs test**, and **spherocytes** on peripheral smear, all highly suggestive of **warm autoimmune hemolytic anemia (AIHA)**. - **Glucocorticoids** are the first-line treatment for warm AIHA, as they suppress the immune system and reduce IgG antibody production against red blood cells. *Avoidance of fava beans* - This intervention is relevant for individuals with **glucose-6-phosphate dehydrogenase (G6PD) deficiency**, which can cause hemolytic anemia upon exposure to oxidative stressors like fava beans. - However, the patient's symptoms and lab results (especially the positive Coombs test) are not consistent with G6PD deficiency, which typically presents with **Heinz bodies** and an absence of a positive Direct Coombs test. *Chelation therapy* - **Chelation therapy** is used to remove excess heavy metals from the body, most commonly in cases of **iron overload (hemochromatosis)** or **lead poisoning**. - There is no indication of heavy metal toxicity or iron overload in this patient's presentation; direct evidence of autoimmune hemolytic anemia points away from this treatment. *Vitamin supplementation* - **Vitamin supplementation**, particularly with **iron, folate, or vitamin B12**, is appropriate for **nutritional deficiencies** causing anemia. - While vitamin deficiencies can cause anemia, the presence of spherocytes, splenomegaly, and a positive Coombs test strongly indicate an autoimmune etiology for hemolysis, not a nutritional deficiency. *Chronic blood transfusions* - While **blood transfusions** might be necessary for patients with severe, symptomatic anemia in AIHA, they are typically a supportive measure rather than a primary treatment. - The focus is on treating the underlying autoimmune process to prevent further red blood cell destruction, making chronic transfusions an inappropriate initial or sole treatment strategy for AIHA.

Question 43: A 22-year-old woman comes to the physician for gradual worsening of her vision. Her father died at 40 years of age. She is 181 cm (5 ft 11 in) tall and weighs 69 kg (152 lb); BMI is 21 kg/m2. A standard vision test shows severe myopia. Genetic analysis shows an FBN1 gene mutation on chromosome 15. This patient is at greatest risk of mortality due to which of the following causes?

A. Eccentric ventricular hypertrophy
B. Obstruction of the superior vena cava lumen
C. Increased pressure in the pulmonary arteries
D. Intimal tear of the aortic root (Correct Answer)
E. Supraventricular tachyarrhythmia

Explanation: ***Intimal tear of the aortic root*** - This patient presents with features highly suggestive of **Marfan syndrome**: tall stature, severe myopia, and an **FBN1 gene mutation**. - The most common cause of mortality in Marfan syndrome is **aortic dissection** or rupture, which typically begins with an intimal tear in the aortic root due to defective connective tissue. *Eccentric ventricular hypertrophy* - While Marfan syndrome can lead to **aortic regurgitation** and subsequent eccentric hypertrophy, it is not the primary cause of sudden mortality. - The direct threat comes from the **integrity of the aortic wall**, not the secondary hypertrophy. *Obstruction of the superior vena cava lumen* - **Superior vena cava (SVC) syndrome** is usually caused by external compression from tumors or thrombosis, not directly associated with Marfan syndrome's primary pathology. - There is no clinical information in the vignette to suggest SVC obstruction. *Increased pressure in the pulmonary arteries* - **Pulmonary hypertension** can be a complication of various cardiac conditions, but it is not the most direct or common life-threatening cardiovascular manifestation of Marfan syndrome. - The primary vascular risk in Marfan syndrome involves the **systemic aorta**. *Supraventricular tachyarrhythmia* - While arrhythmias can occur in Marfan syndrome, they are generally **less life-threatening** than aortic dissection or rupture. - The FBN1 gene mutation primarily affects connective tissue strength, particularly in the vasculature, making aortic complications the gravest risk.

Question 44: A 65-year-old male presents to the emergency department with a 2-day onset of right-lower quadrant and right flank pain. He also states that over this period of time he has felt dizzy, light-headed, and short of breath. He denies any recent trauma or potential inciting event. His vital signs are as follows: T 37.1 C, HR 118, BP 74/46, RR 18, SpO2 96%. Physical examination is significant for an irregularly irregular heart rhythm as well as bruising over the right flank. The patient's medical history is significant for atrial fibrillation, hypertension, and hyperlipidemia. His medication list includes atorvastatin, losartan, and coumadin. IV fluids are administered in the emergency department, resulting in an increase in blood pressure to 100/60 and decrease in heart rate to 98. Which of the following would be most useful to confirm this patient's diagnosis and guide future management?

A. Magnetic resonance angiography
B. Ultrasound of the right flank
C. Radiographs of the abdomen and pelvis
D. CT abdomen/pelvis (Correct Answer)
E. MRI abdomen/pelvis

Explanation: ***CT abdomen/pelvis*** - The patient's presentation with **flank pain**, **hypotension**, and **bruising over the flank (Grey Turner's sign)** in the context of anticoagulation points strongly to a **retroperitoneal hemorrhage**. A CT scan is the **gold standard** for diagnosing retroperitoneal hemorrhage, quantifying its size, and identifying any underlying cause or source of bleeding. - CT provides **rapid, detailed imaging** of soft tissues, organs, and vascular structures in the abdomen and pelvis, making it crucial for confirming the diagnosis and guiding management in an acutely unstable patient. *Magnetic resonance angiography* - While MRA provides detailed vascular imaging, it is less readily available in an emergency setting and takes longer to perform than CT, which could delay critical interventions for an unstable patient. - Its primary role is in evaluating vascular pathology, but a general CT scan is usually performed first to identify the source of bleeding and overall hemorrhage. *Ultrasound of the right flank* - Ultrasound can identify fluid collections and some soft tissue abnormalities but has **limited penetration and resolution** for deep retroperitoneal structures and active bleeding. - It is not sensitive enough to accurately diagnose and characterize a significant retroperitoneal hemorrhage or identify a specific bleeding source in an emergent setting. *Radiographs of the abdomen and pelvis* - Radiographs provide very **limited information** about soft tissue pathology like hemorrhage and are primarily useful for skeletal abnormalities or detecting free air. - They would not be able to visualize or diagnose a retroperitoneal hematoma or its source. *MRI abdomen/pelvis* - MRI offers excellent soft tissue contrast, but it is **time-consuming**, expensive, and often less accessible in an emergency setting, delaying diagnosis and management in a hemodynamically unstable patient. - Patients with metallic implants or claustrophobia may not be able to undergo an MRI, and it's generally reserved for more stable patients or specific diagnostic questions not amenable to CT.

Question 45: A 27-year-old woman presents to her primary care physician for a wellness checkup. She states that she is currently doing well but is unable to engage in exercise secondary to her asthma. Her asthma is well-controlled at baseline, and her symptoms only arise when she is trying to exercise once a week at volleyball practice. She is currently only using an albuterol inhaler once a month. The patient’s physical exam is notable for good bilateral air movement without wheezing on pulmonary exam. Which of the following is the best next step in management?

A. Add inhaled fluticasone to her asthma regimen
B. Recommend cessation of athletic endeavors
C. Add oral prednisone to her asthma regimen
D. Recommend she use her albuterol inhaler prior to exercise (Correct Answer)
E. Add montelukast to her asthma regimen

Explanation: ***Recommend she use her albuterol inhaler prior to exercise*** - This patient presents with **exercise-induced bronchoconstriction (EIB)**, as her asthma symptoms are exclusively triggered by exercise. - The most appropriate initial management for EIB is to use a **short-acting beta-agonist (SABA)** like albuterol 15-30 minutes before exercise. *Add inhaled fluticasone to her asthma regimen* - This option is used for **persistent asthma** that is not well-controlled with SABA alone, indicated by more frequent daily or nocturnal symptoms. - The patient's asthma is well-controlled at baseline, only using albuterol once a month, suggesting that she does not require a daily inhaled corticosteroid at this time. *Add oral prednisone to her asthma regimen* - Oral prednisone is a **systemic corticosteroid** reserved for acute asthma exacerbations or severe, difficult-to-control asthma. - The patient's symptoms are mild and intermittent, occurring only with exercise, and thus do not warrant systemic corticosteroids. *Recommend cessation of athletic endeavors* - This is an **unnecessary and restrictive** recommendation, as EIB can typically be well-managed with appropriate medication, allowing patients to participate in sports. - Limiting physical activity can have negative impacts on a patient's overall health and well-being. *Add montelukast to her asthma regimen* - **Montelukast**, a leukotriene receptor antagonist, can be used as an alternative or add-on therapy for persistent asthma, or sometimes for EIB. - However, the **first-line treatment** for preventing EIB symptoms is a SABA like albuterol, and montelukast is a less effective initial choice than pre-exercise SABA for this specific presentation.

Question 46: A 60-year-old man presents to the clinic for his annual check-up. The patient says that he has occasional leg cramps, and his legs feel heavy especially after standing for long hours to teach his classes. His past medical history is significant for hypertension which is controlled by metoprolol and lisinopril. He has smoked half a pack of cigarettes daily for the past 30 years. He does not drink alcohol. Family history is significant for myocardial infarction (MI) in his father at the age of 55 years. The blood pressure is 130/80 mm Hg and the pulse rate is 78/min. On physical examination, there are tortuosities of the veins over his lower limb, more pronounced over the left leg. Peripheral pulses are 2+ on all extremities and there are no skin changes. Strength is 5 out of 5 in all extremities bilaterally. Sensation is intact. No pain in the dorsiflexion of the foot. The rest of the examination and the laboratory tests are normal. Which of the following best describes the pathophysiology responsible for this patient’s symptoms?

A. Inflammation of the skin and subcutaneous tissue
B. Atherosclerosis of medium- and large-sized arteries of the lower limb
C. Age-related fatigability
D. Valvular incompetence of lower limb veins and increased venous pressure (Correct Answer)
E. Intramural thrombus in a deep vein of the leg

Explanation: ***Valvular incompetence of lower limb veins and increased venous pressure*** - The patient's symptoms of **leg heaviness**, **cramps**, and **tortuous veins** (varicosities), especially after prolonged standing, are classic signs of **chronic venous insufficiency**. - This condition is caused by the **failure of venous valves** in the lower limbs, leading to blood pooling, increased venous pressure, and subsequent distention of the veins. *Inflammation of the skin and subcutaneous tissue* - This description typically refers to conditions like **cellulitis** or **erysipelas**, which would present with redness, warmth, swelling, and pain, none of which are noted in the patient's presentation. - There are no reported skin changes, making inflammation unlikely. *Atherosclerosis of medium- and large-sized arteries of the lower limb* - This condition, known as **peripheral artery disease** (PAD), usually causes **intermittent claudication**, which is leg pain upon exertion that is relieved by rest, and often presents with diminished peripheral pulses or cool extremities. - The patient's peripheral pulses are 2+ (normal), and his symptoms improve with activity, which is inconsistent with PAD. *Age-related fatigability* - While age can contribute to a general decrease in endurance, it does not specifically explain the localized leg symptoms of heaviness, cramps, and tortuous veins, nor does it account for the exacerbation with standing. - This is a non-specific explanation and does not address the specific vascular findings. *Intramural thrombus in a deep vein of the leg* - An **intramural thrombus in a deep vein** (deep vein thrombosis or DVT) typically presents with acute symptoms such as sudden onset of unilateral leg pain, swelling, warmth, and erythema, often with tenderness along the course of the vein. - The patient's symptoms are chronic, bilateral (though worse on one side), and lack the acute inflammatory signs or pain on dorsiflexion (Homan's sign is negative).

Question 47: An 18-year-old man is hospitalized after a suicide attempt, his 6th such attempt in the last 4 years. He was diagnosed with depression 5 years ago, for which he takes fluoxetine. He is currently complaining of severe and worsening left knee swelling and pain since he attempted suicide by jumping out of his second-story bedroom window. He sustained minor injuries at the time, primarily lacerations to his arms and knees, and he was admitted to the hospital’s psychiatric unit. His blood pressure is 110/72 mm Hg, heart rate is 88/min, and temperature is 38°C (100.4°F). On examination, the knee is erythematous and edematous, and it feels warm to the touch. The patient’s lab studies reveal a hemoglobin level of 11.9 g/dL, leukocyte count of 11,200/µL, and a platelet count of 301,000/µL. Arthrocentesis yields 15 mL of fluid with a leukocyte count of 61,000/µL, 93% neutrophils, and an absence of crystals under polarized light microscopy. A gram stain of joint fluid is negative; however, mucosal, blood and synovial fluid cultures are still pending. Which of the following is the most appropriate next step in the management of this patient?

A. Obtain a radiograph of the knee and administer indomethacin
B. Administer naproxen and colchicine
C. Administer naproxen and oral antibiotics
D. Administer naproxen
E. Administer intravenous antibiotics and repeat arthrocentesis (Correct Answer)

Explanation: ***Administer intravenous antibiotics and repeat arthrocentesis*** - The patient presents with classic signs of **septic arthritis**, including acute, painful, erythematous, and warm monoarthritis with fever, elevated leukocyte count, and elevated synovial fluid white blood cell count with predominant neutrophils. - While initial Gram stain is negative, **empiric intravenous antibiotics** are crucial given the high suspicion of infection to prevent joint destruction, and **repeat arthrocentesis** is necessary to monitor treatment response and for further diagnostic clarification if cultures remain negative. *Obtain a radiograph of the knee and administer indomethacin* - While a radiograph may show soft tissue swelling or joint effusion, it is **not the most urgent diagnostic or therapeutic step** in suspected septic arthritis. - **Indomethacin** is an NSAID primarily used for inflammatory conditions like gout or pseudogout, which are less likely given the highly purulent synovial fluid and absence of crystals; it does not address the underlying infection. *Administer naproxen and colchicine* - **Naproxen** is an NSAID that can help with pain and inflammation but does not treat the suspected infection. - **Colchicine** is specifically used for gout and pseudogout to reduce inflammation from crystal deposition, which is ruled out by the absence of crystals in the synovial fluid. *Administer naproxen and oral antibiotics* - **Oral antibiotics** are generally insufficient for treating septic arthritis, which requires **intravenous antibiotics** to achieve adequate joint penetration and rapid bactericidal effect. - While naproxen may address pain, it is secondary to the need for aggressive infection treatment. *Administer naproxen* - **Naproxen**, an NSAID, would only provide symptomatic relief for pain and inflammation but would **not treat the underlying bacterial infection**, which could lead to rapid joint destruction and systemic complications.

Question 48: A 45-year-old man presents with 2 weeks of low-grade fever, malaise, night sweats, orthopnea, and shortness of breath. Past medical history is unremarkable. He reports a long-standing history of intravenous drug use for which he has been hospitalized a couple of times in the psychiatry ward. His vital signs upon admission show a blood pressure of 100/80 mm Hg, pulse of 102/min, a respiratory rate of 20/min, and a body temperature of 38.4°C (101.0°F). On cardiac auscultation, there is an S3 gallop and a 3/6 holosystolic murmur heard best along the right sternal border. There are fine rattles present over the lung bases bilaterally. Which of the following tests would be of the greatest diagnostic value in this patient?

A. Blood culture (Correct Answer)
B. Procalcitonin
C. CPK-MB
D. C-reactive protein
E. B-type natriuretic peptide

Explanation: ***Blood culture*** - The patient's history of **intravenous drug use (IVDU)** combined with fever, night sweats, and a **newly developed heart murmur** strongly suggests **infective endocarditis**. - **Blood cultures** are crucial for identifying the causative microorganism and guiding appropriate antibiotic therapy, making them the most definitive diagnostic test in this scenario. *Procalcitonin* - **Procalcitonin** is a biomarker that can indicate a **bacterial infection** and sepsis severity but does not identify the specific pathogen or location of infection. - While it may be elevated in this patient, it is not as diagnostically valuable as blood cultures for confirming infective endocarditis and guiding treatment. *CPK-MB* - **Creatine phosphokinase-MB (CPK-MB)** is a marker used to diagnose **myocardial infarction (heart attack)**. - The patient's symptoms are more consistent with infection and valvular dysfunction rather than myocardial ischemia. Therefore, CPK-MB would not be the most valuable diagnostic test. *C-reactive protein* - **C-reactive protein (CRP)** is an **acute-phase reactant** that indicates inflammation or infection but is non-specific. - While CRP levels would likely be elevated in this patient, it does not provide information about the specific pathogen or the location of the infection, unlike blood cultures. *B-type natriuretic peptide* - **B-type natriuretic peptide (BNP)** is a biomarker released in response to **ventricular stretch** and is used to diagnose and assess the severity of **heart failure**. - While the patient exhibits symptoms of heart failure (orthopnea, shortness of breath, S3 gallop, crackles), identifying the underlying cause (infective endocarditis) is paramount, for which BNP is not the most direct or specific test.

Question 49: A 60-year-old-man presents to his physician with worsening myalgias and new symptoms of early fatigue, muscle weakness, and drooping eyelids. His wife presents with him and states that he never used to have such symptoms. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type II, and pilocytic astrocytoma as a teenager. He denies smoking, drinks a 6-pack of beer per day, and endorses a past history of cocaine use but currently denies any illicit drug use. His vital signs include temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 15/min. Physical examination shows minimal bibasilar rales, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, 3/5 strength in all extremities, and benign abdominal findings. The Tensilon test result is positive. Which of the following options explains why a chest CT should be ordered for this patient?

A. Evaluation for mediastinal botulinum abscess
B. Evaluation of congenital vascular anomaly
C. Exclusion of underlying lung cancer
D. Assessment for motor neuron disease
E. Exclusion of a thymoma (Correct Answer)

Explanation: ***Exclusion of a thymoma*** - The positive **Tensilon test** strongly indicates **myasthenia gravis**, a condition frequently associated with **thymoma**, a tumor of the thymus gland. - A **chest CT** is crucial for identifying or excluding a **thymoma** in patients with myasthenia gravis, as its resection can improve symptoms. *Evaluation for mediastinal botulinum abscess* - **Botulism** would present with descending paralysis and autonomic dysfunction, and an abscess is not a typical manifestation or diagnostic consideration in this context. - While mediastinal abscesses can occur, they are usually associated with infection, trauma, or surgery and not directly linked to the patient's symptoms or positive Tensilon test. *Evaluation of congenital vascular anomaly* - Congenital vascular anomalies are typically diagnosed earlier in life and are not directly associated with the new onset of myalgias, fatigue, muscle weakness, and ptosis in a 60-year-old. - There are no clinical signs or symptoms presented that would suggest a vascular anomaly as a cause for his current presentation. *Exclusion of underlying lung cancer* - Although lung cancer can cause **paraneoplastic syndromes** such as Lambert-Eaton myasthenic syndrome, the symptoms of myalgias, muscle weakness, and ptosis improving with Tensilon strongly point to **myasthenia gravis**, not a paraneoplastic process. - The specific combination of symptoms and a positive Tensilon test makes myasthenia gravis and its association with thymoma a more direct concern requiring evaluation. *Assessment for motor neuron disease* - **Motor neuron diseases** (e.g., ALS) typically present with progressive muscle weakness, spasticity, and fasciculations, but they do not show improvement with a **Tensilon test**. - The positive Tensilon test specifically rules against motor neuron disease as the primary cause for the reported symptoms.

Question 50: A 69-year-old woman is brought to the emergency department by her husband for evaluation of the sudden onset of chest pain and breathlessness 2 hours ago. The pain increases with deep inspiration. She had a total hip replacement 20 days ago. She has hypertension, for which she takes a calcium channel blocker. She has smoked 1 pack of cigarettes daily since adolescence. Her vital signs include a blood pressure of 100/60 mm Hg, pulse of 82/min, and respiratory rate of 30/min. She is cyanotic. Examination of the chest revealed tenderness over the right lower lung with dullness to percussion. A chest CT scan showed a focal, wedged-shaped, pleura-based triangular area of hemorrhage in the right lower lobe of the lung. What is the most probable cause of the pulmonary lesion?

A. Vasculitis
B. Pulmonary atherosclerosis
C. Arteriosclerosis
D. Embolism (Correct Answer)
E. Thrombosis

Explanation: ***Embolism*** - The patient's history of recent **total hip replacement** (a major risk for DVT/PE), sudden onset of **chest pain and breathlessness**, pleuritic pain, and **cyanosis** are highly suggestive of a **pulmonary embolism (PE)**. - The CT scan finding of a **focal, wedge-shaped, pleura-based triangular area of hemorrhage** in the lung is characteristic of a **pulmonary infarct** secondary to PE. *Vasculitis* - Vasculitis involves inflammation of blood vessels, which can lead to various organ system manifestations, but typically presents with more systemic symptoms and abnormal inflammatory markers not detailed here. - While it can cause lung involvement, the acute presentation with pleuritic pain and a specific wedge-shaped infarct points away from a primary vasculitic process. *Pulmonary atherosclerosis* - This condition involves the hardening and narrowing of the pulmonary arteries due to plaque buildup, typically associated with pulmonary hypertension. - It would not explain the acute onset of symptoms or the wedge-shaped infarct as seen in this patient. *Arteriosclerosis* - Arteriosclerosis is a general term for the hardening of arteries, often affecting systemic circulation rather than acutely causing a lung infarct. - It does not directly account for the patient's acute symptoms, surgical history, or the specific CT findings. *Thrombosis* - While a thrombosis (blood clot) is the underlying cause, the term "thrombosis" itself describes the formation of the clot in a blood vessel, typically a deep vein. - The symptom complex and lung lesion are specifically a result of the **embolization** (travel) of this thrombus to the pulmonary circulation, causing an embolism.

Question 51: A 9-year-old boy presents with persistent epistaxis. The patient’s mother says that his nosebleed started suddenly 2 hours ago, and has not ceased after more than 20 minutes of applying pressure. She states that he has a history of nosebleeds since he was a toddler, but, in the past, they usually stopped after a few minutes of applying pressure. The patient is otherwise healthy and has been meeting all developmental milestones. The family history is significant for a grandfather and an uncle who had excessive bleeding tendencies. Which of the following is the most likely cause of this patient’s symptoms?

A. Presence of a factor VIII inhibitor
B. Vitamin K deficiency
C. Presence of the lupus anticoagulant
D. von Willebrand disease
E. Factor IX deficiency (Correct Answer)

Explanation: ***Factor IX deficiency*** - This presentation, with a history of recurrent nosebleeds, a recent increase in severity, and a family history of excessive bleeding in male relatives, is highly suggestive of an **X-linked recessive bleeding disorder** like **hemophilia B (Factor IX deficiency)**. - The inheritance pattern (affecting grandfather and uncle) and the male patient's symptoms are classic for hemophilia. *Presence of a factor VIII inhibitor* - The presence of a **Factor VIII inhibitor** would typically cause bleeding symptoms similar to hemophilia A, but it typically develops secondary to exposure to Factor VIII (e.g., in patients receiving replacement therapy for hemophilia A) or as an **autoimmune phenomenon**, which is less likely to present as a lifelong, consistent bleeding diathesis from toddlerhood. - An acquired inhibitor would present more acutely and severely, rather than a long-standing history of nosebleeds. *Vitamin K deficiency* - **Vitamin K deficiency** primarily affects the synthesis of clotting factors II, VII, IX, and X, leading to a generalized bleeding tendency. - While it can cause epistaxis, it's typically acquired through dietary insufficiency, malabsorption, or antibiotic use, and would not explain a lifelong history of nosebleeds and the **X-linked family history**. *Presence of the lupus anticoagulant* - The **lupus anticoagulant** is an antibody associated with **antiphospholipid syndrome**, which typically causes a **prothrombotic state** (blood clots), not a bleeding disorder. - While it can sometimes prolong PTT in vitro, it does not typically lead to lifelong bleeding tendencies or a familial pattern of excessive bleeding. *von Willebrand disease* - **Von Willebrand disease** is the most common inherited bleeding disorder, often presenting with mucocutaneous bleeding like epistaxis. - However, it typically has an **autosomal dominant** inheritance pattern, affecting both males and females, which does not fit the exclusively male family history provided (grandfather and uncle).

Question 52: A 55-year-old man presents to his primary care physician for leg pain. The patient works as a mailman but states he has had difficulty completing his deliveries for the past month. He complains of a burning and tingling pain in his legs when he walks that goes away when he sits down and takes a break. The patient has a past medical history of obesity, diabetes, stable angina, and constipation. His current medications include insulin and metformin. The patient has a 22-pack-year smoking history and he drinks 2-3 alcoholic beverages per day. Physical exam reveals a stout man with a ruddy complexion. His gait is stable and he demonstrates 5/5 strength in his upper and lower extremities. Which of the following is the best next step in management?

A. Arterial ultrasound
B. Ankle-brachial index (Correct Answer)
C. Atorvastatin
D. Arteriography
E. Aspirin

Explanation: ***Ankle-brachial index*** - The patient's symptoms of **claudication** (leg pain with exertion relieved by rest) and risk factors (smoking, diabetes, obesity) strongly suggest **peripheral artery disease (PAD)**. The **ankle-brachial index (ABI)** is the most appropriate initial diagnostic test for PAD due to its non-invasive nature and high diagnostic accuracy. - ABI is calculated by dividing the **ankle systolic pressure** by the **brachial systolic pressure**, with a ratio <0.9 indicating PAD. *Arterial ultrasound* - While an arterial ultrasound can visualize arterial narrowing and blood flow, it is generally considered a **secondary diagnostic tool** or used for further characterization after an abnormal ABI. - It is more expensive and operator-dependent than ABI, making it less suitable as the *best initial* step. *Atorvastatin* - **Atorvastatin** is a statin commonly used for **lipid-lowering** and cardiovascular risk reduction, which would be an important part of treatment for PAD. - However, it is a **treatment** for PAD, not a diagnostic step to confirm the diagnosis. The priority here is to diagnose the cause of the leg pain. *Arteriography* - **Arteriography** (angiography) is an **invasive procedure** involving injection of contrast dye to visualize the arteries. - It is typically reserved for **pre-procedural planning** of revascularization (e.g., angioplasty or bypass surgery) or in cases where non-invasive tests are inconclusive, not as an initial diagnostic step. *Aspirin* - **Aspirin** is an **antiplatelet agent** indicated for cardiovascular risk reduction and preventing thrombotic events in patients with PAD. - Similar to atorvastatin, it is a **treatment** for PAD, not a diagnostic test to establish the diagnosis.

Question 53: A 58-year-old woman with a history of rheumatic fever has been experiencing exertional fatigue and dyspnea. She has begun using several pillows at night to sleep and occasionally wakes up at night gasping for air. On exam, she appears dyspneic and thin. Cardiac exam reveals a loud S1, opening snap, and apical diastolic rumble. Which of the following is the strongest predictor of the severity of her cardiac problem?

A. Short time between A2 and the opening snap (Correct Answer)
B. Greater intensity of the diastolic rumble
C. Presence of rales
D. Presence of a soft P2
E. Shorter duration of the diastolic rumble

Explanation: ***Short time between A2 and the opening snap*** - A **short A2-OS interval** indicates a higher left atrial pressure and **more severe mitral stenosis**, as the valve opens earlier due to increased pressure - This interval **directly correlates with the severity** of the obstruction at the mitral valve - A2-OS interval < 80ms suggests severe stenosis, while > 120ms suggests mild stenosis - This is the **strongest clinical predictor** of MS severity *Greater intensity of the diastolic rumble* - The **intensity of the diastolic rumble** is more indicative of the **flow velocity** across the mitral valve than the severity of the stenosis itself - A loud rumble can occur with less severe stenosis if cardiac output is high, making it a less reliable indicator of true severity - Intensity can also be affected by chest wall thickness and patient body habitus *Presence of rales* - The presence of **rales** indicates **pulmonary congestion** due to left heart failure, which is a complication of severe mitral stenosis but **not a direct measure** of the valve disease severity itself - Rales can also be present in other conditions like pneumonia, ARDS, or non-cardiac pulmonary edema - This is a sign of decompensation rather than a measure of stenosis severity *Presence of a soft P2* - A **soft P2** (pulmonic component of S2) suggests **low pulmonary artery pressure** - In **severe mitral stenosis**, chronic elevation of left atrial pressure leads to **pulmonary hypertension**, which causes a **loud (not soft) P2** - Therefore, a **soft P2 would suggest LESS severe disease** (no significant pulmonary hypertension has developed yet) - This makes soft P2 a poor predictor of severity, as it would actually indicate milder disease *Shorter duration of the diastolic rumble* - The **duration of the diastolic rumble** reflects the length of time blood flows through the stenotic valve during diastole - A **longer (not shorter) rumble** indicates more severe stenosis with a persistent pressure gradient throughout diastole - A **shorter rumble** suggests milder stenosis where the pressure gradient equalizes earlier in diastole - Duration is useful but less specific than the A2-OS interval

Question 54: A 33-year-old African American woman presents to the clinic complaining of pain and swelling of her hands and wrists for the past 5 months. The symptoms are worse in the morning and are associated with stiffness that lasts about 15 minutes. She also complains of profound fatigue and decreased appetite. She is sexually active with one partner in a monogamous relationship. Past medical history is unremarkable and she is taking oral contraceptives. She smokes 1–2 cigarettes per day and drinks alcohol socially on the weekends. Temperature is 37.2°C (99.1°F), blood pressure is 130/82 mm Hg, pulse is 76/min, and respirations are 12/min. Physical examination reveals wrists that are tender to palpation, warm, and mildly swollen. Several metacarpophalangeal and proximal interphalangeal joints on both hands are also tender. Hand and wrist strength is 5/5 bilaterally. A non-tender ulcer on the buccal mucosa is also noted. When asked about it, the patient reports that it has been there for several months and does not bother her. Laboratory results are as follows: Complete blood count Hemoglobin 10.3 g/dL Platelets 90,000/mm3 Leukocytes 6,700/mm3 Blood urea nitrogen 16 mg/dL Creatinine 2.1 mg/dL Urinalysis Blood 10–20 red blood cells/hpf Protein 2+ protein B-HCG Negative Which of the following is the most likely diagnosis in this patient?

A. Gouty arthritis
B. Systemic lupus erythematosus (Correct Answer)
C. Disseminated gonococcal arthritis
D. Parvovirus B19 infection
E. Behcet disease

Explanation: ***Systemic lupus erythematosus*** - This patient presents with a constellation of symptoms that meet multiple **SLE diagnostic criteria** including **arthritis** (non-erosive, symmetric polyarthritis), **oral ulcers** (painless mucosal ulcers), **hematologic disorder** (anemia with Hgb 10.3 g/dL, thrombocytopenia with platelets 90,000/mm³), and **renal disorder** (elevated creatinine 2.1 mg/dL, proteinuria 2+, hematuria with 10-20 RBCs/hpf). - The patient's demographic profile (young African American woman) significantly increases the pre-test probability for SLE, as the disease is more common and severe in this population. - Constitutional symptoms like fatigue and decreased appetite are also common in SLE due to chronic inflammation. *Gouty arthritis* - Gout typically presents as **acute, monoarticular arthritis** with severe pain, often affecting the **first metatarsophalangeal joint** (podagra), which is not seen here. - The polyarticular symmetric distribution, morning stiffness, and systemic manifestations (cytopenias, renal involvement, oral ulcers) are not characteristic of gout. *Disseminated gonococcal arthritis* - This condition presents with **migratory polyarthralgia**, **tenosynovitis**, and **dermatitis** (pustular skin lesions), usually following a **gonococcal infection**. - The chronic 5-month duration, absence of recent infection symptoms, lack of skin lesions or tenosynovitis, and the presence of oral ulcers, cytopenias, and chronic renal disease make this diagnosis unlikely. *Parvovirus B19 infection* - **Parvovirus B19 infection** can cause **symmetric polyarthralgia/arthritis** and a **"slapped cheek" rash** or reticular rash in adults, sometimes mimicking rheumatoid arthritis. - However, it typically causes an acute, self-limited illness, not a chronic 5-month presentation, and does not typically cause sustained thrombocytopenia, chronic painless oral ulcers, or significant renal involvement with elevated creatinine and proteinuria. *Behcet disease* - **Behcet disease** is characterized by **recurrent oral and genital ulcers**, **ocular involvement** (uveitis), and **skin lesions** (erythema nodosum, papulopustular lesions). - While oral ulcers are present, the significant cytopenias (anemia and thrombocytopenia), chronic symmetric polyarthritis, and clear evidence of lupus nephritis (elevated creatinine, hematuria, proteinuria) are not typical features of Behcet disease.

Question 55: A 62-year-old man presents to the physician because of difficulty initiating urination, terminal dribbling of urine, and bone pain for 3 months. He has no medical history of serious illness, and he currently takes no medications. His father had prostate cancer at age 58. His vital signs are within normal limits. The physical examination shows tenderness over the lower lumbar vertebrae and the right pelvis. The digital rectal exam (DRE) shows a prostate size equivalent to 2 finger pads with a hard nodule. The laboratory tests show the following results: Serum Prostate-specific antigen (PSA) 15 ng/mL Testosterone 350 ng/mL (N=270–1070 ng/mL) The prostate biopsy confirms the presence of prostate cancer with aggressive histologic features. The MRI shows local extension of the tumor. The radionuclide bone scan shows multiple metastatic sites. Which of the following is the most appropriate next step in management?

A. Radiation therapy
B. Radical prostatectomy
C. Androgen deprivation therapy (Correct Answer)
D. Active surveillance
E. Chemotherapy

Explanation: ***Androgen deprivation therapy*** - This patient presents with **metastatic prostate cancer**, as indicated by the bone pain, positive bone scan, elevated PSA, and aggressive histologic features with local extension. **Androgen deprivation therapy (ADT)** is the cornerstone of treatment for metastatic prostate cancer because prostate cancer growth is often **androgen-dependent**. - ADT aims to reduce androgen levels (primarily testosterone) which can be achieved through surgical castration (orchiectomy) or medical castration using GnRH agonists or antagonists, leading to tumor regression and symptom palliation. *Radiation therapy* - **External beam radiation therapy** is typically used for localized prostate cancer or for treating localized metastatic sites to alleviate pain. - It is **not sufficient as a monotherapy** for **widespread metastatic disease** as seen in this patient, where systemic treatment is required. *Radical prostatectomy* - **Radical prostatectomy** is a surgical procedure to remove the prostate gland and is a curative option for **localized prostate cancer**. - It is **contraindicated and ineffective** for **metastatic disease** that has spread beyond the prostate, as it cannot remove all cancer cells in other parts of the body. *Active surveillance* - **Active surveillance** is an appropriate management strategy for **low-risk, localized prostate cancer** in older patients or those with significant comorbidities, where the risks of treatment outweigh the benefits. - This patient has **aggressive, metastatic disease** with symptomatic bone pain, making active surveillance an entirely inappropriate and harmful choice. *Chemotherapy* - **Chemotherapy** is generally reserved for **castration-resistant prostate cancer (CRPC)**, meaning the cancer has progressed despite androgen deprivation therapy. - While chemotherapy can be used later in the disease course, initial management for **hormone-sensitive metastatic prostate cancer** like this case is typically ADT.

Question 56: A previously healthy 48-year-old man comes to the physician for a 3-month history of myalgias and recurrent episodes of retrosternal chest pain and dizziness. He has had a 5-kg (11-lb) weight loss during this period. His temperature is 39.1°C (102.3°F), pulse is 90/min, and blood pressure is 160/102 mm Hg. Physical examination shows lacy, purplish discoloration of the skin with multiple erythematous, tender subcutaneous nodules on the lower legs. Some of the nodules have central ulcerations. Serum studies show an erythrocyte sedimentation rate of 76 mg/dL and creatinine level of 1.8 mg/dL. Renal MR angiography shows irregular areas of dilation and constriction in the renal arteries bilaterally. Further evaluation of this patient is most likely to show which of the following?

A. Presence of anti-myeloperoxidase antibodies in the serum
B. Presence of anti-proteinase 3 antibodies in the serum
C. Pulmonary artery microaneurysms on pulmonary angiography
D. Transmural inflammation with fibrinoid necrosis on arterial biopsy (Correct Answer)
E. Multinucleated giant cells with elastic membrane fragmentation on arterial biopsy

Explanation: ***Transmural inflammation with fibrinoid necrosis on arterial biopsy*** - The patient's symptoms (myalgias, recurrent chest pain, dizziness, weight loss, fever, hypertension, elevated ESR, acute kidney injury) combined with **livedo reticularis** and **subcutaneous nodules with ulcerations** are highly suggestive of **polyarteritis nodosa (PAN)**, a medium-vessel vasculitis. - Classic histological findings in PAN are **segmental transmural inflammation of medium-sized arteries**, often with **fibrinoid necrosis**, leading to luminal narrowing, thrombosis, or microaneurysm formation. *Presence of anti-myeloperoxidase antibodies in the serum* - **Anti-myeloperoxidase (MPO) antibodies** are associated with **microscopic polyangiitis** and **eosinophilic granulomatosis with polyangiitis (Churg-Strauss)**, which are small-vessel vasculitides, not typically presenting with the widespread systemic findings and medium-vessel involvement seen here. - While these can cause renal involvement and systemic symptoms, the **cutaneous nodules with ulcerations** and **renal artery aneurysms/stenosis** are more characteristic of PAN, which is typically ANCA-negative. *Presence of anti-proteinase 3 antibodies in the serum* - **Anti-proteinase 3 (PR3) antibodies** are characteristic of **granulomatosis with polyangiitis (Wegener's)**, which is also a small-vessel vasculitis. - Granulomatosis with polyangiitis predominantly affects the upper and lower respiratory tracts and kidneys, and classic findings like **nasal septal perforation** or **pulmonary nodules with cavitation** are absent. *Pulmonary artery microaneurysms on pulmonary angiography* - While aneurysms can occur in vasculitis, **pulmonary artery microaneurysms** are a less common or specific finding for PAN, which primarily affects medium-sized arteries in various organs, including renal, mesenteric, and skin arteries. - The constellation of symptoms and the appearance of **renal artery irregular dilation and constriction** point more strongly to a systemic medium-vessel vasculitis like PAN, where such findings in the kidney are typical. *Multinucleated giant cells with elastic membrane fragmentation on arterial biopsy* - **Multinucleated giant cells** and **elastic membrane fragmentation** are characteristic histological features of **giant cell (temporal) arteritis** or **Takayasu arteritis**, both of which are large-vessel vasculitides. - Giant cell arteritis typically affects older individuals and presents with symptoms like **headache**, **jaw claudication**, and **visual disturbances**, while Takayasu arteritis affects the aorta and its major branches, leading to pulse deficits, neither of which aligns with this patient's presentation.

Question 57: A previously healthy 35-year-old woman comes to the emergency department because of a sudden onset of difficulty breathing that began when she woke up that morning. She also reports a dry cough and chest pain that is worse with inspiration. She does not smoke, drink alcohol, or use illicit drugs. Her only medication is an oral contraceptive. Her temperature is 38°C (100.4°F), pulse is 90/min, respirations are 22/min, and blood pressure is 120/70 mm Hg. Oxygen saturation is 93% on room air. Physical examination is unremarkable. An ECG shows non-specific ST segment changes. An x-ray of the chest shows no abnormalities. In addition to oxygen supplementation, which of the following is the most appropriate next step in management?

A. Perform pulmonary angiography
B. Start noninvasive positive pressure ventilation
C. Measure fibrin degradation products (Correct Answer)
D. Administer ibuprofen
E. Order ventilation and perfusion scintigraphy

Explanation: ***Measure fibrin degradation products*** - This patient presents with **sudden-onset dyspnea**, **pleuritic chest pain**, **tachycardia**, **tachypnea**, and **hypoxemia**, along with a risk factor for **venous thromboembolism** (oral contraceptive use). These findings are highly suspicious for **pulmonary embolism (PE)**. - Measuring **D-dimer (fibrin degradation product)** is the most appropriate **initial next step** in this clinical scenario as part of a stepwise diagnostic approach. While imaging (such as CT pulmonary angiography) would be definitive, D-dimer serves as a **rapid, non-invasive screening test** that can guide further management. - A **negative D-dimer** in a patient with low-to-intermediate pretest probability effectively **rules out PE** (high negative predictive value), avoiding unnecessary radiation exposure from imaging. If positive, it would prompt definitive imaging. - This approach is **cost-effective** and follows standard emergency department protocols for suspected PE. *Perform pulmonary angiography* - **Invasive pulmonary angiography** (catheter-based) is the historical **gold standard** for diagnosing PE but has been largely replaced by **CT pulmonary angiography (CTPA)**. - It is **invasive** with associated risks (vascular injury, contrast reactions, bleeding) and is typically reserved for cases where non-invasive imaging is inconclusive or when intervention is planned simultaneously. - This is **not an appropriate initial step** in the diagnostic workup. *Start noninvasive positive pressure ventilation* - This patient's **oxygen saturation is 93%** on room air, indicating **mild hypoxemia** that can be adequately managed with **supplemental oxygen** alone. - **Noninvasive positive pressure ventilation (NIPPV)** is reserved for patients with **severe respiratory distress**, **acute respiratory failure**, or **refractory hypoxemia** (typically SpO2 <90% despite oxygen). - There is no indication for NIPPV in this stable patient. *Administer ibuprofen* - **Ibuprofen** is an **NSAID** used for analgesia and anti-inflammatory effects, but it does **not address the underlying pathology** of suspected **pulmonary embolism**. - While the patient has pleuritic chest pain, the priority is to **diagnose the potentially life-threatening condition** causing her acute symptoms, not merely provide symptomatic relief. - Additionally, NSAIDs have antiplatelet effects that could complicate management if anticoagulation is needed. *Order ventilation and perfusion scintigraphy* - A **ventilation-perfusion (V/Q) scan** is an appropriate imaging study for diagnosing PE, particularly in patients with **normal chest X-ray**, **renal insufficiency** (cannot receive CT contrast), or **pregnancy**. - However, in the **stepwise diagnostic approach** for suspected PE, **D-dimer testing should be performed first** as a rapid screening tool. If D-dimer is elevated, then imaging (V/Q scan or CTPA) would be the next step. - Proceeding directly to V/Q scan **bypasses the screening step** that could potentially rule out PE without radiation exposure, making it less optimal as the immediate next step.

Question 58: A 12-year-old boy presents with a 3-day history of frothy brown urine. He does not complain of any other symptoms. He notes that 3 weeks ago he had a fever with a sore throat, but he did not receive any treatment at the time. His blood pressure is 152/94 mm Hg, heart rate is 72/min, respiratory rate is 15/min, and temperature is 37.0°C (98.6°F). Review of his medical record shows that his blood pressure was 118/74 mm Hg just 4 weeks ago. Laboratory analysis reveals elevated serum creatinine, hematuria with RBC casts, and elevated urine protein without frank proteinuria. What laboratory test can confirm the most likely diagnosis in this patient?

A. Antistreptolysin O (ASO) titer (Correct Answer)
B. Urine Gram stain
C. Urine electrolytes
D. Stool sample
E. Urine catecholamine assessment

Explanation: ***Antistreptolysin O (ASO) titer*** - A 3-week history of a sore throat followed by frothy brown urine, **hematuria with RBC casts**, and **hypertension** in a 12-year-old boy is highly suggestive of **post-streptococcal glomerulonephritis (PSGN)**. - An elevated **ASO titer** indicates recent exposure to *Streptococcus pyogenes*, the causative agent of PSGN, confirming the diagnosis. *Urine Gram stain* - This test is used to detect bacterial infections in the urinary tract, which typically present with symptoms like **dysuria, frequency, and fever**, and often show bacteriuria rather than hematuria with RBC casts. - While a urinary tract infection can cause hematuria, the presence of **RBC casts** and the preceding sore throat point away from a simple bacterial UTI. *Urine electrolytes* - While renal dysfunction can affect electrolyte balance, **urine electrolytes** are not a primary diagnostic tool for glomerulonephritis like PSGN. - This test is more useful for assessing **fluid balance disorders** or specific tubular dysfunctions. *Stool sample* - A **stool sample** is primarily used to diagnose gastrointestinal infections or conditions affecting the bowel. - There is no clinical indication in this patient's presentation (sore throat, frothy brown urine, hypertension, hematuria with RBC casts) that would suggest a gastrointestinal pathology as the cause of his renal symptoms. *Urine catecholamine assessment* - This test is used to screen for **pheochromocytoma**, a rare tumor of the adrenal glands that can cause hypertension. - While the patient has new-onset hypertension, the history of a preceding sore throat and the presence of **hematuria with RBC casts** strongly argue against pheochromocytoma as the primary diagnosis.

Question 59: A 78-year-old male has been hospitalized for the past 3 days after undergoing a revision left total hip replacement. Over the past several hours, the nursing staff reports that the patient has exhibited fluctuating periods of intermittent drowsiness and confusion where he has been speaking to nonexistent visitors in his hospital room. The patient's daughter is present at bedside and reports that the patient lives alone and successfully manages his own affairs without assistance. Which of the following is most likely true of this patient's current condition?

A. Short-term memory is often impaired, with sparing of remote memory
B. Anticholinergic medications may alleviate his symptoms
C. Possible etiologies include infection, trauma, or polypharmacy (Correct Answer)
D. Beta-amyloid plaques and neurofibrillary tangles are pathologic findings associated with this condition
E. The condition is typically irreversible, representing a common complication of aging

Explanation: ***Possible etiologies include infection, trauma, or polypharmacy*** - The patient's presentation of **acute onset, fluctuating confusion, and visual hallucinations** following surgery strongly suggests **delirium**. - Delirium is often caused by an underlying medical condition, such as **infection, trauma (like surgery), medication side effects (polypharmacy)**, metabolic derangements, or withdrawal. *Short-term memory is often impaired, with sparing of remote memory* - While memory impairment is common in delirium, particularly **attention and recent memory**, this statement is characteristic of **dementia**, where **short-term memory** is significantly affected while **remote memory** may be initially preserved. - Delirium is primarily a disorder of **attention and arousal**, leading to intermittent confusion and disorientation rather than a primary global memory deficit. *Anticholinergic medications may alleviate his symptoms* - **Anticholinergic medications** are a *common cause or exacerbating factor* for delirium, especially in elderly patients, and would likely worsen his symptoms. - Treatment for delirium involves identifying and addressing the **underlying cause**, not administering drugs that could precipitate or worsen it. *Beta-amyloid plaques and neurofibrillary tangles are pathologic findings associated with this condition* - **Beta-amyloid plaques** and **neurofibrillary tangles** are the characteristic neuropathological hallmarks of **Alzheimer's disease**, a type of dementia. - These findings are *not directly associated with delirium*, which is an acute, generally reversible state of altered consciousness and cognition. *The condition is typically irreversible, representing a common complication of aging* - Delirium is an **acute** and often **reversible** condition, especially if the underlying cause is identified and treated promptly. - It is a common and serious complication in older hospitalized patients, but it is **not an irreversible** process or a normal part of aging.

Question 60: Eight hours after undergoing successful cholecystectomy, a 65-year-old man with scoliosis complains of shortness of breath. Respirations are 28/min and pulse oximetry on room air shows an oxygen saturation of 85%. Physical examination shows kyphotic deformation of the thorax. Cardiopulmonary examination shows intercostal retractions and diminished breath sounds on the left side. There is trace pedal edema bilaterally. An x-ray of the chest shows bilateral fluffy infiltrates, and the cardiac silhouette is shifted slightly to the left side. Which of the following is the most likely explanation for this patient's hypoxia?

A. Embolus in the pulmonary artery
B. Collapsed alveoli (Correct Answer)
C. Bacterial infiltration of lung parenchyma
D. Fluid in the pleural space
E. Air trapped in the pleural space

Explanation: ***Collapsed alveoli*** - The patient's presentation with **shortness of breath**, **tachypnea**, **hypoxia** (SpO2 85%), **intercostal retractions**, and **diminished breath sounds**, especially in the context of recent abdominal surgery (cholecystectomy), strongly suggests **atelectasis** due to collapsed alveoli. - **Fluffy infiltrates** on chest X-ray can be consistent with atelectasis, particularly in the lower lobes, and the kyphotic deformity (scoliosis) further predisposes the patient to poor lung expansion. *Embolus in the pulmonary artery* - While a **pulmonary embolism** can cause sudden shortness of breath and hypoxia post-surgery, the chest X-ray findings of **bilateral fluffy infiltrates** are not typical. - Furthermore, **diminished breath sounds** and **intercostal retractions** are less characteristic of a PE compared to atelectasis. *Bacterial infiltration of lung parenchyma* - **Bacterial pneumonia** would typically present with fever, productive cough, and more localized infiltrates on chest X-ray, sometimes with consolidation. - The acute onset within 8 hours post-surgery makes bacterial pneumonia less likely as the primary cause of hypoxia. *Fluid in the pleural space* - **Pleural effusion** would cause diminished breath sounds and potentially dyspnea, but the chest X-ray typically shows blunting of costophrenic angles and a meniscus sign, rather than diffuse "fluffy infiltrates." - While some fluid could accumulate post-operatively, it doesn't fully explain the widespread nature of the "fluffy infiltrates" or the intercostal retractions as the primary cause of hypoxia. *Air trapped in the pleural space* - **Pneumothorax** (air in the pleural space) would lead to very diminished or absent breath sounds on the affected side and would typically show a visible pleural line and lung collapse on chest X-ray. - The description of "bilateral fluffy infiltrates" and diffuse intercostal retractions is inconsistent with a simple pneumothorax.

Question 61: A 27-year-old male basketball player presents to his primary care physician for a normal check-up. He has not been seen by a physician in ten years. He reports that he feels well and has no complaints. His temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 85/min, and respirations are 16/min. On examination, the patient's height is 76 in (193 cm) with an arm span of 78 in (198 cm). His BMI is 19 kg/m^2. His fingers and toes are long and tapered and his sternum appears sunken into his chest. The patient also has moderate scoliosis. Upon further questioning, the patient reports that his father had a similar physique but passed away in his 40s. Which of the following complications is this patient at greatest risk for?

A. Hyperparathyroidism
B. Septic arthritis
C. Aortic stenosis
D. Hearing loss
E. Aortic aneurysm (Correct Answer)

Explanation: ***Aortic aneurysm*** * The patient's presentation with **tall stature**, **long fingers and toes (arachnodactyly)**, **pectus excavatum (sunken sternum)**, **scoliosis**, and a family history of sudden death in a similarly built father strongly suggests **Marfan syndrome**. * **Aortic aneurysm and dissection** are the most serious cardiovascular complications of Marfan syndrome, often leading to premature death if untreated, due to the inherent connective tissue weakness in the aorta. *Hyperparathyroidism* * **Hyperparathyroidism** is not typically associated with Marfan syndrome. Its primary complications involve **hypercalcemia** and related symptoms such as kidney stones or bone pain. * There are no clinical features in the patient's presentation or family history to suggest a risk for this endocrine disorder. *Septic arthritis* * **Septic arthritis** is an infection of a joint, usually characterized by acute pain, swelling, warmth, and limited range of motion in the affected joint, often with systemic signs of infection. * The patient has no symptoms or risk factors for infection, and genetic connective tissue disorders like Marfan syndrome do not predispose individuals to septic arthritis. *Aortic stenosis* * **Aortic stenosis** involves narrowing of the aortic valve, classically causing symptoms of chest pain, syncope, and dyspnea on exertion. While Marfan syndrome can affect valves, it more commonly causes **aortic root dilation and regurgitation**, not stenosis. * The primary and most dangerous cardiovascular complication in Marfan syndrome is **aortic root dilation leading to aneurysm and dissection**, not typically primary stenosis of the valve. *Hearing loss* * While certain genetic syndromes can be associated with **hearing loss**, it is **not a prominent or direct complication of Marfan syndrome**. * The patient's symptoms are classic for connective tissue abnormalities affecting the skeletal and cardiovascular systems, not the auditory system.

Question 62: An 18-year-old man is brought to the emergency department due to the confusion that started earlier in the day. His parents report that the patient had recovered from vomiting and diarrhea 3 days ago without medical intervention. They mention that although nausea and vomiting have resolved, the patient continued to have diffuse abdominal pain and decreased appetite. Past medical history is unremarkable, except for a recent weight loss and increased thirst. The patient does not use tobacco products or alcohol. He is not sexually active and does not use illicit drugs. He appears lethargic but responds to questions. His mucous membranes appear dry. Temperature is 36.9°C (98.4°F), blood pressure is 105/60 mm Hg, pulse is 110/min, and respiratory rate is 27/min with deep and rapid respiration. There is diffuse abdominal tenderness without guarding, rebound tenderness or rigidity. Which of the following is the next best step in the management of this patient?

A. Abdominal ultrasound
B. ECG
C. MRI of the brain
D. Capillary blood glucose measurement (Correct Answer)
E. CT of the abdomen

Explanation: ***Capillary blood glucose measurement*** - The patient's symptoms, including **confusion**, recent **weight loss**, **increased thirst**, **lethargy**, dry mucous membranes, **tachycardia**, and **Kussmaul respirations** (deep and rapid breathing), are highly suggestive of **diabetic ketoacidosis (DKA)**. - A rapid assessment of **blood glucose** is crucial for confirming DKA and initiating prompt treatment. *Abdominal ultrasound* - While the patient has **diffuse abdominal tenderness**, there are no signs pointing specifically to an intra-abdominal pathology requiring immediate imaging. - The patient's systemic symptoms and Kussmaul respirations are more indicative of a metabolic derangement than a localized abdominal issue. *ECG* - An ECG might be performed later to assess for **cardiac abnormalities** in DKA, especially related to **electrolyte disturbances**, but it's not the immediate diagnostic step. - The priority is to confirm and begin treatment for the metabolic crisis. *MRI of the brain* - Given the patient's acute confusion and other systemic symptoms, an MRI of the brain is not the initial investigation. - **Cerebral edema** can be a complication of DKA, but it typically develops later in the course or during treatment, and initial management focuses on correcting the metabolic state. *CT of the abdomen* - Similar to abdominal ultrasound, a CT scan of the abdomen is not the next best step given the clinical picture. - The symptoms are more consistent with a **metabolic emergency** like DKA, which requires immediate biochemical assessment rather than imaging for abdominal pain.

Question 63: A 14-year-old Asian girl is brought to the physician because of a 6-week history of fatigue. During this period, she has had a 3-kg (6.6-lb) weight loss and intermittent low-grade fevers. She also reports recurrent episodes of pain in her left wrist and right knee. She has no personal history of serious illness. Her aunt has rheumatoid arthritis. The patient appears pale. Her temperature is 38°C (100.4°F). Examination shows diffuse lymphadenopathy. Oral examination shows several painless oral ulcers. The left wrist and the right knee are swollen and tender to touch. The remainder of the examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 10 g/dL, a leukocyte count of 3,000/mm3, and a platelet count of 80,000/mm3. Urinalysis shows excessive protein. Further evaluation of this patient is most likely to show which of the following findings?

A. Anti-citrullinated peptide antibodies
B. Excessive lymphoblasts
C. Anti-dsDNA antibodies (Correct Answer)
D. Elevated serum IgA levels
E. Positive monospot test

Explanation: ***Anti-dsDNA antibodies*** - The patient's presentation with **fatigue**, **weight loss**, **fevers**, **polyarthritis**, **oral ulcers**, **lymphadenopathy**, **anemia**, **leukopenia**, **thrombocytopenia**, and **proteinuria** is highly suggestive of **Systemic Lupus Erythematosus (SLE)**. - **Anti-dsDNA antibodies** are highly specific for SLE and often correlate with disease activity, particularly **lupus nephritis**, which is indicated by the proteinuria. *Anti-citrullinated peptide antibodies* - These antibodies are characteristic of **rheumatoid arthritis (RA)**, a chronic inflammatory autoimmune disease primarily affecting the joints. - While the patient has arthritis, her overall clinical picture with oral ulcers, cytopenias, and proteinuria is not typical of RA, and the symptoms are more consistent with SLE. *Excessive lymphoblasts* - The presence of **excessive lymphoblasts** in the blood or bone marrow is a hallmark of **acute lymphoblastic leukemia (ALL)**. - While the patient has fatigue, weight loss, fevers, lymphadenopathy, and cytopenias (anemia, leukopenia, thrombocytopenia), her prominent polyarthritis, oral ulcers, and proteinuria are not typical features of ALL. *Elevated serum IgA levels* - Elevated serum IgA levels can be seen in various conditions, including **IgA nephropathy**, **celiac disease**, and some chronic liver diseases. - However, they are not a specific marker for the constellation of symptoms presented by the patient, and do not explain the widespread systemic involvement seen. *Positive monospot test* - A **positive monospot test** indicates the presence of heterophile antibodies, which are characteristic of **infectious mononucleosis**, typically caused by the **Epstein-Barr virus**. - While infectious mononucleosis can cause fatigue, fever, lymphadenopathy, and occasionally rash, it does not typically cause persistent polyarthritis, oral ulcers, cytopenias, or proteinuria, thereby making it an unlikely diagnosis in this case.

Question 64: A 34-year-old man comes to the physician because of increasing lower back and neck pain for the past 7 months. The pain is worse in the morning and improves when he plays basketball. He has noticed shortness of breath while playing for the past 2 months. He is sexually active with 2 female partners and uses condoms inconsistently. He appears lethargic. His vital signs are within normal limits. Examination of the back shows tenderness over the sacroiliac joints. Range of motion is limited. The lungs are clear to auscultation. Chest expansion is decreased on full inspiration. His leukocyte count is 14,000/mm3 and erythrocyte sedimentation rate is 84 mm/h. An x-ray of the spine shows erosion and sclerosis of the sacroiliac joints and loss of spinal lordosis. Further evaluation of this patient is most likely to show which of the following?

A. Paresthesia over the anterolateral part of the thigh
B. Nail pitting and separation of the nail from the nailbed
C. Ulnar deviation of the fingers bilaterally
D. Erythema and inflammation of the conjunctiva
E. Tenderness at the Achilles tendon insertion site (Correct Answer)

Explanation: ***Tenderness at the Achilles tendon insertion site*** - This patient's symptoms (morning stiffness, improved with activity, sacroiliac joint tenderness, decreased chest expansion, elevated inflammatory markers, sacroiliac erosions, and loss of spinal lordosis) are highly consistent with **ankylosing spondylitis**. - **Enthesitis**, the inflammation of the sites where tendons or ligaments insert into bone, particularly at the **Achilles tendon insertion**, is a common extraskeletal manifestation of ankylosing spondylitis and other spondyloarthropathies. *Paresthesia over the anterolateral part of the thigh* - This symptom, also known as **meralgia paresthetica**, is caused by compression of the **lateral femoral cutaneous nerve**. - While it can occur in the general population, it is not a direct or common manifestation of ankylosing spondylitis. *Nail pitting and separation of the nail from the nailbed* - These are characteristic features of **psoriatic arthritis** and psoriasis, which are not specifically indicated by the patient's symptoms or findings. - Although psoriasis can be associated with spondyloarthropathies, the primary presentation points more strongly to ankylosing spondylitis without overt skin or nail manifestations mentioned. *Ulnar deviation of the fingers bilaterally* - **Ulnar deviation** of the fingers is a classic finding in advanced **rheumatoid arthritis**, which primarily affects peripheral joints symmetrically. - The patient's axial skeleton involvement (sacroiliac and spine) and morning stiffness improving with activity are atypical for rheumatoid arthritis. *Erythema and inflammation of the conjunctiva* - **Conjunctivitis** (erythema and inflammation of the conjunctiva) can be a feature of **reactive arthritis** or, less commonly, other spondyloarthropathies. - While reactive arthritis is in the differential for seronegative spondyloarthropathies, the chronicity of symptoms (7 months), classic spinal involvement, and resolution with activity point more definitively to ankylosing spondylitis as the primary diagnosis, with enthesitis being a more direct and common complication.

Question 65: A 31-year-old man presents with a several-month history of foot sensory changes. He has noticed that he has a hard time telling the difference between a hardwood floor and carpet beneath his feet. He's also had a couple of falls lately; these falls were not preceded by any lightheadedness or palpitations. He is adopted, so his family history is unknown. On physical exam, he has leg and foot muscular atrophy and 4/5 strength throughout his bilateral lower extremities. Sensation to light touch and pinprick is decreased up to the mid-calf. Ankle jerk reflex is absent bilaterally. He has a significant pes cavus deformity of both feet. Nerve conduction studies show decreased conduction velocities in his bilateral peroneal nerves. Which of the following is the best treatment for this patient?

A. Referral to physical therapy (Correct Answer)
B. Aspirin
C. Gabapentin
D. Cilostazol
E. Referral to orthopedic surgery

Explanation: ***Referral to physical therapy*** - This patient presents with signs and symptoms highly suggestive of **Charcot-Marie-Tooth disease**, a hereditary neuropathy characterized by **progressive muscle weakness**, **sensory loss**, and **foot deformities** like **pes cavus**. - **Physical therapy** is crucial for maintaining function, improving balance, preventing contractures, and enhancing quality of life in patients with chronic progressive neuropathies. *Aspirin* - **Aspirin** is an **antiplatelet agent** used in the prevention of cardiovascular events or for pain relief. - It does not address the underlying neurological degeneration or symptomatic progression of hereditary neuropathies. *Gabapentin* - **Gabapentin** is primarily used to treat **neuropathic pain** or as an **antiepileptic**. - While it might address some discomfort, it does not improve motor function, prevent falls, or alter the disease course in Charcot-Marie-Tooth disease. *Cilostazol* - **Cilostazol** is a **phosphodiesterase inhibitor** used to treat **intermittent claudication** in peripheral artery disease, which is not indicated here. - Its mechanism of action is unrelated to neurological or musculoskeletal conditions seen in this patient. *Referral to orthopedic surgery* - While orthopedic surgery might be considered for severe deformities like pes cavus, it is typically reserved for cases where conservative management fails or when the deformity significantly impairs ambulation. - In a patient with **progressive neuropathy**, other supportive measures like physical therapy are generally the initial and ongoing management strategies.

Question 66: A 16-year-old boy comes to the physician because his parents are concerned about his persistently poor performance at school. He has had increased impulsivity and has difficulty making and keeping friends. On questioning, he reports that he is being bullied by his classmates for his high-pitched voice, thin build, and poor grades. He is at the 94th percentile for height and 50th percentile for weight. Physical examination shows bilateral gynecomastia, sparse pubic hair, and long limbs compared with the trunk. Genital examination shows small, firm testes. Serum studies show increased levels of luteinizing hormone and follicle-stimulating hormone and a slightly decreased serum testosterone. This patient is at increased risk of which of the following complications?

A. Aortic dissection
B. Acute leukemia
C. Prostate cancer
D. Breast cancer (Correct Answer)
E. Optic glioma

Explanation: ***Breast cancer*** - This patient's presentation is consistent with **Klinefelter syndrome (47, XXY)**, characterized by **gynecomastia**, **small testes**, **tall stature**, and **low testosterone with high LH/FSH**. - Individuals with Klinefelter syndrome have a significantly increased risk (approximately 20-50 times) of developing **male breast cancer** due to the estrogen-androgen imbalance and the presence of an extra X chromosome. *Aortic dissection* - **Aortic dissection** is a known risk in conditions like **Marfan syndrome** due to connective tissue abnormalities, which can also present with tall stature and long limbs. - However, Marfan syndrome does not typically involve **gynecomastia**, **small testes**, or the specific hormonal profile (high LH/FSH, low testosterone) seen in Klinefelter syndrome. *Acute leukemia* - There is no direct significant association between **Klinefelter syndrome** and an increased risk of **acute leukemia**. - While chromosomal abnormalities can sometimes be linked to leukemia, the characteristic features described here do not point to a predisposition for leukemia. *Prostate cancer* - **Prostate cancer** is typically linked to **androgens**; in Klinefelter syndrome, **low testosterone** levels are observed, which would generally be protective against prostate cancer. - Therefore, Klinefelter syndrome does not increase the risk of prostate cancer; in fact, some studies suggest a slightly lower incidence. *Optic glioma* - **Optic glioma** is a tumor of the optic nerve and is often associated with neurofibromatosis type 1. - This condition does not have a direct association with the classic features of **Klinefelter syndrome** described in the patient.

Question 67: A 55-year-old man is brought to the emergency department by ambulance after being found disoriented. He has limited ability to communicate in English but indicates that he has left flank pain and a fever. Chart review reveals that he has diabetes and sleep apnea but both are well controlled. He also has a 30-pack-year smoking history and has lost about 20 pounds since his last presentation. Physical exam reveals a bulge in his left scrotum and ultrasound reveals bilateral kidney stones. Which of the following findings is also associated with the most likely cause of this patient's symptoms?

A. Gynecomastia
B. Cavitary lung lesion
C. Jaundice
D. Increased hematocrit (Correct Answer)
E. Aniridia

Explanation: ***Increased hematocrit*** - This patient's symptoms (disorientation, left flank pain, fever, weight loss, smoking history, and **left scrotal bulge suggesting varicocele**) are highly suggestive of **renal cell carcinoma (RCC)**. - The **left-sided varicocele** in an adult male is particularly significant, as it may indicate **left renal vein obstruction** by the tumor (the left testicular vein drains into the left renal vein). - Approximately 3-10% of patients with RCC develop **erythrocytosis** due to **ectopic erythropoietin (EPO) production** by the tumor, leading to **increased hematocrit** as a paraneoplastic syndrome. - Other paraneoplastic manifestations of RCC include hypercalcemia (PTHrP production), hypertension (renin production), and Stauffer syndrome (hepatic dysfunction). *Gynecomastia* - While paraneoplastic syndromes can occur with RCC, **gynecomastia** is not a common associated finding. - Gynecomastia is more often associated with **testicular tumors** (hCG-secreting), liver disease, or certain medications. *Cavitary lung lesion* - While RCC can metastasize to the lungs, presenting as **nodules or masses** (cannonball metastases), a **cavitary lesion** is more characteristic of infections (e.g., tuberculosis, fungal infections) or **squamous cell carcinoma** of the lung. - The primary presentation here points to renal pathology with paraneoplastic manifestations. *Jaundice* - **Jaundice** indicates **hyperbilirubinemia** and is not a direct paraneoplastic syndrome of RCC. - It may occur with extensive metastatic disease to the liver causing biliary obstruction or in Stauffer syndrome (non-metastatic hepatic dysfunction), but this is less common than erythrocytosis. *Aniridia* - **Aniridia** (absence of the iris) is a rare congenital condition strongly associated with **Wilms' tumor** (nephroblastoma), a pediatric kidney cancer, as part of the **WAGR syndrome** (Wilms tumor, Aniridia, Genitourinary abnormalities, intellectual disability/Range of developmental delays). - It is not associated with adult renal cell carcinoma.

Question 68: A 57-year-old female presents to her primary care physician with a chief complaint of feeling tired all the time. She states her symptoms began several months ago, around the time that her husband committed suicide. Since then she has had thoughts of joining her husband. She complains of feeling excessively weak and states that she no longer has enough energy to go to the gym which she attributes to her 15 pound weight gain over the last month. The patient's medical history includes joint pain, a skin rash that recently resolved, obstructive sleep apnea, and metabolic syndrome. The patient takes ibuprofen and omeprazole as needed but otherwise cannot remember any other medications that she takes. On physical exam you note an overweight woman who has an overall depressed affect. The patient's cardiac exam reveals a normal rate and rhythm. The pulmonary exam reveals bilateral clear lung fields with good air movement. The patient's skin is very dry and tight appearing and her hair is coarse. Overall the patient appears somewhat unkempt. Laboratory work is performed and reveals the following: Hemoglobin: 13.0 g/dL Hematocrit: 37% Leukocyte count: 4,500 cells/mm^3 with normal differential Platelets: 250,000/mm^3 Serum: Na+: 140 mEq/L K+: 4.4 mEq/L Cl-: 102 mEq/L BUN: 15 mg/dL Glucose: 122 mg/dL Creatinine: 1.0 mg/dL Thyroid-stimulating hormone: 5.3 µU/mL Ca2+: 10.2 mg/dL AST: 11 U/L ALT: 13 U/L Which of the following laboratory findings is most likely to be abnormal in this patient?

A. Anti-DNA topoisomerase antibodies
B. Anti-thyroid peroxidase antibodies (Correct Answer)
C. Anti-nuclear antibodies
D. Anti-histidyl-tRNA synthetase antibodies
E. 5-hydroxyindoleacetic acid in CSF

Explanation: ***Anti-thyroid peroxidase antibodies*** - The patient presents with classic symptoms of **hypothyroidism** (fatigue, weight gain, dry skin, coarse hair, depressed affect) and an elevated **TSH of 5.3 µU/mL** (normal: 0.4-4.0 µU/mL), indicating **subclinical or early primary hypothyroidism**. - **Hashimoto's thyroiditis** (chronic autoimmune thyroiditis) is the most common cause of primary hypothyroidism in iodine-sufficient areas, and **anti-thyroid peroxidase (anti-TPO) antibodies** are found in **90-95% of cases**. - Given the elevated TSH and hypothyroid symptoms, anti-TPO antibodies are the most likely abnormal laboratory finding in this patient. *Anti-DNA topoisomerase antibodies* - These antibodies (anti-Scl-70) are characteristic of **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form. - While the patient has "tight appearing" skin, this description more likely represents **myxedema** (non-pitting edema from hypothyroidism) rather than scleroderma, and the **elevated TSH** directly points to thyroid pathology as the primary issue. *Anti-nuclear antibodies* - **Antinuclear antibodies (ANAs)** are a non-specific screening test for various autoimmune diseases including SLE, scleroderma, and mixed connective tissue disease. - While an ANA could be positive given her history of resolved rash and joint pain, it is a **non-specific finding** seen in up to 10-15% of healthy individuals, whereas the **elevated TSH** points directly to a specific thyroid autoimmune process. *Anti-histidyl-tRNA synthetase antibodies* - These antibodies (anti-Jo-1) are specific for **polymyositis** and **dermatomyositis**, which present with proximal muscle weakness and often elevated creatine kinase. - While the patient complains of weakness, this is generalized fatigue from hypothyroidism rather than true muscle weakness, and there are no other signs of inflammatory myopathy (normal muscle enzymes would be expected). *5-hydroxyindoleacetic acid in CSF* - **Low levels of 5-HIAA** (a serotonin metabolite) in CSF have been associated with **impulsive behavior, aggression, and suicidal ideation** in psychiatric research. - While the patient has significant depressive symptoms and suicidal thoughts following her husband's death, the question asks for the most likely abnormal finding given **all presented clinical data**, and the combination of hypothyroid symptoms plus elevated TSH strongly indicates thyroid autoimmunity as the primary pathology to investigate.

Question 69: A 45-year-old man presents to the emergency department with crushing substernal chest pain. The patient has a past medical history of obesity, diabetes, and hypertension. He drinks 5 alcoholic drinks every night and has a 40 pack-year smoking history. The patient works as a truck driver and leads a sedentary lifestyle. His initial electrocardiogram (ECG) is notable for ST elevation in V2-V5 with reciprocal changes. The patient is sent for cardiac catheterization, and several stents are placed. The patient is being monitored after the procedure, when he suddenly becomes less responsive. His temperature is 98.5°F (36.9°C), blood pressure is 87/48 mmHg, pulse is 150/min, respirations are 18/min, and oxygen saturation is 97% on room air. Jugular venous distension is absent and pulmonary exam is notable for clear breath sounds bilaterally. The patient states that he is experiencing back and flank pain and is tender to palpation over his lumbar back and flanks. The patient is given 3 liters of Lactated Ringer solution and his blood pressure improves to 110/70 mmHg and his pulse is 95/min. Which of the following is the best next step in management?

A. Aspirin and clopidogrel
B. CT scan (Correct Answer)
C. Repeat cardiac catheterization
D. Emergency surgery
E. FAST exam

Explanation: **CT scan** - The patient's presentation with **back and flank pain**, **hypotension**, and a history of recent **cardiac catheterization** (which often involves arterial access in the groin, increasing the risk of retroperitoneal bleeding) strongly suggests **retroperitoneal hemorrhage**. - A **CT scan** of the abdomen and pelvis is the gold standard for diagnosing retroperitoneal hematoma, allowing for accurate localization, size assessment, and identification of ongoing bleeding. *Aspirin and clopidogrel* - These are **antiplatelet medications** used to prevent stent thrombosis and further cardiac events after PCI. - While important for post-PCI care, they would **exacerbate the retroperitoneal hemorrhage** if given immediately, as the patient's current instability is more likely due to bleeding than recurrent cardiac ischemia. *Repeat cardiac catheterization* - This procedure carries risks and is only indicated if there is strong evidence of **reocclusion of the coronary arteries** or other procedure-related complications directly affecting the heart. - The patient's new symptoms of back/flank pain and improved hemodynamics after fluid resuscitation are not typical of cardiac reocclusion, instead pointing to a bleeding source. *Emergency surgery* - While emergency surgery might be the definitive treatment for a severe retroperitoneal hemorrhage, it is not the *best next step* in management. - **Diagnostic imaging (CT scan)** is needed first to confirm the diagnosis, assess the extent of bleeding, and determine if surgical intervention is indeed required or if less invasive approaches (e.g., coiling, conservative management) are appropriate. *FAST exam* - A **Focused Assessment with Sonography for Trauma (FAST) exam** is primarily used to detect **free fluid in the peritoneum, pericardium, and pleural spaces** in trauma patients. - While useful for rapid assessment of intra-abdominal hemorrhage, it is **less sensitive for retroperitoneal bleeding** which is often contained within the retroperitoneal space and not easily visualized as free fluid in the peritoneal cavity.

Question 70: In a patient with suspected interstitial lung disease, which of the following is most appropriate to confirm the diagnosis?

A. High-resolution CT scan of the chest (Correct Answer)
B. Bronchoalveolar lavage
C. Mycobacterial sputum culture
D. Sweat chloride test
E. Pulmonary function tests

Explanation: ***High-resolution CT scan of the chest*** - **HRCT of the chest** is the most appropriate imaging modality for diagnosing and characterizing interstitial lung diseases (ILDs) due to its ability to visualize subtle parenchymal abnormalities. - It can identify specific patterns such as **ground-glass opacities, reticular opacities, honeycombing, and traction bronchiectasis**, which are crucial for differential diagnosis and assessing disease severity. *Bronchoalveolar lavage* - **Bronchoalveolar lavage (BAL)** is a diagnostic procedure used to sample cells and fluids from the airways and alveoli, which can help in diagnosing certain ILDs by analyzing cell counts and differentials. - While BAL can provide supportive evidence, it is typically not sufficient on its own to confirm an ILD diagnosis and is often used in conjunction with imaging and sometimes biopsy. *Mycobacterial sputum culture* - **Mycobacterial sputum culture** is performed to diagnose tuberculosis or other mycobacterial infections, which can sometimes present with symptoms mimicking ILD. - It is specifically used to identify infectious causes and is not a general diagnostic tool for the broad spectrum of non-infectious interstitial lung diseases. *Sweat chloride test* - The **sweat chloride test** is the gold standard for diagnosing **cystic fibrosis**, a genetic disorder that primarily affects the lungs and digestive system. - While cystic fibrosis can cause lung disease, it is not a direct diagnostic test for the general category of interstitial lung diseases. *Pulmonary function tests* - **Pulmonary function tests (PFTs)** measure lung volumes, capacities, and flow rates (e.g., FVC, FEV1, DLCO) and are essential for assessing the physiological impact of ILD and monitoring disease progression. - PFTs show a **restrictive pattern** in ILDs, but they are not specific enough to confirm a diagnosis; they indicate the presence of lung impairment rather than its specific cause.

Question 71: A 74-year-old Hispanic man comes to the physician because of a three-week history of dizziness upon standing and a brief loss of consciousness one hour ago. The patient suddenly collapsed on his way to the bathroom after waking up in the morning. He did not sustain any injuries from his collapse. He has a history of gastroesophageal reflux disease, benign prostatic hyperplasia, and gout. The patient's mother died of a grand mal seizure at the age of 53 years. He has smoked one pack of cigarettes daily for 55 years. He drinks three beers and two glasses of whiskey daily. Current medications include ranitidine, dutasteride, tamsulosin, and allopurinol. He is 166 cm (5 ft 5 in) tall and weighs 62 kg (137 lb); BMI is 22.5 kg/m2. He appears pale. Temperature is 36.7°C (98.0°F), pulse is 83/min, and blood pressure is 125/80 mm Hg supine and 100/70 mm Hg one minute after standing with no change in pulse rate. Physical examination shows conjunctival pallor. A plopping sound is heard on auscultation, immediately followed by a low-pitched, rumbling mid-diastolic murmur heard best at the apex. The remainder of the examination shows no abnormalities. An ECG shows regular sinus rhythm. Which of the following is the most likely diagnosis?

A. Drug-induced hypotension
B. Grand mal seizure
C. Aortic valve stenosis
D. Cardiac myxoma (Correct Answer)
E. Infective endocarditis

Explanation: ***Cardiac myxoma*** - The patient's syncopal episode with dizziness upon standing, **conjunctival pallor**, and the characteristic **"tumor plop" sound** followed by a mid-diastolic rumbling murmur are highly suggestive of **left atrial myxoma**. - Myxomas can cause intermittent obstruction of the mitral valve orifice, leading to positional syncope, and can produce **constitutional symptoms** including anemia (from IL-6 production causing anemia of chronic disease), fever, and weight loss. - The **tumor plop** occurs when the pedunculated mass prolapses through the mitral valve during diastole. *Drug-induced hypotension* - While **tamsulosin** can cause orthostatic hypotension, the patient's blood pressure drop is relatively mild (25/10 mm Hg) and not accompanied by a compensatory increase in heart rate. - The presence of a **cardiac murmur** and "tumor plop" points away from simple drug-induced hypotension as the primary cause. *Grand mal seizure* - The patient's mother had a grand mal seizure, and syncope can sometimes be confused with seizures, but the absence of post-ictal confusion, tonic-clonic movements, or sustained loss of consciousness makes a seizure unlikely. - The **cardiac physical exam findings** (plopping sound, murmur) are not consistent with a seizure. *Aortic valve stenosis* - Aortic stenosis typically presents with a **systolic ejection murmur** heard best at the right upper sternal border, often radiating to the carotids. - The patient's murmur is described as **mid-diastolic** and heard best at the apex, which is inconsistent with aortic stenosis. *Infective endocarditis* - Infective endocarditis usually presents with **fever**, new or changing murmurs, and signs of systemic embolization or immune phenomena, none of which are prominently described here. - While it can cause murmurs, the specific **"tumor plop"** and rumbling mid-diastolic murmur from an obstructing mass are not typical for endocarditis.

Question 72: A 65-year-old man presents to the emergency department for a loss of vision. He was outside gardening when he suddenly lost vision in his right eye. He then immediately called emergency medical services, but by the time they arrived, the episode had resolved. Currently, he states that he feels fine. The patient has a past medical history of diabetes and hypertension. His current medications include lisinopril, atorvastatin, metformin, and insulin. His temperature is 99.5°F (37.5°C), blood pressure is 140/95 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 98% on room air. Cardiac exam is notable for a systolic murmur along the right sternal border that radiates to the carotids. Pulmonary exam reveals mild bibasilar crackles. Neurological exam reveals cranial nerves II-XII as grossly intact with 5/5 strength and normal sensation in the upper and lower extremities. The patient has a negative Romberg's maneuver, and his gait is stable. A CT scan of the head demonstrates mild cerebral atrophy but no other findings. Which of the following is the next best step in management?

A. No further management necessary
B. Tissue plasminogen activator
C. Ultrasound of the neck (Correct Answer)
D. MRI
E. Heparin bridge to warfarin

Explanation: ***Ultrasound of the neck*** - The patient experienced a **transient monocular vision loss (amaurosis fugax)**, which is a common symptom of **carotid artery stenosis**, often due to an **embolus from an atherosclerotic plaque**. - The presence of a **systolic murmur radiating to the carotids**, along with a history of **diabetes and hypertension**, further increases suspicion for **carotid atherosclerosis**, making an ultrasound of the neck (carotid duplex) the appropriate next step to assess the degree of stenosis. *No further management necessary* - Ignoring this episode would be **negligent** given the patient's risk factors and the transient nature of the symptoms, which suggest a **transient ischemic attack (TIA)**. - TIAs are **warning signs** for future stroke, and identifying the cause is crucial for **stroke prevention**. *Tissue plasminogen activator* - **tPA is indicated for acute ischemic stroke** within a specific time window, typically 3-4.5 hours from symptom onset, and when there is persistent neurological deficit. - The patient's symptoms have **already resolved**, and there is **no ongoing stroke**, making tPA inappropriate. *MRI* - While an **MRI of the brain is more sensitive than CT** for detecting acute ischemic changes and TIAs, the primary concern here is the **source of the embolus** affecting the eye, which is likely the carotid artery. - An MRI might be pursued later if the carotid workup is inconclusive or to further characterize cerebral findings, but **carotid imaging takes precedence** given the presentation. *Heparin bridge to warfarin* - This is a treatment for conditions like **atrial fibrillation** or **deep vein thrombosis** to prevent clot formation and is a form of **anticoagulation**. - While some patients with embolic TIA might require anticoagulation, the **initial step is to identify the source** of the embolus, which in this case is highly suspected to be carotid stenosis, treatable with **antiplatelet agents** or **surgery/stenting**, rather than immediate anticoagulation.

Question 73: A 45-year-old male presents to the hospital complaining of frequent headaches and a decreased libido. During the physical exam, the patient also states that he has recently been experiencing vision problems. The patient is suffering from what type of adenoma?

A. Lactotroph (Correct Answer)
B. Somatotroph
C. Thyrotroph
D. Gonadotroph
E. Corticotroph

Explanation: ***Lactotroph*** - A **lactotroph adenoma**, or **prolactinoma**, is the most common type of pituitary adenoma. - In males, it presents with symptoms such as **hypogonadism** (decreased libido, erectile dysfunction), **headaches**, and **visual field defects** due to compression of the optic chiasm. *Somatotroph* - A **somatotroph adenoma** secretes excessive **growth hormone**, leading to **acromegaly** in adults (e.g., increased hand/foot size, facial changes) or gigantism in children. - Headache and vision problems can occur due to tumor mass effect, but decreased libido is not a primary symptom. *Thyrotroph* - A **thyrotroph adenoma** secretes excessive **TSH**, resulting in **hyperthyroidism** (e.g., weight loss, palpitations, heat intolerance). - While large tumors can cause headaches and visual disturbances, the primary endocrine symptoms are related to thyroid hormone excess. *Gonadotroph* - **Gonadotroph adenomas** secrete FSH and LH, but they are often **non-functional** or only mildly active, with hormonal effects being variable. - When symptomatic, they may present with mass effects like headaches and visual problems, but marked hypogonadism or galactorrhea are less common than with prolactinomas. *Corticotroph* - A **corticotroph adenoma** secretes excessive **ACTH**, leading to **Cushing's disease** (e.g., central obesity, moon facies, striae, hypertension). - While mass effects like headaches can occur, the primary clinical features are those of hypercortisolism, not decreased libido.

Question 74: A 62-year-old man presents for evaluation of an adrenal nodule, which was accidentally discovered while performing a computerized tomography (CT) scan of the abdomen for recurrent abdominal pain. The CT was negative except for a 3 cm low-density, well-circumscribed nodule in the left adrenal gland. He reports weight gain of 12 kg (26.4 lb) over the past 3 years. He has type 2 diabetes mellitus and hypertension, which have been difficult to control with medications. Which of the following is the best initial test for this patient?

A. 1 mg overnight dexamethasone suppression test (Correct Answer)
B. ACTH stimulation test
C. CT of the chest, abdomen and pelvis
D. Inferior petrosal sampling
E. Pituitary magnetic resonance imaging (MRI)

Explanation: ***1 mg overnight dexamethasone suppression test*** - The patient presents with an adrenal incidentaloma and clinical features suggestive of **Cushing's syndrome**, including uncontrolled hypertension and type 2 diabetes, and weight gain. - The **1 mg overnight dexamethasone suppression test** is the screening test of choice to evaluate for **cortisol overproduction** in patients suspected of having Cushing's syndrome. *ACTH stimulation test* - The **ACTH stimulation test** is used to evaluate for **adrenal insufficiency**, not adrenal hyperfunction. - It assesses the adrenal gland's ability to produce cortisol in response to exogenous ACTH. *CT of the chest, abdomen and pelvis* - A CT scan of the abdomen has already identified the adrenal nodule; a repeat or extended scan for localization of the adrenal nodule itself is unnecessary as an initial diagnostic step for hormonal activity. - While imaging is used to characterize the nodule for malignant potential, the primary concern here given the clinical context is hormonal activity. *Inferior petrosal sampling* - **Inferior petrosal sinus sampling (IPSS)** is a specialized and invasive test used to differentiate between **Cushing's disease** (pituitary ACTH-secreting tumor) and ectopic ACTH secretion or primary adrenal disease after biochemical tests confirm ACTH-dependent Cushing's syndrome. - This is an advanced diagnostic step, not an initial screening test. *Pituitary magnetic resonance imaging (MRI)* - A **pituitary MRI** is performed to identify a pituitary adenoma in patients with confirmed **ACTH-dependent Cushing's syndrome**, typically after initial biochemical screening tests and possibly IPSS. - It is not an initial test for patients with an adrenal incidentaloma and suspected cortisol excess.

Question 75: A 49-year-old man presents to a physician with the complaint of pain in the thigh after walking. He says that he is an office clerk with a sedentary lifestyle and usually drives to his office. On 2 occasions last month he had to walk to his office, which is less than a quarter of a mile from his home. On both occasions, soon after walking, he experienced pain in the right thigh which subsided spontaneously within a few minutes. His past medical history is negative for hypertension, hypercholesterolemia, or ischemic heart disease. He is a non-smoker and non-alcoholic. His father has ischemic heart disease. His physical examination is within normal limits, and the peripheral pulses are palpable in all extremities. His detailed diagnostic evaluation, including magnetic resonance angiogram (MRA) and exercise treadmill ankle-brachial index (ABI) testing, suggests a diagnosis of peripheral vascular disease due to atherosclerosis of the right iliac artery. Which of the following is the best initial treatment option?

A. Percutaneous angioplasty with stenting
B. Exercise therapy (Correct Answer)
C. Pentoxifylline
D. Mediterranean diet
E. A combination of aspirin and clopidogrel

Explanation: ***Exercise therapy*** - **Supervised exercise programs** are the cornerstone of initial treatment for patients with claudication and PAD, demonstrating significant improvement in walking distance and quality of life. - It helps in developing **collateral circulation**, improving endothelial function, and increasing pain-free walking distance. *Percutaneous angioplasty with stenting* - While effective for revascularization, this is typically reserved for patients with **severe claudication** that significantly impacts daily life and is refractory to conservative management. - It carries risks such as **restenosis** and potential complications from the procedure itself. *Pentoxifylline* - This medication is a **xanthine derivative** that can improve blood flow by increasing erythrocyte flexibility and reducing blood viscosity. - Its efficacy in improving walking distance in PAD is **modest at best**, and it is generally less effective than supervised exercise. *Mediterranean diet* - A healthy diet, such as the Mediterranean diet, is crucial for **overall cardiovascular risk reduction** in PAD patients by managing risk factors like hypercholesterolemia. - However, it is a **preventive and supportive measure** rather than an initial treatment for alleviating claudication symptoms. *A combination of aspirin and clopidogrel* - **Antiplatelet therapy** (e.g., aspirin, clopidogrel) is essential for reducing the risk of cardiovascular events in PAD patients, but it **does not directly improve claudication symptoms**. - Dual antiplatelet therapy is often reserved for post-procedure management or in higher-risk patients, not as an initial treatment for claudication itself.

Question 76: A 50-year-old female is evaluated by her physician for recent weight gain. Physical examination is notable for truncal obesity, wasting of her distal musculature and moon facies. In addition she complains of abnormal stretch marks that surround her abdomen. The physician suspects pituitary adenoma. Which of the following high-dose dexamethasone suppression test findings and baseline ACTH findings would support his view?

A. Cortisol suppression, normal baseline ACTH
B. Elevation of cortisol above pre-test levels, high baseline ACTH
C. No cortisol suppression, low baseline ACTH
D. No cortisol suppression, high baseline ACTH
E. Cortisol suppression, high baseline ACTH (Correct Answer)

Explanation: **Cortisol suppression, high baseline ACTH** - A **pituitary adenoma** (Cushing's disease) causes **excessive ACTH production**, leading to high baseline ACTH levels and **cortisol overproduction**. - In the high-dose dexamethasone suppression test, the large dose of synthetic glucocorticoid can **suppress ACTH secretion** from the adenoma, leading to a reduction in cortisol levels. *Cortisol suppression, normal baseline ACTH* - This pattern generally suggests **exogenous glucocorticoid use** as the cause of Cushing's syndrome, where the adrenal axis is suppressed. - A **pituitary adenoma** would typically cause **elevated ACTH**, not normal levels, before suppression. *Elevation of cortisol above pre-test levels, high baseline ACTH* - Elevation of cortisol above pre-test levels is not expected in any form of Cushing's syndrome with a dexamethasone suppression test. - While a high baseline ACTH is consistent with an ACTH-dependent cause, the **lack of suppression and increase** is unusual. *No cortisol suppression, low baseline ACTH* - This pattern is characteristic of **ACTH-independent Cushing's syndrome**, such as an **adrenal tumor**. - In this case, the adrenal glands are autonomously producing cortisol, and the high cortisol suppresses pituitary ACTH release. *No cortisol suppression, high baseline ACTH* - This finding is typical of an **ectopic ACTH-producing tumor** (e.g., small cell lung cancer). - These tumors often produce a large amount of ACTH that is **not suppressed** by even high doses of dexamethasone.

Question 77: A 25-year-old man presents to the emergency department with back pain. He states that it started yesterday and has been gradually getting worse. He states that the pain is worsened with moving and lifting and is relieved with rest and ibuprofen. He has a past medical history of smoking and IV drug abuse and states he last used IV drugs 2 days ago. He thinks his symptoms may be related to lifting a heavy box. His temperature is 99.3°F (37.4°C), blood pressure is 122/88 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for focal back pain lateral to the patient’s spine on the left. There is no midline tenderness and the rest of the patient’s exam is unremarkable. There are scars in the antecubital fossae bilaterally. Laboratory values including a C-reactive protein are unremarkable. Which of the following is the most likely diagnosis?

A. Epidural hematoma
B. Epidural abscess
C. Compression fracture
D. Herniated nucleus pulposus
E. Muscle strain (Correct Answer)

Explanation: ***Muscle strain*** - The patient's presentation with **sudden onset back pain** worsened by movement/lifting and relieved by rest/NSAIDs, along with focal tenderness lateral to the spine, is classic for a **muscle strain**. - The absence of fever, neurologic deficits, and unremarkable lab values (including CRP) makes more serious conditions less likely, even with a history of IV drug use. *Epidural hematoma* - An **epidural hematoma** would typically present with more acute, severe pain, often following trauma or in patients on anticoagulants. - Neurological deficits, such as **radiculopathy** or **myelopathy**, would be expected, which are not described here. *Epidural abscess* - An **epidural abscess** is highly suspected in a patient with a history of **IV drug abuse** and back pain; however, it typically presents with **fever**, elevated inflammatory markers (e.g., **CRP**, ESR), and possibly neurological compromise, which are absent here. - The patient's normal temperature and CRP significantly reduce the likelihood of an active infection. *Compression fracture* - A **compression fracture** usually occurs in older patients with **osteoporosis** or following significant trauma in younger individuals. - While pain can be worsened by movement, the focal, non-midline tenderness and lack of a significant traumatic event make this less likely. *Herniated nucleus pulposus* - A **herniated nucleus pulposus** would typically present with **radicular pain** (shooting pain down the leg), numbness, or weakness in a dermatomal or myotomal distribution. - The patient's pain is described as focal back pain lateral to the spine, with no mention of radicular symptoms.

Question 78: A 34-year-old female presents to her primary care physician complaining of fatigue. Over the last three months she has experienced decreased energy and gained 7 pounds. Review of systems is negative for symptoms of depression but is positive for constipation, myalgias, and cold intolerance. Physical exam is notable for delayed deep tendon reflex relaxation. Vital signs are as follows: T 37.1 C, HR 61, BP 132/88, RR 16, and SpO2 100%. Which of the following is the best initial screening test for this patient?

A. Serum TSH (Correct Answer)
B. Morning cortisol and plasma ACTH
C. Serum Free T4
D. Level of anti-thyroid peroxidase (TPO) antibodies
E. Hemoglobin and hematocrit

Explanation: ***Serum TSH*** - The patient presents with classic symptoms of **hypothyroidism**, including fatigue, weight gain, constipation, myalgias, and cold intolerance, along with a delayed relaxation of deep tendon reflexes and bradycardia (HR 61), making **TSH** the best initial screening test. - An elevated TSH level is the most **sensitive** and **specific** indicator of primary hypothyroidism, as the pituitary gland increases TSH production in response to low thyroid hormone levels. *Morning cortisol and plasma ACTH* - These tests are used to evaluate **adrenal insufficiency** (Addison's disease), which can cause fatigue and weight loss, but not typically weight gain, constipation, or cold intolerance. - The constellation of symptoms is more indicative of thyroid dysfunction rather than adrenal pathology. *Serum Free T4* - While **Free T4** directly measures the active thyroid hormone, it is usually ordered *after* an abnormal TSH level is found. - TSH is a more sensitive initial screen for primary hypothyroidism, as small changes in T4 can cause large inverse changes in TSH. *Level of anti-thyroid peroxidase (TPO) antibodies* - **Anti-TPO antibodies** are indicative of **Hashimoto's thyroiditis**, an autoimmune cause of hypothyroidism, but they are not the initial screening test for thyroid function itself. - TSH should first be evaluated to determine if there is indeed thyroid dysfunction. *Hemoglobin and hematocrit* - These tests are used to screen for **anemia**, which can cause fatigue. However, the other distinct symptoms like cold intolerance, constipation, weight gain, and delayed deep tendon reflex relaxation are not characteristic of anemia. - While anemia can coexist with hypothyroidism, it is not the primary screening test for the patient's presented symptoms.

Question 79: A 63-year-old woman with a previous diagnosis of rheumatoid arthritis and Sjogren syndrome was referred for a second opinion. She has had a known chronic idiopathic pericardial effusion for about a year and has dealt with intermittent chest pain ever since. She underwent 2 diagnostic pericardiocenteses, but the fluid returned each time. She also has used empiric anti-inflammatory therapies with NSAIDs and colchicine without significant changes in the size of the pericardial effusion. The etiological testing was negative. At this visit, she is still complaining of pain in her chest but has no evidence of distended neck veins. An ECG shows sinus rhythm with low QRS voltages. What will be the procedure of choice that would be both therapeutic and diagnostic?

A. Pericardial window (Correct Answer)
B. Pericardiectomy
C. Pericardiodesis
D. Non-surgical management
E. Repeated pericardiocentesis

Explanation: ***Pericardial window*** - A **pericardial window** allows continuous drainage of pericardial fluid into the pleural space or peritoneum, preventing reaccumulation and providing symptomatic relief for **recurrent pericardial effusions**. - It also enables **biopsy of the pericardium**, offering a diagnostic opportunity in cases where previous fluid analysis was inconclusive, which is crucial given the patient's autoimmune history and persistent effusion. *Pericardiectomy* - **Pericardiectomy** involves surgical removal of part or all of the pericardium and is typically reserved for **constrictive pericarditis** or highly refractory recurrent effusions with significant hemodynamic compromise. - While it offers a definitive solution, it is a more invasive procedure than a pericardial window and might be excessive given the absence of overt **constrictive physiology** (e.g., no jugular venous distention indicating tamponade). *Pericardiodesis* - **Pericardiodesis** involves instilling an irritant (e.g., talc, tetracycline) into the pericardial space to induce inflammation and adhesion between the pericardial layers, aiming to prevent fluid reaccumulation. - This procedure is primarily used in cases of **malignant pericardial effusions** and is less suitable for chronic idiopathic or inflammatory effusions, especially if the underlying cause is not definitively ruled out. *Non-surgical management* - **Non-surgical management** with NSAIDs and colchicine has already been attempted in this patient without success, indicating its ineffectiveness for this chronic, recurrent effusion. - Given the persistent symptoms and effusion despite medical therapy and previous drainage attempts, further non-surgical approaches alone are unlikely to be sufficient or diagnostic. *Repeated pericardiocentesis* - While pericardiocentesis provides temporary relief, the history explicitly states the fluid **returned each time**, making repeated procedures ineffective for long-term management and prevention of recurrence. - Repeated pericardiocentesis does not offer a definitive diagnostic yield beyond initial fluid analysis, nor does it address the underlying issue of recurrent fluid accumulation.

Question 80: A 68-year-old woman is brought to the physician by her husband for the evaluation of confusion and memory deficits for the last month. During this period, she has also had mild weakness in her left leg. She has hypertension and hyperlipidemia. Her current medications include enalapril and atorvastatin. She has smoked two packs of cigarettes daily for the last 45 years. She drinks a glass of wine every day. Her temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 135/85 mm Hg. She is oriented only to person. She recalls 2 out of 3 objects immediately and none after 5 minutes. The patient is unable to lift her eyebrows or to smile. Muscle strength is decreased in the left lower extremity. A T2-weighted MRI scan of the head shows several hyperintense round lesions in the frontal and temporal lobe at the border of the gray and white matter. Which of the following is the most likely diagnosis?

A. Multiple sclerosis
B. Lung cancer (Correct Answer)
C. Progressive multifocal leukoencephalopathy
D. Glioblastoma multiforme
E. Colorectal cancer

Explanation: **Lung cancer** - The patient's extensive smoking history of **45 pack-years** significantly increases her risk for lung cancer, which commonly metastasizes to the brain. - The MRI findings of **multiple hyperintense round lesions** at the gray-white matter junction are highly suggestive of **brain metastases**, a frequent complication of lung cancer. *Multiple sclerosis* - While MS can cause **demyelinating plaques** that appear as hyperintense lesions on MRI, it typically presents with **neurological symptoms that are relapsing-remitting** and tends to affect younger patients. - The patient's age and the **progressive nature** of her symptoms, along with significant risk factors for malignancy, make MS less likely. *Progressive multifocal leukoencephalopathy (PML)* - PML is a rare opportunistic infection caused by the **JC virus** that primarily affects immunocompromised individuals. - There is no indication of **immunocompromise** in this patient, and the MRI lesions of PML are typically **asymmetric white matter lesions** that do not enhance, which differs from the likely metastatic pattern described. *Glioblastoma multiforme* - Glioblastoma is a **primary brain tumor** that often presents as a single, large, irregularly enhancing mass on MRI, sometimes with necrosis and surrounding edema. - The presence of **multiple, round hyperintense lesions** points away from a primary glioblastoma and towards metastatic disease. *Colorectal cancer* - While colorectal cancer can metastasize to the brain, the patient's strong smoking history makes **lung cancer** a much more probable primary source for brain metastases. - There are no clinical symptoms or risk factors specifically pointing towards **gastrointestinal malignancy** in this case.

Question 81: A 54-year-old man comes to the physician for an annual health maintenance examination. He reports that he feels well. He has smoked one pack of cigarettes daily for 22 years and drinks three 12-oz bottles of beer each night. He works as an accountant and says he does not have time to exercise regularly. He is 178 cm (5 ft 10 in) tall and weighs 98 kg (216 lb); BMI is 31 kg/m2. His blood pressure is 146/90 mm Hg. Physical examination shows no abnormalities. His serum cholesterol concentration is 232 mg/dL and hemoglobin A1C is 6.9%. Which of the following preventative measures is likely to have the greatest impact on this patient's all-cause mortality risk?

A. Antidiabetic medication
B. Smoking cessation (Correct Answer)
C. Blood pressure reduction
D. Reduced alcohol intake
E. Increased physical activity

Explanation: **Smoking cessation** - **Smoking** is a leading cause of preventable death and significantly increases the risk of **cardiovascular disease**, **cancer**, and **pulmonary disease**, making its cessation the most impactful intervention for all-cause mortality. - The patient's history of smoking one pack per day for 22 years represents a substantial modifiable risk factor. *Antidiabetic medication* - While the patient's HbA1c of 6.9% indicates **pre-diabetes** or early **Type 2 Diabetes**, suggesting a need for intervention, smoking cessation typically yields a greater and more immediate impact on overall mortality risk. - Lifestyle modifications, including diet and exercise, are usually the first line of treatment for this HbA1c level. *Blood pressure reduction* - The patient's blood pressure of **146/90 mmHg** indicates **hypertension**, which is a significant risk factor for cardiovascular events. - However, the immediate and widespread benefits of **stopping smoking** generally outweigh the benefits of isolated blood pressure control in terms of all-cause mortality, especially with this patient's heavy smoking history. *Reduced alcohol intake* - The patient's daily consumption of three 12-oz bottles of beer contributes to his overall health risks, particularly for **liver disease** and **hypertension**. - While reducing alcohol intake is beneficial, it typically does not have as profound an impact on **all-cause mortality** as quitting smoking, especially given the duration and intensity of the patient's smoking habit. *Increased physical activity* - The patient's **sedentary lifestyle** and **obesity (BMI 31 kg/m2)** are significant health concerns and increasing physical activity would offer numerous health benefits. - However, compared to quitting smoking, the cumulative impact of increased physical activity alone on **all-cause mortality** is generally less dramatic, particularly in a patient with a heavy smoking history.

Question 82: A 76-year-old woman comes to the physician because of increasing muscle pain and stiffness, weakness of her shoulders and legs, and generalized fatigue for the past 4 months. She has been having great difficulty getting out of bed in the morning. On two occasions her son had to come over and help her stand up. She has had a 4-kg (9-lb) weight loss and has not been sleeping well during this period. She has had multiple episodes of left-sided headaches and pain in her jaw while chewing over the past 2 months. She had a fall and hit her head on the staircase banister 3 months ago. Her temperature is 38°C (100.4°F), pulse is 101/min, and blood pressure is 128/88 mm Hg. Examination shows conjunctival pallor. Range of motion of the shoulder and hip is mildly limited by pain. Muscle strength in bilateral upper and lower extremities is normal. Deep tendon reflexes are 2+ bilaterally. On mental status examination, she admits her mood 'is not that great'. Her erythrocyte sedimentation rate is 59 mm/h and serum creatine kinase is 38 mg/dL. Which of the following is the most likely cause of this patient's headache?

A. Chronic subdural hematoma
B. Migraine
C. Temporomandibular joint dysfunction
D. Tension headache
E. Giant cell arteritis (Correct Answer)

Explanation: ***Correct: Giant cell arteritis*** - This patient's symptoms of new-onset headaches, **jaw claudication** (pain while chewing), and constitutional symptoms (fatigue, weight loss, difficulty sleeping, low-grade fever) in an elderly woman are highly suggestive of **giant cell arteritis (GCA)** - The elevated **ESR (59 mm/h)** supports this diagnosis - GCA is frequently associated with **polymyalgia rheumatica (PMR)** - characterized by proximal muscle pain and stiffness with morning stiffness in shoulders and hips, which is also present in this patient - **Jaw claudication** is highly specific for GCA and helps distinguish it from other causes of headache *Incorrect: Chronic subdural hematoma* - While a fall three months prior raises suspicion, the headache in chronic subdural hematoma is typically **non-specific** and constant, without features like **jaw claudication** - This condition would not explain the prominent systemic symptoms (fever, elevated ESR) or the specific **jaw pain with chewing** - **Normal mental status** and lack of focal neurological deficits make this unlikely *Incorrect: Migraine* - Migraine headaches are typically **pulsatile**, often unilateral, and associated with **photophobia, phonophobia**, or nausea, which are not described here - The patient's **age of onset (76 years)** and systemic symptoms (fever, elevated ESR, weight loss) are atypical for new-onset migraine - **Jaw claudication** does not occur with migraine *Incorrect: Temporomandibular joint dysfunction* - TMJ dysfunction causes jaw pain aggravated by chewing, but it is typically associated with **TMJ clicking** or locking - It does not explain the widespread muscle pain and stiffness, **elevated ESR**, constitutional symptoms (fever, weight loss), or new-onset headaches - This is a **localized mechanical problem**, not a systemic inflammatory condition *Incorrect: Tension headache* - Tension headaches are usually described as a **tight band-like pressure** around the head, typically bilateral, and generally not associated with systemic symptoms like fever, weight loss, or **elevated ESR** - They do not typically cause **jaw pain on chewing** or proximal muscle stiffness - The prominent inflammatory markers and constitutional symptoms argue against this diagnosis

Question 83: A 14-year-old boy is brought to the physician because of fever, malaise, and severe right knee joint pain and swelling for 3 days. He had also had episodes of abdominal pain and epistaxis during this period. Five days ago, he had swelling and pain in his left ankle joint which has since resolved. He reports having a sore throat 3 weeks ago while he was camping in the woods, for which he received symptomatic treatment. His immunizations are up-to-date. His temperature is 38.7°C (101.6°F), pulse is 119/min, and blood pressure is 90/60 mm Hg. Examination shows a swollen, tender right knee; range of motion is limited. There are painless 3- to 4-mm nodules over the elbow. Cardiopulmonary examination is normal. His hemoglobin concentration is 12.3 g/dL, leukocyte count is 11,800/mm3, and erythrocyte sedimentation rate is 58 mm/h. Arthrocentesis of the right knee joint yields clear, straw-colored fluid; no organisms are identified on Gram stain. Analysis of the synovial fluid shows a leukocyte count of 1,350/mm3 with 17% neutrophils. Which of the following is the most likely diagnosis?

A. Lyme disease
B. Kawasaki disease
C. Acute rheumatic fever (Correct Answer)
D. Infective endocarditis
E. Juvenile idiopathic arthritis

Explanation: ***Acute rheumatic fever*** - The migrating polyarthritis, prior history of **sore throat (Streptococcal pharyngitis)**, fever, and subcutaneous nodules are classic manifestations of **acute rheumatic fever (ARF)**, fulfilling several **Jones criteria**. - The **elevated ESR** and **leukocytosis** support an inflammatory process, and the non-septic synovial fluid helps rule out septic arthritis. *Lyme disease* - While Lyme disease can cause **migratory arthritis** and fever, the presence of **subcutaneous nodules** and a preceding sore throat strongly point away from Lyme disease. - Patients with Lyme disease typically have **erythema migrans** (a bull's-eye rash), which is not mentioned here. *Kawasaki disease* - Kawasaki disease primarily affects **young children** (typically <5 years old) and presents with **fever, rash, conjunctivitis, lymphadenopathy**, and mucositis; arthritis is less common. - The patient's age (14 years) and specific rheumatological findings like migratory polyarthritis and subcutaneous nodules do not align with Kawasaki disease. *Infective endocarditis* - While infective endocarditis can cause fever, malaise, and arthralgia due to immune complex deposition, the prominent **migratory polyarthritis** and **subcutaneous nodules** are not typical primary manifestations. - There is no mention of a **heart murmur** or other signs of cardiac involvement, which would be expected with endocarditis. *Juvenile idiopathic arthritis* - JIA is a chronic arthritic condition lasting at least 6 weeks; this patient presents with an acute, migrating pattern of joint involvement that resolves in some joints. - While JIA can cause joint pain and swelling, the preceding sore throat and resolving arthritic pattern are not characteristic features of JIA, which typically shows persistent joint inflammation.

Question 84: A 62-year-old woman comes to the physician in June for a routine check-up. She has chronic back pain and underwent an appendectomy at the age of 27. She is married and has two kids. The patient recently got back from a cruise to Mexico where she celebrated her 40th wedding anniversary. Her last mammogram was 6 months ago and showed no abnormalities. Her last Pap smear was 2 years ago and unremarkable. A colonoscopy 5 years ago was normal. Her mother died of breast cancer last year and her father has arterial hypertension. Her immunization records show that she has never received a pneumococcal or a shingles vaccine, her last tetanus booster was 6 years ago, and her last influenza vaccine was 2 years ago. She drinks 1– 2 alcoholic beverages every weekend. She takes a multivitamin daily and uses topical steroids. She regularly attends water aerobic classes and physical therapy for her back pain. She is 168 cm (5 ft 6 in) tall and weighs 72 kg (160 lb); BMI is 26 kg/m2. Her temperature is 36.7°C (98°F), pulse is 84/min, and blood pressure is 124/70 mm Hg. Which of the following is the most appropriate recommendation at this time?

A. Dual-energy x-ray absorptiometry screening
B. Influenza vaccine
C. Shingles vaccine (Correct Answer)
D. Tetanus vaccine
E. Colonoscopy

Explanation: ***Shingles vaccine*** - The patient is 62 years old, and the **Advisory Committee on Immunization Practices (ACIP)** recommends **shingles vaccine (recombinant zoster vaccine)** for immunocompetent adults aged **50 years and older**. - The patient has never received a shingles vaccine and is within the recommended age group, making this an appropriate and high-priority recommendation. *Dual-energy x-ray absorptiometry screening* - **DEXA screening** is recommended for women aged 65 years and older, or younger postmenopausal women with risk factors. - While she is postmenopausal, she is currently 62 years old, and there are no specific risk factors mentioned (e.g., low body weight, medication use) that would necessitate screening before age 65. *Influenza vaccine* - The patient's last influenza vaccine was 2 years ago, meaning she is due for an influenza vaccine. However, the question states it is June, and influenza vaccines are typically recommended annually in the fall (September-October) before influenza season. - While important, it is not the most appropriate recommendation *at this time* (June) compared to a vaccine that can be given year-round to an eligible patient. *Tetanus vaccine* - The patient's last tetanus booster was 6 years ago. A **Td (tetanus and diphtheria) booster** is recommended every 10 years. - She is not currently due for a tetanus vaccine booster, as 6 years is within the 10-year interval. *Colonoscopy* - The patient's last colonoscopy was 5 years ago and was normal. **Routine colonoscopy screening** for average-risk individuals is recommended every 10 years. - Given her last normal colonoscopy was 5 years ago, she is not due for another one at this time.

Question 85: An 83-year-old woman with a past medical history of poorly controlled diabetes, hyperlipidemia, hypertension, obesity, and recurrent urinary tract infections is brought to the emergency room by her husband due to confusion, generalized malaise and weakness, nausea, and mild lower abdominal pain. Her medications include metformin and glyburide, atorvastatin, lisinopril, and hydrochlorothiazide. At presentation, her oral temperature is 38.9°C (102.2°F), the pulse is 122/min, blood pressure is 93/40 mm Hg, and oxygen saturation is 96% on room air. On physical examination, she is breathing rapid shallow breaths but does not have any rales or crackles on pulmonary auscultation. No murmurs are heard on cardiac auscultation and femoral pulses are bounding. Her skin is warm, flushed, and dry to touch. There is trace bilateral pedal edema present. Her abdomen is soft and non-distended, but she has some involuntary guarding on palpation of the suprapubic region. ECG shows normal amplitude sinus tachycardia without evidence of ST-segment changes or T-wave inversions. Which of the following would most likely be the relative pulmonary artery catheterization measurements of pulmonary capillary wedge pressure (PCWP), mixed venous oxygen saturation (SvO2), calculated cardiac output (CO), and systemic vascular resistance (SVR) in this patient?

A. Normal PCWP; normal SvO2; increased CO; decreased SVR
B. Decreased PCWP; decreased SvO2; decreased CO; increased SVR
C. Increased PCWP; decreased SvO2; decreased CO; increased SVR
D. Decreased PCWP; slightly increased SvO2; increased CO; decreased SVR (Correct Answer)
E. Decreased PCWP; normal SvO2; decreased CO; decreased SVR

Explanation: ***Decreased PCWP; slightly increased SvO2; increased CO; decreased SVR*** - The patient's presentation with **fever**, **hypotension**, **tachycardia**, and signs of infection (recurrent UTIs, abdominal pain, involuntary guarding) in conjunction with **warm, flushed skin** and **bounding pulses** points strongly to **septic shock**. - In **septic shock**, systemic vascular resistance (SVR) is typically **decreased** due to widespread vasodilation, leading to a compensatory **increase in cardiac output (CO)** to maintain perfusion. The pulmonary capillary wedge pressure (PCWP) is usually **decreased** or normal due to volume redistribution or relative hypovolemia, and mixed venous oxygen saturation (SvO2) is often **slightly increased** due to impaired tissue oxygen extraction. *Increased PCWP; decreased SvO2; decreased CO; increased SVR* - This profile is characteristic of **cardiogenic shock**, where there is primary pump failure, leading to **increased PCWP** (due to left ventricular failure), **decreased CO**, and compensatory **increased SVR**. SvO2 would be decreased due to poor tissue perfusion. - The patient's bounding pulses and warm skin contradict cardiogenic shock; she shows no signs of pulmonary congestion (e.g., rales or crackles), and ECG is normal. *Decreased PCWP; normal SvO2; decreased CO; decreased SVR* - This combination is not typical for any specific shock state. While decreased PCWP and SVR can be seen in some forms of shock, a **decreased CO** in the presence of **decreased SVR** would lead to profound hypotension and would not align with the compensatory mechanisms observed in most shock types. - A **normal SvO2** would be unusual in a severe shock state where tissue oxygen delivery or extraction is significantly impaired. *Normal PCWP; normal SvO2; increased CO; decreased SVR* - While **increased CO** and **decreased SVR** are consistent with **septic shock**, a **normal PCWP** and **normal SvO2** are less typical. PCWP can be normal or low, but an increased SvO2 due to peripheral oxygen extraction abnormalities is a more characteristic finding. - The severe hypotension (93/40 mm Hg) with increased CO often implies a low PCWP as the primary cause of poor filling pressures and decreased venous return. *Decreased PCWP; decreased SvO2; decreased CO; increased SVR* - This profile suggests **hypovolemic shock** or late-stage, decompensated septic shock with severe hypovolemia. In hypovolemic shock, there is **decreased preload (PCWP)**, leading to **decreased CO**, and a compensatory **increased SVR**. - However, the patient's **warm, flushed skin** and **bounding pulses** are inconsistent with the vasoconstriction and cool extremities typically seen in hypovolemic shock. Additionally, early septic shock presents with increased CO and decreased SVR.

Question 86: A 59-year-old patient with COPD is admitted with difficulty breathing and increased sputum production. Approx. a week ago, he developed an upper respiratory tract infection. On admission, his blood pressure is 130/80 mm Hg, the heart rate 92/min, the respiratory rate 24/min, the temperature 37.6°C (99.7°F), and SaO2 on room air 87%. Chest radiograph shows consolidation in the lower lobe of the right lung. Arterial blood gases (ABG) are taken and antibiotics are started. A nasal cannula provides 2L of oxygen to the patient. When the ABG results arrive, the patient’s SaO2 is 93%. The results are as follows: pH 7.32 PaO2 63 mm Hg PaCO2 57 mm Hg HCO3- 24 mEq/L What is the most appropriate next step in the management of this patient?

A. Increase oxygen to SaO2 > 95%
B. Intubate and start invasive ventilation
C. Re-take the ABG and observe the patient until the results are available
D. Administer oral corticosteroids
E. Start non-invasive positive pressure ventilation (Correct Answer)

Explanation: ***Start non-invasive positive pressure ventilation*** - The patient has severe **acute exacerbation of COPD (AE-COPD)** with **respiratory acidosis** (pH 7.32, PaCO2 57 mmHg) and **hypoxemia** (PaO2 63 mmHg, SaO2 93% on O2). **Non-invasive positive pressure ventilation (NIPPV)** is the most appropriate next step for hypoxemic and hypercapnic respiratory failure in COPD exacerbation, as it improves gas exchange and reduces work of breathing while avoiding the risks of intubation. - NIPPV can help to reduce **PaCO2** and improve **pH** and oxygenation by providing ventilatory support without requiring an artificial airway. *Increase oxygen to SaO2 > 95%* - Increasing oxygen further could worsen **hypercapnia** in a patient with COPD by blunting the **hypoxic drive** and increasing ventilation-perfusion mismatch, especially given the already elevated **PaCO2**. - The target SaO2 for COPD patients is typically 88-92%; aiming for >95% is usually unnecessary and potentially harmful. *Intubate and start invasive ventilation* - While the patient is in respiratory acidosis, NIPPV is generally preferred as the first-line intervention for AE-COPD with respiratory failure, as it is associated with fewer complications than **invasive ventilation**. - Intubation is reserved for patients who fail NIPPV, have contraindications to NIPPV, or present with immediate life-threatening conditions such as altered mental status or aspiration. *Re-take the ABG and observe the patient until the results are available* - The current ABG results clearly indicate **acute respiratory acidosis** which requires immediate intervention, not just re-evaluation. - Delaying treatment while awaiting new ABG results or observing the patient could lead to further clinical deterioration and worsening acidosis. *Administer oral corticosteroids* - Corticosteroids (systemic) are an important part of AE-COPD management for reducing inflammation and improving lung function. However, they do not address the acute **hypercapnic respiratory failure** directly. - While corticosteroids should be administered, they are not the immediate next step to manage the acute ventilatory failure, which requires respiratory support.

Question 87: A 72-year-old man comes to the physician for a routine physical examination. He says that he has felt well except for occasional headaches. He has no history of major medical illness. His temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 155/90 mm Hg. An ultrasound of the kidneys shows a normal right kidney and a left kidney that is 2 cm smaller in length. Further evaluation is most likely to show which of the following?

A. Hematuria
B. Abdominal bruit (Correct Answer)
C. Varicocele
D. Elevated urine metanephrines
E. Polycythemia

Explanation: **Abdominal bruit** - A persistent **abdominal bruit** can be heard in cases of **renal artery stenosis**, which explains the **unilateral kidney atrophy** and **hypertension**. - **Atherosclerosis** is a common cause of renal artery stenosis in elderly patients, leading to reduced blood flow to one kidney and subsequent size reduction. *Hematuria* - While hematuria can indicate renal pathology, it is not a direct consequence of **renal artery stenosis** leading to unilateral kidney atrophy. - It might be seen in conditions like **renal calculi** or **glomerulonephritis**, which are not suggested by the patient's presentation. *Varicocele* - A varicocele is a swelling of the veins in the **scrotum**, which is unrelated to **kidney size discrepancy** or **hypertension**. - Its presence would be an incidental finding and not explained by the current clinical picture. *Elevated urine metanephrines* - Elevated urine metanephrines are indicative of a **pheochromocytoma**, a tumor that causes **secondary hypertension** but does not typically lead to **unilateral kidney atrophy**. - The type of hypertension and kidney findings do not align with pheochromocytoma. *Polycythemia* - **Polycythemia** (an increase in red blood cell mass) can be caused by increased **erythropoietin** production, sometimes seen in renal cell carcinoma or renal cysts. - However, it is not a characteristic finding associated with **renal artery stenosis** and resultant unilateral kidney size reduction.

Question 88: A 61-year-old man presents to the office with a past medical history of hypertension, diabetes mellitus type II, hypercholesterolemia, and asthma. Recently, he describes increasing difficulty with breathing, particularly when performing manual labor. He also endorses a new cough, which occurs both indoors and out. He denies any recent tobacco use, despite a 40-pack-year history. He mentions that his symptoms are particularly stressful for him since he has been working in the construction industry for the past 30 years. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, and respiratory rate 14/min. On physical examination you notice clubbing of his digits, wheezing on auscultation, and normal heart sounds. A chest radiograph demonstrates linear opacities at the bilateral lung bases and multiple calcified pleural plaques. What is his most likely diagnosis?

A. Berylliosis
B. Silicosis
C. Asbestosis (Correct Answer)
D. Hypersensitivity pneumonitis
E. Coal miner’s disease

Explanation: ***Asbestosis*** - The patient's 30-year history in the **construction industry** strongly suggests exposure to **asbestos** (commonly found in insulation, roofing materials, and cement). - Clinical findings such as **digital clubbing**, **bilateral basilar linear opacities** on chest X-ray, and **calcified pleural plaques** are pathognomonic for asbestosis. - The combination of lower lobe fibrosis with pleural plaques is the hallmark of asbestos-related lung disease. *Berylliosis* - Berylliosis is associated with exposure to **beryllium** in industries such as aerospace, ceramics, and nuclear power, which is not indicated in this patient's occupational history. - While it can manifest with granulomas and diffuse lung disease similar to sarcoidosis, it does not typically cause **calcified pleural plaques**. *Silicosis* - Silicosis results from exposure to **silica dust**, which can occur in construction (sandblasting, concrete cutting), but typically presents with **upper lobe predominant nodular opacities** and **"eggshell" calcifications** of hilar lymph nodes, not pleural plaques. - The basilar linear pattern and pleural plaques point away from silicosis. *Hypersensitivity pneumonitis* - Hypersensitivity pneumonitis involves an immune response to inhaled organic antigens (bird droppings, mold, hay), often presenting with **recurrent flu-like symptoms** and diffuse infiltrates. - It typically does not cause **pleural plaques** or the chronic fibrotic pattern seen with pneumoconioses. *Coal miner's disease* - Coal worker's pneumoconiosis is caused by inhaling **coal dust** and is characteristic of coal mining occupations, not construction work. - It classically presents with **small nodular opacities** throughout the lungs, particularly in the upper lobes, and is not associated with **pleural plaques**.

Question 89: A 28-year-old woman comes to the emergency department because of increasing weakness and numbness of her legs for 3 days. She noticed that the weakness was more severe after she had a hot shower that morning. A year ago, she had an episode of partial vision loss in her left eye that resolved within 3 weeks. She is sexually active with 3 male partners and uses condoms inconsistently. She appears anxious. Her temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 108/77 mm Hg. Examination shows spasticity and decreased muscle strength in bilateral lower extremities. Deep tendon reflexes are 4+ bilaterally. Plantar reflex shows an extensor response bilaterally. The abdominal reflex is absent. Sensation to vibration and position over the lower extremities shows no abnormalities. Tandem gait is impaired. MRI of the brain and spine is inconclusive. Further evaluation is most likely to show which of the following?

A. Elevated intrinsic factor antibody level
B. Demyelination on nerve biopsy
C. Positive rapid plasma reagin test
D. Slow nerve conduction velocity
E. Oligoclonal bands in cerebrospinal fluid (Correct Answer)

Explanation: ***Oligoclonal bands in cerebrospinal fluid*** - The patient's presentation with **recurrent neurological symptoms** (leg weakness, numbness, previous partial vision loss), worsening with heat (**Uhthoff phenomenon**), **spasticity**, hyperactive reflexes, and absent abdominal reflexes, strongly suggests **multiple sclerosis (MS)**. - **Oligoclonal bands** in the CSF are highly indicative of MS, reflecting **intrathecal immunoglobulin production** due to CNS inflammation and demyelination. *Elevated intrinsic factor antibody level* - This is associated with **pernicious anemia**, which causes **vitamin B12 deficiency** and can lead to subacute combined degeneration of the spinal cord (sensory ataxia, weakness, paresthesias). - However, MS is a more fitting diagnosis given the patient's relapsing-remitting course and heat sensitivity, and **vibration/position sensation is normal**, which would typically be affected in B12 deficiency. *Demyelination on nerve biopsy* - While MS involves **demyelination**, it is primarily a disease of the **central nervous system**, and nerve biopsies are rarely used for diagnosis as they typically assess peripheral nerves. - The symptoms are more consistent with CNS involvement than a peripheral neuropathy. *Positive rapid plasma reagin test* - A positive rapid plasma reagin (RPR) test indicates **syphilis**, which can cause neurological symptoms in its tertiary stage (**neurosyphilis**), affecting the brain and spinal cord (e.g., tabes dorsalis). - While neurosyphilis can mimic some aspects of MS (e.g., ataxia, neurological deficits), the clinical history of relapsing symptoms and worsening with heat are more classic for MS, and there is no direct evidence of syphilis. *Slow nerve conduction velocity* - **Slow nerve conduction velocity** is characteristic of **peripheral nerve demyelination** (e.g., Guillain-Barré syndrome, CIDP). - Given the patient's signs of **upper motor neuron dysfunction** (spasticity, hyperreflexia, extensor plantar response) and the typical CNS involvement of MS, nerve conduction studies would likely be normal or only mildly affected in MS.

Question 90: A 39-year-old woman comes to the physician because of a 5-day history of pain and stiffness in her hands and wrists and a nonpruritic generalized rash. The stiffness is worst in the morning and improves after 15–20 minutes of activity. She had fever and a runny nose 10 days ago that resolved without treatment. She is sexually active with a male partner and uses condoms inconsistently. She works as an elementary school teacher. Her temperature is 37.3°C (99.1°F), pulse is 78/min, and blood pressure is 120/70 mm Hg. Examination shows swelling, tenderness, and decreased range of motion of the wrists as well as the metacarpophalangeal and proximal interphalangeal joints. There is a lacy macular rash over the trunk and extremities. Laboratory studies, including erythrocyte sedimentation rate and anti-nuclear antibody and anti-dsDNA serology, show no abnormalities. Which of the following is the most likely cause of this patient's symptoms?

A. Disseminated gonococcal disease
B. Rheumatoid arthritis
C. Systemic lupus erythematosus
D. Parvovirus arthritis (Correct Answer)
E. Psoriatic arthritis

Explanation: ***Parvovirus arthritis*** - This patient's symptoms, including **polyarthralgia** and a **lacy macular rash**, following a prodromal illness (fever, runny nose), are highly characteristic of parvovirus B19 infection. The joint involvement often resembles **rheumatoid arthritis** but is typically self-limiting. - The patient's profession as an **elementary school teacher** increases her risk of exposure to parvovirus B19, which is common in children. *Disseminated gonococcal disease* - While it can cause **migratory polyarthralgia** and a rash, the rash is typically **pustular or vesicular** on an erythematous base, often with hemorrhagic lesions, which differs from the described lacy macular rash. - The rash in DGI also tends to be sparse, unlike the generalized lacy rash described. *Rheumatoid arthritis* - Although it causes **symmetrical polyarthritis** with morning stiffness, the rash is not typical for RA, and symptoms usually persist for longer than 6 weeks to meet diagnostic criteria. - Furthermore, **anti-nuclear antibody** (ANA) and **ESR** would likely be elevated in active RA, but are normal here. *Systemic lupus erythematosus* - SLE can present with **arthralgia** and various rashes, but the classic rash associated with SLE is a **malar (butterfly) rash** or **discoid rash**. A lacy macular rash is not typical. - **ANA** and **anti-dsDNA** serologies are usually positive in SLE, but are normal in this patient. *Psoriatic arthritis* - Psoriatic arthritis is associated with **psoriasis skin lesions**, which are typically erythematous, scaly plaques, not a lacy macular rash. - While it can affect the hands and wrists, the rash and preceding viral-like illness do not fit the typical presentation of psoriatic arthritis.

Question 91: A 30-year-old woman comes to the physician because of severe headaches and lightheadedness for 2 months. She has also been hearing a 'swoosh' sound in her left ear for the past month. She has allergic rhinitis and acne. Her sister is being treated for thyroid cancer. Current medications include levocetirizine, topical clindamycin, and azelastine-fluticasone nasal spray. She appears anxious. She is 155 cm (5 ft 1 in) tall and weighs 77 kg (170 lb); BMI is 32 kg/m2. Her temperature is 37°C (98.6°F), pulse is 96/min, respirations are 14/min, and blood pressure is 168/96 mm Hg. Examination shows cystic acne over the face and back. The pupils are equal and reactive. There is a bruit on the left side of the neck. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. The abdomen is soft and nontender. There is an abdominal bruit on the left side. Neurologic examination shows no focal findings. Further evaluation of this patient is most likely to show which of the following?

A. Adrenal adenoma
B. Abnormal breathing pattern at night
C. Parathyroid adenoma
D. Elevated renin level (Correct Answer)
E. Increased 24-hour urine cortisol

Explanation: ***Elevated renin level*** - The patient presents with **severe headaches, lightheadedness, pulsatile tinnitus ('swoosh' sound), hypertension**, and **abdominal and neck bruits**, which are classic signs of **renovascular hypertension**. - The clinical picture is highly suggestive of **fibromuscular dysplasia (FMD)**, the most common cause of renovascular hypertension in **young women**, which can affect both renal and carotid arteries. - **Renal artery stenosis** leads to decreased renal blood flow, which activates the **renin-angiotensin-aldosterone system (RAAS)** and results in **elevated renin levels**. - The neck bruit and pulsatile tinnitus suggest concurrent carotid artery involvement, which is common in FMD. *Adrenal adenoma* - This would lead to **primary hyperaldosteronism (Conn's syndrome)**, characterized by hypertension, but typically with **low renin levels** due to negative feedback from aldosterone excess. - While hypertension is present, the presence of **vascular bruits** and the absence of **hypokalemia** make this less likely. *Abnormal breathing pattern at night* - This suggests **obstructive sleep apnea (OSA)**, which can cause **secondary hypertension** and headaches, especially in obese patients. - However, OSA does not explain the presence of **vascular bruits** (neck and abdominal) or pulsatile tinnitus, which point to a primary vascular etiology. *Parathyroid adenoma* - A parathyroid adenoma causes **primary hyperparathyroidism**, characterized by **hypercalcemia** and potential bone, kidney stone, and psychiatric symptoms. - While it can be associated with hypertension, it does not explain the **bruits** or pulsatile tinnitus, and there is no mention of hypercalcemia or related symptoms. *Increased 24-hour urine cortisol* - This is indicative of **Cushing's syndrome**, which presents with hypertension, weight gain, central obesity, moon facies, striae, and possibly acne. - While the patient has hypertension, obesity, and acne, the presence of **vascular bruits** and **pulsatile tinnitus** are not typical features of Cushing's syndrome, and other classic signs like central obesity, moon facies, or striae are not mentioned.

Question 92: A 27-year-old male with a history of injection drug use has been feeling short of breath and fatigued for the past several weeks. He is having trouble climbing the stairs to his apartment and occasionally feels like his heart is racing out of control. His past medical history is most notable for a previous bout of infective endocarditis after which he was lost to follow-up. On exam, you note that his carotid pulse has rapid rise and fall. Which of the following would you also expect to find?

A. Mid-systolic click
B. Venous hum
C. Systolic murmur that increases with valsalva
D. Fixed, split S2
E. Widened pulse pressure (Correct Answer)

Explanation: ***Widened pulse pressure*** - The patient's history of **injection drug use** and prior **infective endocarditis** suggests a likely etiology of **aortic regurgitation**, which is commonly complicated by **widened pulse pressure**. - **Aortic regurgitation** leads to a large stroke volume and rapid fall in diastolic pressure, directly causing a **widened pulse pressure** and the described **rapid rise and fall (water-hammer) pulse**. *Mid-systolic click* - A **mid-systolic click** is characteristic of **mitral valve prolapse**, a condition not directly suggested by the patient's symptoms or risk factors for **infective endocarditis** affecting the aortic valve. - While it can be associated with valvular issues, it does not explain the **rapid rise and fall carotid pulse** or the clinical picture of **aortic regurgitation**. *Venous hum* - A **venous hum** is a continuous murmur heard over the **internal jugular vein** in children and young adults, often benign, and not specifically associated with the cardiac pathology indicated here. - It is unrelated to **aortic valve dysfunction** or the signs of heart failure and valvular regurgitation presented in the scenario. *Systolic murmur that increases with valsalva* - A **systolic murmur that increases with Valsalva maneuver** is characteristic of **hypertrophic obstructive cardiomyopathy**, which is not supported by the patient's history of **injection drug use** and prior **infective endocarditis**. - The presentation strongly points to a valvular issue, specifically **aortic regurgitation**, rather than an outflow tract obstruction. *Fixed, split S2* - A **fixed, split S2** is a classic finding in an **atrial septal defect (ASD)**, which is an acyanotic congenital heart defect. - This finding is unrelated to the patient's signs and symptoms, which are suggestive of acquired valvular heart disease resulting from **infective endocarditis**.

Question 93: A 72-year-old man presents to the emergency department for a change in his behavior. The patient's wife called 911 and he was brought in by emergency medical services. She noticed that he seemed somnolent and not very responsive. The patient has a past medical history of type II diabetes, obesity, osteoarthritis, and migraine headaches. His current medications include naproxen, insulin, atorvastatin, metformin, ibuprofen, omeprazole, and fish oil. His temperature is 99.5°F (37.5°C), blood pressure is 170/115 mmHg, pulse is 80/min, respirations are 19/min, and oxygen saturation is 98% on room air. On physical exam, the patient is somnolent and has a Glasgow Coma Scale of 11. Cardiac and pulmonary exams are notable for bibasilar crackles and a systolic murmur that radiates to the carotids. Neurological exam is deferred due to the patient's condition. Laboratory values are shown below. Hemoglobin: 12 g/dL Hematocrit: 36% Leukocyte count: 9,500 cells/mm^3 with normal differential Platelet count: 199,000/mm^3 Serum: Na+: 144 mEq/L Cl-: 98 mEq/L K+: 4.0 mEq/L HCO3-: 16 mEq/L BUN: 44 mg/dL Glucose: 202 mg/dL Creatinine: 2.7 mg/dL Ca2+: 9.2 mg/dL AST: 12 U/L ALT: 22 U/L The patient is started on IV fluids. Which of the following represents the best next step in management?

A. Bicarbonate
B. Potassium
C. Insulin and potassium (Correct Answer)
D. Insulin
E. Discontinue the patient's home medications

Explanation: ***Insulin and potassium*** - The patient presents with **hyperglycemia** (glucose 202 mg/dL), a **high anion gap metabolic acidosis** (anion gap = 144 - (98 + 16) = 30), and altered mental status, consistent with **diabetic ketoacidosis (DKA)** in a patient with type 2 diabetes. - **Insulin therapy** is essential to halt ketogenesis, correct hyperglycemia, and reverse metabolic acidosis. - **Potassium replacement** must be initiated simultaneously when serum K+ is between 3.3-5.2 mEq/L (patient's K+ is 4.0 mEq/L). Insulin drives potassium intracellularly, and without replacement, **life-threatening hypokalemia** can develop rapidly. - Current **DKA management guidelines** recommend starting both insulin and potassium together when potassium is in the normal range to prevent cardiac arrhythmias from hypokalemia. *Insulin* - While insulin is critical for DKA management, giving insulin **without potassium replacement** when K+ is normal risks precipitating **severe hypokalemia** as insulin shifts potassium into cells. - Hypokalemia can lead to cardiac arrhythmias, muscle weakness, and respiratory failure. - Modern protocols emphasize **concurrent potassium administration** with insulin therapy. *Bicarbonate* - Bicarbonate therapy is **not routinely recommended** in DKA management and is reserved only for severe acidosis with pH <6.9 to prevent cardiovascular collapse. - The patient's acidosis (HCO3- 16 mEq/L) will correct with insulin therapy as ketone production ceases. - Bicarbonate can cause complications including **cerebral edema, paradoxical CNS acidosis, hypokalemia**, and rebound alkalosis. *Potassium* - While potassium replacement is necessary, it must be given **with insulin**, not alone. - Potassium monotherapy would not address the underlying hyperglycemia and ongoing ketoacidosis. - The patient's current potassium is normal (4.0 mEq/L), making isolated potassium therapy unnecessary without insulin. *Discontinue the patient's home medications* - The patient is taking multiple **NSAIDs** (naproxen and ibuprofen) that likely contributed to his **acute kidney injury** (Cr 2.7 mg/dL). - While discontinuing nephrotoxic medications is important, this does not address the **immediate life-threatening metabolic crisis** of DKA. - The priority is correcting the acidosis and hyperglycemia; medication reconciliation can occur after stabilization.

Question 94: A 49-year-old woman comes to the physician because of a 4-month history of a dry cough and shortness of breath on exertion. She also reports recurrent episodes of pain, stiffness, and swelling in her wrist and her left knee over the past 6 months. She had two miscarriages at age 24 and 28. Physical examination shows pallor, ulcerations on the palate, and annular hyperpigmented plaques on the arms and neck. Fine inspiratory crackles are heard over bilateral lower lung fields on auscultation. Which of the following additional findings is most likely in this patient?

A. Increased airway resistance
B. Decreased A-a gradient
C. Decreased right atrial pressure
D. Decreased diffusing capacity (Correct Answer)
E. Increased lung compliance

Explanation: ***Decreased diffusing capacity*** - This patient presents with symptoms highly suggestive of **systemic lupus erythematosus (SLE)**, including recurrent miscarriages, joint pain, oral ulcers, skin lesions (annular hyperpigmented plaques), and pulmonary involvement (dry cough, dyspnea, crackles). - **Interstitial lung disease (ILD)**, a common pulmonary manifestation of SLE, leads to **fibrosis** of the alveolar-capillary membrane, thereby **decreasing the diffusing capacity of the lung for carbon monoxide (DLCO)**. *Increased airway resistance* - Increased airway resistance is characteristic of **obstructive lung diseases** like asthma or COPD, which primarily involve narrowing of the airways. - The patient's presentation with **inspiratory crackles** and symptoms of restrictive disease (shortness of breath on exertion, dry cough) is not consistent with increased airway resistance. *Decreased A-a gradient* - A **decreased alveolar-arterial (A-a) gradient** indicates efficient gas exchange and is typically seen in healthy individuals or in conditions causing hypoventilation without intrinsic lung disease. - In conditions like pulmonary fibrosis or ILD, there is impaired gas exchange leading to an **increased A-a gradient**. *Decreased right atrial pressure* - **Decreased right atrial pressure** would typically signify reduced venous return or normal cardiac function. - Given the patient's respiratory symptoms and potential for pulmonary hypertension secondary to ILD, an **increased right atrial pressure** would be more likely due to increased pulmonary vascular resistance. *Increased lung compliance* - **Increased lung compliance** is seen in conditions where the lung tissue becomes more distensible, such as **emphysema**, due to destruction of elastic fibers. - **Interstitial lung disease** and pulmonary fibrosis, as suggested by the patient's symptoms and signs, lead to **decreased lung compliance** due to stiffening of the lung tissue.

Question 95: A 29-year-old woman, gravida 1, para 0 at 11 weeks' gestation comes to the physician because of a 2-day history of left lower extremity pain and swelling. Her temperature is 37.9°C (100.2°F). Physical examination shows a tender, palpable cord on the lateral aspect of the left lower leg. The overlying skin is erythematous and indurated. Duplex ultrasound shows vascular wall thickening and subcutaneous edema. Which of the following is the most likely diagnosis?

A. Erysipelas
B. Deep vein thrombosis
C. Erythema nodosum
D. Varicose vein
E. Superficial thrombophlebitis (Correct Answer)

Explanation: ***Superficial thrombophlebitis*** - The presence of a **tender, palpable cord** with overlying **erythema** and **induration** along a superficial vein is classic for superficial thrombophlebitis. - **Duplex ultrasound** findings of vascular wall thickening and subcutaneous edema further support this diagnosis by indicating inflammation and thrombosis of a superficial vessel rather than a deep one. *Erysipelas* - This is a **superficial cellulitis** characterized by a well-demarcated, rapidly spreading erythematous lesion, often with a "raised edge." - While it causes erythema and induration, it typically does not present with a **palpable cord** indicative of a thrombosed vessel. *Deep vein thrombosis* - While presenting with **leg pain and swelling**, a DVT typically causes symptoms in the **proximal veins** and would not present with a palpable cord on the *lateral* aspect of the lower leg. - Duplex ultrasound for DVT would show **non-compressibility** of a deep vein, which is different from "vascular wall thickening" and "subcutaneous edema" seen in superficial thrombophlebitis. *Erythema nodosum* - Presents as **tender, red nodules** typically on the shins, reflecting inflammation of subcutaneous fat (panniculitis), not superficial veins. - It does not involve a **palpable cord** or symptoms related to vascular thrombosis. *Varicose vein* - Varicose veins are **dilated, tortuous superficial veins** that can be palpable, but they typically are not acutely tender, erythematous, or associated with a palpable cord indicating thrombosis unless a complication like phlebitis occurs. - The ultrasound findings of **vascular wall thickening** and **subcutaneous edema** point to an active inflammatory and thrombotic process, beyond simple varicosity.

Question 96: A 34-year-old woman comes to the emergency department with midsternal chest pain, shortness of breath, and cough with bloody sputum for the past 3 hours. The pain started after moving furniture at home and worsens when taking deep breaths. The patient has a history of hypertension. She has smoked one pack of cigarettes daily for the past 20 years. She drinks 1–2 glasses of wine per day. Current medications include enalapril and an oral contraceptive. Her temperature is 38.2°C (100.8°F), pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Oxygen saturation is 92% on room air. Physical examination shows decreased breath sounds over the left lung base. There is calf pain on dorsal flexion of the right foot. Examination of the extremities shows warm skin and normal pulses. Further evaluation of this patient is most likely to show which of the following findings?

A. Thrombus in the left atrium on TEE
B. Elevated serum CK-MB
C. Wedge-shaped filling defect on chest CT (Correct Answer)
D. Tracheal deviation on CXR
E. Diffuse fluffy bilateral lung infiltrates on CXR

Explanation: ***Wedge-shaped filling defect on chest CT*** - This finding, specifically a **wedge-shaped perfusion defect**, points to a **pulmonary embolism (PE)**, which is strongly suggested by the patient's acute onset of dyspnea, pleuritic chest pain, hemoptysis, tachycardia, hypoxia, and risk factors (oral contraceptive use, smoking, calf pain indicating DVT). - A definitive diagnostic test for PE is a **CT pulmonary angiography (CTPA)**, which would show such a filling defect in the pulmonary arterial tree. *Thrombus in the left atrium on TEE* - A left atrial thrombus is typically associated with **atrial fibrillation** or other conditions causing stasis in the left atrium, which are not suggested by the patient's presentation. - While a **TEE** can visualize left atrial thrombi, it's not the primary diagnostic test for the described symptoms of acute chest pain, dyspnea, and hemoptysis, which are more consistent with PE. *Elevated serum CK-MB* - **Elevated CK-MB** is a marker for **myocardial injury** or infarction. Although the patient has chest pain, the pain is pleuritic (worsens with deep breaths) and is associated with hemoptysis and dyspnea, making **acute coronary syndrome** less likely. - The other symptoms and risk factors point more strongly to **pulmonary embolism** rather than cardiac ischemia. *Tracheal deviation on CXR* - **Tracheal deviation** on a chest X-ray typically indicates a medical emergency such as tension pneumothorax or a very large pleural effusion/mass. - While a **tension pneumothorax** can cause acute chest pain and dyspnea, her symptoms of hemoptysis and calf pain are not consistent, and a tension pneumothorax would present with more profound hemodynamic instability. *Diffuse fluffy bilateral lung infiltrates on CXR* - **Diffuse fluffy bilateral lung infiltrates** are characteristic of conditions like **pulmonary edema** or **acute respiratory distress syndrome (ARDS)**. - While PE can cause some lung changes, diffuse infiltrates are not the classic presentation, and the patient's symptoms are more consistent with a focal process in the pulmonary vasculature.

Question 97: A 38-year-old man comes to the physician because of fever, malaise, productive cough, and left-sided chest pain for 2 weeks. During this time, he has woken up to a wet pillow in the morning on multiple occasions and has not been as hungry as usual. He was diagnosed with HIV infection 1 year ago. He currently stays at a homeless shelter. He has smoked one pack of cigarettes daily for 22 years. He has a history of intravenous illicit drug use. He drinks 5–6 beers daily. He is receiving combined antiretroviral therapy but sometimes misses doses. His temperature is 38.6°C (101.5°F), pulse is 106/min, and blood pressure is 125/85 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Auscultation shows decreased breath sounds over the left base of the lung. There is dullness to percussion on the left lower part of the chest. Laboratory studies show: Hemoglobin 14 g/dL Leukocyte count 5,000/mm3 CD4+ T lymphocytes 240/mm3 (N > 500) Serum Creatinine 0.9 mg/dL γ-Glutamyltransferase (GGT) 65 U/L (N = 5–50) Aspartate aminotransferase (AST) 15 U/L Alanine aminotransferase (ALT) 19 U/L Alkaline phosphatase 40 U/L Lactate dehydrogenase (LDH) 50 U/L An x-ray of the chest shows a left-sided pleural effusion and hilar lymphadenopathy. Analysis of the pleural fluid shows an effusion with lymphocyte-predominant leukocytosis, high protein, an LDH of 500 U/L, and high adenosine deaminase. Which of the following is the most likely cause of this patient's condition?

A. Rheumatoid arthritis
B. Pulmonary tuberculosis (Correct Answer)
C. Pneumocystis jirovecii pneumonia
D. Cirrhosis
E. Lung cancer

Explanation: ***Pulmonary tuberculosis*** - The patient's presentation with **fever, night sweats (wet pillow), weight loss (not as hungry), productive cough, and chest pain** is highly suggestive of pulmonary tuberculosis, especially given his **HIV infection with a low CD4+ count (240/mm3)**, **homelessness**, and **intravenous drug use**, which are all significant risk factors. - Pleural fluid analysis showing **lymphocyte-predominant leukocytosis, high protein, very high LDH (500 U/L), and high adenosine deaminase** is characteristic of tuberculous pleural effusion. The chest X-ray findings of **pleural effusion and hilar lymphadenopathy** further support this diagnosis. *Rheumatoid arthritis* - While rheumatoid arthritis can cause pleural effusions, the patient's acute symptoms, particularly **persistent fever, night sweats, and productive cough**, are not typical presentations of rheumatoid pleuritis. - The **high adenosine deaminase level in the pleural fluid** is a strong indicator of mycobacterial infection and is not associated with rheumatoid pleural effusions. *Pneumocystis jirovecii pneumonia* - *Pneumocystis jirovecii* pneumonia (PJP) usually presents with **dry cough, dyspnea, and hypoxemia**, and is less commonly associated with a **large pleural effusion or hilar lymphadenopathy**. - PJP is also typically seen in patients with **CD4+ counts below 200/mm3**, while this patient's CD4 is 240/mm3, although he is at risk. Pleural fluid in PJP would typically not show elevated adenosine deaminase. *Cirrhosis* - Cirrhosis can lead to **hepatic hydrothorax**, which is typically a **transudative pleural effusion** (low protein, low LDH), not an exudative effusion with high protein and very high LDH as seen in this patient. - The patient's **liver enzymes (AST, ALT, ALP) are largely normal**, although GGT is mildly elevated, suggesting that cirrhosis is not the primary cause of his respiratory symptoms or effusion. *Lung cancer* - While lung cancer can cause pleural effusions and hilar lymphadenopathy, the patient's acute systemic symptoms of **fever, night sweats, and productive cough for 2 weeks** are more consistent with an acute infectious process. - The **lymphocyte-predominant exudative effusion with high adenosine deaminase** is more indicative of tuberculosis than a typical malignant effusion.

Question 98: A 44-year-old female is brought to the emergency room after losing consciousness at a shopping mall. Her husband states that they were shopping when the patient appeared sweaty and tremulous, became confused, then collapsed. She was unconscious for 5 minutes until a paramedic arrived. Fingerstick glucose at that time was 31 mg/dL and intramuscular glucagon was administered. The patient regained consciousness as she was being transported to the ambulance. On arrival in the emergency room, she is conscious but sleepy. She is able to report that her last meal prior to the mall was 5 hours ago. Her husband notes that over the last 3 months, she has complained of headaches and a milky discharge from both breasts, as well as nausea if she goes too long without eating. She works as an inpatient nurse and was exposed to tuberculosis 10 years ago but adequately treated. Because she was adopted as an infant, family history is unknown. Temperature is 98.4 deg F (36.9 deg C), blood pressure is 101/59 mmHg, pulse is 88/min, and respiration is 14/min. Preliminary lab values are shown below: Plasma glucose: 54 mg/dL Plasma insulin: 29 pmol/L (normal < 19 pmol/L) Plasma C-peptide: 272 pmol/L (normal < 200 pmol/L) Plasma proinsulin: 8 pmol/L (normal < 5 pmol/L) Plasma ß-hydroxybutyrate: 1.2 mmol/L (normal > 2.7 mmol/L after fasting) Which of the following is the most likely cause of this patient’s hypoglycemic episode?

A. Noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS)
B. Primary adrenal insufficiency
C. Insulinoma (Correct Answer)
D. Sulfonylurea use
E. Exogenous insulin use

Explanation: ***Insulinoma*** - The patient's presentation with **recurrent hypoglycemic episodes** (sweaty, tremulous, confused, collapsed) that resolve with glucose administration (intramuscular glucagon) is highly suggestive of an insulinoma. - The laboratory findings of **elevated insulin, C-peptide, and proinsulin levels** during hypoglycemia, coupled with suppressed beta-hydroxybutyrate, confirm endogenous hyperinsulinism, characteristic of an insulin-producing tumor. The **galactorrhea** and **headaches** suggest a possible co-occurring **pituitary adenoma** as part of **MEN1**, which is often associated with insulinomas. *Noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS)* - NIPHS typically presents with **postprandial hypoglycemia** and is more common after gastric bypass surgery, which is not mentioned in this patient's history. - While it also involves endogenous hyperinsulinism, the patient's symptoms are more consistent with **fasting hypoglycemia**, a hallmark of insulinoma. *Primary adrenal insufficiency* - Adrenal insufficiency can cause hypoglycemia due to **cortisol deficiency**, which impairs gluconeogenesis. - However, the lab results show **elevated insulin and C-peptide**, indicating hyperinsulinism, which is not characteristic of primary adrenal insufficiency. *Sulfonylurea use* - Sulfonylureas stimulate insulin release from pancreatic beta cells, leading to **elevated insulin and C-peptide** levels during hypoglycemia. - However, the patient's history does not mention diabetes or sulfonylurea use, and her persistent symptoms over months without a diagnosis of diabetes make this less likely. A **sulfonylurea screen** would distinguish this. *Exogenous insulin use* - Exogenous insulin administration would result in **high insulin levels** but **suppressed C-peptide levels**, as C-peptide is co-secreted with endogenous insulin. - The patient's lab results show **elevated C-peptide**, ruling out exogenous insulin as the sole cause of hyperinsulinism.

Question 99: A 48-year-old man comes to the physician for the evaluation of dyspnea and cough. He was diagnosed with esophageal cancer 10 months ago, for which he received radiochemotherapy. He has a history of atopic dermatitis and has smoked one pack of cigarettes daily for 30 years. Auscultation of the lungs shows decreased breath sounds bilaterally. Spirometry shows an FVC of 78% and an FEV1/FVC ratio of 95%. Which of the following is the most likely underlying condition?

A. Pulmonary embolism
B. Chronic bronchitis
C. Pulmonary emphysema
D. Pulmonary fibrosis (Correct Answer)
E. Allergic asthma

Explanation: ***Pulmonary fibrosis*** - A history of **radiochemotherapy for esophageal cancer** significantly increases the risk of **radiation-induced pulmonary fibrosis**, which can manifest as dyspnea and cough. - The **Spirometry results of FVC 78% and FEV1/FVC ratio of 95%** indicate a **restrictive lung disease pattern**, consistent with pulmonary fibrosis, as the FEV1/FVC ratio is preserved or even elevated. *Pulmonary embolism* - While pulmonary embolism can cause dyspnea, it typically presents with **acute onset** symptoms and can have risk factors such as **malignancy** or immobility. - However, spirometry would likely show normal or mildly restrictive patterns, but not typically a preserved FEV1/FVC ratio in the setting of chronic symptoms. *Chronic bronchitis* - Characterized by a **chronic cough with sputum production** for at least three months in two consecutive years, often due to **smoking**. - Spirometry in chronic bronchitis typically shows an **obstructive pattern**, with a **reduced FEV1/FVC ratio**, which is not present here. *Pulmonary emphysema* - Also strongly associated with **smoking**, emphysema primarily causes **airflow obstruction** due to destruction of alveolar walls. - Spirometry would reveal an **obstructive pattern** with a **decreased FEV1/FVC ratio**, which contradicts the patient's spirometry findings. *Allergic asthma* - Allergic asthma is characterized by **reversible airway obstruction** and hyperresponsiveness, often triggered by allergens. - Spirometry would show an **obstructive pattern**, typically with a **reduced FEV1/FVC ratio** that improves with bronchodilators, which is inconsistent with the given data.

Question 100: A 44-year-old woman is brought to the emergency department for confusion and lethargy for the past 2 hours. Per the husband, the patient was behaving weirdly and forgot how to get to the bathroom at her house. She was also difficult to wake up from her nap. The husband denies any fever, weight loss, headaches, dizziness, chest pain, or gastrointestinal changes. He reports that she had frequent diarrhea over the past 3 days but attributed it to food poisoning. In the emergency room, the patient had a 1-minute episode of seizure activity. Following initial resuscitation and stabilization, laboratory studies were performed and the results are shown below. Hemoglobin: 13 g/dL Hematocrit: 38% Leukocyte count: 7,600/mm^3 with normal differential Platelet count: 170,000/mm^3 Serum: Na+: 125 mEq/L Cl-: 90 mEq/L K+: 3.2 mEq/L HCO3-: 20 mEq/L BUN: 22 mg/dL Glucose: 101 mg/dL Creatinine: 1.0 mg/dL Thyroid-stimulating hormone: 3.2 µU/mL Ca2+: 9.3 mg/dL AST: 19 U/L ALT: 22 U/L What is the most appropriate treatment for this patient?

A. Restrict fluids
B. Start patient on maintenance anti-epileptic medications
C. Increase the serum sodium slowly with hypertonic saline solution (Correct Answer)
D. Increase the serum sodium slowly with normal saline solution
E. Increase the serum potassium with potassium solution

Explanation: ***Increase the serum sodium slowly with hypertonic saline solution*** - The patient presents with **severe symptomatic hyponatremia** (Na+ 125 mEq/L) evidenced by confusion, lethargy, and a new-onset seizure. This warrants intervention with **hypertonic saline** to raise serum sodium levels. - Due to the chronicity and symptoms, the sodium should be raised cautiously (e.g., 4-6 mEq/L in the first few hours) to avoid **osmotic demyelination syndrome**. *Restrict fluids* - Fluid restriction is appropriate for **asymptomatic mild to moderate hyponatremia**, often in the context of SIADH or dilutional hyponatremia, but not for severe symptomatic cases. - Given the patient's neurological symptoms and seizure, fluid restriction alone would be insufficient and potentially dangerous as it would not rapidly correct the sodium deficit. *Start patient on maintenance anti-epileptic medications* - The seizure is likely a direct consequence of **severe hyponatremia**, which lowers the seizure threshold. - Addressing the underlying electrolyte imbalance is the primary treatment; anti-epileptic medications are generally not needed for seizures caused solely by reversible metabolic derangements once the cause is corrected. *Increase the serum sodium slowly with normal saline solution* - **Normal saline (0.9% NaCl)** contains 154 mEq/L of sodium, which is only slightly higher than the patient's current serum sodium of 125 mEq/L. - This would not effectively or rapidly increase serum sodium in a patient with severe symptomatic hyponatremia, and it could even worsen hyponatremia if her effective circulating volume is not depleted. *Increase the serum potassium with potassium solution* - The patient's **potassium level (3.2 mEq/L)** is slightly low but not critically so, and it is not the primary cause of her severe neurological symptoms. - Addressing hyponatremia is the priority; while potassium replacement might be considered later, it does not address the acute, life-threatening issue.

Question 101: A 61-year-old man with a past medical history significant for asthma and psoriasis presents to the clinic for a wellness visit. He has no specific complaints. The patient’s blood pressure is 121/73 mm Hg, the pulse is 81/min, the respiratory rate is 16/min, and the temperature is 37.2°C (99.1°F). Physical examination reveals a 3.3 cm (1.2 in) lesion overlying his left elbow with an erythematous border, covered with a silver scale. What type of lesion is on the patient’s elbow?

A. Patch
B. Lichenification
C. Papule
D. Plaque (Correct Answer)
E. Excoriation

Explanation: ***Plaque*** - A **plaque** is a **solid, elevated lesion** greater than 1 cm in diameter, often formed by the coalescence of papules. - The description of a 3.3 cm lesion with an erythematous border and silver scale, in a patient with **psoriasis**, is classic for a psoriatic plaque. *Patch* - A **patch** is a large, **flat discoloration** (>1 cm) of the skin that is not elevated or depressed. - The described lesion is elevated and palpable, which distinguishes it from a patch. *Lichenification* - **Lichenification** refers to a **thickening of the skin** with exaggerated normal skin lines, usually due to chronic scratching or rubbing. - While associated with chronic skin conditions, the described lesion's size and scaly appearance do not fit the definition of lichenification. *Papule* - A **papule** is a **solid, elevated lesion** that is less than 1 cm in diameter. - The lesion described is 3.3 cm, making it too large to be classified as a papule. *Excoriation* - An **excoriation** is a **linear break in the skin** surface, often caused by scratching. - The described lesion is a raised, scaly patch, not a break in the skin from scratching.

Question 102: A 74-year-old man comes to the attention of the inpatient hospital team because he started experiencing shortness of breath and left-sided back pain 3 days after suffering a right hip fracture that was treated with hip arthroplasty. He says that the pain is sharp and occurs with deep breathing. His past medical history is significant for diabetes and hypertension for which he takes metformin and lisinopril. On physical exam, he is found to have a friction rub best heard in the left lung base. His right calf is also swollen with erythema and induration. Given this presentation, which of the following most likely describes the status of the patient's lungs?

A. Hypoventilation
B. Creation of a shunt
C. Obstructive lung disease
D. Restrictive lung disease
E. Increased dead space (Correct Answer)

Explanation: ***Increased dead space*** - The patient's symptoms (shortness of breath, left-sided back pain, friction rub, swollen leg) 3 days after hip surgery are highly suggestive of a **pulmonary embolism (PE)**. - A PE causes **increased dead space** by obstructing blood flow to a portion of the lung, where ventilation continues but gas exchange cannot occur due to lack of perfusion. *Hypoventilation* - Hypoventilation refers to reduced ventilation, typically leading to increased PCO2 and decreased PO2. - While patients with PE may appear tachypneic due to dyspnea, their underlying lung issue is a **perfusion defect**, not primarily a problem with moving air in and out of the lungs. *Creation of a shunt* - A shunt occurs when there is perfusion without adequate ventilation (e.g., in pneumonia or atelectasis), leading to deoxygenated blood bypassing gas exchange. - In PE, the primary problem is the opposite: **ventilation without perfusion**, which leads to increased dead space rather than shunting. *Obstructive lung disease* - Obstructive lung diseases (e.g., asthma, COPD) are characterized by **airflow limitation**, making it difficult to exhale air. - The patient's symptoms and risk factors point to an acute vascular event, not a chronic airway obstruction. *Restrictive lung disease* - Restrictive lung diseases (e.g., pulmonary fibrosis) involve reduced lung volumes and compliance, making it difficult to inhale air. - There is nothing in the patient's presentation that suggests a chronic restrictive lung pathology; his symptoms are acute and related to surgery.

Question 103: A 35-year-old woman comes to the clinic with complaints of joint pain and stiffness for the past few months. Her hands, lower back, and left knee are involved and associated with morning stiffness that improves throughout the day with activities. She also complains that her fingers change color upon exposure to cold. She has also noticed a tightening of the skin on her face and thinning of her lips. She feels tired throughout the day and has taken over-the-counter multivitamins that do not seem to help her much. The patient does not smoke cigarettes and drinks alcohol socially. She was diagnosed with hypertension 1 year ago and has been taking hydralazine for the past year. She lost her parents in a road traffic accident 3 years ago. Temperature is 36.7°C (98°F), blood pressure is 140/85 mm Hg, pulse is 72/min, respirations are 12/min, and BMI is 25 kg/m2. Her skin appears shiny and slightly thickened, especially her face and hands. Laboratory investigation: Complete blood count Hemoglobin 9.5 g/dl Leucocytes 5,500/mm3 Platelets 150,000/mm3 ANA positive Anti-centromere Antibody negative Anti Scl-70 positive Anti Jo-1 negative Anti-histone negative Anti DsDNA negative What is the most likely diagnosis in this patient?

A. Polymyositis
B. SLE
C. Limited cutaneous systemic scleroderma
D. Diffuse cutaneous systemic scleroderma (Correct Answer)
E. Drug-induced lupus

Explanation: ***Diffuse cutaneous systemic scleroderma*** - The presence of **anti-Scl-70 (anti-topoisomerase I) antibodies**, along with **widespread skin thickening** involving the hands and face, and **internal organ involvement** (hypertension, joint pain, Raynaud's phenomenon), points to diffuse cutaneous systemic scleroderma. - This variant is associated with rapid skin thickening, significant internal organ involvement (e.g., lung fibrosis, renal crisis), and a poorer prognosis compared to the limited form. *Polymyositis* - Characterized primarily by **proximal muscle weakness** and elevated muscle enzymes (e.g., CK), which are not described as prominent features in this patient's presentation. - While ANA can be positive, **anti-Jo-1 antibodies** are more specific for polymyositis/dermatomyositis, and they are negative in this case. *SLE* - Although the patient presents with **arthralgias**, **fatigue**, and **positive ANA**, several key features of SLE, such as malar rash, discoid rash, serositis, renal involvement (beyond hypertension, which can be seen in scleroderma), are absent. - The prominent **skin thickening** and **positive anti-Scl-70** are not typical for SLE and make this diagnosis less likely. *Limited cutaneous systemic scleroderma* - This variant is characterized by **skin thickening restricted** to areas distal to the elbows and knees, with or without face/neck involvement. - It is strongly associated with **anti-centromere antibodies**, which are negative in this patient, and typically has a slower progression and is associated with PAH. *Drug-induced lupus* - Although the patient is on **hydralazine**, a known cause of drug-induced lupus, the negative **anti-histone antibodies** make this diagnosis less likely. - The extensive **skin thickening**, **Raynaud's phenomenon**, and **anti-Scl-70 antibodies** are not characteristic features of drug-induced lupus.

Question 104: A 73-year-old female is hospitalized following a pelvic fracture. She undergoes surgical repair without complication. Four days into her hospital stay, she develops acute dyspnea and chest pain accompanied by oxyhemoglobin desaturation. Which of the following arterial blood gas values is the patient most likely to have? (normal values: pH 7.35 - 7.45, PaO2 80 - 100 mm Hg, PaCO2 35-45 mm Hg, HCO3 22-26)

A. pH 7.5, PaO2 60, PaCO2 30, HCO3 22 (Correct Answer)
B. pH 7.3, PaO2 60, PaCO2 30, HCO3 20
C. pH 7.4, PaO2 60, PaCO2 40, HCO3 24
D. pH 7.5, PaO2 60, PaCO2 50, HCO3 28
E. pH 7.3, PaO2 60, PaCO2 50, HCO3 24

Explanation: ***pH 7.5, PaO2 60, PaCO2 30, HCO3 22*** - This patient's presentation with acute **dyspnea**, **chest pain**, and **desaturation** after a pelvic fracture and surgery is highly suggestive of a **pulmonary embolism (PE)**. A PE leads to **hypoxemia (PaO2 60)** and often causes **hyperventilation** due to irritation and compensatory mechanisms, leading to a **low PaCO2 (30)** and consequently **respiratory alkalosis (pH 7.5)**. - The **bicarbonate (HCO3 22)** is within the normal range, indicating an **uncompensated respiratory alkalosis**, which is typical for an acute event like PE. *pH 7.3, PaO2 60, PaCO2 30, HCO3 20* - This represents a **metabolic acidosis (low pH, low HCO3)** with a compensatory **respiratory alkalosis (low PaCO2)**. - While there is hypoxemia, the primary acid-base disturbance here is metabolic acidosis, which is not characteristic of an acute pulmonary embolism as the initial presentation. *pH 7.4, PaO2 60, PaCO2 40, HCO3 24* - This ABG shows **hypoxemia (PaO2 60)** but otherwise **normal pH, PaCO2, and HCO3**, suggesting an **uncompensated hypoxemia** without an acute acid-base disturbance. - An acute PE typically causes significant ventilatory changes leading to an acid-base imbalance, most commonly respiratory alkalosis, rather than a completely compensated picture. *pH 7.5, PaO2 60, PaCO2 50, HCO3 28* - This ABG indicates **hypoxemia (PaO2 60)** and **metabolic alkalosis (high pH, high HCO3)** with concomitant **respiratory acidosis (high PaCO2)**. - While hypoxemia is present, this specific combination of acid-base disturbances is not typical for an acute pulmonary embolism. *pH 7.3, PaO2 60, PaCO2 50, HCO3 24* - This ABG demonstrates **hypoxemia (PaO2 60)** and **respiratory acidosis (low pH, high PaCO2)** with normal bicarbonate. - This would suggest **hypoventilation**, which is contrary to the hyperventilation commonly seen in acute pulmonary embolism.

Question 105: A 39-year-old female with a long history of major depressive disorder presents to the emergency room with altered mental status. Her husband found her on the floor unconscious and rushed her to the emergency room. He reports that she has been in a severe depressive episode over the past several weeks. Vital signs are temperature 38.1 degrees Celsius, heart rate 105 beats per minute, blood pressure 110/70, respiratory rate 28, and oxygen saturation 99% on room air. Serum sodium is 139, chloride is 100, and bicarbonate is 13. Arterial blood gas reveals a pH of 7.44 with a pO2 of 100 mmHg and a pCO2 of 23 mmHg. Which of the following correctly identifies the acid base disorder in this patient?

A. Mixed respiratory alkalosis and anion gap metabolic acidosis (Correct Answer)
B. Pure non-gap metabolic acidosis
C. Mixed respiratory acidosis and metabolic alkalosis
D. Mixed respiratory alkalosis and non-gap metabolic acidosis
E. Pure respiratory alkalosis

Explanation: ***Mixed respiratory alkalosis and anion gap metabolic acidosis*** - The **pH of 7.44** indicates a mild alkalemia. The **bicarbonate of 13 mEq/L** suggests a metabolic acidosis, while the **pCO2 of 23 mmHg** indicates a respiratory alkalosis. - Calculation of the **anion gap ([Na+] - [Cl-] - [HCO3-])** = 139 - 100 - 13 = 26 mEq/L) reveals a high anion gap, confirming an **anion gap metabolic acidosis**. Using **Winter's formula**, the expected pCO2 for metabolic acidosis compensation (1.5 × HCO3 + 8 ± 2 = 1.5 × 13 + 8 = 27.5-29.5 mmHg) is higher than the measured pCO2 of 23 mmHg, indicating an additional **respiratory alkalosis** beyond appropriate compensation. Therefore, given the significant metabolic acidosis and prominent respiratory alkalosis with an essentially normal pH, a **mixed acid-base disorder** is present. *Pure non-gap metabolic acidosis* - This is incorrect because the **anion gap is elevated (26 mEq/L)**, not normal. - A pure non-gap metabolic acidosis would have a **normal anion gap (8-12 mEq/L)** and typically a lower pH than observed here, unless partially compensated. *Mixed respiratory acidosis and metabolic alkalosis* - This is incorrect because the **pCO2 is low (23 mmHg)**, indicating respiratory alkalosis, not acidosis. - The **bicarbonate is low (13 mEq/L)**, suggesting metabolic acidosis, not alkalosis. *Mixed respiratory alkalosis and non-gap metabolic acidosis* - This is incorrect because the **anion gap is elevated (26 mEq/L)**, not normal, ruling out a non-gap metabolic acidosis. - While respiratory alkalosis is present, the metabolic component is high anion gap. *Pure respiratory alkalosis* - This is incorrect because the **bicarbonate is significantly low (13 mEq/L)**, which is not consistent with a pure respiratory alkalosis where bicarbonate would be near normal or only slightly decreased as compensation. - A pure respiratory alkalosis would have a high pH due to low pCO2, but a relatively normal bicarbonate or only a minimal compensatory decrease.

Question 106: A 32-year-old woman presents to the emergency department due to severe, intractable headaches, and bilateral ocular pain. Her symptoms began approximately 2 weeks prior to presentation and have progressively worsened. She initially had right-sided headaches that were sharp, interfered with sleep, and were unresponsive to pain medications. The headache was around her right eye and cheek, and she noticed diplopia with right lateral gaze. Her symptoms were accompanied by fatigue, fever, and edema around the right eye. Approximately 2 days after these symptoms, she developed swelling around the left eye. Medical history is significant for a recent rhinosinusitis infection. Her temperature is 101°F (38.3°C), blood pressure is 133/72 mmHg, pulse is 90/min, and respirations are 18/min. On physical exam, there is ptosis, proptosis, chemosis, and periorbital swelling of both eyes. There is hyperesthesia in the bilateral ophthalmic and maxillary divisions of the trigeminal nerve. Fundoscopic exam demonstrates bilateral papilledema. There is mydriasis and eye muscle weakness in all directions. Which of the following is the most likely diagnosis?

A. Acute angle-closure glaucoma
B. Preseptal cellulitis
C. Orbital cellulitis
D. Cavernous sinus thrombosis (Correct Answer)
E. Bacterial endophthalmitis

Explanation: **Cavernous sinus thrombosis** - **Bilateral ophthalmic symptoms** including proptosis, chemosis, periorbital swelling, ptosis, mydriasis, and ophthalmoplegia, developing after a **rhinosinusitis infection**, are highly suggestive of **cavernous sinus thrombosis**. The symptoms began unilaterally and then spread to the other eye, which is a classic presentation due to the **intercavernous connections**. - Other key findings are **intractable headaches** (sharp, severe, interfering with sleep), **fever**, and **hyperesthesia in the trigeminal nerve divisions** (CN V1 and V2), indicating involvement of the structures within or adjacent to the cavernous sinus. **Papilledema** suggests increased intracranial pressure. *Acute angle-closure glaucoma* - Characterized by **sudden onset of unilateral eye pain, headache, blurred vision, and halos around lights**, often accompanied by nausea and vomiting. - While it causes severe eye pain and headache, it does **not typically involve bilateral symptoms, proptosis, significant periorbital edema, ophthalmoplegia**, or spread from one eye to the other over days as seen in this case. *Preseptal cellulitis* - Involves infection of the **eyelid and periorbital tissues anterior to the orbital septum**, causing swelling, redness, and tenderness of the eyelids. - It does **not cause proptosis, chemosis, ophthalmoplegia, or papilledema**, as the infection does not extend into the orbit or involve the extraocular muscles and nerves. *Orbital cellulitis* - Involves infection **posterior to the orbital septum**, causing **proptosis, ophthalmoplegia, pain with eye movement, and vision changes**, usually unilaterally. - While it can cause proptosis and ophthalmoplegia, the **bilateral involvement, spreading pattern, trigeminal nerve involvement, and severe intractable headaches** are much more characteristic of cavernous sinus thrombosis. *Bacterial endophthalmitis* - An **intraocular infection** causing inflammation of the vitreous and aqueous humor, leading to **severe vision loss, eye pain, and redness**. - It usually presents with a **red eye, hypopyon, and significantly decreased vision**, but does **not typically involve proptosis, periorbital swelling, ophthalmoplegia, or trigeminal nerve symptoms** as described.

Question 107: A 68-year-old man is referred to the cardiology department with complaints of shortness of breath on exertion that has been progressive for the last 6 months. He has a history of diabetes mellitus type II which is controlled with diet alone. He has a temperature of 37.1℃ (98.8℉), the pulse is 76/min, and the blood pressure is 132/86 mm Hg. Physical examination is notable for a systolic murmur heard best at the right upper sternal border with radiation to the carotid arteries. ECG shows left ventricular hypertrophy and absent Q waves. Transthoracic echocardiogram shows an elevated aortic pressure gradient with severe leaflet calcification and left ventricular diastolic dysfunction. Which of the following has a survival benefit for this patient’s cardiac problem?

A. A combination of captopril and hydrochlorothiazide
B. Atorvastatin
C. Sodium nitroprusside
D. Serial clinical and echocardiographic follow-up
E. Transcatheter aortic valve replacement (Correct Answer)

Explanation: ***Transcatheter aortic valve replacement*** - The patient's presentation with **shortness of breath**, exertional symptoms, a **systolic murmur radiating to the carotid arteries**, **left ventricular hypertrophy**, and echocardiographic findings of **severe aortic valve calcification** and **elevated aortic pressure gradient** are all classic for **severe aortic stenosis**. - **Transcatheter aortic valve replacement (TAVR)** is the definitive treatment for severe aortic stenosis and provides significant survival benefit, especially in symptomatic patients or those with a high surgical risk. *A combination of captopril and hydrochlorothiazide* - This combination of an **ACE inhibitor** and a **diuretic** is typically used for **hypertension** and heart failure with reduced ejection fraction, but it does not address the underlying **structural valve defect** in aortic stenosis. - In severe aortic stenosis, aggressive **vasodilation** can be dangerous as it may lead to hypotension due to the fixed outflow obstruction, thus it does not improve survival. *Atorvastatin* - **Statins** like atorvastatin are primarily used for **lipid lowering** and cardiovascular risk reduction in patients with atherosclerotic disease. - While the patient has diabetes, statins do not have a direct survival benefit for **severe symptomatic aortic stenosis** itself. *Sodium nitroprusside* - **Sodium nitroprusside** is a potent **vasodilator** used in hypertensive emergencies or decompensated heart failure to rapidly reduce preload and afterload. - Its use is generally **contraindicated** or should be approached with extreme caution in severe aortic stenosis due to the risk of precipitous hypotension by reducing preload and afterload in the presence of a **fixed outflow obstruction**. *Serial clinical and echocardiographic follow-up* - While important for monitoring disease progression in **mild to moderate aortic stenosis**, this approach is insufficient and delays definitive treatment in **severe symptomatic aortic stenosis**. - Once symptomatic, the prognosis for severe aortic stenosis without intervention is poor, with a mean survival of approximately **2-3 years**.

Question 108: A 28-year-old woman comes to the physician because of a 4-day history of lower extremity numbness, weakness, and urinary incontinence. She has not had any trauma. Neurologic examination shows bilateral lower extremity weakness. Stroking the lateral side of the sole of the foot from the heel to the base of the small toe and medially to the base of the big toe elicits dorsiflexion of the big toe and fanning of the other toes. Further examination of this patient is most likely to show which of the following additional findings?

A. Hyporeflexia
B. Atrophy
C. Spasticity (Correct Answer)
D. Palmar grasp reflex
E. Fasciculation

Explanation: ***Spasticity*** - The combination of **lower extremity weakness**, **urinary incontinence**, and a **positive Babinski sign** (dorsiflexion of the big toe and fanning of other toes) indicates an **upper motor neuron (UMN) lesion**. - **Spasticity** is a classic sign of UMN lesions, characterized by an increase in muscle tone, hyperreflexia, and clonus. *Hyporeflexia* - **Hyporeflexia** (diminished reflexes) is characteristic of a **lower motor neuron (LMN) lesion**, which is inconsistent with the positive Babinski sign observed. - LMN lesions involve damage to the motor neurons in the spinal cord or their peripheral nerves. *Atrophy* - **Atrophy** can occur in both UMN and LMN lesions, but **significant atrophy** typically develops over time in LMN lesions due to denervation. - In acute UMN lesions, muscle atrophy is usually due to disuse and is less prominent than in LMN lesions. *Palmar grasp reflex* - The **palmar grasp reflex** is a primitive reflex that, if present in an adult, may indicate **frontal lobe dysfunction** or diffuse cerebral damage, often seen in neurodegenerative diseases. - It is not a direct or expected finding for a spinal cord UMN lesion presenting with these symptoms. *Fasciculation* - **Fasciculations** are visible, spontaneous contractions of a fascicle of muscle fibers, which are a hallmark sign of **lower motor neuron (LMN) pathology**. - They are typically not seen in pure upper motor neuron lesions.

Question 109: A 25-year-old woman presents to a medical clinic with complaints of right-sided chest pain, which is exacerbated during inspiration. She also reports intermittent fevers for the past 3 months associated with pain in both knee joints. She gives a history of an unintended 3 kg (6 lbs) weight loss in the past 2 months. The blood pressure is 110/84 mm Hg and the pulse is 86/min. On physical examination, a red rash is noted on her face overlying the nose and cheeks. The laboratory findings show that the hemoglobin is 9 g/dL and the total white cell count is 1500/mm3. Which of the following tests would be most specific to help diagnose this patient’s condition?

A. Antibody to phospholipid of cell membranes
B. Antibody to histone protein
C. Antibody to ribonucleoprotein
D. Antibody to double-stranded deoxyribonucleic acid (Correct Answer)
E. Antibody to microsomal cellular organelles

Explanation: ***Antibody to double-stranded deoxyribonucleic acid*** - The patient's symptoms (pleuritic chest pain, joint pain, fever, weight loss, malar rash, anemia, leukopenia) are highly suggestive of **Systemic Lupus Erythematosus (SLE)**. - **Anti-double-stranded DNA (anti-dsDNA) antibodies** are highly specific (95-98%) for SLE and correlate with disease activity, particularly lupus nephritis. - Anti-dsDNA is included in the **ACR/EULAR diagnostic criteria** for SLE and is the most commonly used specific serologic marker. - While anti-Smith (anti-Sm) antibodies have slightly higher specificity, anti-dsDNA has better sensitivity and clinical utility for diagnosis and monitoring. *Antibody to phospholipid of cell membranes* - **Antiphospholipid antibodies** (anticardiolipin, anti-β2 glycoprotein I, lupus anticoagulant) are associated with antiphospholipid syndrome. - These can occur in SLE patients but are not specific for diagnosing SLE itself. - They indicate thrombotic risk rather than serving as a primary diagnostic marker for lupus. *Antibody to histone protein* - **Anti-histone antibodies** are the hallmark of **drug-induced lupus** (seen in >95% of cases). - Common culprit drugs include hydralazine, procainamide, isoniazid, and quinidine. - This patient has no mention of drug exposure and presents with classic idiopathic SLE. *Antibody to ribonucleoprotein* - This typically refers to **anti-U1 RNP antibodies**, which are found in SLE but are more characteristic of **mixed connective tissue disease (MCTD)**. - **Anti-Sm (Smith) antibodies** (also a ribonucleoprotein) are highly specific for SLE (>99%) but have low sensitivity (20-30%). - Anti-U1 RNP is less specific for SLE as it occurs in multiple connective tissue diseases. *Antibody to microsomal cellular organelles* - **Anti-microsomal antibodies** (anti-thyroid peroxidase) are associated with autoimmune thyroid diseases like **Hashimoto's thyroiditis** and Graves' disease. - These antibodies are not relevant to the diagnosis of SLE.

Question 110: A 49-year-old man comes to the physician because of a 6-hour history of fever, an itchy rash, and generalized body aches. Ten days ago, he received treatment in the emergency department for a snake bite. His temperature is 38.5°C (101.3°F), pulse is 80/min, and blood pressure is 120/84 mm Hg. Physical examination shows multiple well-demarcated, raised, erythematous plaques over the trunk. There is tenderness to palpation and decreased range of motion of the metacarpophalangeal and wrist joints bilaterally. Urine dipstick shows 2+ protein. Further evaluation is most likely to show which of the following?

A. Keratinocyte necrosis on skin biopsy
B. Increased serum tryptase concentration
C. Increased antistreptolysin O titers
D. Positive ELISA for anti-hemidesmosome antibodies
E. Decreased serum complement concentration (Correct Answer)

Explanation: ***Decreased serum complement concentration*** - The patient's symptoms (fever, itchy rash, body aches, joint pain, proteinuria) developing 10 days after a snake bite treated with antivenom are highly suggestive of **serum sickness**. - **Serum sickness** is a type III hypersensitivity reaction characterized by the formation of **immune complexes** that deposit in tissues, activating the complement system and leading to its consumption, hence **decreased serum complement levels**. *Keratinocyte necrosis on skin biopsy* - This finding is characteristic of conditions like **erythema multiforme** or **toxic epidermal necrolysis (TEN)**, which typically present with target lesions or widespread epidermal detachment, not the raised erythematous plaques described. - While an allergic reaction can cause skin involvement, necrosis of keratinocytes is not the primary dermatological feature of serum sickness. *Increased serum tryptase concentration* - **Elevated serum tryptase** is a marker of **mast cell degranulation**, commonly seen in anaphylaxis. - Although serum sickness is an immune reaction, it is a type III hypersensitivity involving immune complexes, not primarily mast cell-mediated immediate hypersensitivity (Type I). *Increased antistreptolysin O titers* - **Increased antistreptolysin O (ASO) titers** indicate a recent **Streptococcus pyogenes infection**, typically associated with rheumatic fever or post-streptococcal glomerulonephritis. - This patient's symptoms and history of snake bite and antivenom administration do not point towards a streptococcal infection. *Positive ELISA for anti-hemidesmosome antibodies* - This finding is characteristic of **bullous pemphigoid**, an autoimmune blistering skin disease. - The patient's rash of raised, erythematous plaques and systemic symptoms are inconsistent with bullous pemphigoid, which primarily involves subepidermal blistering.

Question 111: A 59-year-old man presents to the emergency department with a sudden onset of severe pain (10/10 in severity) between the shoulder blades. He describes the pain as tearing in nature. Medical history is positive for essential hypertension for 11 years. The patient has smoked 10–15 cigarettes daily for the past 30 years. His temperature is 36.6°C (97.8°F), the heart rate is 107/min, and the blood pressure is 179/86 mm Hg in the right arm and 157/72 mm Hg in the left arm. CT scan of the chest shows an intimal flap limited to the descending thoracic aorta. Which of the following best describes the most likely predisposing factor for this condition?

A. Coronary atherosclerosis
B. Aortic coarctation
C. Hypertensive urgency
D. Aortic atherosclerosis
E. Abnormal elastic properties of the aorta (Correct Answer)

Explanation: ***Abnormal elastic properties of the aorta*** - Chronic **hypertension** (11 years) is the #1 risk factor for aortic dissection, causing **cystic medial degeneration** (breakdown of elastic fibers and smooth muscle in the tunica media). - This degenerative process results in **abnormal elastic properties** and weakening of the aortic wall, predisposing to dissection. - The tearing pain, blood pressure differential between arms, and CT findings of intimal flap are classic for **Type B aortic dissection**. - While often associated with connective tissue disorders in younger patients, cystic medial degeneration is also the pathophysiologic result of chronic hypertension in older patients. *Aortic atherosclerosis* - Atherosclerosis primarily affects the **intima** layer, while aortic dissection occurs in the **media** layer. - Though hypertension and smoking contribute to atherosclerosis, this is not the primary predisposing mechanism for dissection. - The underlying pathology is medial degeneration with abnormal elastic properties, not atherosclerotic plaque. *Coronary atherosclerosis* - This affects the coronary arteries supplying the heart, not the aortic wall structure. - Does not explain the anatomical location of dissection or the tearing interscapular pain. - Not a predisposing factor for aortic dissection. *Hypertensive urgency* - This refers to elevated blood pressure without acute end-organ damage. - The patient has **aortic dissection**, which represents acute end-organ damage (hypertensive emergency, not urgency). - While hypertension can precipitate dissection, the underlying **predisposing factor** is the chronic medial wall changes (abnormal elastic properties), not the acute blood pressure elevation itself. *Aortic coarctation* - This is a **congenital** narrowing of the aorta, typically diagnosed in childhood or young adulthood. - Classic finding is upper extremity hypertension with **lower extremity hypotension** (opposite pattern from arm-to-arm differential seen in dissection). - The patient's age, presentation, and 11-year history of essential hypertension make this unlikely.

Question 112: A 44-year-old male presents to the emergency department complaining of a headache. He reports that he developed a severe throbbing headache with blurred vision two hours ago. He has never experienced symptoms like these before. His past medical history is notable for hyperlipidemia and poorly controlled hypertension. He currently takes atorvastatin and lisinopril. His temperature is 98.6°F (37°C), blood pressure is 210/110 mmHg, pulse is 90/min, and respirations are 20/min. He is oriented to person, place, and time. No bruits or murmurs are noted. Strength is 2+ bilaterally in the upper and lower extremities. What is the next best step in the management of this patient?

A. Funduscopic exam
B. Head CT
C. Administer IV labetalol (Correct Answer)
D. Administer oral hydralazine
E. Renal ultrasound

Explanation: ***Administer IV labetalol*** - This patient presents with **hypertensive emergency**, characterized by **severe hypertension** (BP 210/110 mmHg) with new-onset or worsening **end-organ damage** (severe headache, blurred vision possibly indicating retinal changes). - Rapid but controlled reduction of blood pressure using **intravenous antihypertensives** like labetalol is crucial to prevent further organ damage. *Funduscopic exam* - While a **funduscopic exam** is important to assess for **hypertensive retinopathy** (e.g., papilledema, hemorrhages, exudates) in a patient with a hypertensive emergency, it is not the *immediate next step* in management. - The priority is to stabilize the patient by lowering blood pressure before a full diagnostic workup. *Head CT* - A **head CT** would be considered to rule out conditions like **intracranial hemorrhage** or **ischemic stroke**, especially given the severe headache and blurred vision. - However, in the setting of a clear **hypertensive emergency**, the initial priority is to commence pharmacological blood pressure reduction while preparing for imaging. *Administer oral hydralazine* - **Oral medications** are generally not indicated for the *initial management* of a **hypertensive emergency** because their onset of action is slower and their effects are less predictable and controllable compared to intravenous agents. - Furthermore, **hydralazine** can cause reflex tachycardia and is not a first-line agent for hypertensive emergencies due to its potential for unpredictable blood pressure drops. *Renal ultrasound* - A **renal ultrasound** could be part of a complete workup for the *causes* of secondary hypertension or to assess for **hypertensive nephrosclerosis** in the long term. - However, in the acute setting of a **hypertensive emergency**, it is not an immediate diagnostic or therapeutic priority.

Question 113: A 21-year-old man presents to his physician with a cough that has persisted for 4 weeks. His cough is usually nocturnal and awakens him from sleep. He denies having a fever, but was diagnosed with asthma when he was 15 years old and uses inhaled albuterol for relief of his symptoms. He usually needs to use a rescue inhaler once or twice a month. However, over the last 4 weeks, he has had to use inhaled albuterol almost daily. He does not have symptoms such as sneezing, running nose, nasal congestion, nasal discharge, headache, nausea, vomiting, regurgitation of food, or burning in the epigastrium. On physical examination, his temperature is 36.8°C (98.4°F), pulse rate is 96/min, blood pressure is 116/80 mm Hg, and respiratory rate is 16/min. On auscultation of the chest, end-expiratory wheezing is present bilaterally. The peak expiratory flow rate (PEFR) is 74% of that expected for his age, sex, and height. Which of the following is the best next step in the treatment of this patient?

A. Add daily inhaled ipratropium bromide to the current regimen.
B. Use inhaled albuterol 4 times daily and follow up after 4 weeks.
C. Add daily oral levocetirizine to the current regimen.
D. Add daily inhaled formoterol to the current regimen.
E. Add daily inhaled corticosteroids to the current regimen. (Correct Answer)

Explanation: ***Add daily inhaled corticosteroids to the current regimen.*** * The patient's increased frequency of albuterol use (from monthly to daily) and nocturnal symptoms indicate **poorly controlled asthma**, necessitating an escalation in therapy. * **Inhaled corticosteroids (ICS)** are the most effective long-term control medications for persistent asthma, reducing airway inflammation and hyperresponsiveness. *Add daily inhaled ipratropium bromide to the current regimen.* * **Ipratropium bromide** is a short-acting anticholinergic that primarily targets muscarinic receptors in the airways, leading to bronchodilation. * It is less effective than beta-2 agonists for acute exacerbations and is generally not recommended as a first-line daily maintenance therapy for asthma control, especially when ICS are not optimized. *Use inhaled albuterol 4 times daily and follow up after 4 weeks.* * Increasing the use of **short-acting beta-agonists (SABAs)** like albuterol for daily maintenance is not recommended as it does not address the underlying inflammation and can mask worsening asthma control. * Overuse of SABAs is associated with increased risk of severe exacerbations and adverse outcomes. *Add daily oral levocetirizine to the current regimen.* * **Levocetirizine** is an antihistamine used primarily for allergic rhinitis and chronic urticaria. * While allergies can trigger asthma, an antihistamine would not be the primary next step for controlling persistent asthma symptoms, especially given the clear indication for anti-inflammatory therapy. *Add daily inhaled formoterol to the current regimen.* * **Formoterol** is a long-acting beta-agonist (LABA) and should **never be used as monotherapy** for asthma due to an increased risk of severe asthma exacerbations and asthma-related death. * LABAs are indicated as add-on therapy **only in conjunction with inhaled corticosteroids** in patients whose asthma is not adequately controlled on ICS alone.

Question 114: A 35-year-old man who is a professional baseball player presents with stiffness in his hands. He says he is unable to bat as he would like and feels like he lacks power in his swings. He also has noticed that he sometimes seems to be dragging his feet while walking, and his voice seems to have changed. On physical examination, strength is 3 out of 5 in the extensor and flexor muscle groups in both upper and lower limbs bilaterally. Sensation is intact. Widespread muscle fasciculations are noted. Which of the following is the most likely diagnosis in this patient?

A. Amyotrophic lateral sclerosis (Correct Answer)
B. Multiple sclerosis
C. Myasthenia gravis
D. Primary lateral sclerosis
E. Lambert-Eaton Syndrome

Explanation: **Amyotrophic lateral sclerosis** - The patient's presentation with **progressive weakness** (lack of power, dragging feet, dysphonia), widespread **fasciculations**, and both **upper** (stiffness) and **lower motor neuron signs** (fasciculations, weakness) is highly characteristic of **Amyotrophic Lateral Sclerosis (ALS)**. - **ALS** typically involves the degeneration of motor neurons in the brain and spinal cord, leading to a combination of **spasticity** (upper motor neuron sign) and **flaccid weakness** with atrophy and fasciculations (lower motor neuron signs). *Multiple sclerosis* - **Multiple sclerosis (MS)** is characterized by demyelination in the central nervous system, leading to a variety of neurological symptoms. - While it can cause weakness and gait disturbances, it typically presents with **sensory deficits**, **optic neuritis**, and exacerbations/remissions, and **fasciculations are not a common feature**. *Myasthenia gravis* - **Myasthenia gravis** is an autoimmune disorder affecting the neuromuscular junction, causing **fluctuating muscle weakness** that worsens with activity and improves with rest. - Classic symptoms include **ptosis**, **diplopia**, and **difficulty swallowing or speaking**, but **fasciculations** are not typical, and weakness patterns differ from ALS. *Primary lateral sclerosis* - **Primary lateral sclerosis (PLS)** predominantly affects **upper motor neurons**, leading to progressive stiffness and spasticity. - Unlike ALS, **PLS** does not typically involve **lower motor neuron signs** like **fasciculations** or significant muscle atrophy. *Lambert-Eaton Syndrome* - **Lambert-Eaton Myasthenic Syndrome (LEMS)** is a rare autoimmune disorder of the neuromuscular junction, often associated with small cell lung cancer. - It causes **proximal muscle weakness** that paradoxically **improves with activity** (Lambert's sign), and may include autonomic dysfunction, but **fasciculations are not a primary feature**.

Question 115: A previously healthy 32-year-old woman comes to the emergency department with fatigue and bilateral leg swelling. Her pulse is 92/min, and respirations are 24/min. Physical examination shows jugular venous distention and pitting edema of the lower extremities. Her abdomen is distended with shifting dullness and tender hepatomegaly is present. Cardiovascular examination shows a holosystolic murmur heard best at the left lower sternal border that increases in intensity with inspiration. Which of the following is the most likely predisposing factor for this patient's condition?

A. Streptococcal pharyngitis
B. 45,XO genotype
C. Intravenous drug use (Correct Answer)
D. Vitamin B1 deficiency
E. Fibrillin gene defect

Explanation: ***Intravenous drug use*** - The patient presents with symptoms of **right-sided heart failure**, including **jugular venous distention**, pitting edema, ascites, and tender hepatomegaly. - The **holosystolic murmur** at the left lower sternal border increasing with inspiration is characteristic of **tricuspid regurgitation**, a common complication of infective endocarditis in intravenous drug users due to contaminated needles introducing bacteria (especially *Staphylococcus aureus*) to the right side of the heart. *Streptococcal pharyngitis* - While **rheumatic fever** following streptococcal pharyngitis can cause valvular heart disease, it typically affects the **mitral valve** and less commonly the aortic valve, leading primarily to left-sided heart failure symptoms. - It is unlikely to cause isolated tricuspid regurgitation and right-sided heart failure in a 32-year-old presenting without a history of carditis. *45,XO genotype* - A **45,XO genotype** (Turner syndrome) is associated with congenital heart defects such as **bicuspid aortic valve** and **coarctation of the aorta**, which lead to left-sided heart problems, not typically isolated right-sided heart failure and tricuspid regurgitation. - The patient's presentation does not describe any other features commonly seen in Turner syndrome. *Vitamin B1 deficiency* - Severe **thiamine (Vitamin B1) deficiency** can cause **wet beriberi**, leading to **high-output heart failure** with symptoms like edema and tachycardia. - However, it typically causes a dilated cardiomyopathy affecting both ventricles and does not commonly present with a specific holosystolic murmur of tricuspid regurgitation as the primary valvular lesion. *Fibrillin gene defect* - A **fibrillin gene defect** is associated with **Marfan syndrome**, which can cause cardiovascular complications like **aortic root dilation** and **mitral valve prolapse**, often leading to aortic or mitral regurgitation and left-sided heart failure. - It is not typically associated with tricuspid regurgitation and isolated right-sided heart failure as described.

Question 116: A 75-year-old man with hypercholesterolemia, coronary artery disease, and history of a transient ischemic attack (TIA) comes to your office for evaluation of hypertension. Previously, his blood pressure was controlled with diet and an ACE inhibitor. Today, his blood pressure is 180/115 mm Hg, and his creatinine is increased from 0.54 to 1.2 mg/dL. The patient reports that he has been compliant with his diet and blood pressure medications. What is the most likely cause of his hypertension?

A. Pheochromocytoma
B. Coarctation of the aorta
C. Renal artery stenosis (Correct Answer)
D. Progression of his essential hypertension
E. Hypothyroidism

Explanation: **Renal artery stenosis** - The sudden, severe elevation in blood pressure, coupled with a significant increase in **creatinine** while on an **ACE inhibitor**, strongly suggests **renal artery stenosis**. - ACE inhibitors can cause **acute kidney injury** in patients with bilateral renal artery stenosis (or stenosis of a solitary functioning kidney) by dilating the efferent arteriole, leading to a decrease in **glomerular filtration pressure**. *Pheochromocytoma* - While pheochromocytoma can cause severe hypertension, it's typically associated with paroxysmal episodes, **palpitations**, **headaches**, and **sweating**, which are not reported here. - It would not typically explain the **acute renal dysfunction** seen with ACE inhibitor use. *Coarctation of the aorta* - Most commonly diagnosed in **childhood or early adulthood** and presents with a blood pressure difference between the upper and lower extremities. - It is unlikely to present for the first time in a 75-year-old with this specific clinical picture of **renal dysfunction secondary to ACE inhibitor use**. *Progression of his essential hypertension* - While essential hypertension can worsen, the **acute and severe increase** in blood pressure along with the substantial rise in **creatinine** strongly points to a **secondary cause**, especially in the context of ACE inhibitor use. - Simple progression would not typically cause such a dramatic and acute change in **creatinine levels**. *Hypothyroidism* - Hypothyroidism can contribute to **diastolic hypertension** and increased cardiovascular risk, but it does not typically cause a **sudden, severe hypertensive crisis** or **acute kidney injury** in response to ACE inhibitors. - Other symptoms of hypothyroidism (**fatigue**, **weight gain**, **cold intolerance**) are not mentioned.

Question 117: A 34-year-old man presents to the emergency department with a headache that has lasted for 2 hours. His headache is severe and he rates it as a 10/10 on the pain scale. It is generalized and associated with nausea and photophobia. He denies any history of head trauma or fever. He has a history of migraines, but he says this headache is worse than any he has had before. He has no other significant past medical history and takes no medications. His father has chronic kidney disease. Physical examination reveals: blood pressure 125/66 mm Hg, heart rate 80/min, and temperature 37.2°C (99.0°F). The patient is awake, alert, and oriented, but he is in severe distress due to the pain. On physical examination, his neck is stiff with flexion. Motor strength is 5/5 in all 4 limbs and sensation is intact. Fundoscopic examination results are within normal limits. What is the next best step in the management of this patient?

A. Acetazolamide
B. CT head (Correct Answer)
C. Lumbar puncture
D. Sumatriptan
E. Antibiotics

Explanation: ***Correct: CT head*** - A **sudden, severe headache** ("worst headache of my life") along with **nuchal rigidity** (stiff neck) is highly concerning for a **subarachnoid hemorrhage (SAH)**. - A non-contrast **CT head** is the immediate and most appropriate first diagnostic step to rule out acute intracranial bleeding. - CT scan has **high sensitivity (>95%) for SAH within the first 6 hours** and should always precede lumbar puncture to avoid risk of herniation. *Incorrect: Acetazolamide* - **Acetazolamide** is a carbonic anhydrase inhibitor used in conditions like **idiopathic intracranial hypertension** or to reduce cerebrospinal fluid production. - It is not indicated for the acute management of a sudden-onset severe headache with signs of meningeal irritation. *Incorrect: Lumbar puncture* - While a **lumbar puncture** (LP) can diagnose SAH if the CT is negative and suspicion remains high (xanthochromia in CSF), it should only be performed **after a CT scan** has ruled out mass effect or hydrocephalus. - Performing an LP before a CT scan in the presence of increased intracranial pressure could lead to **herniation**. *Incorrect: Sumatriptan* - **Sumatriptan** is a triptan medication used for the abortive treatment of **migraine headaches**. - This patient's headache is described as "worse than any he has had before" and is accompanied by nuchal rigidity, making it atypical for a routine migraine and warranting investigation for a secondary cause. *Incorrect: Antibiotics* - **Antibiotics** would be considered if there was strong evidence of bacterial meningitis (e.g., fever, rash, altered mental status, and CSF findings consistent with bacterial infection). - While nuchal rigidity is seen in meningitis, the absence of fever and the sudden onset suggest SAH as a primary concern, and antibiotics would not be the initial step without further investigation.

Question 118: A 70-year-old man with hypertension and type 2 diabetes mellitus is admitted to the hospital 8 hours after the onset of impaired speech and right-sided weakness. Two days after admission, he becomes confused and is difficult to arouse. His pulse is 64/min and blood pressure is 166/96 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 95%. Fundoscopic examination shows bilateral optic disc swelling. He is intubated and mechanically ventilated. A CT scan of the brain shows hypoattenuation in the territory of the left middle cerebral artery with surrounding edema and a 1-cm midline shift to the right. Which of the following interventions is most likely to result in a decrease in this patient's intracranial pressure?

A. Decrease the blood pressure
B. Increase the fraction of inhaled oxygen
C. Decrease the heart rate
D. Increase the respiratory rate (Correct Answer)
E. Increase the positive end-expiratory pressure

Explanation: ***Increase the respiratory rate*** - Increasing the respiratory rate (and thus minute ventilation) leads to a decrease in the partial pressure of **arterial carbon dioxide (PaCO2)**. - A lower PaCO2 causes **cerebral vasoconstriction**, which reduces cerebral blood volume and subsequently decreases intracranial pressure (ICP). *Decrease the blood pressure* - While uncontrolled hypertension is harmful, a drastic reduction in blood pressure could compromise **cerebral perfusion pressure (CPP)**, especially in the setting of elevated ICP. - Maintaining an adequate CPP is crucial to prevent further brain ischemia. *Increase the fraction of inhaled oxygen* - The patient's oxygen saturation is already 95% on room air, indicating adequate oxygenation. - Increasing the fraction of inspired oxygen (FiO2) would not directly reduce ICP and is not the primary intervention for this purpose, unless hypoxemia is present. *Decrease the heart rate* - The patient's pulse of 64/min is within a normal range; there's no indication that a high heart rate is contributing to elevated ICP. - Bradycardia as an isolated intervention would not effectively lower ICP. *Increase the positive end-expiratory pressure* - **Positive end-expiratory pressure (PEEP)** can increase intrathoracic pressure, which may impede venous outflow from the brain, potentially *increasing* ICP. - While PEEP is used for lung protection, high levels should be used cautiously in patients with elevated ICP.

Question 119: A 39-year-old woman with a history of migraine headaches is brought to the emergency room because of a severe, sudden-onset, throbbing headache and double vision for 1 hour. She says that she has been having frequent headaches and has not had her period in several months. Her blood pressure is 93/61 mm Hg. Visual field testing shows decreased visual acuity and bilateral temporal visual field defects. Which of the following is the most likely diagnosis?

A. Migraine with aura
B. Cluster headache
C. Pituitary apoplexy (Correct Answer)
D. Sheehan syndrome
E. Transient ischemic attack

Explanation: ***Pituitary apoplexy*** - The sudden onset of a **severe headache**, **double vision** (due to cranial nerve compression), **bitemporal hemianopsia** (loss of peripheral vision in both eyes due to optic chiasm compression), and **hypotension** in a patient with a history of headaches and amenorrhea (suggesting pituitary dysfunction) are classic signs of pituitary apoplexy. - Pituitary apoplexy is an acute hemorrhage or infarction of the pituitary gland, often occurring in the setting of a pre-existing pituitary adenoma, which can cause both mass effect symptoms and endocrine dysfunction (e.g., amenorrhea from prolactinoma or hypogonadism). *Migraine with aura* - While the patient has a history of migraines, the **sudden onset**, associated **double vision** (cranial nerve palsy), and **bitemporal visual field deficits** are not typical features of a standard migraine with aura, which usually presents with transient neurological symptoms followed by headache. - Migraines typically don't cause acute hormonal deficiencies leading to amenorrhea or the specific pattern of visual field loss seen here. *Cluster headache* - Cluster headaches are characterized by **severe, unilateral ocular or periorbital pain** accompanied by ipsilateral autonomic symptoms (e.g., ptosis, miosis, lacrimation, nasal congestion). - They do not typically present with double vision, bitemporal hemianopsia, or signs of pituitary dysfunction like hypotension and amenorrhea. *Sheehan syndrome* - Sheehan syndrome results from **ischemic necrosis of the pituitary gland** due to massive postpartum hemorrhage, leading to chronic hypopituitarism. - While it causes amenorrhea and other signs of hypopituitarism, it is a chronic condition and does not present with acute, sudden-onset severe headache, double vision, and bitemporal visual field defects like pituitary apoplexy. *Transient ischemic attack* - A TIA involves **transient neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia** without acute infarction. - While it can cause transient visual disturbances or weakness, it would not explain the severe headache, bitemporal visual field loss pattern, double vision due to cranial nerve compression, or the patient's history of amenorrhea related to pituitary dysfunction.

Question 120: A 67-year-old male presents to his primary care physician complaining of increased fatigue over the last year. He also says that his friends say he appears to be more pale. His past medical history is significant for 10 years of arthritis. Physical exam reveals conjunctival pallor. Based on clinical suspicion RBC tests are ordered showing a mean corpuscular volume (MCV) of 75 fl (normal 80-100 fl) and a peripheral blood smear is obtained and found to be normal. Iron studies show a serum iron of 30 micromolar (normal range 50-170) and a serum ferritin of 300 micrograms/liter (normal range 15-200). What is the most likely diagnosis in this patient?

A. Lead poisoning anemia
B. Alpha-thalassemia
C. Iron deficiency anemia
D. Anemia of chronic disease (Correct Answer)
E. Beta-thalassemia

Explanation: ***Anemia of chronic disease*** - This patient's **microcytic anemia** (MCV 75 fL) with **chronic inflammation** (10 years of arthritis), **low serum iron** (30 µmol), and **elevated ferritin** (300 µg/L) is classic for anemia of chronic disease. - The **elevated ferritin** is the key finding that distinguishes this from iron deficiency anemia. In anemia of chronic disease, inflammatory cytokines stimulate **hepcidin production**, which blocks iron release from macrophages and intestinal absorption, creating a functional iron deficiency despite adequate body iron stores (reflected by high ferritin). - Chronic inflammatory conditions like rheumatoid arthritis commonly cause this type of anemia through IL-6 mediated hepcidin upregulation. *Iron deficiency anemia* - Although iron deficiency causes **microcytic anemia** and **low serum iron**, it is characterized by **low ferritin** (typically <15 µg/L), not elevated ferritin as seen in this patient. - The **elevated ferritin (300 µg/L)** definitively rules out iron deficiency anemia, as ferritin levels reflect body iron stores and would be depleted in true iron deficiency. - Both conditions can present with fatigue and pallor, but the iron studies clearly differentiate them. *Lead poisoning anemia* - Lead poisoning causes **microcytic anemia** through inhibition of heme synthesis, but the **peripheral blood smear would show basophilic stippling**, which is specifically noted as normal in this case. - There is no history of occupational exposure, old housing, or other risk factors for lead poisoning. - Iron studies in lead poisoning typically show elevated or normal ferritin with increased iron stores, not the specific pattern seen in anemia of chronic disease. *Alpha-thalassemia* - Alpha-thalassemia causes **microcytic anemia** but is a **hereditary hemoglobinopathy** that typically presents earlier in life with lifelong mild anemia. - New-onset symptoms at age 67 with progressive fatigue over one year argues against a congenital disorder. - Iron studies in thalassemia show **normal or elevated ferritin** and normal-to-high serum iron, not the low serum iron seen here due to inflammation. *Beta-thalassemia* - Like alpha-thalassemia, beta-thalassemia is a **genetic disorder** typically diagnosed in childhood or early adulthood, making new diagnosis at age 67 unlikely. - Iron studies would show **normal or elevated iron stores** (often with secondary hemochromatosis in transfusion-dependent cases), not the pattern of functional iron deficiency seen with chronic inflammation. - The presence of chronic arthritis and the specific iron study pattern strongly favor an acquired inflammatory anemia rather than a hereditary hemoglobinopathy.

Question 121: A 55-year-old patient is brought to the emergency department because he has had sharp chest pain for the past 3 hours. He reports that he can only take shallow breaths because deep inspiration worsens the pain. He also reports that the pain increases with coughing. Two weeks ago, he underwent cardiac catheterization for an acute myocardial infarction. Current medications include aspirin, ticagrelor, atorvastatin, metoprolol, and lisinopril. His temperature is 38.54°C (101.1°F), pulse is 55/min, respirations are 23/min, and blood pressure is 125/75 mm Hg. Cardiac examination shows a high-pitched scratching sound best heard when the patient is sitting upright and during expiration. An ECG shows diffuse ST elevations and ST depression in aVR and V1. An echocardiography shows no abnormalities. Which of the following is the most appropriate treatment in this patient?

A. Perform pericardiocentesis
B. Increase aspirin dose (Correct Answer)
C. Administer nitroglycerin
D. Start heparin infusion
E. Perform CT angiography

Explanation: ***Increase aspirin dose*** - This patient presents with symptoms and signs consistent with **post-myocardial infarction pericarditis**. The classic treatment involves high-dose aspirin (750-1000 mg three times daily). - The patient's cardiac medications, including current low-dose aspirin (for antiplatelet effect), do not adequately address the inflammation associated with pericarditis. Increasing the dose provides the necessary anti-inflammatory effect. - This occurs within days to weeks after MI due to transmural myocardial inflammation. NSAIDs are often avoided post-MI due to concerns about impaired ventricular healing, making high-dose aspirin the preferred anti-inflammatory agent. *Perform pericardiocentesis* - **Pericardiocentesis** is indicated for **cardiac tamponade** or large, symptomatic pericardial effusions causing hemodynamic compromise. - The echocardiography in this patient shows no abnormalities, ruling out significant pericardial effusion or tamponade. *Administer nitroglycerin* - **Nitroglycerin** is used to relieve **angina** by causing vasodilation and reducing myocardial oxygen demand. - The patient's chest pain, diffuse ST elevations, and friction rub are indicative of **pericarditis**, not ongoing myocardial ischemia, making nitroglycerin inappropriate. *Start heparin infusion* - **Heparin** is an anticoagulant used to prevent thrombus formation, often in conditions like **deep vein thrombosis**, **pulmonary embolism**, or in acute coronary syndromes to prevent clot propagation. - There is no indication of active thrombus formation or worsening acute coronary syndrome that would warrant heparin infusion. Moreover, anticoagulation is **contraindicated in pericarditis** as it increases the risk of hemorrhagic pericardial effusion. *Perform CT angiography* - **CT angiography** is primarily used to diagnose **pulmonary embolism** or **aortic dissection**. - The clinical presentation, including the diffuse ST elevations, pericardial friction rub, and recent MI, strongly points to pericarditis, making CT angiography an unnecessary investigation in this context.

Question 122: A 30-year-old man with Down syndrome is brought to the physician by his mother for the evaluation of fatigue. Physical examination shows bluish-colored lips and digital clubbing that were not present at his most recent examination. Right heart catheterization shows a right atrial pressure of 32 mmHg. Which of the following is most likely involved in the pathogenesis of this patient's current condition?

A. Aortic valve regurgitation
B. Reversible pulmonary hypertension
C. Reversed intracardiac shunting (Correct Answer)
D. Asymmetric septal hypertrophy
E. Right ventricular hypertrophy

Explanation: ***Reversed intracardiac shunting*** - The patient's signs of **cyanosis** (bluish lips) and **digital clubbing**, in the context of Down syndrome, indicate **Eisenmenger syndrome** - a reversal of an intracardiac shunt from left-to-right to right-to-left. - In Down syndrome, common congenital heart defects like **atrioventricular septal defect (AVSD)**, **ventricular septal defect (VSD)**, or **atrial septal defect (ASD)** initially cause left-to-right shunting with chronic pulmonary overcirculation. - This leads to **irreversible pulmonary vascular remodeling** and **pulmonary hypertension**, eventually causing the shunt to reverse (right-to-left), resulting in **deoxygenated blood bypassing the lungs** and causing cyanosis and clubbing. - The markedly elevated **right atrial pressure (32 mmHg)** reflects the severe pulmonary hypertension and right heart strain. *Aortic valve regurgitation* - **Aortic valve regurgitation** primarily causes **left ventricular volume overload** and symptoms of left-sided heart failure (e.g., dyspnea on exertion, bounding pulses), not typically cyanosis or digital clubbing. - While chronic severe aortic regurgitation can eventually lead to pulmonary hypertension, it would not cause right-to-left shunting or the degree of right atrial pressure elevation seen here. *Reversible pulmonary hypertension* - The presence of **cyanosis** and **digital clubbing** indicates **Eisenmenger syndrome** with **irreversible** pulmonary vascular disease where the shunt has permanently reversed from left-to-right to right-to-left. - **Reversible pulmonary hypertension** would not yet have progressed to such prominent signs of chronic hypoxemia like clubbing, and interventions could still reduce pulmonary pressures before shunt reversal occurs. *Asymmetric septal hypertrophy* - **Asymmetric septal hypertrophy** is characteristic of **hypertrophic cardiomyopathy**, which causes **left ventricular outflow tract obstruction** and symptoms like syncope, chest pain, and dyspnea. - It does not explain the development of cyanosis, digital clubbing, or the markedly elevated right atrial pressures seen with reversed intracardiac shunting. *Right ventricular hypertrophy* - While **right ventricular hypertrophy** is a consequence of chronic pulmonary hypertension and elevated right atrial pressure, it is a **compensatory structural change** rather than the primary pathogenetic mechanism causing cyanosis. - The underlying cause of the cyanotic condition is the **reversed intracardiac shunt** (right-to-left) due to severe pulmonary hypertension overwhelming the left-sided pressures.

Question 123: A 35-year-old woman presents to the ER with shortness of breath, cough, and severe lower limb enlargement. The dyspnea was of sudden onset, started a week ago, and increased with exercise but did not disappear with rest. Her cough was dry, persistent, and non-productive. She has a family history of maternal hypertension. Her vital signs include heart rate 106/min, respiratory rate 28/min, and blood pressure 140/90 mm Hg. On physical examination, thoracic expansion was diminished on the right side with rhonchi and crackles on the lower two-thirds of both sides, with left predominance. A systolic murmur was heard on the tricuspid foci, which increased in intensity with inspiration. There was jugular engorgement when the bed was placed at 50°. Palpation of the abdomen was painful on the right hypochondrium, with hepatomegaly 4 cm below the lower costal edge. Hepatojugular reflux was present. Soft, painless, pitting edema was present in both lower limbs up until the middle third of both legs. Lung computed tomography (CT) and transthoracic echocardiogram were performed and detected right heart failure and severe pulmonary fibrosis. What is the most likely diagnosis?

A. Left-sided heart failure
B. Liver disease
C. Cor pulmonale (Correct Answer)
D. Budd-Chiari syndrome
E. Coronary artery disease

Explanation: ***Cor pulmonale*** - The combination of **shortness of breath**, **dependent edema**, **jugular venous distension**, **hepatomegaly** with **hepatojugular reflux**, and a **right-sided systolic murmur** that increases with inspiration are all classic signs of **right-sided heart failure**. - The presence of **severe pulmonary fibrosis** identified on CT supports the diagnosis, as chronic lung disease is a common cause of **pulmonary hypertension** leading to **right ventricular hypertrophy** and failure, known as cor pulmonale. *Left-sided heart failure* - While **dyspnea** and **cough** are present, there is a clear predominance of signs pointing to **right-sided heart failure**, such as pronounced **peripheral edema**, **JVD**, and **hepatomegaly**. - **Left-sided heart failure** typically presents with pulmonary congestion (e.g., pulmonary edema, Orthopnea, paroxysmal nocturnal dyspnea) and would not explain the prominent signs of fluid overload in the systemic circulation. *Liver disease* - **Hepatomegaly** and **edema** can be present in liver disease, but the patient also exhibits significant **dyspnea**, **cough**, and **right-sided cardiac findings** (e.g., tricuspid murmur, JVD, right-sided heart failure on echo). - The primary symptoms and diagnostic findings point towards a **cardiopulmonary etiology** rather than primary liver pathology. *Budd-Chiari syndrome* - This syndrome involves **hepatic venous outflow obstruction**, leading to **hepatomegaly**, **abdominal pain**, and **ascites**. While **hepatomegaly** and abdominal pain are present, the overall clinical picture with **severe pulmonary fibrosis** and clear signs of **right heart failure** is more consistent with cor pulmonale. - **Budd-Chiari syndrome** typically does not present with primary respiratory symptoms or right-sided heart murmurs secondary to pulmonary issues. *Coronary artery disease* - **Coronary artery disease** primarily affects the left ventricle and would lead to symptoms of **left-sided heart failure** (e.g., angina, shortness of breath on exertion due to pulmonary congestion). - The patient's presentation is overwhelmingly indicative of **right-sided heart failure**, with pulmonary fibrosis as the likely underlying cause, rather than ischemic heart disease.

Question 124: A 33-year-old man presents to the emergency department with dizziness. He states he has experienced a sustained sense of disequilibrium for the past 2 days. He feels that the floor is unstable/moving. The patient is otherwise healthy and does not have any other medical diagnoses. The patient is currently taking vitamin C as multiple family members are currently ill and he does not want to get sick. His temperature is 98.1°F (36.7°C), blood pressure is 120/83 mmHg, pulse is 73/min, respirations are 16/min, and oxygen saturation is 98% on room air. Physical exam is notable for a horizontal nystagmus. The Dix-Hallpike maneuver does not provoke symptoms and examination of the patient’s cranial nerves is unremarkable. Which of the following is the most likely diagnosis?

A. Vertebrobasilar stroke
B. Benign paroxysmal positional vertigo
C. Labyrinthitis
D. Meniere disease
E. Vestibular neuritis (Correct Answer)

Explanation: ***Vestibular neuritis*** - The patient's **acute onset of sustained dizziness, horizontal nystagmus**, and otherwise healthy status points to a peripheral vestibular cause, with **vestibular neuritis** being highly likely in the absence of hearing loss. - The **normal Dix-Hallpike maneuver** and lack of positional vertigo rule out BPPV, while the absence of other neurological deficits argues against a central cause like stroke. *Vertebrobasilar stroke* - A vertebrobasilar stroke would typically present with additional **neurological deficits**, such as cranial nerve palsies, ataxia, or motor weakness, which are absent here. - While a stroke can cause dizziness, the isolated **horizontal nystagmus** without other "HINTS" exam findings (Head Impulse, Nystagmus, Test of Skew) suggesting a central lesion makes this less likely. *Benign paroxysmal positional vertigo* - This condition is characterized by brief episodes of vertigo triggered by specific **head movements**, and would typically be provoked by a **Dix-Hallpike maneuver**. - The patient's **sustained sense of disequilibrium** for two days, rather than brief positional vertigo, makes BPPV unlikely. *Labyrinthitis* - Labyrinthitis is an inflammation of the inner ear that causes **dizziness and hearing loss**, which is not mentioned in this case. - While it shares some symptoms with vestibular neuritis (sustained dizziness), the **absence of hearing symptoms** helps differentiate it. *Meniere disease* - Meniere disease presents with a classic triad of **vertigo, tinnitus, and fluctuating hearing loss**, along with aural fullness. - The patient's symptoms do not include tinnitus, hearing changes, or aural fullness, making Meniere disease an improbable diagnosis.

Question 125: A 35-year-old woman comes to the physician because of fatigue and a 9-kg (20-lb) weight gain over the past 12 months. She also has irregular menstrual cycles and difficulty sleeping. Menses occur at irregular 35- to 50-day intervals and last 3–7 days. Menarche was at age of 13 years and her last menstrual period was 4 weeks ago. She has 1-year history of hypertension treated with hydrochlorothiazide. She drinks a glass of wine daily. She is 163 cm (5 ft 4 in) tall and weighs 85 kg (187 lb); BMI is 32 kg/m2. Her temperature is 37°C (98.6°F), pulse is 82/min, respirations are 16/min, and blood pressure is 125/86 mm Hg. Examination shows acne on the face and hair on the chin and around the umbilicus. The face has a rounded shape and is reddened. There are several smaller bruises on both forearms. This patient is most likely to have which of the following findings?

A. Decreased bone mineral density (Correct Answer)
B. Discoloration of the corneal margin
C. Decreased serum sodium
D. Increased serum erythropoietin
E. Enlarged ovaries with multiple follicles

Explanation: ***Decreased bone mineral density*** - The patient's symptoms, including **weight gain, irregular menses, acne, hirsutism, rounded/reddened face** (**moon facies/plethora**), and **easy bruising**, are highly suggestive of **Cushing's syndrome**. - **Excess glucocorticoids** in Cushing's syndrome lead to increased bone resorption and decreased bone formation, resulting in **osteoporosis** and **decreased bone mineral density**. *Discoloration of the corneal margin* - **Corneal arcus** (discoloration of the corneal margin) is associated with **hyperlipidemia** in younger individuals or can be a benign age-related finding. It is not a characteristic feature of Cushing's syndrome. - While patients with Cushing's can have dyslipidemia, corneal arcus is a less direct or common finding compared to bone density changes. *Decreased serum sodium* - **Cushing's syndrome** typically causes **fluid retention** and can lead to **mild hypernatremia** or normal sodium levels due to the **mineralocorticoid effects of excess cortisol**. - **Hyponatremia** is not a characteristic electrolyte abnormality associated with Cushing's syndrome. *Increased serum erythropoietin* - **Increased erythropoietin** is seen in conditions associated with **hypoxemia** (e.g., chronic lung disease, high altitude) or in some **renal cell carcinomas**. - While patients with Cushing's can have **polycythemia** (increased red blood cell mass), it is due to direct effects of glucocorticoids on erythropoiesis, not primarily an increase in erythropoietin production. *Enlarged ovaries with multiple follicles* - **Enlarged ovaries with multiple follicles** are characteristic of **Polycystic Ovary Syndrome (PCOS)**, which also presents with **oligomenorrhea, hirsutism, and obesity**. - However, the presence of **moon facies, plethora, easy bruising, and uncontrolled hypertension despite medication** are more specific to Cushing's syndrome and less typical for PCOS alone.

Question 126: A 25-year-old woman comes to the physician because of a 4-month history of anxiety and weight loss. She also reports an inability to tolerate heat and intermittent heart racing for 2 months. She appears anxious. Her pulse is 108/min and blood pressure is 145/87 mm Hg. Examination shows a fine tremor of her outstretched hands. After confirmation of the diagnosis, the patient is scheduled for radioactive iodine ablation. At a follow-up visit 2 months after the procedure, she reports improved symptoms but new-onset double vision. Examination shows conjunctival injections, proptosis, and a lid lag. Slit-lamp examination shows mild corneal ulcerations. The patient is given an additional medication that improves her diplopia and proptosis. Which of the following mechanisms is most likely responsible for the improvement in this patient's ocular symptoms?

A. Replacement of thyroid hormones
B. Decreased production of proinflammatory cytokines (Correct Answer)
C. Decreased uptake of iodine
D. Elimination of excess fluid
E. Inhibition of iodide oxidation

Explanation: ***Decreased production of proinflammatory cytokines*** - The patient's initial symptoms are consistent with **hyperthyroidism due to Graves' disease**, which is an autoimmune condition. The new-onset double vision, conjunctival injection, proptosis, and lid lag suggest **Graves' ophthalmopathy**. - **Graves' ophthalmopathy** is an autoimmune process characterized by **inflammation, fibrosis, and edema of the extraocular muscles and orbital soft tissues**. Medications like glucocorticoids, which reduce proinflammatory cytokines, are used to manage the inflammatory component of Graves' ophthalmopathy and improve symptoms like diplopia and proptosis. *Replacement of thyroid hormones* - While thyroid hormone replacement is necessary after radioactive iodine ablation to treat the induced hypothyroidism, it does not directly treat or improve the underlying inflammatory process of **Graves' ophthalmopathy**. - Replacing thyroid hormones would address systemic symptoms of hypothyroidism but would not resolve the orbital inflammation and its ophthalmic manifestations. *Decreased uptake of iodine* - Radioactive iodine ablation works by destroying thyroid cells, thereby **decreasing the uptake of iodine** by the thyroid gland and reducing thyroid hormone production. - While this addresses the hyperthyroidism, it does not directly manage the autoimmune inflammatory process of **Graves' ophthalmopathy**, which can even worsen after radioactive iodine ablation in some cases. *Elimination of excess fluid* - Although edema is a component of orbital involvement in Graves' ophthalmopathy, the primary treatment for improving diplopia and proptosis focuses on **reducing inflammation and fibrosis**, not merely eliminating excess fluid. - Diuretics are not the primary treatment for the ocular symptoms of Graves' ophthalmopathy, which are driven by an autoimmune inflammatory response. *Inhibition of iodide oxidation* - Inhibition of iodide oxidation is the mechanism of **antithyroid drugs** like methimazole and propylthiouracil, which are used to treat hyperthyroidism by reducing thyroid hormone synthesis. - This mechanism treats hyperthyroidism but does not address the autoimmune inflammation responsible for **Graves' ophthalmopathy** once it has developed, especially post-ablation.

Question 127: A 49-year-old man comes to the physician because of increasing difficulty achieving an erection for 6 months. During this period, he has had to reduce his hours as a construction worker because of pain in his lower back and thighs and a progressive lower limb weakness when walking for longer distances. His pain resolves after resting for a few minutes, but it recurs when he returns to work. He also reports that his pain is improved by standing still. He is sexually active with 4 female partners and uses condoms irregularly. His father has coronary artery disease and his mother died of a ruptured intracranial aneurysm at the age of 53 years. He has smoked one pack of cigarettes daily for 35 years. He has recently taken sildenafil, given to him by a friend, with no improvement in his symptoms. His only other medication is ibuprofen as needed for back pain. His last visit to a physician was 25 years ago. He is 172.5 cm (5 ft 8 in) tall and weighs 102 kg (225 lb); BMI is 34.2 kg/m2. His temperature is 36.9°C (98.4°F), pulse is 76/min, and blood pressure is 169/98 mm Hg. A complete blood count and serum concentrations of electrolytes, urea nitrogen, and creatinine are within the reference ranges. His hemoglobin A1c is 6.2%. Which of the following is the most likely finding on physical examination?

A. Internuclear ophthalmoplegia
B. Decreased bilateral femoral pulses (Correct Answer)
C. Decreased anal tone
D. Jugular venous distention
E. Papular rash over the palms and soles

Explanation: ***Decreased bilateral femoral pulses*** - This patient's symptoms of **erectile dysfunction**, **claudication**-like leg pain (worsens with activity, improves with rest), and **lower limb weakness** are highly suggestive of **peripheral artery disease (PAD)**, specifically **aortoiliac occlusion** (Leriche syndrome). The absence of femoral pulses would be a key physical sign reflecting the reduced blood flow. - Risk factors like **smoking**, **obesity**, **hypertension**, and **elevated HbA1c** (prediabetes) further support a vascular etiology. *Internuclear ophthalmoplegia* - This condition is characterized by impaired adduction of one eye during conjugate gaze with nystagmus of the abducting eye, typically caused by a lesion in the **medial longitudinal fasciculus**. - It is often associated with **multiple sclerosis** or brainstem stroke and does not align with the patient's presenting symptoms of claudication and erectile dysfunction. *Decreased anal tone* - **Decreased anal tone** usually indicates a lesion affecting the **sacral spinal cord** or cauda equina, potentially leading to bowel/bladder dysfunction, saddle anesthesia, and lower limb weakness. - While the patient has lower limb weakness and back pain, the episodic nature of the leg pain related to exertion and resolution with rest, along with erectile dysfunction, points more strongly to a vascular issue rather than a neurological one causing decreased anal tone. *Jugular venous distention* - **Jugular venous distention (JVD)** is a sign of **elevated central venous pressure**, primarily associated with **right-sided heart failure**, fluid overload, or other conditions impairing venous return to the heart. - The patient's symptoms are localized to lower limb ischemia and erectile dysfunction, not systemic fluid retention or heart failure. *Papular rash over the palms and soles* - A **papular rash over the palms and soles** is a classic sign of **secondary syphilis**. - While the patient reports irregular condom use and multiple partners, this rash is a dermatological finding not directly related to or explaining his primary symptoms of erectile dysfunction and exertional leg pain/weakness, which are indicative of vascular insufficiency.

Question 128: A 68-year-old man comes to the physician in July for a routine health maintenance examination. He is a retired teacher and lives in a retirement community. He has hypercholesterolemia, hypertension, and osteoarthritis of the left knee. Last year, he was diagnosed with chronic lymphocytic leukemia. A colonoscopy 8 years ago was normal. The patient had a normal digital examination and a normal prostate specific antigen level 8 months ago. The patient has never smoked and does not drink alcohol. Current medications include aspirin, lisinopril, simvastatin, chlorambucil, rituximab, and a multivitamin. His last immunizations were at a health maintenance examination 7 years ago. His temperature is 37°C (98.6°F), pulse is 82/min, respirations are 14/min, and blood pressure is 133/85 mm Hg. Examination shows a grade 2/6 systolic ejection murmur along the upper right sternal border and painless cervical lymphadenopathy. Which of the following health maintenance recommendations is most appropriate at this visit?

A. Varicella vaccine
B. Pneumococcal conjugate vaccine 13
C. Meningococcal conjugate vaccine
D. Abdominal ultrasound
E. Influenza vaccine (Correct Answer)

Explanation: ***Correct: Influenza vaccine*** - **Annual influenza vaccination is critical** for immunocompromised patients with conditions like CLL, as they are at high risk for severe influenza complications - **July timing is ideal** - The CDC recommends vaccination as soon as vaccine becomes available (typically July-August), especially for high-risk patients, to ensure protection before flu season peaks - This patient **hasn't received immunizations in 7 years**, making him significantly overdue for annual influenza vaccination - The **inactivated influenza vaccine** (not live) is safe and recommended for immunocompromised individuals *Incorrect: Pneumococcal conjugate vaccine 13* - While pneumococcal vaccination is important for CLL patients, **PCV13 is no longer routinely recommended** as of 2022 ACIP guidelines - Current recommendations favor **PCV20 or PCV15 followed by PPSV23**, not PCV13 - Even with updated vaccines, pneumococcal vaccination timing is less urgent than annual influenza vaccination for an immunocompromised patient entering flu season *Incorrect: Meningococcal conjugate vaccine* - Meningococcal vaccine is primarily recommended for immunocompromised individuals with **specific conditions** like asplenia, complement deficiencies, or HIV - CLL alone does not constitute a routine indication for meningococcal vaccination - This is not a standard health maintenance recommendation for CLL patients *Incorrect: Varicella vaccine* - The varicella vaccine is a **live attenuated vaccine**, which is **absolutely contraindicated** in immunocompromised patients receiving chemotherapy like chlorambucil and rituximab - Live vaccines pose a risk of disseminated vaccine-strain infection in immunosuppressed individuals - This would be dangerous for this patient with CLL on active treatment *Incorrect: Abdominal ultrasound* - There are no clinical findings, symptoms, or risk factors presented that would warrant routine abdominal ultrasound screening - His colonoscopy 8 years ago was normal, and he has no abdominal complaints - This is not a standard health maintenance recommendation for this clinical scenario

Question 129: A 16-year-old boy comes to the physician for a routine health maintenance examination. He feels well. He has no history of serious illness. He is at the 60th percentile for height and weight. Vital signs are within normal limits. The lungs are clear to auscultation. A grade 3/6 ejection systolic murmur is heard along the lower left sternal border. The murmur decreases in intensity on rapid squatting and increases in intensity when he performs the Valsalva maneuver. This patient is at increased risk for which of the following complications?

A. Sudden cardiac death (Correct Answer)
B. Pulmonary apoplexy
C. Infective endocarditis
D. Cerebral aneurysm
E. Angiodysplasia

Explanation: ***Sudden cardiac death*** - The murmur characteristics (decreases with squatting, increases with Valsalva) are classic for **hypertrophic obstructive cardiomyopathy (HOCM)**, which is a leading cause of **sudden cardiac death** in young athletes. - HOCM causes **left ventricular outflow tract obstruction** due to asymmetric septal hypertrophy and systolic anterior motion of the mitral valve, predisposing to fatal arrhythmias. *Pulmonary apoplexy* - This refers to severe **pulmonary hemorrhage**, which is not associated with the cardiac murmur described. - It is typically seen in conditions like **Goodpasture's syndrome** or severe vasculitis. *Infective endocarditis* - While structural heart disease can increase the risk, the primary concern with HOCM is **sudden cardiac death** due to arrhythmia, not infective endocarditis, which generally requires specific predisposing factors like prosthetic valves or prolonged IV access. - The murmur itself is due to obstruction, not typically indicative of an infection risk without other signs. *Cerebral aneurysm* - There is no direct association between the murmur characteristics described and an increased risk of **cerebral aneurysms**. - Cerebral aneurysms are often linked to conditions like **polycystic kidney disease** or specific connective tissue disorders. *Angiodysplasia* - **Angiodysplasia** involves vascular malformations in the GI tract leading to bleeding, which is unrelated to the cardiovascular findings in this patient. - It is often seen in older individuals or those with **aortic stenosis**, but not typically HOCM.

Question 130: A 73-year-old man presents to your clinic for a routine checkup. His medical history is notable for a previous myocardial infarction. He states that he has not seen a doctor in "many years". He has no complaints. When you auscultate over the cardiac apex with the bell of your stethoscope, you notice an additional sound immediately preceding S1. This extra heart sound is most likely indicative of which of the following processes?

A. Decreased left ventricular compliance (Correct Answer)
B. Increased left ventricular compliance
C. Increased pulmonary compliance
D. Decreased left ventricular filling volume
E. Increased left ventricular filling volume

Explanation: ***Decreased left ventricular compliance*** - An additional sound immediately preceding S1 suggests a **fourth heart sound (S4)**, which occurs during **atrial contraction** against a stiff, non-compliant ventricle. - A myocardial infarction can lead to left ventricular hypertrophy and **fibrosis**, causing **decreased left ventricular compliance**. *Increased left ventricular compliance* - **Increased ventricular compliance** would allow for easier filling and would not generate an audible S4. - This condition is typically seen in dilated ventricles, which accommodate larger volumes **without significant pressure increases**. *Increased pulmonary compliance* - **Pulmonary compliance** refers to the lungs' ability to stretch and expand, and it is unrelated to an additional heart sound preceding S1. - This concept describes the **elastic properties of lung tissue** and has no direct bearing on cardiac auscultation in this context. *Decreased left ventricular filling volume* - A **decreased left ventricular filling volume** might reduce the intensity of heart sounds but would not, in itself, cause an S4 before S1. - S4 is related to the **atrial kick** into a resistant ventricle, not the overall volume available for filling. *Increased left ventricular filling volume* - While increased filling volume can occur in conditions like **valvular regurgitation**, it does not directly lead to an S4. - An S4 is specifically due to a forceful atrial contraction against a **non-compliant ventricle**, regardless of the absolute filling volume.

Question 131: A 32-year-old woman comes to the physician because of a 3-month history of recurrent headaches and nausea. The headaches occur a few times a month and alternately affect the right or left side. The headaches are exacerbated by loud sounds or bright light. She is in graduate school and has been under a lot of stress recently. She does not smoke or drink alcohol but does drink 2–3 cups of coffee daily. Her only medication is an oral contraceptive. Physical examination shows no abnormalities; visual acuity is 20/20. Which of the following is the most likely diagnosis?

A. Pseudotumor cerebri
B. Tension headache
C. Migraine headache (Correct Answer)
D. Trigeminal neuralgia
E. Cluster headache

Explanation: ***Migraine headache*** - The patient's symptoms of **recurrent, unilateral headaches** with associated **nausea, photophobia, and phonophobia** are classic features of migraine. - Migraines are often triggered by **stress** and can be exacerbated by **oral contraceptives** due to hormonal influences. *Pseudotumor cerebri* - While it can cause headaches and nausea, it is typically associated with **papilledema** and visual disturbances, which are absent in this case. - The headaches in pseudotumor cerebri are usually **constant and diffuse**, not unilateral and episodic. *Tension headache* - Characterized by a **band-like pressure** or tightness around the head and is not usually associated with nausea, photophobia, or phonophobia. - They are typically **bilateral** and do not have the pulsating quality often seen in migraines. *Trigeminal neuralgia* - Presents as **severe, sudden, shock-like pain** in the distribution of the trigeminal nerve, often triggered by touching the face, chewing, or speaking. - It does not involve recurrent generalized headaches, nausea, or light sensitivity. *Cluster headache* - Although very severe and unilateral, cluster headaches have distinct features such as **lacrimation, conjunctival injection, nasal congestion**, or ptosis on the affected side. - They tend to occur in **clusters** with periods of remission and pain is typically localized around the eye or temple.

Question 132: A 35-year-old man presents to his primary care provider complaining of dull pain in his scrotum and lower back pain over the last 3 months. He is a computer engineer working in a private IT company. He had an uncomplicated appendectomy at the age of 22 years, but is otherwise without a significant past medical history. He smokes 2–3 cigarettes on weekends and drinks alcohol occasionally. He is sexually active with his wife. Today his heart rate is 90/min and blood pressure is 132/76 mm Hg. Scrotal examination reveals a firm, small and painless nodule on the left testicle. Scrotal ultrasound reveals a 0.9 x 0.5 cm irregular, non-cystic mass. He undergoes a left radical orchiectomy and histopathological examination reveals uniform tumor cells with abundant clear cytoplasm and distinct cell borders, consistent with a seminoma. Subsequent PET/CT scans show supraclavicular and para-aortic lymph node involvement. Which is the next and most appropriate step in the management of this patient?

A. Immunotherapy
B. Radiotherapy
C. Chemotherapy (Correct Answer)
D. Observation
E. Surgery

Explanation: ***Chemotherapy*** - The patient has **metastatic seminoma** (supraclavicular and para-aortic lymph node involvement) following orchiectomy, which requires **systemic treatment**. - **Chemotherapy** is the primary treatment for metastatic seminoma due to its high cure rates, especially with regimens like BEP (bleomycin, etoposide, cisplatin). *Immunotherapy* - **Immunotherapy** is generally not a first-line treatment for seminoma and is primarily used in refractory or metastatic cases of other solid tumors, not typically germ cell tumors. - While research is ongoing, current guidelines do not recommend immunotherapy as the initial treatment for this stage of seminoma. *Radiotherapy* - **Radiotherapy** can be effective for localized seminoma involving lymph nodes, but it is typically reserved for local control and not for widespread metastatic disease involving both supraclavicular and para-aortic nodes. - Systemic disease with involvement of distant lymph nodes (like supraclavicular) necessitates a systemic approach like chemotherapy rather than localized radiation. *Observation* - **Observation** is only appropriate for Stage I seminoma following orchiectomy, where there is no evidence of metastatic spread. - In this case, the patient has clear evidence of **metastasis** to supraclavicular and para-aortic lymph nodes, making observation an inappropriate and dangerous choice. *Surgery* - **Surgery** (radical orchiectomy) has already been performed to remove the primary tumor. - While surgical resection of residual masses after chemotherapy may be considered in some cases, it is not the primary next step for initial management of widespread lymph node metastases.

Question 133: A 72-year-old woman comes to the physician because of a 1-month history of progressive fatigue and shortness of breath. Physical examination shows generalized pallor. Laboratory studies show: Hemoglobin 5.8 g/dL Hematocrit 17% Mean corpuscular volume 86 μm3 Leukocyte count 6,200/mm3 with a normal differential Platelet count 240,000/mm3 A bone marrow aspirate shows an absence of erythroid precursor cells. This patient’s condition is most likely associated with which of the following?

A. Cold agglutinins
B. Thymic tumor (Correct Answer)
C. HbF persistence
D. Parvovirus B19 infection
E. Lead poisoning

Explanation: ***Thymic tumor*** - The patient's **normocytic anemia** (Hb 5.8 g/dL, Hct 17%, MCV 86 μm3) and the **absence of erythroid precursor cells** in the bone marrow aspirate are characteristic findings of **pure red cell aplasia (PRCA)**. - **Pure red cell aplasia (PRCA)** in adults is frequently associated with an underlying **thymoma**, with up to 50% of adult PRCA cases linked to this condition. *Cold agglutinins* - Cold agglutinins are characteristic of **cold agglutinin disease**, an **autoimmune hemolytic anemia**. - This condition typically presents with signs of **hemolysis** (e.g., elevated reticulocytes, bilirubin, LDH) and would not show an **absence of erythroid precursor cells** in the bone marrow. *HbF persistence* - **Hereditary persistence of fetal hemoglobin (HPFH)** is a benign condition where **HbF** production continues into adulthood. - It is not associated with anemia or bone marrow aplasia and usually results in normal hematological parameters, except for elevated HbF. *Parvovirus B19 infection* - **Parvovirus B19** can cause transient **aplastic crisis** by infecting and destroying erythroid precursors. - While it causes PRCA-like features, it is typically an acute self-limiting condition, particularly in immunocompetent individuals, and is less likely to be an ongoing chronic cause in a 72-year-old without other risk factors for chronic infection or immunodeficiency. *Lead poisoning* - **Lead poisoning** typically causes a **microcytic hypochromic anemia** with **basophilic stippling** on peripheral blood smear. - It primarily interferes with **heme synthesis** and would not cause a complete absence of erythroid precursor cells in the bone marrow.

Question 134: A 51-year-old woman comes to the physician because of fatigue and progressive pain and stiffness in her hands for 3 months. She used to play tennis but stopped 1 month ago because of difficulties holding the racket and her skin becoming “very sensitive to sunlight.” Her last menstrual period was 1 year ago. She has diabetes mellitus controlled with insulin. She does not smoke or drink alcohol. Vital signs are within normal limits. The patient appears tanned. The second and third metacarpophalangeal joints of both hands are tender to palpation and range of motion is limited. Which of the following is the most appropriate next step in diagnosis?

A. Synovial fluid analysis
B. Testing for parvovirus B19 antibodies
C. Testing for rheumatoid factors
D. Testing for anti-nuclear antibodies
E. Iron studies (Correct Answer)

Explanation: ***Iron studies*** - The patient's presentation with **"tanned" appearance**, **diabetes mellitus**, and **arthropathy specifically involving the 2nd and 3rd metacarpophalangeal joints** is the **classic triad of hemochromatosis** (hereditary iron overload). - The bronze/tan skin pigmentation results from **iron deposition in the skin**, while diabetes occurs from **iron deposition in the pancreas** ("bronze diabetes"). - **MCP 2 and 3 joint involvement** is pathognomonic for hemochromatosis arthropathy, distinguishing it from other arthritides. - **Iron studies** (serum ferritin and transferrin saturation) are the most appropriate initial diagnostic tests, typically showing **elevated ferritin (>200 ng/mL in women) and transferrin saturation >45%**. - Early diagnosis is crucial as hemochromatosis is treatable with phlebotomy, preventing progression to cirrhosis and cardiac complications. *Testing for anti-nuclear antibodies* - While **photosensitivity** could suggest **systemic lupus erythematosus (SLE)**, the patient lacks other characteristic SLE features (malar rash, oral ulcers, serositis). - The **"tanned" appearance** is not typical of photosensitivity, which usually manifests as a **rash or erythema with sun exposure**, not generalized hyperpigmentation. - The **specific involvement of MCP 2 and 3 joints** is more characteristic of hemochromatosis than SLE, which typically has a more diffuse polyarticular pattern. - ANA testing would be appropriate if other SLE features were present, but the constellation of findings here points to iron overload. *Synovial fluid analysis* - This test is performed to evaluate for **septic arthritis**, **crystal arthropathy (gout, pseudogout)**, or other inflammatory conditions when there is **acute monoarticular** or **oligoarticular** involvement. - The patient's **chronic, symmetrical polyarticular** presentation and systemic features make a systemic metabolic disorder (hemochromatosis) more likely than conditions requiring synovial fluid analysis as the initial diagnostic step. *Testing for parvovirus B19 antibodies* - **Parvovirus B19** can cause acute arthropathy mimicking rheumatoid arthritis, typically following a viral prodrome. - However, the **3-month chronicity**, **diabetes**, and **bronze pigmentation** are not explained by parvovirus infection, making this an unlikely diagnosis. *Testing for rheumatoid factors* - While **rheumatoid arthritis (RA)** can present with symmetrical small joint arthritis, it typically involves **PIP and MCP joints more diffusely**, not specifically MCP 2 and 3. - RA does not explain the **tanned appearance** or the specific association with **diabetes mellitus** seen in this patient. - The MCP 2 and 3 predilection is a distinguishing feature of hemochromatosis arthropathy.

Question 135: A 55-year-old man presents to his physician complaining of pain. He states that in the morning he feels rather stiff and has general discomfort and pain in his muscles. The patient has a past medical history of diabetes and is not currently taking any medications. His temperature is 99.2°F (37.3°C), blood pressure is 147/98 mmHg, pulse is 80/min, respirations are 12/min, and oxygen saturation is 99% on room air. Physical exam demonstrates mild tenderness of the patient's musculature diffusely. The patient has 2+ reflexes and 5/5 strength in his upper and lower extremities. Laboratory values are notable for an elevated erythrocyte sedimentation rate. Which of the following is the best next step in management?

A. Temporal artery biopsy
B. Thyroxine
C. Glucocorticoids (Correct Answer)
D. Muscle biopsy
E. Aldolase levels

Explanation: ***Glucocorticoids*** - The patient's symptoms (morning stiffness, muscle discomfort, elevated **ESR**) are highly suggestive of **polymyalgia rheumatica** (PMR), which responds dramatically to glucocorticoids. - While other conditions might be considered, the immediate priority in PMR and to prevent progression to **giant cell arteritis** (GCA) is prompt steroid therapy. *Temporal artery biopsy* - This is the gold standard for diagnosing **giant cell arteritis** (GCA), which can coexist with or develop from polymyalgia rheumatica. - However, it's not the initial treatment for PMR symptoms and would be considered if there were signs of GCA (e.g., headache, jaw claudication, vision changes). *Thyroxine* - **Hypothyroidism** can cause muscle pain and fatigue, but the patient's presentation with prominent morning stiffness and elevated ESR without other clear signs of thyroid dysfunction makes PMR a more likely diagnosis. - Thyroid hormone replacement would be appropriate if **hypothyroidism** were confirmed through thyroid function tests. *Muscle biopsy* - A muscle biopsy is typically performed to diagnose inflammatory myopathies such as **polymyositis** or **dermatomyositis**. - These conditions usually present with **muscle weakness** (not just pain and stiffness) and elevated muscle enzymes (CK, aldolase), which are not mentioned here. *Aldolase levels* - **Aldolase** is a muscle enzyme that can be elevated in conditions causing muscle damage, such as **inflammatory myopathies** (e.g., polymyositis, dermatomyositis). - While it could be part of a workup for muscle pain, the classic presentation points more strongly towards PMR, where imaging and symptom response to steroids are more diagnostic than muscle enzymes.

Question 136: A 26-year-old African-American woman comes to the physician because of a 4-day history of a nonproductive cough and chest pain. The pain is sharp and worse when she breathes deeply. During this time, she has also had two episodes of hematuria. Over the past 6 months, she has had intermittent pain, stiffness, and swelling in her fingers and left knee. She had two miscarriages at age 22 and 24. Her only medication is minocycline for acne vulgaris. Her temperature is 38.1°C (100.6°F), pulse is 75/min, and blood pressure is 138/85 mm Hg. Physical examination shows an erythematous rash on her face. There is mild tenderness over the metacarpophalangeal joints bilaterally with no warmth or erythema. Further evaluation of this patient is most likely to show which of the following findings?

A. Anti-histone antibodies
B. Bilateral enlargement of the hilar lymph nodes
C. Low serum levels of C3 and C4 (Correct Answer)
D. Erosions of the metacarpophalangeal joints
E. Cytotoxic glomerular antibodies

Explanation: ***Low serum levels of C3 and C4*** - The patient's symptoms (malar rash, arthritis, serositis, hematuria, miscarriages) are highly suggestive of **Systemic Lupus Erythematosus (SLE)**. - In active SLE, particularly with **lupus nephritis** (evidenced by hematuria), complement components **C3 and C4 are consumed**, leading to low serum levels. - This is a characteristic laboratory finding that helps confirm the diagnosis and assess disease activity. *Anti-histone antibodies* - While minocycline can cause **drug-induced lupus** (DIL), and anti-histone antibodies are highly positive in DIL, this patient's presentation is **not consistent with drug-induced lupus**. - DIL typically presents with **mild constitutional symptoms, arthralgia, and serositis** but rarely causes **renal involvement (hematuria)**, recurrent miscarriages, or severe multi-organ disease. - The constellation of symptoms—**hematuria, recurrent miscarriages, significant arthritis, malar rash, and pleurisy**—in a young African-American woman points strongly toward **idiopathic SLE** rather than drug-induced lupus. - Therefore, testing for anti-histone antibodies would not be the most useful next step; complement levels are more diagnostic. *Bilateral enlargement of the hilar lymph nodes* - **Bilateral hilar lymphadenopathy (BHL)** is a classic finding in **sarcoidosis**. - While sarcoidosis can cause arthritis and skin manifestations, it typically does not cause **hematuria**, recurrent miscarriages, or the complement consumption characteristic of SLE. - The malar rash is not typical of sarcoidosis, which more commonly presents with lupus pernio or erythema nodosum. *Erosions of the metacarpophalangeal joints* - **Erosive arthritis** affecting the MCP joints is characteristic of **rheumatoid arthritis (RA)**. - SLE typically causes **non-erosive arthritis** (Jaccoud arthropathy in chronic cases). - The patient's presentation with malar rash, hematuria, serositis, and recurrent miscarriages is not typical for RA, which primarily causes symmetrical, destructive arthritis without these systemic features. *Cytotoxic glomerular antibodies* - **Anti-glomerular basement membrane (anti-GBM) antibodies** are a hallmark of **Goodpasture syndrome**. - Goodpasture's syndrome presents with rapidly progressive glomerulonephritis and pulmonary hemorrhage, but does not cause the widespread systemic features like arthritis, malar rash, serositis, and recurrent miscarriages seen in this patient. - The recurrent miscarriages suggest antiphospholipid antibodies (associated with SLE), not anti-GBM antibodies.

Question 137: A 20-year-old man is brought to the emergency department because of fever and lethargy for the past 2 days. He reports that during this time he has had occasional palpitations and shortness of breath. He has asthma and sickle cell disease. Current medications include inhaled albuterol, hydroxyurea, and folic acid. He appears fatigued. His temperature is 38.4°C (101.1°F), pulse is 122/min, respirations are 25/min, and blood pressure is 110/72 mm Hg. Examination shows pale conjunctivae. Cardiac examination shows a midsystolic ejection murmur. Laboratory studies show: Hemoglobin 6.5 g/dl Leukocyte count 5,000/mm3 Platelet count 165,000/mm3 Mean corpuscular volume 82 μm3 Reticulocyte count 0.2% Which of the following is the most likely cause of these findings?

A. Adverse effect of medication
B. Hyperhemolysis
C. Dysfunctional erythrocyte membrane proteins
D. Splenic sequestration crisis
E. Viral infection (Correct Answer)

Explanation: ***Viral infection*** - The patient's **rapidly declining hemoglobin** (6.5 g/dL) and **markedly low reticulocyte count (0.2%)** in the context of sickle cell disease strongly suggest an **aplastic crisis**, commonly triggered by **Parvovirus B19** infection. - **Parvovirus B19** specifically targets and destroys **erythroid progenitor cells** in the bone marrow, leading to a temporary cessation of red blood cell production, especially detrimental in patients with accelerated red blood cell turnover like those with sickle cell disease. *Adverse effect of medication* - While medications can cause anemia, the sudden and severe drop in hemoglobin with such a low reticulocyte count is not typically associated with **hydroxyurea** or **folic acid** as an acute, isolated event. - **Hydroxyurea** can cause myelosuppression, but it usually presents as a more gradual reduction in cell lines, and an isolated aplastic crisis of this severity is less typical as a primary adverse effect. *Hyperhemolysis* - **Hyperhemolysis** involves an increased rate of red blood cell destruction, which would typically lead to an **elevated reticulocyte count** as the bone marrow tries to compensate. - The patient's **low reticulocyte count** rules out increased destruction as the primary cause of his anemia in this scenario. *Dysfunctional erythrocyte membrane proteins* - **Dysfunctional erythrocyte membrane proteins** (e.g., in hereditary spherocytosis) cause chronic hemolytic anemia, but they do not explain the **acute onset** of symptoms, the **fever**, and especially the **low reticulocyte count**, which points to impaired production rather than increased destruction. - Sickle cell disease itself involves **abnormal hemoglobin (HbS)**, not membrane protein defects, and the acute aplastic picture here is a superimposed event triggered by infection, not an intrinsic feature of the chronic hemolysis. *Splenic sequestration crisis* - A **splenic sequestration crisis** involves the sudden pooling of a large number of red blood cells in the spleen, leading to a rapid drop in hemoglobin and often **thrombocytopenia**, both of which are absent here (platelet count is normal). - Also, a sequestration crisis would typically present with a **tender, enlarged spleen**, and would not necessarily lead to such a profoundly low reticulocyte count without an associated bone marrow insult.

Question 138: A 51-year-old woman comes to the physician because of a 1-year history of occasional discoloration and tingling in her fingers. She has no history of major medical illness and takes no medications. Examination of the hands and fingers shows thickened, waxy skin and several firm white nodules on the fingertips. Further evaluation of this patient is most likely to show which of the following findings?

A. Interstitial lung disease
B. Upper eyelid rash
C. Serositis
D. Telangiectasia (Correct Answer)
E. Endocardial immune complex deposition

Explanation: ***Telangiectasia*** - This patient's symptoms (Raynaud phenomenon, thickened waxy skin, firm white nodules suggesting **calcinosis cutis**) are indicative of **CREST syndrome**, a limited form of systemic sclerosis. - **Telangiectasias** (spider veins) are a common component of CREST syndrome, along with **Calcinosis**, **Raynaud phenomenon**, Esophageal dysmotility, and Sclerodactyly. *Interstitial lung disease* - While **interstitial lung disease** can occur in systemic sclerosis, it is more commonly associated with the **diffuse cutaneous form**, which typically presents with wider skin involvement and more severe internal organ disease. - The patient's presentation with localized skin changes and classic CREST features makes telangiectasia a more direct and expected finding. *Upper eyelid rash* - An **upper eyelid rash**, specifically a **heliotrope rash**, is characteristic of **dermatomyositis**, a different connective tissue disease. - The other symptoms described (Raynaud's, calcinosis, sclerodactyly) do not align with dermatomyositis. *Serositis* - **Serositis**, inflammation of the serous membranes (e.g., pleuritis, pericarditis), is a common manifestation of **systemic lupus erythematosus (SLE)**. - The clinical picture of Raynaud's phenomenon, waxy skin, and calcinosis is not typical for SLE and points more strongly to systemic sclerosis. *Endocardial immune complex deposition* - **Endocardial immune complex deposition** is a hallmark of **Libman-Sacks endocarditis**, a non-infectious endocarditis primarily associated with **systemic lupus erythematosus (SLE)**. - The patient's symptoms are inconsistent with SLE and more characteristic of systemic sclerosis.

Question 139: A 72-year-old woman comes to the emergency department 4 hours after the sudden onset of a diffuse, dull, throbbing headache. During this time, she also reports blurred vision, nausea, and one episode of vomiting. She has a history of hypertension and type 2 diabetes mellitus. Her medications include hydrochlorothiazide, lisinopril, atorvastatin, and metformin. She has smoked 1 pack of cigarettes daily for the past 30 years and drinks 1–2 glasses of wine per day. Her temperature is 36.6 °C (97.9 °F), pulse is 90/min, respirations are 14/min, and blood pressure is 185/110 mm Hg. Fundoscopic examination shows bilateral blurring of the optic disc margins. Physical and neurologic examinations show no other abnormalities. A complete blood count and serum concentrations of electrolytes, urea nitrogen, and creatinine are within the reference range. Urinalysis shows 2+ protein but no WBCs or RBCs. Which of the following is the most likely diagnosis?

A. Ischemic stroke
B. Hypertensive emergency (Correct Answer)
C. Transient ischemic attack
D. Subarachnoid hemorrhage
E. Idiopathic intracranial hypertension

Explanation: ***Hypertensive emergency*** - The patient presents with **sudden onset of severe headache**, blurred vision, nausea, and vomiting, along with **markedly elevated blood pressure (185/110 mm Hg)** which are classic symptoms of hypertensive emergency. - **Bilateral blurring of the optic disc margins (papilledema)** indicates end-organ damage to the central nervous system due to severe hypertension, further supporting this diagnosis. *Ischemic stroke* - While a cerebral infarct can cause sudden-onset headache, it typically presents with **focal neurological deficits**, which are absent in this patient. - The symptoms described are more consistent with generalized intracranial pressure elevation rather than a localized ischemic event. *Transient ischemic attack* - A TIA involves **transient neurological deficits** that resolve completely, typically within an hour, and would not usually be associated with persistent symptoms like blurred vision and papilledema. - The significant and sustained elevation in blood pressure with end-organ damage points away from a TIA. *Subarachnoid hemorrhage* - Often causes a **"thunderclap" headache** described as the worst headache of one's life, which is more severe and abrupt than the "dull, throbbing" headache mentioned. - While it can cause nausea and vomiting, the absence of meningeal signs or focal neurological deficits, and the presence of severe uncontrolled hypertension with papilledema, make subarachnoid hemorrhage less likely. *Idiopathic intracranial hypertension* - This condition typically affects young, obese women and is characterized by symptoms of **increased intracranial pressure (headache, vision changes, papilledema)**, but without an identifiable cause. - The patient's age (72 years), history of uncontrolled hypertension, and very high blood pressure suggest a secondary cause for her intracranial hypertension, specifically a hypertensive emergency.

Question 140: A 56-year-old man comes to the physician for a follow-up examination. Physical examination shows hyperpigmented plaques on the posterior neck and in the axillae. His hemoglobin A1c concentration is 7.4% and fasting serum glucose concentration is 174 mg/dL. Which of the following is the strongest predisposing factor for this patient's laboratory findings?

A. High waist circumference (Correct Answer)
B. Elevated systolic blood pressure
C. Increased serum testosterone level
D. Increased BMI during childhood
E. History of smoking

Explanation: ***High waist circumference*** - The presence of **hyperpigmented plaques** (**acanthosis nigricans**) in the axillae and posterior neck, along with elevated **HbA1c** (7.4%) and **fasting glucose** (174 mg/dL), indicates **insulin resistance** and **Type 2 Diabetes Mellitus**. - **High waist circumference** is a primary indicator of **visceral obesity**, which is strongly correlated with **insulin resistance** and significantly increases the risk of developing **Type 2 Diabetes Mellitus**. *Elevated systolic blood pressure* - While **hypertension** is a common comorbidity with **Type 2 Diabetes Mellitus** and **insulin resistance**, it is typically a consequence or a co-occurring symptom of metabolic syndrome, rather than the strongest predisposing factor. - **High blood pressure** alone does not directly cause the **insulin resistance** and hyperglycemia seen in this patient, though it shares common underlying risk factors. *Increased serum testosterone level* - **Increased serum testosterone** levels are more commonly associated with conditions like **polycystic ovary syndrome (PCOS)** in women, which can involve **insulin resistance**. - In men, high testosterone is **not** a predisposing factor for **Type 2 Diabetes Mellitus**; in fact, **low testosterone** levels are associated with insulin resistance and metabolic syndrome in men, not high levels. *Increased BMI during childhood* - While **childhood obesity** does increase the risk of developing **Type 2 Diabetes Mellitus** in adulthood, the question asks for the strongest **predisposing factor** for the *current* laboratory findings in a 56-year-old man. - **Current visceral adiposity**, indicated by a **high waist circumference**, is a more immediate and direct driver of the present metabolic derangements than a historical BMI status. *History of smoking* - **Smoking** is a significant risk factor for many chronic diseases, including **cardiovascular disease** and certain cancers, and it can exacerbate **insulin resistance**. - However, **smoking** is not considered the primary or strongest predisposing factor for the development of **insulin resistance** and **Type 2 Diabetes Mellitus** when compared to central obesity.

Question 141: A previously healthy 42-year-old man is brought to the emergency department 1 hour after he was involved in a motor vehicle collision. He is conscious. He smoked one pack of cigarettes daily for 16 years but quit 8 years ago. Physical examination shows several ecchymoses over the trunk and abdomen. The abdomen is soft, and there is tenderness to palpation of the right upper quadrant without guarding or rebound. Vital signs are within normal limits. An x-ray of the chest shows no fractures; a 10-mm solid pulmonary nodule is present in the central portion of the right upper lung field. No previous x-rays of the patient are available. A CT scan of the chest is performed, which shows that the nodule has irregular, scalloped borders. Which of the following is the most appropriate next step in the management of this patient's pulmonary nodule?

A. Reassurance
B. Follow-up CT scan in 12 months
C. Positron emission tomography (Correct Answer)
D. Antituberculous therapy
E. Follow-up chest x-ray in 12 months

Explanation: ***Positron emission tomography*** - A 10-mm solid pulmonary nodule with **irregular, scalloped borders** in a patient with a significant **smoking history** (even if quit 8 years ago) and age (42 years) has an intermediate to high probability of malignancy, warranting further investigation. - **PET scan** is highly sensitive for detecting metabolically active malignant cells and can help differentiate benign from malignant nodules, guiding the need for biopsy or surgical resection. *Reassurance* - Reassurance is inappropriate given the **suspicious features** of the nodule (size, irregular borders) and the patient's **smoking history**, which increase the risk of malignancy. - Ignoring these findings would be a significant oversight in patient care. *Follow-up CT scan in 12 months* - A 12-month follow-up is too long for a nodule with **suspicious characteristics** and no prior imaging, especially given the patient's risk factors for malignancy. - This approach is typically reserved for **smaller, less suspicious nodules** or those with known stability over time. *Antituberculous therapy* - There is **no clinical evidence** presented (e.g., fever, night sweats, weight loss, contact history, or endemic region exposure) to suggest tuberculosis as the cause of this pulmonary nodule. - Empiric treatment for tuberculosis without diagnostic confirmation is not indicated. *Follow-up chest x-ray in 12 months* - A chest x-ray has **limited sensitivity** for characterizing pulmonary nodules compared to a CT scan, and waiting 12 months is too long given the nodule's features. - A CT scan has already been performed, and another x-ray would not provide additional diagnostic detail for this suspicious nodule.

Question 142: A 60-year-old man comes to the physician for a routine health maintenance examination. He feels well. Five years ago, he underwent a colonoscopy, which was unremarkable. He has no history of serious illness except for an episode of poststreptococcal glomerulonephritis at the age of 10 years. His father died of bladder carcinoma at the age of 55 years. The patient works at a rubber factory. He has smoked one pack of cigarettes daily for the past 25 years. He drinks 1–2 cans of beer per day. He takes no medications. He has never received any pneumococcal vaccination. His temperature is 37°C (98.6°F), pulse is 70/min, and blood pressure is 120/80 mm Hg. Digital rectal examination shows mild symmetrical enlargement of the prostate with no masses. Which of the following is the most appropriate next step in management?

A. Recommend colonoscopy
B. Obtain renal ultrasound
C. Obtain CT urography
D. Administer pneumococcal conjugate vaccination (Correct Answer)
E. Discuss PSA assessment with patient

Explanation: ***Administer pneumococcal conjugate vaccination*** - This 60-year-old patient is a **current smoker** (25 pack-years), which is a specific indication for pneumococcal vaccination in adults aged 19-64 years according to **ACIP guidelines**. - He has **never received pneumococcal vaccination**, making this a clear preventive care gap that should be addressed. - Smoking significantly increases the risk of invasive pneumococcal disease, and vaccination is a concrete, evidence-based intervention. - For adults <65 with smoking history, **PCV15 or PCV20** should be administered, followed by PPSV23 if using PCV15. *Discuss PSA assessment with patient* - While this patient has risk factors for prostate cancer (age 60, mild prostatic enlargement), **USPSTF gives PSA screening a Grade C recommendation** (individual decision) for men aged 55-69. - Shared decision-making about PSA is reasonable but not more urgent than addressing the clear vaccination gap in a smoker. - The decision to screen should be individualized based on patient preferences, but it's not the most immediate preventive priority. *Recommend colonoscopy* - The patient had an **unremarkable colonoscopy 5 years ago**. For individuals with average risk, the recommended interval is **every 10 years**. - There are no new symptoms or high-risk features (e.g., family history of early-onset colorectal cancer) to warrant an earlier repeat colonoscopy. *Obtain renal ultrasound* - The patient had poststreptococcal glomerulonephritis at age 10, but this is **remote history** (50 years ago) with no current sequelae. - He has **normal blood pressure** and no symptoms suggesting kidney dysfunction (no edema, proteinuria mentioned). - Routine renal imaging is not indicated without clinical evidence of current kidney disease. *Obtain CT urography* - CT urography evaluates the **urinary tract for masses, stones, or hematuria**, typically when bladder cancer is suspected. - Despite his father's bladder cancer history and occupational exposure (rubber factory workers have increased bladder cancer risk), there are **no current symptoms** such as hematuria to warrant this invasive, radiation-exposing study. - Screening for bladder cancer in asymptomatic individuals is not recommended even with risk factors.

Question 143: A 45-year-old woman comes to the physician because of fatigue, lightheadedness, dizziness upon standing, abdominal pain, and muscle pain over the past 6 months. She has also had an unintended weight loss of 5.8 kg (12.8 lb) over the past 3 years. She has had a history of hypoparathyroidism since she was a teenager. Her current medications include calcitriol and calcium carbonate. Her pulse is 85/min and blood pressure is 81/45 mm Hg. Physical examination shows tanned skin, as well as sparse axillary and pubic hair. Which of the following is the most likely cause of this patient's symptoms?

A. Enzyme disorder
B. Abdominal neoplasia
C. Occult hemorrhage
D. Autoimmune destruction (Correct Answer)
E. Amyloid deposition

Explanation: ***Autoimmune destruction*** - The constellation of **fatigue, lightheadedness, orthostatic hypotension, weight loss, tanned skin, and sparse axillary/pubic hair** in a patient with a history of another autoimmune condition (hypoparathyroidism) is highly suggestive of **Addison's disease** (primary adrenal insufficiency), which is most commonly caused by autoimmune destruction of the adrenal glands. - The skin tanning is due to increased **ACTH** (adrenocorticotropic hormone) and **melanocyte-stimulating hormone (MSH)** production as the pituitary tries to compensate for insufficient cortisol from the damaged adrenal glands. *Enzyme disorder* - While enzyme disorders can cause chronic symptoms, they typically do not present with the specific combination of **orthostatic hypotension, hyperpigmentation, and sparse secondary sexual hair** seen here. - This presentation is a classic endocrine pattern, not typically associated with an isolated enzyme deficiency. *Abdominal neoplasia* - **Neoplasia** could explain weight loss and fatigue, but it typically doesn't cause **hyperpigmentation** or **sparse secondary sexual hair**, and it's less likely to directly cause **orthostatic hypotension** in this manner. - The patient's symptoms are more consistent with an endocrine dysfunction rather than a localized abdominal mass effect or paraneoplastic syndrome that would mimic this exact presentation. *Occult hemorrhage* - Occult hemorrhage would likely cause **anemia**, leading to fatigue and lightheadedness, and potentially orthostatic changes. - However, it would not explain the **tanned skin** (hyperpigmentation) or the **loss of axillary/pubic hair**, which are key features pointing to adrenal insufficiency. *Amyloid deposition* - Amyloidosis can affect various organs, including the adrenals, leading to adrenal insufficiency and other symptoms like fatigue and weight loss. - While it's a possibility, **hyperpigmentation** and **sparse axillary/pubic hair** are more characteristic of autoimmune Addison's disease due to the specific hormonal changes (increased ACTH/MSH and decreased adrenal androgens).

Question 144: A 48-year-old woman presents to her family physician for evaluation of increasing shortness of breath. She returned from a trip to China 2 weeks ago and reports fever, myalgias, headaches, and a dry cough for the past week. Over the last 2 days, she has noticed increasingly severe shortness of breath. Her past medical history is non-contributory. The heart rate is 84/min, respiratory rate is 22/min, temperature is 38.0°C (100.4°F), and blood pressure is 120/80 mm Hg. A chest X-ray shows bilateral patchy infiltrates. Laboratory studies show leukopenia. After appropriate implementation of infection prevention and control measures, the patient is hospitalized. Which of the following is the most appropriate next step in management?

A. Lopinavir-ritonavir treatment
B. RT-PCR testing (Correct Answer)
C. Supportive therapy and monitoring
D. Remdesivir treatment
E. Systemic corticosteroid administration

Explanation: ***RT-PCR testing*** - The patient presents with **severe acute respiratory illness** with fever, dry cough, progressive dyspnea, bilateral infiltrates, and leukopenia following travel to an endemic area. - Before initiating specific antiviral or immunomodulatory therapy, **confirming the etiology** is essential through RT-PCR testing for respiratory pathogens (SARS-CoV-2, influenza, RSV, etc.). - RT-PCR is the **gold standard diagnostic test** for viral respiratory infections, providing rapid, specific identification that guides treatment decisions and infection control measures. - While the patient is already hospitalized with infection control precautions, **diagnostic confirmation is the priority** before escalating to specific therapies. *Lopinavir-ritonavir treatment* - This protease inhibitor combination was studied early in COVID-19 but has been shown to be **ineffective** in multiple randomized trials. - Initiating empiric antiviral therapy **without diagnostic confirmation** is inappropriate and may delay effective treatment. - This medication is primarily used for **HIV infection**, not acute respiratory viral illnesses. *Supportive therapy and monitoring* - While **supportive care** (oxygen, fluids, monitoring) is crucial and should be ongoing, it is not the specific "next step" being asked for in this question. - The question seeks the **diagnostic action** needed to guide further management, not the continuation of standard supportive measures. - Supportive care alone does not provide the etiologic diagnosis necessary for targeted therapy decisions. *Remdesivir treatment* - Remdesivir is an antiviral approved for certain hospitalized patients with COVID-19, but it is a **treatment, not a diagnostic step**. - Administering specific antiviral therapy **before confirming the diagnosis** is premature and potentially inappropriate. - Treatment decisions should be guided by **confirmed etiology**, patient severity, and evidence-based guidelines. *Systemic corticosteroid administration* - Corticosteroids (e.g., dexamethasone) have benefit in **severe COVID-19 requiring oxygen**, but should not be given empirically. - In other viral infections (e.g., influenza), corticosteroids may be **harmful** and delay viral clearance. - Diagnosis must be confirmed first to determine if corticosteroid therapy is indicated or contraindicated.

Question 145: A 68-year-old, overweight gentleman with a 20-pack-year history of smoking presents to the primary care physician after noticing multiple blood-stained tissues after coughing attacks in the last month. His vital signs are within normal limits except for an O2 saturation of 93% on room air. He states that over the last 5 years his cough has continued to worsen and has never truly improved. He states that his shortness of breath has also worsened over this time period, as now he can barely make it up the flight of stairs in his home. In this patient, what is the most likely cause of his hemoptysis?

A. Chronic bronchitis
B. Bronchogenic carcinoma (Correct Answer)
C. Lung abscess
D. Acute pulmonary edema
E. Goodpasture's disease

Explanation: ***Bronchogenic carcinoma (Lung cancer)*** - **Hemoptysis in a smoker is lung cancer until proven otherwise** - this is a critical clinical principle in respiratory medicine. - This patient has major risk factors: **20-pack-year smoking history**, age 68, and chronic progressive symptoms. - **Hemoptysis** is a common presenting symptom of lung cancer, occurring in 20-50% of patients, caused by tumor invasion of bronchial vessels. - The **chronic progressive dyspnea** and **worsening cough over 5 years** suggest an evolving mass lesion or bronchial obstruction. - **Hypoxemia** (O2 sat 93%) indicates significant pulmonary compromise. - While this patient likely has underlying COPD/chronic bronchitis as a comorbidity, the presence of hemoptysis mandates urgent evaluation for malignancy. *Chronic bronchitis* - While this patient likely has chronic bronchitis (a type of COPD) given the smoking history and chronic productive cough, **hemoptysis is NOT a typical feature** of uncomplicated chronic bronchitis. - Hemoptysis in chronic bronchitis is rare and usually minimal; its presence should prompt investigation for other causes, particularly malignancy. - Chronic bronchitis explains the dyspnea and chronic cough but does not explain the hemoptysis. *Lung abscess* - A lung abscess typically presents with **acute onset of fever**, chills, night sweats, and **foul-smelling purulent sputum**, none of which are mentioned in this case. - The **chronic, progressive nature over five years** is inconsistent with an acute infectious process. *Acute pulmonary edema* - Acute pulmonary edema presents with **sudden onset of severe dyspnea**, orthopnea, and often pink frothy sputum due to acute cardiac decompensation. - The **gradual progression over five years** rules out an acute cardiac event. - Vital signs are stable, with no mention of cardiac findings. *Goodpasture's disease* - This rare autoimmune disorder causes **pulmonary-renal syndrome** with glomerulonephritis and pulmonary hemorrhage. - Typically affects younger patients (20s-30s) with acute presentation. - There are **no renal symptoms** (hematuria, oliguria, elevated creatinine) to suggest this diagnosis.

Question 146: A 44-year-old woman presents to the outpatient clinic after she ran into a minor car accident. She says that she did not see the other car coming from the side and this is not the first time this has happened. When asked about any health issues she expresses concerns about whitish discharge dripping from both of her nipples that soils her blouse often. She is sexually active and has missed her periods for the last 3 months which she attributes to early signs of menopause. She denies nausea, vomiting, or recent weight gain. She currently does not take any medication. A visual field test reveals loss of bilateral temporal vision. Which of the following tests would best aid in diagnosing this patient’s condition?

A. A mammogram
B. Thyroid stimulating hormone levels
C. A urine pregnancy test
D. Serum prolactin levels (Correct Answer)
E. Serum estrogen and progesterone levels

Explanation: ***Serum prolactin levels*** - The patient presents with **galactorrhea** (**whitish nipple discharge**), **amenorrhea** (**missed periods**), and **bitemporal hemianopsia** (**visual field loss**), forming a classic triad suggestive of a **prolactinoma**. - Measuring **serum prolactin levels** is the most direct and initial diagnostic step to confirm hyperprolactinemia, which is characteristic of prolactinomas. *A mammogram* - A mammogram is used to screen for or diagnose **breast cancer** and would not explain the patient's neurological symptoms or amenorrhea. - While nipple discharge can be a symptom of breast cancer, the **bilateral nature** and co-occurrence with vision changes and amenorrhea point away from this diagnosis. *Thyroid stimulating hormone levels* - **Hypothyroidism** can cause irregular periods and even galactorrhea, but it does not typically lead to **bitemporal hemianopsia**, which is a specific neurological sign of pituitary compression. - While thyroid function should be assessed in cases of menstrual irregularities, it's not the primary test for the constellation of symptoms presented. *A urine pregnancy test* - **Pregnancy** can cause amenorrhea and sometimes nipple discharge, but it would not explain the **bitemporal hemianopsia** or the **bilateral galactorrhea** in a non-pregnant state. - The patient's description of symptoms, including the accidental car incident due to vision issues, makes pregnancy an unlikely sole explanation. *Serum estrogen and progesterone levels* - While these hormones are important for reproductive health and would be assessed in cases of **amenorrhea**, they would not directly explain the **galactorrhea** or, more importantly, the **bitemporal hemianopsia**. - The primary issue here points towards a pituitary mass disrupting both hormonal regulation and optic chiasm function, for which prolactin is the key indicator.

Question 147: A 60-year-old man comes to the physician for a routine health maintenance examination. Over the past year, he has had problems initiating urination and the sensation of incomplete bladder emptying. He has a history of hypertension and hypercholesterolemia. He has smoked one pack of cigarettes daily for the past 40 years. He does not drink alcohol. His medications include lisinopril, atorvastatin, and daily aspirin. Vital signs are within normal limits. Physical examination shows a pulsatile abdominal mass at the level of the umbilicus and a bruit on auscultation. Digital rectal examination shows a symmetrically enlarged, smooth, firm, nontender prostate with rubbery texture. Laboratory studies are within normal limits. Which of the following is the most appropriate next step in management?

A. Prostate biopsy
B. PSA level testing
C. CT scan of the abdomen with contrast
D. Abdominal ultrasonography (Correct Answer)
E. Aortic arteriography

Explanation: ***Abdominal ultrasonography*** - The presence of a **pulsatile abdominal mass** and a **bruit at the umbilicus** in an elderly patient with a history of hypertension, hypercholesterolemia, and smoking strongly suggests an **abdominal aortic aneurysm (AAA)**. - **Abdominal ultrasonography** is the initial, non-invasive, and cost-effective test of choice for screening, diagnosis, and monitoring of AAA. *Prostate biopsy* - While the patient has symptoms of **benign prostatic hyperplasia (BPH)** and an enlarged prostate on digital rectal examination (DRE), these findings do not indicate an immediate need for biopsy. - A prostate biopsy is typically performed after an elevated **PSA level** or suspicious findings on DRE suggest prostate cancer, neither of which is present here. *PSA level testing* - Although the patient has urinary symptoms suggestive of BPH, his prostate exam describes a **symmetrically enlarged, smooth, firm, nontender prostate with rubbery texture**, which is characteristic of BPH rather than cancer. - While a PSA test could be part of a routine workup for urinary symptoms, it is not the most appropriate *next step* given the more urgent finding of a suspected AAA. *CT scan of the abdomen with contrast* - A **CT scan with contrast** can confirm an AAA and provide detailed anatomical information for surgical planning, but it is typically performed *after* an initial screening with ultrasonography. - It involves radiation exposure and a contrast agent, making it less suitable as the *initial* diagnostic step compared to ultrasound, especially in an asymptomatic screening scenario when an AAA is merely suspected. *Aortic arteriography* - **Aortic arteriography** is an invasive procedure primarily used for detailed visualization of the aorta and its branches, often in preparation for endovascular repair or open surgery. - It carries risks such as vessel injury, bleeding, and contrast-induced nephropathy, and is not indicated as the initial diagnostic test for a suspected AAA.

Question 148: A 48-year-old man is brought to the emergency department by his neighbor, who found him lying unconscious at the door of his house. The patient lives alone and no further history is available. On physical examination, his temperature is 37.2ºC (98.9ºF), pulse rate is 114/min, blood pressure is 116/78 mm Hg, and respiratory rate is 22/min. His Glasgow Coma Scale score is 7 and the patient is intubated. A stat serum osmolality is reported at 260 mmol/kg. Based on the provided information, which of the following conditions is most likely present in this patient?

A. Syndrome of inappropriate antidiuretic hormone (Correct Answer)
B. Diabetic ketoacidosis
C. Acute ethanol intoxication
D. Central diabetes insipidus
E. Nonketotic hyperosmolar hyperglycemic coma

Explanation: ***Syndrome of inappropriate antidiuretic hormone (SIADH)*** - The patient's **unconsciousness** and Glasgow Coma Scale of 7 suggest significant neurological impairment. A serum osmolality of **260 mmol/kg** is low, indicating **hypotonicity** which is characteristic of SIADH due to excess water retention. - While other causes of altered consciousness exist, the combination of **hyponatremia** (implied by low osmolality) and neurological symptoms points strongly towards SIADH, especially in an unknown medical history setting where various conditions can trigger ADH release. *Diabetic ketoacidosis (DKA)* - DKA typically presents with **hyperglycemia**, **acidosis**, and **ketonuria**, which would result in a high serum osmolality, not the low osmolality seen in this patient. - While DKA can cause altered mental status, the **serum osmolality of 260 mmol/kg** rules it out as the primary cause here. *Acute ethanol intoxication* - Acute ethanol intoxication can cause **unconsciousness** and respiratory depression. However, it usually leads to **mild or no change in serum osmolality**, or occasionally a slightly elevated osmolality due to ethanol itself and associated dehydration, not a significantly low value of 260 mmol/kg. - The physiological changes associated with pure ethanol intoxication do not typically include the marked **hypotonicity** indicated by such a low serum osmolality. *Central diabetes insipidus* - Central diabetes insipidus is characterized by an inability to produce ADH, leading to **polyuria**, **polydipsia**, and frequently **hypernatremia** and **high serum osmolality** due to free water loss. - It would not cause the **hypotonic state** with a serum osmolality of 260 mmol/kg, making it inconsistent with the clinical picture. *Nonketotic hyperosmolar hyperglycemic coma (NKHHC)* - NKHHC is characterized by **extreme hyperglycemia** and **severe dehydration**, leading to a much **higher serum osmolality** (typically >320 mOsm/kg) than observed in this patient. - Although it causes altered mental status, the reported **low serum osmolality of 260 mmol/kg** makes NKHHC an unlikely diagnosis.

Question 149: A 72-year-old man presents to his primary care physician for a general checkup. The patient works as a farmer and has no concerns about his health. He has a past medical history of hypertension and obesity. His current medications include lisinopril and metoprolol. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a murmur after S2 over the left sternal border. The patient demonstrates a stable gait and 5/5 strength in his upper and lower extremities. Which of the following is another possible finding in this patient?

A. Murmur that radiates to the carotids
B. Wedge pressure lower than expected
C. Femoral artery murmur (Correct Answer)
D. Rumbling heard at the cardiac apex
E. Audible click heard at the cardiac apex

Explanation: ***Femoral artery murmur*** - A murmur heard after S2 over the left sternal border in an elderly patient suggests **aortic regurgitation (AR)**. - In AR, a **femoral artery murmur (Duroziez's sign)** can be heard, characterized by a systolic murmur over the femoral artery with proximal compression and a diastolic murmur with distal compression. *Murmur that radiates to the carotids* - A murmur radiating to the carotids is characteristic of **aortic stenosis**, which typically presents as a systolic murmur, not a diastolic one as heard in this patient. - Aortic stenosis is also associated with a **crescendo-decrescendo murmur**, in contrast to the diastolic murmur described. *Wedge pressure lower than expected* - This patient likely has **aortic regurgitation**, which increases **left ventricular end-diastolic pressure** and, consequently, **pulmonary capillary wedge pressure (PCWP)**. - A lower than expected wedge pressure would be inconsistent with the volume overload often seen in significant AR. *Rumbling heard at the cardiac apex* - A rumbling murmur at the cardiac apex is characteristic of **mitral stenosis**, which is typically preceded by an opening snap. - The patient's murmur is heard after S2 (diastolic) at the left sternal border, not the apex, making mitral stenosis less likely. *Audible click heard at the cardiac apex* - An audible click at the cardiac apex is typically associated with **mitral valve prolapse**, often followed by a mid-systolic murmur. - This finding is not consistent with the diastolic murmur heard after S2 at the left sternal border.

Question 150: A 52-year-old man presents to a medical clinic to establish care. He has no known chronic illnesses but has not seen a physician in over 20 years. He generally feels well but occasionally has shortness of breath when he jogs and exercises. He smokes 2-5 cigarettes per day and uses IV heroin “now and then.” Physical exam is unremarkable. ECG shows prominent QRS voltage and left axis deviation. Trans-thoracic echocardiogram shows mild concentric left ventricular hypertrophy but is otherwise normal. Which of the following is the most likely etiology of the echocardiogram findings?

A. Chronic obstructive pulmonary disease
B. Pulmonary hypertension
C. Aortic regurgitation
D. Systemic hypertension (Correct Answer)
E. Mitral stenosis

Explanation: ***Systemic hypertension*** - Chronic **systemic hypertension** is a common cause of **concentric left ventricular hypertrophy** due to increased afterload, which the left ventricle must overcome. - The ECG findings of **prominent QRS voltage** and **left axis deviation** are also consistent with left ventricular hypertrophy, supporting chronic hypertension as the most likely cause. *Chronic obstructive pulmonary disease* - COPD primarily affects the lungs and typically leads to **right ventricular hypertrophy** (cor pulmonale) due to increased pulmonary vascular resistance, not left ventricular hypertrophy. - While smoking is a risk factor for COPD, the patient's echocardiogram shows left, not right, heart changes. *Pulmonary hypertension* - Pulmonary hypertension causes increased afterload on the **right ventricle**, leading to **right ventricular hypertrophy**, not left ventricular hypertrophy. - The echocardiogram specifically reports **left ventricular hypertrophy**. *Aortic regurgitation* - **Aortic regurgitation** leads to **volume overload** of the left ventricle, causing **eccentric left ventricular hypertrophy** (dilation along with thickening), not concentric hypertrophy. - The echocardiogram finding of **concentric** (symmetric thickening without significant dilation) hypertrophy points away from aortic regurgitation. *Mitral stenosis* - **Mitral stenosis** causes increased pressure in the **left atrium** and **pulmonary circulation**, which can eventually lead to **right ventricular hypertrophy**, not left ventricular hypertrophy. - It would not explain the **concentric left ventricular hypertrophy** noted in the echocardiogram.

Question 151: A 34-year-old woman comes to the physician because of a 3-month history of fatigue and a 4.5-kg (10-lb) weight loss despite eating more than usual. Her pulse is 115/min and blood pressure is 140/60 mm Hg. Physical examination shows warm, moist skin, and a diffuse, non-tender swelling over the anterior neck. Ophthalmologic examination shows swelling of the eyelids and proptosis bilaterally. Which of the following is the most likely cause of this patient's symptoms?

A. Constitutively active TSH receptor
B. Thyrotropin receptor autoantibodies (Correct Answer)
C. Parafollicular cell hyperplasia
D. Thyroid peroxidase autoantibodies
E. Nongranulomatous thyroid inflammation

Explanation: ***Thyrotropin receptor autoantibodies*** * The patient presents with symptoms of **hyperthyroidism** (fatigue, weight loss despite increased appetite, tachycardia, warm moist skin, diffuse goiter) along with **exophthalmos** (proptosis) and **eyelid swelling**. * These clinical features are classic for **Graves' disease**, which is caused by antibodies stimulating the **TSH receptor** on thyroid follicular cells, leading to excessive thyroid hormone production. *Constitutively active TSH receptor* * While a constitutively active TSH receptor can lead to hyperthyroidism, it typically occurs in conditions like **toxic multinodular goiter** or **toxic adenoma**, or rarely, in a **hereditary form** of hyperthyroidism. * It does **not explain the exophthalmos and eyelid swelling**, which are characteristic autoimmune manifestations of Graves' disease. *Parafollicular cell hyperplasia* * **Parafollicular cells** (C cells) produce calcitonin, and their hyperplasia is associated with **medullary thyroid carcinoma**. * This condition primarily affects calcium metabolism and does **not cause hyperthyroidism or exophthalmos**. *Thyroid peroxidase autoantibodies* * **Thyroid peroxidase (TPO) antibodies** are characteristic of autoimmune thyroid diseases but are most strongly associated with **Hashimoto's thyroiditis**, which typically causes **hypothyroidism**. * While TPO antibodies can be present in Graves' disease, the primary pathology driving the hyperthyroidism and ophthalmopathy is the **TSH receptor antibody**. *Nongranulomatous thyroid inflammation* * **Nongranulomatous inflammation** can occur in various thyroid conditions, including subacute thyroiditis (de Quervain's thyroiditis) or silent thyroiditis. * These conditions usually present with a **transient phase of hyperthyroidism** followed by hypothyroidism, and they typically **do not cause ophthalmopathy or a diffuse, non-tender goiter** as seen here.

Question 152: A 40-year-old man presents to the physician for a scheduled checkup. He was diagnosed with type 2 diabetes mellitus 5 years ago and has been taking his prescribed metformin daily, as prescribed. He also started exercising and has improved his diet. He has no particular complaints at the time. The patient has no other medical concerns and takes no medications. There is no family history of cardiovascular disease or diabetes. He does not smoke tobacco, drink alcohol, or use illicit drugs. Vitals are normal. There are no physical findings. His laboratory tests show: Serum glucose (fasting) 149 mg/dL Hemoglobin A1c 7.7 % Serum electrolytes Sodium 142 mEq/L Potassium 3.9 mEq/L Chloride 101 mEq/L Serum creatinine 0.8 mg/dL Blood urea nitrogen 9 mg/dL Urinalysis Glucose Negative Ketones Negative Leucocytes Negative Nitrite Negative Red blood cells (RBC) Negative Casts Negative Which of the following lipid profile abnormalities is most likely to be seen?

A. Normal lipid profile
B. Normal triglycerides, elevated LDL
C. Low HDL, elevated LDL
D. Elevated triglycerides, low HDL (Correct Answer)
E. Elevated HDL, low LDL

Explanation: ***Elevated triglycerides, low HDL*** - Patients with **type 2 diabetes mellitus** often exhibit **dyslipidemia** characterized by **elevated triglycerides** and **low high-density lipoprotein (HDL)** cholesterol, even with controlled glucose levels. - This pattern is part of the **atherogenic dyslipidemia** frequently observed in insulin resistance, increasing cardiovascular risk. *Normal lipid profile* - Given the patient's diagnosis of **type 2 diabetes** and suboptimal **HbA1c of 7.7%** (target typically <7%), it is **unlikely** he would have a completely normal lipid profile due to the metabolic disturbances associated with insulin resistance. - **Diabetes** itself is a risk factor for **dyslipidemia**, which mandates regular lipid screening even without overt symptoms. *Normal triglycerides, elevated LDL* - While **elevated LDL** cholesterol can occur in diabetes, a **normal triglyceride** level is **less typical** for diabetic dyslipidemia, which classically features hypertriglyceridemia. - The most characteristic lipid abnormality in **type 2 diabetes** is often a combination of **high triglycerides** and **low HDL**, rather than isolated elevated LDL with normal triglycerides. *Low HDL, elevated LDL* - This option partially captures the typical dyslipidemia, as **low HDL** is characteristic. However, the most consistent abnormality alongside low HDL in diabetes is **elevated triglycerides**, often more prominent than just elevated LDL. - While **elevated LDL** can occur, the combined pattern of **low HDL** and **elevated triglycerides** is more specific for **diabetic dyslipidemia**. *Elevated HDL, low LDL* - This lipid profile is generally considered **protective against cardiovascular disease** and is the **opposite** of what is typically seen in patients with **type 2 diabetes**. - **Elevated HDL** and **low LDL** would be a favorable lipid profile, which is inconsistent with the metabolic derangements associated with diabetes.

Question 153: A 35-year-old woman presents with increased anxiety and a reeling sensation. Her complaint started 30 minutes ago with increased sweating and palpitations and is gradually worsening. On examination, the blood pressure was found to be 194/114 mm Hg. She had normal blood pressure at the local pharmacy 5 days ago. She currently works as an event manager and her job involves a lot of stress. The family history is significant for thyroid carcinoma in her father. Which of the following is most likely in this person?

A. Increased urine metanephrines (Correct Answer)
B. Decreased C-peptide
C. Decreased hemoglobin
D. Decreased TSH levels
E. Increased serum serotonin

Explanation: ***Increased urine metanephrines*** - The patient's symptoms (anxiety, reeling sensation, sweating, palpitations, and paroxysmal hypertension) are highly suggestive of a **pheochromocytoma**, which is a tumor of the adrenal medulla that secretes catecholamines. - **Metanephrines** (metabolism products of catecholamines) are often elevated in urine and plasma samples from patients with pheochromocytoma, making this the most likely finding. *Decreased C-peptide* - **Decreased C-peptide** levels are indicative of reduced endogenous insulin production, typically seen in type 1 diabetes, which does not align with the patient's acute presentation of paroxysmal hypertension and anxiety. - Her symptoms are not consistent with **hypoglycemia** or **diabetes mellitus**. *Decreased hemoglobin* - **Decreased hemoglobin** indicates anemia, which would present with fatigue, pallor, and shortness of breath, not the acute hypertensive crisis and anxiety described. - There is no clinical information in the vignette to suggest **blood loss** or **red blood cell destruction**. *Decreased TSH levels* - **Decreased TSH levels** would suggest hyperthyroidism, which can cause anxiety and palpitations, but the sudden onset and extreme hypertension (194/114 mm Hg) are more characteristic of a **catecholamine surge** than typical hyperthyroidism. - While there is a family history of **thyroid carcinoma**, the acute presentation points away from purely thyroid-related issues as the primary cause. *Increased serum serotonin* - **Increased serum serotonin** is associated with carcinoid syndrome, which typically presents with flushing, diarrhea, bronchospasm, and valvular heart disease, not the predominant features of anxiety, palpitations, and paroxysmal hypertension seen in this patient. - The symptoms are more consistent with an acute release of **catecholamines**, not serotonin.

Question 154: A 69-year-old woman is brought to the emergency department because of fatigue and lethargy for 5 days. She has also had weakness and nausea for the last 3 days. She has sarcoidosis, major depressive disorder, and hypertension. She had a stroke 5 years ago. Current medications include aspirin, nifedipine, prednisolone, fluoxetine, and rosuvastatin, but she has not taken any of her medications for 7 days due to international travel. Her temperature is 36.1°C (96.9°F), pulse is 95/min, and blood pressure is 85/65 mm Hg. She is lethargic but oriented. Examination shows no other abnormalities. Her hemoglobin concentration is 13.4 g/dL and leukocyte count is 9,600/mm3. Both serum cortisol and ACTH levels are decreased. This patient is most likely to have which of the following additional laboratory abnormalities?

A. Hyperglycemia
B. Hyperkalemia
C. Hyponatremia (Correct Answer)
D. Hypokalemia
E. Normal anion gap metabolic acidosis

Explanation: ***Hyponatremia*** - This patient has **secondary adrenal insufficiency** due to **HPA axis suppression** from chronic prednisolone use, precipitated by abrupt withdrawal after 7 days without medication. - **Both decreased cortisol and ACTH** confirm secondary (central) adrenal insufficiency, distinguishing it from primary adrenal insufficiency where ACTH would be elevated. - **Hyponatremia** develops due to **cortisol deficiency** impairing free water excretion, leading to dilutional hyponatremia—a hallmark laboratory finding in adrenal insufficiency. - Clinical features include **fatigue, lethargy, hypotension, nausea, and weakness**, consistent with adrenal crisis. *Hyperglycemia* - While **glucocorticoids** cause hyperglycemia, **cortisol deficiency** in adrenal insufficiency leads to **impaired gluconeogenesis** and a tendency toward **hypoglycemia**, not hyperglycemia. - The patient's presentation with hypotension and weakness is consistent with adrenal crisis, not hyperglycemia. *Hyperkalemia* - **Hyperkalemia** is characteristic of **primary adrenal insufficiency** (Addison's disease) due to **aldosterone deficiency** affecting the renin-angiotensin-aldosterone system. - In **secondary adrenal insufficiency**, the hypothalamic-pituitary axis is suppressed but the **renin-angiotensin-aldosterone system remains intact**, so aldosterone secretion is preserved and significant hyperkalemia does not occur. *Hypokalemia* - **Hypokalemia** is not a typical feature of adrenal insufficiency and is more commonly associated with diuretic use, primary hyperaldosteronism, or other conditions not present in this case. - The patient's condition reflects cortisol deficiency with preserved aldosterone function. *Normal anion gap metabolic acidosis* - **Normal anion gap metabolic acidosis** occurs in conditions like **renal tubular acidosis** or **diarrhea**, but is not a direct or common consequence of secondary adrenal insufficiency. - The acute presentation with hypotension and electrolyte disturbance (hyponatremia) is the primary metabolic derangement in this case.

Question 155: A 34-year-old G3P2103 with a past medical history of preeclampsia in her last pregnancy, HIV (CD4: 441/mm^3), and diabetes mellitus presents to her obstetrician for her first postpartum visit. She delivered her third child via C-section one week ago and reports that she is healing well from the surgery. She says that breastfeeding has been going well and that her baby has nearly regained his birth weight. The patient complains that she has been more tired than expected despite her efforts to sleep whenever her baby is napping. She relies on multiple iced coffees per day and likes to eat the ice after she finishes the drink. Her diet is otherwise unchanged, and she admits that she has not been getting outside to exercise as much as usual. Her home medications include metformin and her HAART regimen of dolutegravir, abacavir, and lamivudine. Her temperature is 98.9°F (37.2°C), blood pressure is 128/83 mmHg, pulse is 85/min, and respirations are 14/min. On physical exam, she is tired-appearing with conjunctival pallor. Given this patient's clinical presentation suggestive of iron deficiency anemia, which of the following complications is she most at risk of developing?

A. Iron deficiency anemia
B. Sideroblastic anemia
C. Megaloblastic anemia
D. Hemolytic anemia
E. Restless legs syndrome (Correct Answer)

Explanation: ***Restless legs syndrome*** - **Iron deficiency anemia** is a recognized cause of **restless legs syndrome** (RLS), where the patient experiences an irresistible urge to move their legs, often accompanied by uncomfortable sensations. - Patients with RLS often report **pica** (craving non-nutritive substances like ice), which this patient exhibits, further strengthening the association with iron deficiency. *Iron deficiency anemia* - This option is already presented in the question, as the patient's symptoms are described as "suggestive of **iron deficiency anemia**." - The question asks for a **complication** of iron deficiency anemia, not the condition itself. *Sideroblastic anemia* - This is a type of anemia caused by the body's inability to incorporate iron into hemoglobin, leading to an accumulation of iron in the mitochondria of red blood cell precursors (sideroblasts). - While it involves iron metabolism, it's typically due to **genetic defects**, **myelodysplastic syndromes**, or **toxins** (e.g., lead, alcohol), none of which are suggested here. *Megaloblastic anemia* - This anemia results from **impaired DNA synthesis**, leading to large, immature red blood cells. - It is most commonly caused by **vitamin B12 deficiency** or **folate deficiency**, and is not directly associated with iron deficiency. *Hemolytic anemia* - This is characterized by the **destruction of red blood cells** before their normal lifespan. - It can be caused by various factors like **autoimmune disorders**, **inherited red blood cell defects**, or **infections**, but there's no indication of increased red blood cell destruction in this patient.

Question 156: A 68-year-old man comes to the emergency department because of a 1-week history of difficulty breathing. He has had recurrent palpitations over the past 2 years. During this time, he has also had several episodes of anxiety despite no change in his daily life. He has occasional sharp chest pain localized to the left upper sternal border. He has no abdominal pain or leg swelling. Two years ago, he had streptococcal pharyngitis, which was promptly treated with a 10-day course of penicillin. He has never traveled outside of the country. His temperature is 36.5°C (97.7°F), pulse is 82/min, and blood pressure is 140/85 mm Hg. Physical examination shows a 3/6 holosystolic murmur that is loudest at the apex and radiates to the axilla with a mid-systolic click. Bilateral fine crackles are heard on lung auscultation. Which of the following is the most likely cause of this patient's symptoms?

A. Inflammatory valve degeneration
B. Ectopic production of serotonin
C. Myxomatous valve degeneration (Correct Answer)
D. Calcific valve degeneration
E. Overproduction of catecholamines

Explanation: ***Myxomatous valve degeneration*** - The presence of a **mid-systolic click** followed by a **holosystolic murmur** at the apex radiating to the axilla is highly characteristic of **mitral valve prolapse (MVP)** with **mitral regurgitation (MR)**. - MVP is most commonly caused by **myxomatous degeneration** of the mitral valve leaflets, leading to their billowing into the left atrium during systole. The patient's recurrent palpitations, anxiety, and non-exertional chest pain are common symptoms associated with MVP, while difficulty breathing and crackles suggest **heart failure** from chronic MR. *Inflammatory valve degeneration* - **Inflammatory valve degeneration**, such as that seen in rheumatic heart disease, typically presents with a history of recurrent streptococcal infections leading to valvular scarring and dysfunction (e.g., mitral stenosis). - While the patient had streptococcal pharyngitis, it was treated, and the clinical presentation with a mid-systolic click is more indicative of myxomatous changes rather than rheumatic inflammation. *Ectopic production of serotonin* - **Ectopic production of serotonin** occurs in settings like **carcinoid syndrome**, which typically involves flushing, diarrhea, bronchospasm, and can affect the right-sided heart valves primarily. - The patient's symptoms are centered on left-sided heart issues and do not align with the broader systemic features of carcinoid syndrome. *Calcific valve degeneration* - **Calcific valve degeneration** commonly affects the **aortic valve** leading to **aortic stenosis** in older adults, characterized by a systolic ejection murmur heard at the right upper sternal border. - It does not typically cause a mid-systolic click or affect the mitral valve in this manner, and the murmur description is inconsistent with aortic stenosis. *Overproduction of catecholamines* - **Overproduction of catecholamines**, as seen in conditions like **pheochromocytoma**, causes symptoms such as paroxysmal hypertension, palpitations, sweating, and anxiety. - While some symptoms like palpitations and anxiety overlap, the specific cardiac murmur and signs of heart failure are not directly explained by catecholamine excess alone; a structural heart problem is more likely.

Question 157: A 43-year-old woman comes to the physician for an annual health maintenance examination. On questioning, she has had fatigue and headaches for the last month. A few weeks ago, she had to have her wedding ring resized because it had become too small for her finger. She has mild persistent asthma and anxiety disorder. She drinks 2–3 glasses of red wine per night and has smoked one pack of cigarettes daily for 16 years. She works a desk job in accounting and has recently been working long hours due to an upcoming company merger. Her father has a history of a pituitary adenoma. Current medications include alprazolam, a fluticasone inhaler, and an albuterol inhaler. She is 160 cm (5 ft 3 in) tall and weighs 81.6 kg (180 lb); her BMI is 32 kg/m2. Her temperature is 37.2°C (99°F), pulse is 92/min, and blood pressure is 132/80 mm Hg. Examination shows no abnormalities. Fasting laboratory studies show: Hemoglobin 13 g/dL Serum Na+ 135 mEq/L K+ 4.6 mEq/L Cl- 105 mEq/L HCO3- 22 mEq/L Urea nitrogen 17 mg/dL Glucose 160 mg/dL Creatinine 0.9 mg/dL Which of the following is the most likely underlying mechanism of this patient's hyperglycemia?

A. Decreased insulin production
B. Adverse effect of medication
C. Stress
D. Insulin resistance (Correct Answer)
E. Hypersecretion of ACTH

Explanation: ***Insulin resistance*** - The patient's **obesity (BMI 32 kg/m2)**, **sedentary lifestyle**, and **fasting hyperglycemia** (glucose 160 mg/dL) indicate **insulin resistance**, which is the underlying mechanism of hyperglycemia in **type 2 diabetes**. - The **ring resizing due to finger enlargement**, **fatigue**, **headaches**, and **family history of pituitary adenoma** raise suspicion for **acromegaly** (growth hormone excess), which also causes hyperglycemia through **insulin resistance** - growth hormone antagonizes insulin action at peripheral tissues. - Regardless of whether this represents type 2 diabetes or acromegaly, **insulin resistance is the direct mechanism** causing the hyperglycemia in this patient. *Decreased insulin production* - Decreased insulin production is characteristic of **type 1 diabetes** or late-stage type 2 diabetes with beta-cell exhaustion. - The patient's **obesity** and typical metabolic risk factors suggest **insulin resistance** rather than decreased production as the primary mechanism. - No clinical features suggest autoimmune destruction or significant pancreatic damage. *Adverse effect of medication* - The patient's medications (**alprazolam**, **fluticasone inhaler**, **albuterol**) are unlikely to cause significant fasting hyperglycemia. - While high-dose systemic **corticosteroids** can cause hyperglycemia, **inhaled fluticasone** at typical asthma doses has minimal systemic absorption and is not a common cause of sustained hyperglycemia. - **Alprazolam** and **albuterol** do not typically cause hyperglycemia. *Stress* - **Acute stress** can transiently elevate blood glucose through counter-regulatory hormones (cortisol, catecholamines). - However, the **fasting glucose of 160 mg/dL** suggests a chronic metabolic derangement rather than acute stress response alone. - Work-related stress may be a contributing factor but is not the primary underlying mechanism. *Hypersecretion of ACTH* - **ACTH hypersecretion** (Cushing's disease) causes excess cortisol production, leading to hyperglycemia, weight gain, and fatigue. - This patient lacks classic features of Cushing's syndrome: **central obesity with thin extremities**, **moon facies**, **buffalo hump**, **purple striae**, **skin thinning**, or **easy bruising**. - While the patient is obese, the distribution appears generalized rather than the characteristic centripetal pattern of Cushing's syndrome.

Question 158: A 27-year-old woman comes to the physician because of a 1-year history of progressive shortness of breath. She is now unable to jog for more than 10 minutes without stopping to catch her breath. Cardiac examination shows a harsh systolic, crescendo-decrescendo murmur best heard at the lower left sternal border. The murmur increases in intensity when she moves from a squatting to a standing position and decreases when she clenches her fists. The lungs are clear to auscultation. Which of the following is the most likely cause of her condition?

A. Myosin heavy chain defect (Correct Answer)
B. CTG trinucleotide repeats
C. Dystrophin defect
D. GAA trinucleotide repeats
E. Fibrillin-1 defect

Explanation: ***Myosin heavy chain defect*** - The clinical presentation of **progressive shortness of breath**, a **harsh systolic crescendo-decrescendo murmur** that increases with standing and decreases with handgrip, is highly indicative of **hypertrophic cardiomyopathy (HCM)**. - HCM is most commonly caused by genetic mutations affecting **sarcomeric proteins**, with mutations in the **beta-myosin heavy chain gene** being the most frequent. *CTG trinucleotide repeats* - **CTG trinucleotide repeats** are characteristic of **myotonic dystrophy type 1**, a multisystem disorder. - While myotonic dystrophy can cause cardiac involvement (e.g., conduction abnormalities, dilated cardiomyopathy), it does not typically present with the classic murmur and dynamic changes seen in **HCM**. *Dystrophin defect* - A **dystrophin defect** is responsible for **Duchenne** and **Becker muscular dystrophies**, which primarily affect skeletal muscle. - These conditions can lead to **dilated cardiomyopathy**, but not the type of obstructive outflow murmur associated with **HCM**. *GAA trinucleotide repeats* - **GAA trinucleotide repeats** are associated with **Friedreich ataxia**, a neurodegenerative disorder that can cause **hypertrophic cardiomyopathy** in up to 65% of patients. - However, Friedreich ataxia presents with prominent **neurological symptoms** including progressive **ataxia, dysarthria, areflexia**, and loss of position/vibration sense, which are absent in this patient. - The isolated cardiac presentation with no neurological findings points to **primary HCM** due to sarcomeric protein mutations rather than syndromic forms. *Fibrillin-1 defect* - A **fibrillin-1 defect** causes **Marfan syndrome**, a connective tissue disorder. - Cardiac manifestations typically include **aortic root dilation** and **mitral valve prolapse**, not obstructive hypertrophic cardiomyopathy with the described murmur characteristics.

Question 159: A 27-year-old woman presents to her primary care physician with a chief complaint of pain in her hands, shoulders, and knees. She states that the pain has lasted for several months but seems to have worsened recently. Any activity such as opening jars, walking, or brushing her teeth is painful. The patient has a past medical history of a suicide attempt in college, constipation, anxiety, depression, and a sunburn associated with surfing which was treated with aloe vera gel. Her temperature is 99.5°F (37.5°C), blood pressure is 137/78 mmHg, pulse is 92/min, respirations are 14/min, and oxygen saturation is 98% on room air. Laboratory values are obtained and shown below. Hemoglobin: 9 g/dL Hematocrit: 33% Leukocyte count: 2,500/mm^3 with normal differential Platelet count: 107,000/mm^3 Serum: Na+: 139 mEq/L Cl-: 102 mEq/L K+: 4.4 mEq/L HCO3-: 24 mEq/L BUN: 21 mg/dL Glucose: 90 mg/dL Creatinine: 1.0 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following is the most likely to be found in this patient?

A. Anti-dsDNA antibodies (Correct Answer)
B. Anti-cyclic citrullinated peptide antibodies
C. IgM against parvovirus B19
D. Anti-histone antibodies
E. Degenerated cartilage in weight bearing joints

Explanation: ***Anti-dsDNA antibodies*** - The patient's presentation with **polyarthralgia**, **anemia**, **leukopenia**, and **thrombocytopenia** is highly suggestive of **systemic lupus erythematosus (SLE)**. - **Anti-dsDNA antibodies** are highly specific for SLE and are often associated with **lupus nephritis** and disease activity. *Anti-cyclic citrullinated peptide antibodies* - These antibodies are highly specific for **rheumatoid arthritis**, which primarily causes **inflammatory arthritis** but does not typically present with the **heme abnormalities** (anemia, leukopenia, thrombocytopenia) seen in this patient. - The patient's symptoms of pain in hands, shoulders, and knees are broad and not specifically localized to the **small joints** in a symmetric pattern typical of rheumatoid arthritis. *IgM against parvovirus B19* - **Parvovirus B19 infection** can cause **arthralgia** and some hematological abnormalities, particularly **transient aplastic crisis**, but it typically does not cause the persistent **pancytopenia** or the broad systemic features seen here. - IgM antibodies indicate an **acute infection**, and while it could cause joint pain, it is less likely to explain the constellation of symptoms including chronic multi-joint pain and significant cytopenias over several months. *Anti-histone antibodies* - **Anti-histone antibodies** are most commonly associated with **drug-induced lupus**, which typically develops after exposure to certain medications (e.g., **hydralazine**, **procainamide**). - There is no mention of such drug exposure in the patient's history, and while they can be present in SLE, anti-dsDNA antibodies are more specific for idiopathic SLE. *Degenerated cartilage in weight bearing joints* - **Degenerated cartilage** in weight-bearing joints is characteristic of **osteoarthritis**, which is a **degenerative joint disease**. - Osteoarthritis typically does not present with **systemic symptoms** like fatigue or the **hematological abnormalities** (anemia, leukopenia, thrombocytopenia) observed in this patient.

Question 160: A previously healthy 46-year-old man comes to the physician for an 8-month history of headache that is more severe in the mornings. His blood pressure is 151/92 mm Hg. Examination shows enlargement of the nose, forehead, and jaw as well as the hands, fingers, and feet. Ophthalmologic examination shows impaired vision in the outer peripheral fields of both eyes. Laboratory studies show a serum glucose concentration of 225 mg/dL. Which of the following findings is most likely to confirm the diagnosis?

A. Elevated urine cortisol level
B. Low serum growth hormone level
C. Low serum insulin level
D. Elevated serum insulin-like growth factor-1 level (Correct Answer)
E. Elevated serum prolactin level

Explanation: ***Elevated serum insulin-like growth factor-1 level*** - The patient's symptoms (enlargement of nose, forehead, jaw, hands, and feet; headaches; hypertension; diabetes; bitemporal hemianopsia) are classic for **acromegaly**. - **Insulin-like growth factor-1 (IGF-1)** is the most reliable screening test for acromegaly because its levels are stable throughout the day and reflect integrated GH secretion; elevated levels significantly confirm the diagnosis. *Elevated urine cortisol level* - This would be indicative of **Cushing's syndrome**, which shares some features like hypertension and diabetes, but does not explain the characteristic acral and facial enlargement or the visual field defects. - The primary diagnostic test for Cushing's is via **cortisol measurement** (e.g., 24-hour urinary free cortisol, late-night salivary cortisol). *Low serum growth hormone level* - A **low serum growth hormone (GH) level** would rule out acromegaly, as acromegaly is caused by excessive GH production, typically from a pituitary adenoma. - While GH levels fluctuate, they are typically high in acromegaly, and a low level would be inconsistent with the clinical picture. *Low serum insulin level* - The patient has **diabetes mellitus**, which can be caused by various factors, but a low insulin level is characteristic of **Type 1 diabetes** or late-stage Type 2 diabetes with pancreatic burnout. - In acromegaly, **insulin resistance** is common due to excess GH, often leading to elevated or normal insulin levels to try and compensate for high glucose. *Elevated serum prolactin level* - An elevated serum prolactin level indicates **hyperprolactinemia**, which may coincide with acromegaly if the pituitary adenoma co-secretes prolactin (a mixed tumor) or if the GH-secreting tumor compresses the pituitary stalk. - However, **prolactin elevation alone** would not explain the acral growth and metabolic abnormalities specific to acromegaly.

Question 161: A 51-year-old woman comes to the physician because of swelling of her legs for 4 months. She first noticed the changes on the left leg, followed by the right leg. Sometimes her legs are itchy. She has a 1-month history of hoarseness. She returned from a trip to Mexico 8 months ago. She has a history of hypertension, constipation, and coronary artery disease. She works as a teacher at a primary school. Her mother had type-2 diabetes mellitus. She smoked one-half pack of cigarettes daily for 6 years but stopped smoking 11 years ago. She drinks one glass of wine daily and occasionally more on the weekend. Current medications include aspirin, bisoprolol, and atorvastatin. She is 165 cm (5 ft 5 in) tall and weighs 82 kg (181 lb); BMI is 30.1 kg/m2. Vital signs are within normal limits. Examination shows bilateral pretibial non-pitting edema. The skin is indurated, cool, and dry. Peripheral pulses are palpated bilaterally. The remainder of the examination shows no abnormalities. The patient is at increased risk for which of the following conditions?

A. Cardiovascular complications
B. Respiratory depression
C. Hypothermia
D. Cognitive impairment
E. Myxedema coma (Correct Answer)

Explanation: ***Myxedema coma*** - The patient's symptoms of **non-pitting pretibial edema**, **hoarseness**, **cold and dry skin**, along with **constipation** and elevated BMI (30.1), are highly suggestive of **severe hypothyroidism** - **Myxedema coma** is a life-threatening endocrine emergency representing the most severe manifestation of untreated hypothyroidism - This patient with undiagnosed/untreated hypothyroidism is at highest risk for progression to myxedema coma, particularly if exposed to precipitating factors (infection, cold exposure, medications, surgery) - Myxedema coma has high mortality (20-50%) and requires urgent recognition and treatment *Cardiovascular complications* - While hypothyroidism increases cardiovascular risk (bradycardia, pericardial effusion, heart failure), these are chronic complications - The patient already has coronary artery disease, but the question asks about increased risk given the current presentation of severe hypothyroidism - Myxedema coma represents a more immediate and life-threatening risk *Respiratory depression* - Respiratory depression can occur in severe hypothyroidism due to decreased respiratory drive and respiratory muscle weakness - However, respiratory depression is typically a **feature of myxedema coma** rather than a separate entity - Myxedema coma is the more comprehensive and critical diagnosis *Hypothermia* - Hypothermia is common in severe hypothyroidism due to decreased metabolic rate - However, hypothermia is an **associated finding** of myxedema coma, not a separate complication - Myxedema coma encompasses hypothermia along with altered mental status, cardiovascular collapse, and other systemic manifestations *Cognitive impairment* - Cognitive impairment (slowed thinking, memory problems, depression) can occur in chronic hypothyroidism - This is a less acute and less life-threatening manifestation compared to the severe metabolic decompensation of myxedema coma - Altered mental status in myxedema coma is more severe than chronic cognitive impairment

Question 162: A 35-year-old African American woman comes to the physician because of intermittent palpitations over the past 2 weeks. During this period she has also had constipation and has felt more tired than usual. She was diagnosed with hypertension 4 weeks ago and treatment with chlorthalidone was begun. Her temperature is 36.5°C (97.7°F), pulse is 75/min, and blood pressure is 158/97 mm Hg. Physical examination shows a soft and nontender abdomen. There is mild weakness of the upper and lower extremities. Deep tendon reflexes are 1+ bilaterally. Laboratory studies show: Hemoglobin 13.5 g/dL Leukocyte count 5,000/mm3 Serum Na+ 146 mEq/L Cl− 100 mEq/L K+ 2.8 mEq/L HCO3− 30 mEq/L Glucose 97 mg/dL Urea nitrogen 10 mg/dL Creatinine 0.8 mg/dL Test of the stool for occult blood is negative. An ECG shows premature atrial complexes. Chlorthalidone is discontinued and oral potassium chloride therapy is begun. One week later, the patient's plasma aldosterone concentration is 26 ng/dL (N=3.6 to 24.0 ng/dL) and plasma renin activity is 0.8 ng/mL/h (N=0.3 to 4.2 ng/mL/h). Which of the following is the most appropriate next step in management?

A. Perform adrenalectomy
B. Perform saline infusion test (Correct Answer)
C. Measure urine pH and anion gap
D. Perform CT scan of the abdomen
E. Perform dexamethasone suppression test

Explanation: ***Perform saline infusion test*** - The patient's **hypokalemia**, **hypertension**, and **high aldosterone-to-renin ratio (ARR)**, even after discontinuing chlorthalidone, are highly suggestive of **primary hyperaldosteronism (Conn's syndrome)**. - A **saline infusion test** is the most appropriate next step to confirm primary hyperaldosteronism by assessing **aldosterone suppressibility**. Failure to suppress aldosterone after saline infusion confirms the diagnosis. *Perform adrenalectomy* - Adrenalectomy is a treatment for aldosterone-producing adenomas, but it is not the next step before confirming the diagnosis and localizing the lesion. - The diagnosis of primary hyperaldosteronism first needs biochemical confirmation, usually with a saline suppression test. *Measure urine pH and anion gap* - Measuring urine pH and anion gap is useful in evaluating acid-base disorders or certain renal tubular conditions, but it is not directly relevant to diagnosing primary hyperaldosteronism. - The primary concern here is the workup of hypertension and hypokalemia with suspected endocrine etiology. *Perform CT scan of the abdomen* - While an abdominal CT scan is used to localize an adrenal adenoma, it should be done after biochemical confirmation of primary hyperaldosteronism. - Imaging should not precede diagnostic confirmation, as incidentalomas are common and may lead to unnecessary procedures. *Perform dexamethasone suppression test* - A dexamethasone suppression test is used to evaluate **Cushing's syndrome** (hypercortisolism), which is characterized by symptoms different from this patient's presentation. - This patient's symptoms of hypokalemia and hypertension point toward mineralocorticoid excess, not glucocorticoid excess.

Question 163: A 50-year-old woman comes to the physician for a follow-up examination. Two weeks ago she was seen for adjustment of her antihypertensive regimen and prescribed lisinopril because of persistently high blood pressure readings. A complete blood count and renal function checked at her last visit were within the normal limits. On questioning, she has had fatigue and frequent headaches over the last month. She has hypertension, type 2 diabetes mellitus, polycystic ovarian disease, and hyperlipidemia. Her mother has hyperthyroidism and hypertension. Current medications include amlodipine and hydrochlorothiazide at maximum doses, lisinopril, metformin, glimepiride, and atorvastatin. She has never smoked and drinks 1–2 glasses of wine with dinner every night. She is 167 cm (5 ft 5 inches) and weighs 81.6 kg (180 lbs); BMI is 30 kg/m2. Her blood pressure is 170/110 mm Hg in both arms, heart rate is 90/min, and respirations are 12/min. Examination shows an obese patient and no other abnormalities. Laboratory studies show: Hemoglobin 14 g/dL Leukocyte count 7,800/mm3 Serum Na+ 139 mEq/L K+ 3.4 mEq/L Cl- 100 mEq/L Creatinine 2.1 mg/dL Urea nitrogen 29 mg/dL TSH 3 μU/mL Urine Blood negative Protein negative Glucose 1+ Which of the following is the most likely diagnosis?

A. Obstructive sleep apnea
B. Diabetic kidney disease
C. Hyperthyroidism
D. Polycystic kidney disease
E. Renal artery stenosis (Correct Answer)

Explanation: ***Renal artery stenosis*** - The patient's **worsening hypertension** despite being on maximum doses of multiple antihypertensive medications (including ACE inhibitor lisinopril) and her **new-onset renal dysfunction** (elevated creatinine and BUN) are highly suggestive of renal artery stenosis. - The elevated blood pressure in both arms (170/110 mm Hg), combined with risk factors like **diabetes**, **hyperlipidemia**, and **obesity**, increases the likelihood of **atherosclerotic renovascular disease**. *Obstructive sleep apnea* - While **obesity** is a risk factor for obstructive sleep apnea and it can contribute to **hypertension**, it generally does not explain the **acute worsening of renal function** after starting an ACE inhibitor. - Patients typically present with snoring, daytime sleepiness, and witnessed apneic episodes, which are not mentioned here. *Diabetic kidney disease* - This patient has **diabetes**, which is a risk factor for nephropathy, but the **acute increase in creatinine** after initiation of an ACE inhibitor (lisinopril) points more towards a **hemodynamically mediated renal injury**, such as that seen in renal artery stenosis. - Diabetic kidney disease usually progresses over a longer period, often with **albuminuria**, which is absent in this patient (urine protein negative). *Hyperthyroidism* - The patient's **TSH is within normal limits** (3 μU/mL), making hyperthyroidism an unlikely diagnosis despite a family history. - Although hyperthyroidism can cause hypertension and fatigue, it would not explain the **acute renal dysfunction** observed. *Polycystic kidney disease* - **Polycystic kidney disease** is a genetic disorder typically diagnosed with **renal imaging** showing multiple cysts. - While it can cause hypertension and renal dysfunction, there is no mention of family history (other than for hyperthyroidism and hypertension) or imaging findings supportive of this diagnosis, and the **acute worsening with lisinopril** is not characteristic.

Question 164: A 35-year-old woman comes to the physician because of a 2-month history of progressive fatigue and intermittent abdominal pain. During this time, she has noticed that her urine is darker when she wakes up in the morning. Her stool is of normal color. Five months ago, she was diagnosed with type 2 diabetes mellitus, for which she takes metformin. Physical examination shows pallor and jaundice. There is no splenomegaly. Laboratory studies show: Hemoglobin 7.5 g/dL WBC count 3,500/mm3 Platelet count 100,000/mm3 Serum Creatinine 1.0 mg/dL Total bilirubin 6.0 mg/dL Direct bilirubin 0.2 mg/dl Lactate dehydrogenase 660 U/L Haptoglobin 18 mg/dL (N=41–165 mg/dL) Her urine is red, but urinalysis shows no RBCs. A Coombs test is negative. Peripheral blood smear shows no abnormalities. This patient is at greatest risk for which of the following complications?

A. Cholesterol gallstones
B. Acrocyanosis
C. Venous thrombosis (Correct Answer)
D. Chronic lymphocytic leukemia
E. Hepatocellular carcinoma

Explanation: ***Venous thrombosis*** - The patient's presentation with **fatigue**, **anemia** (Hb 7.5 g/dL), **thrombocytopenia** (platelets 100,000/mm³), **leukopenia** (WBC 3,500/mm³), **dark urine** without RBCs, **indirect hyperbilirubinemia** (total 6.0, direct 0.2), **elevated LDH**, and **low haptoglobin** points to **paroxysmal nocturnal hemoglobinuria (PNH)**. This diagnosis is supported by the **negative Coombs test**, which rules out autoimmune hemolytic anemia, and the absence of abnormalities on peripheral blood smear typical of other hemolytic anemias. - Patients with PNH have a significantly increased risk of developing **venous thromboses**, which can occur in unusual sites such as hepatic, mesenteric, or cerebral veins, and are a major cause of morbidity and mortality for this condition. *Cholesterol gallstones* - While patients with chronic hemolysis, particularly those with conditions like **sickle cell anemia** or **hereditary spherocytosis**, are at increased risk for **pigment gallstones** due to increased bilirubin, they are not typically at increased risk for cholesterol gallstones. - The type of hemolysis seen in PNH, which is primarily intravascular, drives the formation of pigment stones, but the primary acute complication risk is thrombosis. *Acrocyanosis* - **Acrocyanosis** is a benign condition characterized by persistent, painless, blue discoloration of the extremities due to vasospasm of small skin vessels, often exacerbated by cold. - It is not a recognized complication or association with the constellation of symptoms and laboratory findings presented in this patient's case, which strongly suggest a hematologic disorder like PNH. *Chronic lymphocytic leukemia* - The patient's **leukopenia** (WBC 3,500/mm³) is inconsistent with **chronic lymphocytic leukemia (CLL)**, which is characterized by a persistent and absolute **lymphocytosis**. - While CLL can sometimes be associated with autoimmune hemolytic anemia (positive Coombs test), the overall clinical picture, and specifically the degree of leukopenia, makes CLL unlikely. *Hepatocellular carcinoma* - **Hepatocellular carcinoma** is a liver cancer typically associated with chronic liver diseases such as **hepatitis B or C infection**, **alcohol abuse**, **hemochromatosis**, or **non-alcoholic fatty liver disease**. - There is no evidence in the patient's presentation (e.g., normal creatinine, absent splenomegaly) to suggest chronic liver disease or other risk factors for hepatocellular carcinoma.

Question 165: A 50-year-old female presents with a holosystolic murmur heard best over the apex, radiating to the axilla. She has no signs of pulmonary hypertension or edema. What best explains her lack of symptoms?

A. The aorta is compensating with increased compliance
B. Mitral valve prolapse without regurgitation causes no hemodynamic changes
C. The left atrium is compensating with increased compliance (Correct Answer)
D. As long as preload in the left ventricle is maintained there would be no symptoms
E. The right ventricle is compensating with decreased compliance

Explanation: ***The left atrium is compensating with increased compliance*** - In **mitral regurgitation**, the initial compensatory mechanism involves the **left atrium stretching and increasing its compliance** to accommodate the regurgitant volume. - This **prevents a significant rise in left atrial pressure**, thereby averting pulmonary congestion symptoms like edema or pulmonary hypertension. *The aorta is compensating with increased compliance* - **Aortic compliance** primarily affects **afterload** and is not a direct compensatory mechanism for mitral regurgitation. - While aortic stiffening can exacerbate cardiac workload, increased compliance wouldn't specifically mitigate symptoms arising from left atrial volume overload. *Mitral valve prolapse without regurgitation causes no hemodynamic changes* - A **holosystolic murmur** best heard at the apex and radiating to the axilla is characteristic of **mitral regurgitation**, indicating actual blood flow back into the atrium during systole. - **Mitral valve prolapse without regurgitation** might be silent or cause a mid-systolic click without significant hemodynamic changes, but this patient has clear evidence of regurgitation. *As long as preload in the left ventricle is maintained there would be no symptoms* - **Preload maintenance in the left ventricle** is important for maintaining cardiac output, but regurgitation itself diverts blood from forward flow. - Symptoms in mitral regurgitation often arise from **increased left atrial pressure** and subsequent pulmonary congestion, even if left ventricular preload is sufficient to maintain some forward flow. *The right ventricle is compensating with decreased compliance* - **Right ventricular compliance** is primarily relevant to conditions affecting the pulmonary circulation or right heart. - It would not directly compensate for left-sided volume overload in mitral regurgitation; in fact, prolonged left-sided heart failure can eventually lead to right ventricular dysfunction.

Question 166: A 68-year-old man presents to his primary care provider after noticing that his urine has been pink for the last week. He does not have any pain with urination, nor has he had any associated fevers or infections. On his review of systems, the patient notes that he thinks he has lost some weight since his belt is looser, and he has also had occasional dull pressure in his back for the past two months. His temperature is 98.8°F (37.1°C), blood pressure is 132/90 mmHg, pulse is 64/min, and respirations are 12/min. The patient weighs 210 lbs (95.3 kg, BMI 31.9 kg/m²), compared to his weight of 228 lbs (103.4 kg, BMI 34.7 kg/m²) at his last visit 2 years prior. On exam, the patient does not have any back or costovertebral angle tenderness. On abdominal palpation, a firm mass can be appreciated deep in the left abdomen. Given the suspected diagnosis, the clinical workup should also assess for which of the following paraneoplastic syndromes?

A. Hypercalcemia (Correct Answer)
B. Polycythemia
C. Anemia
D. Stauffer syndrome
E. Hypercortisolism

Explanation: ***Hypercalcemia*** - The patient's presentation with **painless hematuria**, unexplained weight loss, flank pain, and a palpable abdominal mass is highly suggestive of **renal cell carcinoma (RCC)**. - **Hypercalcemia** is the **most common paraneoplastic syndrome** associated with RCC, occurring in 10-20% of cases, often due to the tumor secreting **parathyroid hormone-related protein (PTHrP)**. - This is the most important metabolic abnormality to screen for in the initial workup. *Polycythemia* - While **polycythemia** can be a paraneoplastic syndrome in RCC due to **erythropoietin (EPO) production**, it occurs in only 3-10% of cases, making it less common than hypercalcemia. - The patient's symptoms do not specifically point to an excess red blood cell count. *Anemia* - **Anemia** is actually the most common hematologic finding in RCC (20-40% of cases), more common than polycythemia. - It represents a paraneoplastic effect related to chronic disease and inflammatory cytokines. - However, **hypercalcemia is the more critical paraneoplastic syndrome to assess** given its prognostic significance and need for intervention. *Stauffer syndrome* - **Stauffer syndrome** is a paraneoplastic syndrome associated with RCC characterized by **non-metastatic hepatic dysfunction** with elevated alkaline phosphatase and prolonged prothrombin time. - While it occurs in 3-20% of cases, **hypercalcemia is more common** and typically assessed first in the metabolic workup. *Hypercortisolism* - **Hypercortisolism (Cushing's syndrome)** is rarely associated with RCC; it is more typically seen with **small cell lung carcinoma** or **adrenal tumors** producing ectopic ACTH. - There are no symptoms mentioned in the patient's presentation to suggest excess cortisol production.

Question 167: A 52-year-old male presents to clinic with complaints of anxiety and fatigue for 4 months. He has also been experiencing palpitations, muscle weakness, increased sweating, and an increase in the frequency of defecation. Past medical history is insignificant. He neither consumes alcohol nor smokes cigarettes. His pulse is 104/min and irregular, blood pressure is 140/80 mm Hg. On examination, you notice that he has bilateral exophthalmos. There are fine tremors in both hands. Which of the following results would you expect to see on a thyroid panel?

A. High TSH; Low T4; Low T3
B. High TSH; High T4; High T3
C. Normal TSH; Low total T4; Normal Free T4 and T3
D. Low TSH; High T4; High T3 (Correct Answer)
E. Normal TSH; Low T4; Low T3

Explanation: ***Low TSH; High T4; High T3*** - The patient's symptoms (anxiety, fatigue, palpitations, muscle weakness, increased sweating, increased defecation frequency, tachycardia, hypertension, exophthalmos, fine tremors) are classic for **hyperthyroidism**, particularly **Graves' disease**. - In primary hyperthyroidism, the thyroid gland overproduces T3 and T4, leading to **high levels of T4 and T3**. This then causes a negative feedback loop to the pituitary, resulting in **suppressed (low) TSH** levels. *High TSH; Low T4; Low T3* - This pattern is indicative of **primary hypothyroidism**, where the thyroid gland is underactive and cannot produce sufficient T4 and T3, leading to low levels of these hormones and a compensatory rise in TSH. - The presented symptoms are directly opposite to those seen in hypothyroidism. *High TSH; High T4; High T3* - This combination is characteristic of **secondary hyperthyroidism**, which is much rarer and caused by a TSH-secreting pituitary adenoma. - While it presents with hyperthyroid symptoms, the TSH level would be elevated or inappropriately normal, not suppressed. *Normal TSH; Low total T4; Normal Free T4 and T3* - This pattern is often seen in **euthyroid sick syndrome** or conditions causing a decrease in thyroid-binding globulin (TBG). - The patient's clinical presentation is clearly that of hyperthyroidism, not a euthyroid state. *Normal TSH; Low T4; Low T3* - This result is atypical for any specific thyroid disorder and does not align with the patient's symptoms of hyperthyroidism, which demand high circulating thyroid hormone levels. - A "normal TSH, low T4, low T3" might suggest central hypothyroidism if TSH was inappropriately normal for the low thyroid hormones, but this patient's symptoms definitively point to thyroid hormone excess.

Question 168: A 52-year-old man with a history of Type 1 diabetes mellitus presents to the emergency room with increasing fatigue. Two days ago, he ran out of insulin and has not had time to obtain a new prescription. He denies fevers or chills. His temperature is 37.2 degrees Celsius, blood pressure 84/56 mmHg, heart rate 100/min, respiratory rate 20/min, and SpO2 97% on room air. His physical exam is otherwise within normal limits. An arterial blood gas analysis shows the following: pH 7.25, PCO2 29, PO2 95, HCO3- 15. Which of the following acid-base disorders is present?

A. Respiratory alkalosis with appropriate metabolic compensation
B. Respiratory acidosis with appropriate metabolic compensation
C. Mixed metabolic and respiratory acidosis
D. Metabolic acidosis with appropriate respiratory compensation (Correct Answer)
E. Metabolic alkalosis with appropriate respiratory compensation

Explanation: ***Metabolic acidosis with appropriate respiratory compensation*** - The patient's pH of 7.25 and HCO3- of 15 indicate **metabolic acidosis**, while the PCO2 of 29 indicates **respiratory compensation**. - The compensation is **appropriate** as suggested by Winter's formula [Expected PCO2 = (1.5 x HCO3-) + 8 +/- 2; (1.5 x 15) + 8 = 30.5, which is close to 29]. *Respiratory alkalosis with appropriate metabolic compensation* - This would involve a **pH > 7.45** and **low PCO2** with a secondary drop in HCO3-, which is not seen here. - The patient's primary problem is a metabolic disturbance due to insulin deficiency. *Respiratory acidosis with appropriate metabolic compensation* - This disorder is characterized by a **low pH** and a **high PCO2**, with a secondary rise in HCO3-. - The patient's PCO2 is low, indicating a compensatory response rather than a primary respiratory acidosis. *Mixed metabolic and respiratory acidosis* - A mixed disorder would show a **low pH** due to both **low HCO3-** and **high PCO2**. - The patient's PCO2 is low, indicating a compensatory response to metabolic acidosis, not an additional respiratory acidosis. *Metabolic alkalosis with appropriate respiratory compensation* - This would present with a **high pH (>7.45)** and **high HCO3-**, with compensatory **elevated PCO2**. - The patient's pH and HCO3- are low, indicating acidosis, not alkalosis.

Question 169: A 71-year-old woman comes to the physician because of sudden loss of vision in her right eye for 15 minutes that morning, which subsided spontaneously. Over the past 4 months, she has had fatigue, a 4-kg (8.8-lb) weight loss, and has woken up on several occasions at night covered in sweat. She has had frequent headaches and pain in her jaw while chewing for the past 2 months. She does not smoke or drink alcohol. Her temperature is 37.5°C (99.5°F), pulse is 88/min, and blood pressure is 118/78 mm Hg. Examination shows a visual acuity of 20/25 in the left eye and 20/30 in the right eye. The pupils are equal and reactive. There is no swelling of the optic discs. Her hemoglobin concentration is 10.5 g/dL, platelet count is 420,000/mm3, and erythrocyte sedimentation rate is 69 mm/h. The patient's condition puts her at the greatest risk of developing which of the following complications?

A. Pulmonary artery hypertension
B. Rapidly progressive glomerulonephritis
C. Thoracic aortic aneurysm (Correct Answer)
D. Internal carotid artery stenosis
E. Myocardial infarction

Explanation: ***Thoracic aortic aneurysm*** - This patient presents with symptoms highly suggestive of **giant cell arteritis (GCA)**, including sudden, transient vision loss (amaurosis fugax), jaw claudication, headaches, fatigue, weight loss, night sweats, and an elevated ESR. GCA is a **large-vessel vasculitis** that can affect the aorta. - **Aortic aneurysm and dissection** are serious long-term complications of GCA, affecting up to 15-30% of patients, with the thoracic aorta being particularly vulnerable. *Pulmonary artery hypertension* - While systemic inflammatory conditions can sometimes be associated with secondary pulmonary hypertension, it is **not a direct or common complication** of giant cell arteritis. - Pulmonary artery hypertension is more typically associated with conditions like **scleroderma**, chronic thromboembolic disease, or left heart failure. *Rapidly progressive glomerulonephritis* - This condition is characterized by a rapid decline in renal function and is typically seen in **ANCA-associated vasculitides** (e.g., granulomatosis with polyangiitis, microscopic polyangiitis) or anti-GBM disease. - While GCA is a vasculitis, it primarily affects **large and medium-sized arteries** and does not typically cause rapidly progressive glomerulonephritis. *Internal carotid artery stenosis* - While GCA can affect the **carotid arteries**, leading to symptoms like amaurosis fugax due to involvement of the ophthalmic artery (a branch of the internal carotid), it primarily causes **vasculitic inflammation** rather than typical atherosclerotic stenosis which is its own distinct complication. - The risk of an aneurysm in a large vessel like the aorta is a more distinct and severe systemic complication in this context than focal stenosis of the internal carotid due to the vasculitic process itself. *Myocardial infarction* - GCA can increase the risk of cardiovascular events due to sustained inflammation and potential accelerated atherosclerosis, but **myocardial infarction** is not the *greatest risk* or a direct, typical complication of the vasculitic process itself in the way an aortic aneurysm is. - The primary target of inflammation in GCA is the arterial wall, which directly predisposes to conditions like aneurysm and dissection, especially in the aorta.

Question 170: A 39-year-old female presents with confusion. Her husband reports that she doesn't know where she is and cannot remember the date. She was recently diagnosed with small cell lung cancer. Vital signs are T 37C, HR 80, BP 120/80 mmHg, RR 14, and O2 sat 99% on room air. She is not orthostatic. Physical examination reveals moist mucous membranes and normal capillary refill. A basic metabolic profile reveals that serum sodium is 129. Regarding this patient's illness, which of the following is true?

A. Urinary osmolarity will be < 100, and another potential cause of this disorder is excessive water drinking
B. Urinary sodium will be > 20 and another potential cause of this disorder is renal failure
C. Urinary sodium will be > 20 and fractional excretion of sodium will be >1%
D. Urinary osmolarity will be > 100, and this illness will not correct with normal saline infusion (Correct Answer)
E. Urinary sodium will be < 10, and fractional excretion of sodium will be <1%

Explanation: ***Urinary osmolarity will be > 100, and this illness will not correct with normal saline infusion*** - The patient's **hyponatremia** in the context of **small cell lung cancer** (a known cause of SIADH), euvolemia (normal vital signs, moist mucous membranes, normal capillary refill), suggests **SIADH**. In SIADH, **ADH** is inappropriately elevated, leading to water retention, dilute serum, and concentrated urine, so **urinary osmolarity will be > 100 mOsm/kg** (typically > 300 mOsm/kg). - Since SIADH involves excess free water retention due to inappropriate ADH secretion and not volume depletion, administering **normal saline (0.9%)** can actually worsen the hyponatremia by providing additional free water without addressing the underlying ADH excess. The appropriate treatment for symptomatic SIADH is **hypertonic saline (3%)**, fluid restriction, and addressing the underlying cause. *Urinary osmolarity will be < 100, and another potential cause of this disorder is excessive water drinking* - In SIADH, the presence of inappropriately high ADH leads to increased water reabsorption in the collecting ducts, resulting in **concentrated urine**; therefore, **urinary osmolarity will be > 100 mOsm/kg**, not < 100. - **Urinary osmolarity < 100 mOsm/kg** with hyponatremia suggests **primary polydipsia** (excessive water drinking), where ADH is appropriately suppressed and the kidneys produce maximally dilute urine. While polydipsia can cause hyponatremia, it is not consistent with the clinical picture of SIADH, where ADH is elevated and urine is concentrated. *Urinary sodium will be > 20 and another potential cause of this disorder is renal failure* - In SIADH, the kidneys continue to excrete sodium due to the expanded extracellular fluid volume even in the setting of hyponatremia, leading to a **urinary sodium concentration > 20 mEq/L** ✓. - While **renal failure** can cause hyponatremia due to impaired free water excretion, it typically presents with volume overload, elevated BUN/creatinine, and other findings not seen in this euvolemic patient with SIADH. Renal failure is not a typical "other cause" when discussing SIADH specifically. *Urinary sodium will be > 20 and fractional excretion of sodium will be >1%* - In SIADH, the body experiences perceived volume expansion, causing natriuresis despite low serum sodium, resulting in **urinary sodium > 20 mEq/L** ✓. - The **fractional excretion of sodium (FENa)** is typically **>1%** (usually 1-2%) in SIADH because the kidneys appropriately excrete sodium in response to the perceived volume expansion ✓. While this option is medically accurate for SIADH, it doesn't address the critical clinical point about treatment (that normal saline is contraindicated) and the urinary osmolarity, which are more defining diagnostic and therapeutic characteristics. *Urinary sodium will be < 10, and fractional excretion of sodium will be <1%* - **Urinary sodium < 10 mEq/L** and **FENa < 1%** typically indicate **hypovolemic hyponatremia** with effective arterial blood volume depletion (e.g., dehydration, heart failure, cirrhosis), where the kidneys are avidly conserving sodium and water. - This is **not consistent with SIADH**, which presents as **euvolemic hyponatremia** where the urine is concentrated (not maximally dilute) and sodium continues to be excreted, making these values incompatible with the diagnosis.

Question 171: A 70-year-old caucasian woman presents to her primary care provider complaining of a heavy cough with blood-tinged sputum. Her cough has bothered her for the last 2 weeks. Over the counter medications are no longer alleviating her symptoms. She also reports that she has unintentionally lost 6.8 kg (15 lb) in the last 5 months. Her past medical history is significant for peptic ulcer disease that was positive for H. pylori on biopsy and was treated with triple-drug therapy. She is a lifetime non-smoker and worked as a teacher before retiring at the age of 60. Today, her temperature is 36.9°C (98.4°F), blood pressure is 128/82 mm Hg, pulse is 87/min, and pulse oximetry is 90% on room air. On physical exam, her heart has a regular rate and rhythm. Auscultation of the lungs revealed scattered crackles and wheezes. A CT scan of the lungs shows an irregular mass in the peripheral region of the inferior lobe of the right lung and a CT guided biopsy is positive for malignant tissue architecture and gland formation with a significant amount of mucus. Which of the following risk factors most likely predisposed this patient to her condition?

A. Family history
B. Environmental exposure
C. Previous lung disease
D. Age (Correct Answer)
E. Smoking history

Explanation: ***Age*** - The risk of developing **lung cancer** increases significantly with age, with most diagnoses occurring in individuals over 65 years old. This 70-year-old patient falls directly into the high-risk age group. - While other risk factors exist, age is a universal and undeniable contributor to cancer risk due to accumulated cellular damage and mutations over time. *Smoking history* - The patient is explicitly stated to be a **lifetime non-smoker**, making smoking an unlikely risk factor for her lung cancer. - While smoking is the most significant risk factor for lung cancer, its absence here points to other etiologies. *Family history* - The vignette provides **no information regarding a family history** of lung cancer or other malignancies. - Without this information, family history cannot be confirmed or denied as a contributing factor. *Environmental exposure* - The patient worked as a teacher, which is generally not associated with significant **environmental carcinogen exposure** linked to lung cancer (e.g., asbestos, radon). - While possible, there is no evidence presented in the case to suggest environmental exposure as a primary risk factor. *Previous lung disease* - The patient's history is significant for **peptic ulcer disease**, which is unrelated to lung pathology and does not increase the risk of lung cancer. - Previous lung diseases like chronic obstructive pulmonary disease (COPD) or pulmonary fibrosis can increase lung cancer risk, but these are not mentioned for this patient.

Question 172: A 23-year-old man comes to the physician because of lightening of his skin on both hands, under his eyes, and on his neck for 2 years. During this period the lesions slowly grew in size. There is no itchiness or pain. He regularly visits his family in India. Vital signs are within normal limits. Examination shows sharply demarcated, depigmented skin patches on the dorsum of both hands, in the periocular region, and on the neck. Sensation of the skin is intact. The lesions fluorescence blue-white under Wood's lamp. Which of the following findings is most likely to be associated with this patient's diagnosis?

A. Renal angiomyolipoma on abdominal MRI
B. Decreased pigment with normal melanocyte count
C. Elevated anti-TPO antibody levels (Correct Answer)
D. “Spaghetti and meatballs” appearance on KOH scraping
E. Poorly developed retinal pigment epithelium

Explanation: ***Elevated anti-TPO antibody levels*** - This patient's symptoms are highly suggestive of **vitiligo**, characterized by **sharply demarcated, depigmented skin patches** that fluorescence blue-white under Wood's lamp. - Vitiligo is an **autoimmune disease** often associated with other autoimmune conditions, particularly **Hashimoto's thyroiditis**, which is indicated by elevated **anti-thyroid peroxidase (anti-TPO) antibody levels**. *Renal angiomyolipoma on abdominal MRI* - **Renal angiomyolipomas** are benign tumors strongly associated with **tuberous sclerosis complex**, a genetic disorder with distinctive skin lesions like **ash-leaf spots** and facial angiofibromas, which are not described here. - The depigmentation in tuberous sclerosis is typically well-circumscribed but does not have the progressing, widespread nature seen in vitiligo. *Decreased pigment with normal melanocyte count* - This finding describes **post-inflammatory hypopigmentation** or certain forms of albinism, where melanocytes are present but produce less melanin. - In **vitiligo**, the characteristic pathology is the **destruction of melanocytes**, leading to a complete absence of pigment in the affected areas. *"Spaghetti and meatballs" appearance on KOH scraping* - The "spaghetti and meatballs" appearance refers to **hyphae and spores** of *Malassezia* species, typically observed in **tinea versicolor**, a superficial fungal infection. - Tinea versicolor presents with hypo- or hyperpigmented patches, but they are usually **fine and scaly**, and the depigmentation is due to fungal interference with melanocyte function, not melanocyte destruction. *Poorly developed retinal pigment epithelium* - Poorly developed or absent **retinal pigment epithelium** is a hallmark of **ocular albinism** or **oculocutaneous albinism**. - These conditions are characterized by generalized hypopigmentation (or absence of pigment) of the skin, hair, and eyes from birth, which differs significantly from the progressive, patchy depigmentation of vitiligo.

Question 173: A 50-year-old man comes to the physician because of diffuse weakness for the past several months. There is an anterior mediastinal mass on a lateral x-ray of the chest that was performed as part of a pre-employment medical evaluation. He has gastroesophageal reflux disease. His only medication is rabeprazole. He is 178 cm (5 ft 10 in) tall and weighs 77 kg (170 lb); BMI is 24.3 kg/m2. Vital signs are within normal limits. There is no cervical or axillary lymphadenopathy. Cardiopulmonary examination shows no abnormalities. The abdomen is soft and nontender; there is no splenomegaly. Further evaluation of this patient is most likely to show which of the following?

A. Increased urinary catecholamines
B. Elevated TSH and a nodular anterior cervical mass
C. Elevated serum alpha-fetoprotein level
D. Acetylcholine receptor antibodies (Correct Answer)
E. Fever, night sweats, and weight loss

Explanation: ***Acetylcholine receptor antibodies*** - The patient's **diffuse weakness** lasting several months, in conjunction with an **anterior mediastinal mass**, is highly suggestive of **myasthenia gravis**. - Myasthenia gravis is an autoimmune disorder often associated with **thymoma** (an anterior mediastinal mass) and is characterized by **autoantibodies against acetylcholine receptors** at the neuromuscular junction. *Increased urinary catecholamines* - Increased urinary catecholamines are indicative of a **pheochromocytoma**, a tumor of the adrenal medulla, which typically presents with **paroxysmal hypertension**, headaches, and palpitations. - These symptoms are not described in the patient, and a pheochromocytoma is not associated with an anterior mediastinal mass or generalized weakness in this manner. *Elevated TSH and a nodular anterior cervical mass* - Elevated TSH and a nodular anterior cervical mass point towards a **thyroid disorder**, such as **hypothyroidism** with a goiter or a thyroid nodule. - While hypothyroidism can cause weakness, it does not typically present with an **anterior mediastinal mass**, and the clinical picture does not align with thyroid pathology. *Elevated serum alpha-fetoprotein level* - Elevated serum **alpha-fetoprotein (AFP)** is primarily a tumor marker for **hepatocellular carcinoma** or **germ cell tumors**, such as testicular or ovarian cancer. - This finding is unrelated to an anterior mediastinal mass or the diffuse weakness described in the patient. *Fever, night sweats, and weight loss* - **Fever, night sweats, and weight loss** (B symptoms) are classic systemic signs associated with **lymphoma** and some other malignancies. - While an anterior mediastinal mass could be a lymphoma, the primary symptom of **diffuse weakness** strongly points away from lymphoma as the initial leading diagnosis and towards a paraneoplastic syndrome like myasthenia gravis, given the specific presentation.

Question 174: A 52-year-old Caucasian man with hypertension comes to the physician because of frequent urination and increased thirst. He drinks 4 oz of alcohol daily and has smoked 1 pack of cigarettes daily for the past 30 years. He is 180 cm (5 ft 10 in) tall and weighs 106 kg (233 lb); BMI is 33 kg/m2. His blood pressure is 130/80 mm Hg. Laboratory studies show a hemoglobin A1c of 8.5%. Which of the following is the most likely predisposing factor for this patient's condition?

A. High calorie diet (Correct Answer)
B. Alcohol consumption
C. Smoking history
D. Caucasian ethnicity
E. HLA-DR4 status

Explanation: ***High calorie diet*** - This patient presents with **Type 2 Diabetes Mellitus**, evidenced by **polyuria**, **polydipsia**, and **HbA1c of 8.5%** (diagnostic threshold >6.5%). - **Obesity** (BMI 33 kg/m²) resulting from chronic high-calorie intake is the **most significant predisposing factor** for Type 2 DM, as it leads to **insulin resistance** through adipose tissue accumulation and inflammatory cytokine release. - Among all the listed risk factors, obesity from dietary excess is the **strongest and most direct modifiable risk factor** for developing Type 2 DM. *Alcohol consumption* - Moderate alcohol intake (4 oz daily) is not a primary predisposing factor for Type 2 DM. - Excessive chronic alcohol consumption can affect glucose metabolism and contribute to pancreatitis-related diabetes, but this patient's moderate intake is not the primary driver of his condition. *Smoking history* - Smoking increases risk of **cardiovascular complications** and worsens diabetes outcomes, but it is not the primary predisposing factor for **developing** Type 2 DM. - The strongest association with DM onset is obesity and insulin resistance, not smoking. *Caucasian ethnicity* - Caucasian ethnicity confers **lower risk** for Type 2 DM compared to African American, Hispanic, Native American, and Asian populations. - While genetic factors play a role, Caucasian ethnicity is not a specific predisposing factor in this case. *HLA-DR4 status* - **HLA-DR4** is strongly associated with **Type 1 Diabetes Mellitus**, an autoimmune condition typically presenting in younger patients with absolute insulin deficiency. - This patient's age, obesity, and clinical presentation are classic for **Type 2 DM**, which has no association with HLA-DR4.

Question 175: An 80-year-old man presents to the emergency department because of gnawing substernal chest pain that started an hour ago and radiates to his neck and left jaw. A 12-lead ECG is obtained and shows ST-segment elevation with newly developing Q waves. He is admitted for treatment. 4 days after hospitalization he suddenly develops altered mental status, and his blood pressure falls from 115/75 mm Hg to 80/40 mm Hg. Physical examination shows jugular venous distention, pulsus paradoxus, and distant heart sounds. What is the most likely cause of this patient's condition?

A. Pericardial inflammation
B. Compression of heart chambers by blood in the pericardial space (Correct Answer)
C. Arrhythmia caused by ventricular fibrillation
D. Rupture of papillary muscle
E. Acute pulmonary edema from left heart failure

Explanation: ***Compression of heart chambers by blood in the pericardial space*** - The patient's initial presentation with ST-elevation myocardial infarction (STEMI) and subsequent development of **hypotension**, **jugular venous distention**, **pulsus paradoxus**, and **distant heart sounds** (Beck's triad) is highly indicative of **cardiac tamponade.** - In the context of a recent MI, this constellation of symptoms strongly suggests a **cardiac free wall rupture**, leading to blood accumulation in the pericardial sac and compression of the heart. - Free wall rupture typically occurs **3-7 days post-MI** and is a life-threatening mechanical complication. *Pericardial inflammation* - While pericardial inflammation (pericarditis) can occur post-MI, it typically manifests with **pleuritic chest pain** that is relieved by leaning forward and is often associated with a **pericardial friction rub.** - It does not typically lead to acute, severe hypotension, pulsus paradoxus, or sudden circulatory collapse in this manner without significant effusion and tamponade physiology. *Arrhythmia caused by ventricular fibrillation* - **Ventricular fibrillation** would cause immediate cardiac arrest and loss of consciousness, not a gradual development of hypotension, JVD, and pulsus paradoxus. - While arrhythmias are common post-MI, the specific physical findings point away from isolated VFib as the primary cause of hemodynamic collapse. *Acute pulmonary edema from left heart failure* - **Acute pulmonary edema** is a manifestation of **left heart failure**, characterized by severe dyspnea, orthopnea, and crackles on lung auscultation. - While left heart failure can cause hypotension in cardiogenic shock, it would not typically present with the classic signs of cardiac tamponade such as pulsus paradoxus, distant heart sounds, and prominent JVD without pulmonary congestion findings. *Rupture of papillary muscle* - **Papillary muscle rupture** leads to severe **acute mitral regurgitation**, causing acute pulmonary edema, a new holosystolic murmur, and often cardiogenic shock. - While it can lead to hypotension, it doesn't typically present with the classic signs of cardiac tamponade such as pulsus paradoxus and distant heart sounds; instead, a loud murmur would be prominent.

Question 176: A 61-year-old woman comes to the physician because of a 1-week history of dizziness, nausea, vomiting, and repeated falls. Neurologic examination shows past-pointing on a finger-nose test. She has a broad-based gait. Ophthalmologic exam shows rhythmic leftward movement of the globes. A serum antibody assay is positive for anti-Yo antibodies directed at proteins expressed by Purkinje cells. This patient's condition is most likely associated with which of the following tumors?

A. Small cell lung cancer
B. Breast cancer (Correct Answer)
C. Neuroblastoma
D. Ovarian teratoma
E. Thymoma

Explanation: ***Breast cancer*** - **Anti-Yo antibodies**, also known as anti-Purkinje cell cytoplasmic antibodies type 1 (PCA-1), are strongly associated with **paraneoplastic cerebellar degeneration** that most commonly occurs in patients with **breast or gynecological cancers** (particularly ovarian carcinoma). - The patient's symptoms of **dizziness, nausea, vomiting, repeated falls, past-pointing, broad-based gait**, and **nystagmus** are classic signs of cerebellar dysfunction, which is consistent with paraneoplastic cerebellar degeneration. *Small cell lung cancer* - Small cell lung cancer is more commonly associated with other paraneoplastic syndromes and antibodies, such as **Lambert-Eaton myasthenic syndrome (anti-voltage-gated calcium channel antibodies)** or **paraneoplastic encephalomyelitis/sensory neuronopathy (anti-Hu antibodies)**. - While it can cause paraneoplastic cerebellar degeneration, it is not the most frequent tumor type associated with **anti-Yo antibodies**. *Neuroblastoma* - Neuroblastoma is typically found in **children** and is associated with **opsoclonus-myoclonus syndrome (anti-Ri antibodies)**, not anti-Yo antibodies or cerebellar degeneration in an adult. - This patient is a 61-year-old woman, making neuroblastoma highly unlikely. *Ovarian teratoma* - Ovarian **teratoma** is strongly associated with **anti-NMDA receptor encephalitis**, which presents with psychiatric symptoms, seizures, and dyskinesias, different from the cerebellar signs seen here. - Anti-Yo antibodies are associated with **ovarian carcinoma** (epithelial ovarian cancer), not teratomas. The distinction between teratoma and carcinoma is important in paraneoplastic syndromes. *Thymoma* - Thymoma is classically linked to **myasthenia gravis (anti-acetylcholine receptor antibodies)**, which causes fluctuating muscle weakness, not cerebellar dysfunction. - It is not associated with **anti-Yo antibodies** or paraneoplastic cerebellar degeneration.

Question 177: A 48-year-old man presents to the ER with a sudden-onset, severe headache. He is vomiting and appears confused. His wife, who accompanied him, says that he has not had any trauma, and that the patient has no relevant family history. He undergoes a non-contrast head CT that shows blood between the arachnoid and pia mater. What is the most likely complication from this condition?

A. Hemorrhagic shock
B. Arterial Vasospasm (Correct Answer)
C. Renal failure
D. Bacterial Meningitis
E. Blindness

Explanation: **Arterial Vasospasm** - **Arterial vasospasm** is a major delayed complication of **subarachnoid hemorrhage (SAH)**, typically occurring 3-14 days after the initial bleed. - The presence of blood products in the subarachnoid space can irritate cerebral arteries, leading to their narrowing and subsequent **delayed cerebral ischemia** or infarction. *Hemorrhagic shock* - **Subarachnoid hemorrhage (SAH)** typically involves bleeding within the confines of the skull, which is usually not extensive enough to cause systemic **hypovolemia** or **hemorrhagic shock**. - **Hemorrhagic shock** would require significant external blood loss or internal bleeding into a large body cavity, which is not characteristic of an isolated SAH. *Renal failure* - **Renal failure** is not a direct or common complication of **subarachnoid hemorrhage (SAH)**. - While systemic complications can sometimes arise in critically ill patients, there is no direct pathophysiological link between SAH and primary kidney injury. *Bacterial Meningitis* - The presence of blood in the **subarachnoid space** can cause a **chemical meningitis** due to irritation, mimicking some symptoms of bacterial meningitis. - However, it does not typically predispose to **bacterial infection** unless there's an iatrogenic cause (e.g., lumbar puncture contamination). *Blindness* - While damage to the **optic nerves** or visual pathways can occur with severe neurological events or increased intracranial pressure, **blindness** is not a common or direct complication specifically arising from the bleed itself or its immediate sequelae in SAH. - Visual disturbances are possible due to elevated **intracranial pressure** or specific anatomical lesion, but not primary blindness.

Question 178: A 27-year-old diabetic male rushes to the emergency department after finding his blood glucose level to be 492 mg/dL which is reconfirmed in the ED. He currently does not have any complaints except for a mild colicky abdominal pain. His temperature is 37°C (98.6°F), respirations are 15/min, pulse is 67/min, and blood pressure is 122/88 mm Hg. Blood is drawn for labs the result of which is given below: Serum: pH 7.0 pCO2 32 mm Hg HCO3- 15.2 mEq/L Sodium 122 mEq/L Potassium 4.8 mEq/L Urinalysis is positive for ketone bodies. He is admitted to the hospital and given intravenous bicarbonate and then started on an insulin drip and normal saline. 7 hours later, he is found to be confused and complaining of a severe headache. His temperature is 37°C (98.6°F), pulse is 50/min, respirations are 13/min and irregular, and blood pressure is 137/95 mm Hg. What other examination findings would be expected in this patient?

A. Pancreatitis
B. Pupillary constriction
C. Hypoglycemia
D. Peripheral edema
E. Papilledema (Correct Answer)

Explanation: ***Papilledema*** - The patient's presentation with **confusion**, **severe headache**, **bradycardia**, **irregular respirations**, and **elevated blood pressure** (Cushing's triad) 7 hours after treatment for **diabetic ketoacidosis (DKA)** suggests increased intracranial pressure due to **cerebral edema**. - **Papilledema** is a key ophthalmoscopic finding in significant cerebral edema, resulting from increased intracranial pressure transmitted to the optic nerve sheath. *Pancreatitis* - Pancreatitis can cause abdominal pain and may be associated with DKA, but the acute neurological deterioration with signs of increased intracranial pressure after initial treatment points away from pancreatitis as the primary expected finding at this stage. - While initial mild colicky abdominal pain could suggest pancreatitis, the late-onset confusion, headache, and vital sign changes following DKA treatment are not characteristic of pancreatitis, but rather of a severe neurological complication. *Pupillary constriction* - **Pupillary constriction** (miosis) can be associated with opioid overdose, pontine lesions, or certain medications, but it is not a direct or expected finding in cerebral edema causing increased intracranial pressure. - In cerebral edema, pupils are more likely to be dilated or unequal, especially if there is uncal herniation. *Hypoglycemia* - While **hypoglycemia** can occur with insulin therapy, leading to confusion and neurological symptoms, the patient's blood pressure is elevated and heart rate is low (bradycardia), which are not typical signs of hypoglycemia. - Hypoglycemia usually presents with sympathetic activation (tachycardia, diaphoresis) before progressing to bradycardia in severe cases, but the associated hypertension and irregular breathing pattern are more indicative of increased intracranial pressure. *Peripheral edema* - **Peripheral edema** is swelling in the extremities and is generally due to fluid overload, heart failure, kidney disease, or liver disease. - While fluid administration during DKA treatment could potentially lead to some fluid retention, it does not explain the acute neurological deterioration, headache, and vital sign changes (Cushing's triad) seen in this patient, which are far more characteristic of cerebral edema.

Question 179: A 57-year-old construction worker presents with gradually worsening shortness of breath for the past several months and left pleuritic chest pain for 2 weeks. He denies fever, cough, night sweats, wheezing, or smoking. He is recently diagnosed with hypertension and started amlodipine 10 days ago. He has been working in construction for the last 25 years and before that, he worked at a ship dry-dock for 15 years. Physical exam reveals bilateral crackles at the lung bases. Chest X-ray reveals bilateral infiltrates at the lung bases. Pulmonary function tests show a slightly increased FEV1/FVC ratio, but total lung volume is decreased. CT scan shows pleural scarring. What of the following conditions is the most likely explanation in this case?

A. Asbestosis (Correct Answer)
B. Allergic bronchopulmonary aspergillosis
C. Sarcoidosis
D. Tuberculosis
E. Drug-induced interstitial lung disease

Explanation: ***Asbestosis*** - The patient's 15-year history of working at a **ship dry-dock**, a high-risk occupation for **asbestos exposure**, and the absence of smoking are highly suggestive. The presence of **gradually worsening shortness of breath**, **bilateral crackles**, **bilateral infiltrates at lung bases**, **decreased total lung volume**, and **pleural scarring** on CT are classic findings. - **Decreased total lung volume** with a normal or slightly increased FEV1/FVC ratio indicates a **restrictive lung disease**, which is characteristic of asbestosis. *Allergic bronchopulmonary aspergillosis* - This condition is typically associated with **asthma** or **cystic fibrosis**, characterized by **wheezing**, tenacious sputum, and **migratory infiltrates**, none of which are present in this case. - Diagnosis involves elevated IgE levels, positive *Aspergillus* precipitins, and peripheral eosinophilia, which are not described. *Sarcoidosis* - Sarcoidosis often presents with **hilar lymphadenopathy**, erythema nodosum, and systemic symptoms like fever and weight loss, which are absent here. - While it can cause interstitial lung disease, the occupational exposure history and specific CT findings like pleural scarring point away from sarcoidosis. *Tuberculosis* - Tuberculosis usually presents with **fever, night sweats, cough, and weight loss**, which the patient denies. - Chest X-ray typically shows **apical infiltrates**, cavitations, or granulomas, differing from the basilar infiltrates and pleural scarring seen here. *Drug-induced interstitial lung disease* - While several drugs can cause interstitial lung disease, amlodipine (started recently) is not a common cause, and its onset is very recent compared to the patient's gradually worsening symptoms. - The extensive occupational exposure history and characteristic CT findings make an alternative, more common cause much more likely.

Question 180: A 17-year-old boy comes to the physician for a follow-up visit. Two days ago, he had a routine health maintenance examination that showed 3+ proteinuria on urine dipstick testing. During the initial routine examination, the patient reported feeling well, apart from being exhausted from his day at work. He had an upper respiratory infection 1 month ago, which resolved spontaneously within 5 days of onset. He has no history of serious illness. He works as an intern at a shooting range, where he does not usually use appropriate hearing protection. Today, he appears tired and complains about the early morning doctor's appointment. He is 170 cm (5 ft 7 in) tall and weighs 81.5 kg (180 lb); BMI is 28 kg/m2. His temperature is 37°C (98.6°F), pulse is 72/min, and blood pressure is 118/70 mm Hg. Examination shows facial acne. There is mild sensorineural hearing loss bilaterally. The remainder of the examination shows no abnormalities. Laboratory studies show: Serum Urea 8 mg/dL Creatinine 1.0 mg/dL Urine Glucose negative Protein 1+ Blood negative Nitrite negative Leukocytes negative pH 6.0 Specific gravity 1.005 Which of the following is the most likely explanation for this patient's findings?

A. Standing for long periods of time
B. Subepithelial immune complex depositions
C. Increased production of low molecular weight proteins
D. Loss of negative charge on the glomerular basement membrane
E. Splitting of the glomerular basement membrane (Correct Answer)

Explanation: ***Splitting of the glomerular basement membrane*** - This patient's combination of **bilateral sensorineural hearing loss** and **persistent proteinuria** (3+ initially, 1+ on repeat) in a young male is most consistent with **Alport syndrome**, an X-linked disorder caused by defective **type IV collagen** leading to splitting of the glomerular basement membrane. - While occupational noise exposure at the shooting range could contribute to hearing loss, **bilateral sensorineural hearing loss in a 17-year-old** is unusual from occupational causes alone at this age and typically requires prolonged exposure. The combination with proteinuria makes Alport syndrome the most likely unifying diagnosis. - The decrease in proteinuria (3+ → 1+) may reflect the dilute urine specimen (specific gravity 1.005) rather than resolution. Alport syndrome typically presents with microscopic hematuria and progressive proteinuria, though early disease can have variable presentation. *Standing for long periods of time* - **Orthostatic (postural) proteinuria** is common in adolescents and characterized by proteinuria when upright that resolves when supine. The patient works as an intern (prolonged standing) and had 3+ proteinuria when "exhausted from work" versus 1+ at an early morning appointment. - However, orthostatic proteinuria would not explain the **bilateral sensorineural hearing loss**, which is the key distinguishing feature. The hearing loss requires an explanation, making a systemic disorder like Alport syndrome more likely. *Subepithelial immune complex depositions* - Characteristic of **post-streptococcal glomerulonephritis** or **membranous nephropathy**. - These conditions typically present with **hematuria** (absent here), more significant proteinuria with nephrotic-range in membranous disease, and do not cause sensorineural hearing loss. - The recent URI was 1 month ago and resolved spontaneously, making post-infectious GN less likely. *Increased production of low molecular weight proteins* - This occurs in **overflow proteinuria** from conditions like **multiple myeloma** (light chain overproduction). - This patient's age (17 years) makes plasma cell dyscrasias extremely unlikely, and this would not explain the sensorineural hearing loss. *Loss of negative charge on the glomerular basement membrane* - This is the pathophysiologic mechanism of **minimal change disease**, causing selective loss of albumin. - Minimal change disease typically presents with **nephrotic syndrome** (heavy proteinuria >3.5 g/day, edema, hypoalbuminemia), which is not present here. - It does not explain the **bilateral sensorineural hearing loss**, which is the critical clinical clue in this case.

Question 181: A 71-year-old woman presents with a transient episode of right arm and hand weakness that resolved in approximately one hour. Her symptoms started while she was gardening. Her past medical history is notable for hypertension, diabetes, anxiety, and dyslipidemia. Her current medications include insulin, metformin, and fluoxetine. Examination reveals a left carotid bruit. Ultrasound duplex of her carotid arteries demonstrates right and left carotid stenosis of 35% and 50%, respectively. Which of the following is the best next step in management?

A. Bilateral carotid endarterectomy
B. Left carotid endarterectomy only
C. Aspirin (Correct Answer)
D. Observation
E. Warfarin

Explanation: ***Aspirin*** - This patient suffered a **transient ischemic attack (TIA)** given her transient focal neurological deficit. Given that her carotid stenosis is **moderate (35% and 50%)**, **antiplatelet therapy** with aspirin is the initial and best next step to prevent future strokes. - Aspirin helps prevent platelet aggregation, reducing the risk of **thrombus formation** in already stenotic vessels. *Bilateral carotid endarterectomy* - This is not the best next step, as **carotid endarterectomy** is generally reserved for symptomatic patients with **high-grade stenosis** (e.g., typically >70%). - Performing bilateral procedures at once carries higher risks than staged procedures or medical management for moderate stenosis. *Left carotid endarterectomy only* - This is not indicated. While symptoms occurred on the right side (implying a left-sided lesion), a **left carotid endarterectomy** is primarily considered for **high-grade stenosis** in symptomatic patients. - Her left carotid stenosis is 50%, which is considered moderate and not an immediate indication for surgery. *Observation* - This is inappropriate as the patient has experienced a **TIA**, indicating a high risk of future stroke. - Without intervention, including antiplatelet therapy, the risk of a debilitating stroke is significantly increased. *Warfarin* - **Warfarin** is an anticoagulant used for conditions like atrial fibrillation or deep vein thrombosis but is **not the primary treatment for TIA due to carotid stenosis**. - Its use in this context may increase the risk of bleeding without providing superior benefit to aspirin in preventing arterial clots from carotid plaques.

Question 182: A 65-year-old woman comes to the emergency department because of blurry vision for 10 hours. She has also had urinary urgency and discomfort while urinating for the past 4 days. She has been feeling increasingly weak and nauseous since yesterday. She has a history of type 2 diabetes mellitus and arterial hypertension. One year ago she was treated for an infection of her eyes. She drinks 2–3 glasses of wine weekly. Current medications include captopril, metoprolol, metformin, and insulin. Her temperature is 37.5°C (99.5°F), pulse is 107/min, and blood pressure is 95/70 mm Hg. Visual acuity is decreased in both eyes. The pupils are equal and reactive to light. The corneal reflexes are brisk. The mucous membranes of the mouth are dry. The abdomen is soft and not distended. Cardiopulmonary examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Alcoholic ketoacidosis
B. Hypoglycemia
C. Ischemic optic neuropathy
D. Hyperosmolar hyperglycemic state (Correct Answer)
E. Posterior uveitis

Explanation: ***Hyperosmolar hyperglycemic state*** - The patient's history of **type 2 diabetes mellitus**, recent **infection** (urinary urgency and discomfort), blurry vision, weakness, nausea, and signs of **dehydration** (dry mucous membranes, hypotension, tachycardia) are all consistent with Hyperosmolar Hyperglycemic State (HHS). - HHS is characterized by severe hyperglycemia, hyperosmolarity, and dehydration without significant ketoacidosis, often triggered by stress such as infection in patients with T2DM. *Alcoholic ketoacidosis* - Although the patient drinks wine, the amount (2-3 glasses weekly) is not typically sufficient to induce **alcoholic ketoacidosis**. - Alcoholic ketoacidosis usually occurs in chronic alcoholics after an acute reduction in alcohol intake and inadequate nutritional intake, leading to elevated anion gap metabolic acidosis. *Hypoglycemia* - While patients on insulin and metformin are at risk for hypoglycemia, the presented symptoms of **dehydration**, sustained **blurry vision**, and **weakness** over an extended period (10 hours) are not typical for hypoglycemia, which usually presents with rapid onset neuroglycopenic symptoms and resolves quickly with glucose. - The patient's symptoms are more indicative of a state of high blood glucose rather than low. *Ischemic optic neuropathy* - This condition causes **sudden, painless vision loss** due to infarction of the optic nerve, often associated with diabetes and hypertension. - While the patient has blurry vision and risk factors, the presence of systemic symptoms like **urinary infection**, **nausea**, and **dehydration** points to a broader metabolic derangement rather than an isolated ocular event. *Posterior uveitis* - Posterior uveitis involves **inflammation of the choroid and retina**, which can cause blurry vision, floaters, and photophobia. - However, there are no signs of inflammation (e.g., pain, redness), and the systemic symptoms of **dehydration and infection** are not directly explained by uveitis, making a metabolic cause more likely given the patient's diabetes.

Question 183: A 56-year-old woman comes to the physician for follow-up after a measurement of elevated blood pressure at her last visit three months ago. She works as a high school teacher at a local school. She says that she mostly eats cafeteria food and take-out. She denies any regular physical activity. She does not smoke or use any recreational drugs. She drinks 2 to 3 glasses of wine per day. She has hypercholesterolemia for which she takes atorvastatin. Her height is 165 cm (5 ft 5 in), weight is 82 kg (181 lb), and BMI is 30.1 kg/m2. Her pulse is 67/min, respirations are 18/min, and blood pressure is 152/87 mm Hg on the right arm and 155/92 mm Hg on the left arm. She would like to try lifestyle modifications to improve her blood pressure before considering pharmacologic therapy. Which of the following lifestyle modifications is most likely to result in the greatest reduction of this patient's systolic blood pressure?

A. Walking for 30 minutes, 5 days per week
B. Reducing sodium intake to less than 2.4 g per day
C. Losing 15 kg (33 lb) of body weight (Correct Answer)
D. Adopting a DASH diet
E. Decreasing alcohol consumption to maximum of one drink per day

Explanation: ***Losing 15 kg (33 lb) of body weight*** - **Weight reduction** is the most effective lifestyle modification for lowering blood pressure, correlating directly with the amount of weight lost. - A loss of 15 kg (33 lb) in this patient, who is **obese (BMI 30.1)**, could significantly reduce her systolic blood pressure, potentially by 5-20 mmHg per 10 kg weight loss. *Walking for 30 minutes, 5 days per week* - Regular **aerobic physical activity** is beneficial for blood pressure reduction, typically resulting in a 4-9 mmHg decrease in systolic pressure. - While helpful, the magnitude of reduction from exercise alone is generally less than that achieved with significant weight loss in an obese individual. *Reducing sodium intake to less than 2.4 g per day* - **Sodium restriction** is an effective strategy, often leading to a 2-8 mmHg reduction in systolic blood pressure. - Given the patient's diet of cafeteria and take-out food, high sodium intake is likely, making this a relevant intervention, but typically less impactful than substantial weight loss. *Adopting a DASH diet* - The **Dietary Approaches to Stop Hypertension (DASH) diet** emphasizes fruits, vegetables, and low-fat dairy, and can significantly lower blood pressure, by 8-14 mmHg. - This diet is highly effective, but for an obese individual, the blood pressure reduction from achieving a healthy weight is often greater. *Decreasing alcohol consumption to maximum of one drink per day* - Reducing **excessive alcohol intake** can decrease systolic blood pressure by 2-4 mmHg, as the patient reports 2-3 glasses of wine daily. - While beneficial, this reduction is likely to be less substantial compared to major weight loss or other dietary changes.

Question 184: A 7-year-old boy is brought to the physician for a follow-up examination after the removal of a tooth. During the procedure, he had prolonged bleeding that did not resolve with pressure and gauze packing and eventually required suture placement. His older brother had a similar episode a year ago, but his parents and two sisters have never had problems with prolonged bleeding. Physical examination shows no abnormalities. Genetic analysis confirms an X-linked recessive disorder. Which of the following is most likely deficient in this patient?

A. Protein C
B. Factor VIII (Correct Answer)
C. Von Willebrand factor
D. Factor IX
E. Factor XI

Explanation: ***Factor VIII*** - The presentation of **prolonged bleeding** after a minor procedure like tooth extraction, an **X-linked recessive inheritance pattern**, and a male sibling with a similar history are classic features of **Hemophilia A**, which is caused by a deficiency of **Factor VIII**. - X-linked recessive disorders primarily affect males, who inherit the single X chromosome from their mother, while females are typically carriers and do not show symptoms, consistent with the healthy parents and sisters. *Protein C* - Deficiency in **Protein C** is associated with a **hypercoagulable state**, leading to an increased risk of **thrombosis**, not bleeding. - This condition is inherited in an **autosomal dominant** manner, which does not fit the X-linked recessive pattern described. *Von Willebrand factor* - **Von Willebrand disease** is the most common inherited bleeding disorder, often presenting with mucocutaneous bleeding (e.g., nosebleeds, menorrhagia), and while it can cause prolonged bleeding, it is typically inherited in an **autosomal dominant** pattern. - Though some severe forms can be autosomal recessive, an X-linked recessive pattern with affected males and unaffected females in the described family structure is less characteristic of vWD than Hemophilia A. *Factor IX* - A deficiency in **Factor IX** causes **Hemophilia B**, which also presents with an X-linked recessive inheritance pattern and prolonged bleeding symptoms similar to Hemophilia A. - However, Hemophilia A (Factor VIII deficiency) is about four to five times more common than Hemophilia B (Factor IX deficiency), making Factor VIII deficiency the more statistically likely diagnosis given similar clinical presentations. *Factor XI* - **Factor XI deficiency** (Hemophilia C) is a milder bleeding disorder, often characterized by **autosomal recessive** inheritance, though it can also be autosomal dominant or have variable penetrance. - Symptoms are usually less severe than hemophilia A or B, and the inheritance pattern is not typically X-linked recessive.

Question 185: A 48-year-old female suffers a traumatic brain injury while skiing in a remote area. Upon her arrival to the ER, she is severely hypoxemic and not responsive to O2 therapy. She is started on a mechanical ventilator and 2 days later upon auscultation, you note late inspiratory crackles. Which of the following is most likely normal in this patient?

A. Alveolar-arterial gradient
B. Left atrial pressure (Correct Answer)
C. Type II pneumocytes
D. Type I pneumocytes
E. Chest X-ray

Explanation: ***Left atrial pressure*** - A normal left atrial pressure would be expected in a patient with **Non-Cardiogenic Pulmonary Edema**, which is implied by her severe hypoxemia refractory to oxygen, crackles, and history of **Traumatic Brain Injury**. - **Neurogenic Pulmonary Edema**, a form of non-cardiogenic pulmonary edema, is a known complication of severe TBI and does not primarily involve left heart failure, thus maintaining a normal left atrial pressure. *Alveolar-arterial gradient* - The patient's severe **hypoxemia** unresponsive to oxygen therapy indicates a significant **ventilation-perfusion mismatch** or shunt, which would lead to an *increased* alveolar-arterial gradient. - An increased A-a gradient is characteristic of pulmonary edema, where fluid in the alveoli impairs oxygen diffusion into the capillaries. *Type II pneumocytes* - In **acute respiratory distress syndrome (ARDS)**, which is strongly suggested by the patient's presentation (non-cardiogenic pulmonary edema), **Type II pneumocytes often proliferate** in the reparative phase. - While they are normally involved in **surfactant production**, their function can be impaired, and their numbers might increase to replace damaged Type I cells, so they would not be "normal." *Type I pneumocytes* - **Type I pneumocytes** are the primary cells responsible for **gas exchange** and are highly susceptible to injury in conditions like ARDS or pulmonary edema. - In such a critically ill patient with diffuse alveolar damage, these cells would likely be damaged or destroyed, thus *not* normal. *Chest X-ray* - Given the patient's severe hypoxemia, late inspiratory crackles, and probable pulmonary edema, her **Chest X-ray** would likely show **bilateral infiltrates** or **diffuse haziness**, characteristic of ARDS or neurogenic pulmonary edema. - Therefore, a normal chest X-ray is highly unlikely in this clinical scenario.

Question 186: A 60-year-old man comes to the physician because of recurrent nose bleeds that occur with light trauma or at random times during the day. Over the past 6 months, the patient has felt weak and fatigued and has had a 10-kg (22-lb) weight loss. He has poor appetite and describes abdominal discomfort. He does not have night sweats. His pulse is 72/min, blood pressure is 130/70 mm Hg, and his temperature is 37.5°C (99.5°F). The spleen is palpated 10 cm below the left costal margin. Multiple bruises are noted on both upper extremities. Laboratory studies show. Hemoglobin 9.8 g/dL Hematocrit 29.9% Leukocyte count 4,500/mm3 Neutrophils 30% Platelet count 74,000/mm3 Serum Lactate dehydrogenase 410 IU/L A peripheral blood smear detects tartrate-resistant acid phosphatase activity. Which of the following is the most appropriate initial treatment for this patient?

A. Cladribine (Correct Answer)
B. Melphalan
C. Rituximab
D. Transfusion of platelets
E. Transfusion of packed red blood cells

Explanation: ***Cladribine*** - The patient's presentation with **recurrent nosebleeds**, **splenomegaly**, **pancytopenia** (anemia, leukopenia, thrombocytopenia), **weight loss**, and **elevated LDH** is highly suggestive of **hairy cell leukemia (HCL)**. The detection of **tartrate-resistant acid phosphatase (TRAP)** activity on a peripheral blood smear is **pathognomonic for HCL**. - **Cladribine** (2-chlorodeoxyadenosine) is a **purine analog** that is **highly effective** as a first-line treatment for HCL, leading to high rates of complete remission. *Melphalan* - **Melphalan** is an **alkylating agent** primarily used in the treatment of **multiple myeloma** and sometimes ovarian cancer, not hairy cell leukemia. - It works by interfering with DNA replication and transcription, but it is **not the preferred agent** for the profound pancytopenia seen in HCL. *Rituximab* - **Rituximab** is a **monoclonal antibody** targeting the **CD20 antigen** found on B-lymphocytes, commonly used in non-Hodgkin lymphoma and chronic lymphocytic leukemia. - While it can be used in some B-cell malignancies, it is **not the primary initial treatment** for hairy cell leukemia, where purine analogs are superior. *Transfusion of platelets* - While the patient has **thrombocytopenia (74,000/mm³) and nosebleeds**, indicating bleeding risk, **platelet transfusions are temporary measures** to manage acute bleeding. - They do **not address the underlying cause** of the pancytopenia, which is the bone marrow infiltration by hairy cells. *Transfusion of packed red blood cells* - The patient's **anemia (Hb 9.8 g/dL)** may cause fatigue and weakness, but it is **not severe enough (Hb <7-8 g/dL)** to warrant immediate transfusion unless there is acute blood loss or significant symptomatic compromise. - Like platelet transfusions, RBC transfusions are **supportive care** and do **not treat the underlying hairy cell leukemia**.

Question 187: A 66-year-old man is brought to the emergency department because of weakness of his left leg for the past hour. He was unable to get out of bed that morning. His pants are soaked with urine. He has hypertension and coronary artery disease. Current medications include enalapril, carvedilol, aspirin, and simvastatin. His temperature is 37°C (98.6F), pulse is 98/min, and blood pressure is 160/90 mm Hg. Examination shows equal pupils that are reactive to light. Muscle strength is 2/5 in the left lower extremity. Plantar reflex shows an extensor response on the left. Sensation is decreased in the left lower extremity. On mental status examination, he is oriented to time, place, and person and has a flat affect. When asked to count backwards from 20, he stops after counting to 17. When asked to name 10 words beginning with the letter “d,” he stops after naming two words. Fundoscopy shows no abnormalities. Which of the following is the most likely cause of this patient's symptoms?

A. Left anterior cerebral artery occlusion
B. Left middle cerebral artery occlusion
C. Right posterior cerebral artery occlusion
D. Right anterior cerebral artery occlusion (Correct Answer)
E. Hypertensive encephalopathy

Explanation: ***Right anterior cerebral artery occlusion*** - This patient presents with **left lower extremity weakness** and sensory loss, along with **urinary incontinence** and executive dysfunction (difficulty with counting backward and naming words). This constellation of symptoms is highly indicative of an infarct in the **right anterior cerebral artery (ACA) territory**. - The ACA primarily supplies the **medial portion of the frontal and parietal lobes**, including the motor and sensory cortices for the contralateral leg and the supplementary motor area, which can affect executive function and bladder control. *Left anterior cerebral artery occlusion* - A left ACA occlusion would typically result in **right-sided weakness and sensory loss**, primarily affecting the lower extremity, as well as potential language deficits (e.g., transcortical motor aphasia). - This patient's symptoms are on the **left side**, ruling out a left ACA lesion. *Left middle cerebral artery occlusion* - A left MCA occlusion would present with **right-sided hemiparesis/hemiplegia** (face and arm more than leg), **right-sided sensory loss**, and significant **aphasia** (Broca's or Wernicke's), none of which are consistent with the patient's presentation. - While executive dysfunction can occur, the prominent lower extremity weakness and incontinence point away from an isolated MCA stroke. *Right posterior cerebral artery occlusion* - A right PCA occlusion typically causes **contralateral homonymous hemianopia**, visual field deficits, and potentially some sensory deficits or memory impairment. - It does not typically cause significant motor weakness, especially pronounced in the lower extremity, nor urinary incontinence. *Hypertensive encephalopathy* - Hypertensive encephalopathy usually presents with a more generalized and acute neurological decline, including **headache, altered mental status, seizures, and visual disturbances**, often without focal weakness. - While the patient has hypertension, his focal neurological deficits and acute onset are more consistent with an **ischemic stroke**.

Question 188: A 48-year-old Caucasian man presents to your office for initial evaluation as he has recently moved to your community and has become your patient. He has no significant past medical history and has not seen a physician in over 10 years. He takes no medications and denies having any allergies. He has been a smoker for the past 20 years and smokes approximately half a pack daily. His brother and father have diabetes; his brother is treated with metformin, whereas, his father requires insulin. His father has experienced two strokes. On presentation, he is a pleasant obese man with a body mass index of 34 kg/m2. On physical examination, his blood pressure is 170/90 mm Hg in the left arm and 168/89 mm Hg in the right arm. The patient is instructed to follow a low-salt diet, quit smoking, perform daily exercise, and diet to lose weight. He returns several weeks later for a follow-up appointment. The patient reports a 1.8 kg (4 lb) weight loss. His blood pressure on presentation is 155/94 mm Hg in both arms. What is the most appropriate next step in management?

A. Prescribe bisoprolol
B. Reassure the patient and encourage him to continue with lifestyle modifications
C. Prescribe hydrochlorothiazide
D. Prescribe lisinopril and bisoprolol
E. Prescribe lisinopril (Correct Answer)

Explanation: ***Prescribe lisinopril*** - The patient has **stage 2 hypertension** (blood pressure ≥140/90 mm Hg) despite initial lifestyle modifications, necessitating pharmacological intervention. - An **ACE inhibitor** like **lisinopril** is the most appropriate first-line agent for this patient given his **strong family history of diabetes** (both father and brother affected) and multiple cardiovascular risk factors, as it offers **renal protection** and may reduce progression to diabetes. - ACE inhibitors are particularly beneficial in patients at high risk for diabetes and provide cardiovascular and renal protection. *Prescribe bisoprolol* - **Bisoprolol**, a beta-blocker, is not typically recommended as first-line monotherapy for hypertension without specific indications like **coronary artery disease**, **heart failure**, or **post-myocardial infarction**. - Although effective for blood pressure reduction, other agents like ACE inhibitors or thiazide diuretics are generally preferred for initial management due to broader metabolic and cardiovascular benefits. *Reassure the patient and encourage him to continue with lifestyle modifications* - While lifestyle modifications are crucial, the patient's blood pressure remains significantly elevated at **155/94 mm Hg**, constituting **stage 2 hypertension**, which requires pharmacological treatment. - Delaying pharmacological treatment in **stage 2 hypertension** increases the risk of **cardiovascular events** including stroke and myocardial infarction. *Prescribe hydrochlorothiazide* - **Hydrochlorothiazide**, a thiazide diuretic, is also an appropriate first-line agent for hypertension with proven cardiovascular benefits. - However, in this specific patient with a **strong family history of diabetes** and multiple metabolic risk factors (obesity, BMI 34), an **ACE inhibitor** is preferred as it may offer additional benefits in **preventing progression to diabetes** and providing **renal protection**. - Thiazide diuretics can have adverse metabolic effects including increased blood glucose and could be considered as an alternative or add-on agent if needed. *Prescribe lisinopril and bisoprolol* - Initiating two antihypertensive medications at once is typically reserved for patients with **stage 2 hypertension with BP ≥160/100 mm Hg** or those at very high cardiovascular risk requiring rapid BP control. - With BP at 155/94 mm Hg, it is generally recommended to start with **monotherapy** and titrate or add a second agent if the blood pressure target is not achieved within 2-4 weeks.

Question 189: A 60-year-old man presents to the emergency room with a chief complaint of constipation. His history is also significant for weakness, a dry cough, weight loss, recurrent kidney stones, and changes in his mood. He has a 30 pack-year history of smoking. A chest x-ray reveals a lung mass. Labs reveal a calcium of 14. What is the first step in management?

A. Begin alendronate
B. Begin hydrochlorothiazide
C. Administer intravenous fluids (Correct Answer)
D. Administer calcitonin
E. Begin furosemide

Explanation: ***Administer intravenous fluids*** - The patient presents with **severe hypercalcemia (14 mg/dL)**, indicated by symptoms like constipation, weakness, and mood changes, likely due to a paraneoplastic syndrome from the lung mass. - **Intravenous hydration with normal saline** is the initial and most crucial step to dilute calcium, promote renal excretion, and correct dehydration, which often exacerbates hypercalcemia. *Begin alendronate* - **Alendronate** is a bisphosphonate used for long-term management of hypercalcemia by inhibiting osteoclast activity. - It has a **delayed onset of action (2-4 days)** and is not the first-line treatment for acute, severe hypercalcemia requiring rapid calcium reduction. *Begin hydrochlorothiazide* - **Thiazide diuretics** like hydrochlorothiazide can **increase serum calcium levels** by enhancing renal calcium reabsorption. - Therefore, it is contraindicated in hypercalcemia and would worsen the patient's condition. *Administer calcitonin* - **Calcitonin** can lower calcium levels, but its effect is **mild and transient**, often used in conjunction with other therapies. - It is not the initial or most effective sole therapy for significantly elevated calcium and its use is typically reserved for acute, refractory cases or when bisphosphonates are contraindicated. *Begin furosemide* - **Loop diuretics** like furosemide can increase renal calcium excretion, but they should only be used **after adequate rehydration** to prevent volume depletion and worsening hypercalcemia. - Administering furosemide to a dehydrated patient would lead to further dehydration and potentially cause more harm.

Question 190: A 61-year-old male presents to an urgent care clinic with the complaints of pain in his joints and recurrent headaches for a month. He is also currently concerned about sweating excessively even at room temperature. His wife, who is accompanying him, adds that his facial appearance has changed over the past few years as he now has a protruding jaw and a prominent forehead and brow ridge. His wedding ring no longer fits his finger despite a lack of weight gain over the last decade. His temperature is 98.6° F (37° C), respirations are 15/min, pulse is 67/min and blood pressure is 122/88 mm Hg. A general physical exam does not show any abnormality. What lab findings are most likely to be seen in this patient?

A. Elevated cortisol level
B. Low insulin levels
C. Elevated TSH and low FT4
D. Elevated insulin-like growth factor (IGF1) and growth hormone (GH) (Correct Answer)
E. Elevated prolactin levels

Explanation: ***Elevated insulin-like growth factor (IGF1) and growth hormone (GH)*** - The patient's presentation with **acral enlargement** (wedding ring no longer fits), **facial changes** (protruding jaw, prominent forehead), **arthralgias**, **headaches**, and **hyperhidrosis** are classic signs of **acromegaly**, which is caused by excessive growth hormone (GH) secretion, typically from a pituitary adenoma. - **Elevated IGF-1** is the most reliable screening test for acromegaly because its levels remain stable throughout the day, unlike GH which fluctuates significantly. A **glucose suppression test** for GH is used to confirm the diagnosis. *Elevated cortisol level* - **Elevated cortisol** is characteristic of **Cushing's syndrome**, which presents with features such as central obesity, moon facies, buffalo hump, and striae. These signs are not prominent in this patient's presentation. - While headaches can occur in Cushing's, the **acral and facial changes** are highly specific for acromegaly, not Cushing's. *Low insulin levels* - **Low insulin levels** are typically found in **Type 1 diabetes mellitus** due to autoimmune destruction of pancreatic beta cells, or in later stages of Type 2 diabetes. - The patient's symptoms are not consistent with uncontrolled diabetes, and **high GH** in acromegaly can actually lead to **insulin resistance** and elevated insulin levels, not low. *Elevated TSH and low FT4* - This pattern of labs indicates **primary hypothyroidism**, as the thyroid gland is underactive, leading to low thyroid hormone (FT4) and compensatory elevated TSH from the pituitary. - Symptoms of hypothyroidism include fatigue, cold intolerance, weight gain, and dry skin, which are different from the patient's presentation of **hyperhidrosis** and **acral growth**. *Elevated prolactin levels* - **Hyperprolactinemia** can cause symptoms such as **headaches**, galactorrhea, menstrual irregularities (in women), and hypogonadism. - While headaches are present, the characteristic **acral growth** and **facial changes** seen in this patient are not associated with elevated prolactin, making acromegaly a more fitting diagnosis.

Question 191: A 44-year-old man presents for a routine check-up. He has a past medical history of rheumatic fever. The patient is afebrile, and the vital signs are within normal limits. Cardiac examination reveals a late systolic crescendo murmur with a mid-systolic click, best heard over the apex and loudest just before S2. Which of the following physical examination maneuvers would most likely cause an earlier onset of the click/murmur?

A. Inspiration
B. Left lateral decubitus position
C. Rapid squatting
D. Handgrip
E. Standing (Correct Answer)

Explanation: ***Standing*** - Standing is a Valsalva-like maneuver that **decreases venous return** to the heart, leading to a smaller left ventricular volume. - This smaller ventricular volume causes the mitral valve leaflets to prolapse earlier in systole, resulting in an **earlier onset of the click** and a longer murmur. *Inspiration* - Inspiration typically **increases venous return** to the right side of the heart, augmenting right-sided heart murmurs. - Its effect on left-sided murmurs like mitral valve prolapse is variable but generally does not cause an earlier click for a left-sided lesion. *Left lateral decubitus position* - This position brings the heart closer to the chest wall, making left-sided heart sounds and murmurs **more prominent** or easier to hear. - It does not significantly alter the timing of the click or murmur in mitral valve prolapse. *Rapid squatting* - Rapid squatting **increases venous return** to the heart and also **increases systemic vascular resistance** (afterload). - This causes the left ventricle to fill more, delaying the onset of the mitral valve prolapse and thus the click/murmur. *Handgrip* - Handgrip is an isometric exercise that **increases systemic vascular resistance** and, consequently, left ventricular afterload. - This maneuver tends to **delay the onset of the click** and often decreases the intensity of the murmur in mitral valve prolapse by keeping the ventricle more full.

Question 192: A 74-year-old woman with no significant past medical history presents with 1 week of fever, unremitting headache and hip and shoulder stiffness. She denies any vision changes. Physical examination is remarkable for right scalp tenderness and range of motion is limited due to pain and stiffness. Neurological testing is normal. Laboratory studies are significant for an erythrocyte sedimentation rate (ESR) at 75 mm/h (normal range 0-22 mm/h for women). Which of the following is the most appropriate next step in management?

A. Start IV methylprednisolone
B. Obtain CT head without contrast
C. Start oral prednisone (Correct Answer)
D. Perform a temporal artery biopsy
E. Perform a lumbar puncture

Explanation: **Start oral prednisone** - The patient's symptoms (fever, headache, hip and shoulder stiffness, scalp tenderness, elevated ESR) are highly suggestive of **giant cell arteritis (GCA)**, which is closely associated with **polymyalgia rheumatica (PMR)**. - Starting oral prednisone promptly is appropriate to manage the symptoms and prevent potential complications like **vision loss**, especially when classic GCA symptoms are present but there is no acute vision loss. *Start IV methylprednisolone* - **IV methylprednisolone** is typically reserved for patients with **acute vision loss** or other severe ischemic complications of GCA, which are not described in this patient. - While GCA is a serious condition, oral prednisone is usually sufficient for initial management unless impending or active catastrophic events like blindness are present. *Obtain CT head without contrast* - A **CT head without contrast** would primarily be useful for evaluating acute neurological deficits or ruling out intracranial pathology like a hemorrhage or mass, which are not indicated by this patient's presentation (normal neurological exam). - It would not confirm GCA or PMR and would delay appropriate steroid initiation. *Perform a temporal artery biopsy* - A **temporal artery biopsy** is the gold standard for confirming GCA, but it is not the most appropriate *next step in management* for a suspected case. - **Steroid therapy should be initiated immediately** based on clinical suspicion to prevent irreversible vision loss, even before the biopsy results are available. The biopsy can be performed within 1-2 weeks of starting steroids without significantly affecting diagnostic yield. *Perform a lumbar puncture* - A **lumbar puncture** is used to diagnose conditions affecting the central nervous system, such as meningitis or subarachnoid hemorrhage. - The patient's presentation, including normal neurological testing and specific musculoskeletal symptoms, does not point towards an infectious or inflammatory process requiring a lumbar puncture.

Question 193: A 36-year-old woman comes to the physician because of a 4-day history of fever, malaise, chills, and a cough productive of moderate amounts of yellow-colored sputum. Over the past 2 days, she has also had right-sided chest pain that is exacerbated by deep inspiration. Four months ago, she was diagnosed with a urinary tract infection and was treated with trimethoprim/sulfamethoxazole. She appears pale. Her temperature is 38.8°C (101.8°F), pulse is 92/min, respirations are 20/min, and blood pressure is 128/74 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. Examination shows pale conjunctivae. Crackles are heard at the right lung base. Cardiac examination shows no abnormalities. Laboratory studies show: Hemoglobin 12.6 g/dL Leukocyte count 13,300/mm3 Platelet count 230,000/mm3 Serum Na+ 137 mEq/L Cl- 104 mEq/L K+ 3.9 mEq/L Urea nitrogen 16 mg/dL Glucose 89 mg/dL Creatinine 0.8 mg/dL An x-ray of the chest shows an infiltrate at the right lung base. Which of the following is the most appropriate next step in management?

A. Outpatient treatment with oral levofloxacin
B. Inpatient treatment with intravenous ceftriaxone and oral azithromycin
C. Inpatient treatment with intravenous cefepime and oral levofloxacin
D. Inpatient treatment with intravenous clindamycin
E. Outpatient treatment with oral doxycycline (Correct Answer)

Explanation: ***Outpatient treatment with oral doxycycline*** - The patient presents with community-acquired pneumonia (CAP) of moderate severity, with a **CURB-65 score of 0 or 1** (no confusion, urea <7 mmol/L, respiratory rate <30/min, blood pressure >90/60 mmHg, age <65). - **Doxycycline** is an appropriate first-line oral antibiotic for outpatient CAP coverage against typical and atypical pathogens, especially given recent trimethoprim/sulfamethoxazole use (which raises concern for a potential sulfonamide allergy or resistance pattern if another antibiotic of that class were considered). *Outpatient treatment with oral levofloxacin* - While **levofloxacin** is effective against CAP, it is a **respiratory fluoroquinolone** and is generally reserved for patients with comorbidities, prior antibiotic failure, or a higher risk of resistant organisms, which is not clearly indicated here. - Broader spectrum antibiotics like fluoroquinolones should be used judiciously to prevent **antibiotic resistance**. *Inpatient treatment with intravenous ceftriaxone and oral azithromycin* - This regimen is appropriate for **inpatient CAP**, especially for patients requiring hospitalization due to higher CURB-65 scores (2 or more) or significant comorbidities. - The patient's presentation does not meet criteria for **inpatient admission**, as her vital signs are relatively stable and CURB-65 is low. *Inpatient treatment with intravenous cefepime and oral levofloxacin* - This combination, particularly **cefepime**, is a **broad-spectrum** antibiotic reserved for **hospital-acquired pneumonia (HAP)**, **ventilator-associated pneumonia (VAP)**, or severe CAP with concern for multidrug-resistant pathogens. - The patient's pneumonia is community-acquired and does not appear severe enough to warrant such **broad-spectrum inpatient treatment**. *Inpatient treatment with intravenous clindamycin* - **Clindamycin** is primarily used for **anaerobic infections** and certain **gram-positive bacteria**, like methicillin-resistant *Staphylococcus aureus* (MRSA), but it has limited coverage for typical CAP pathogens. - It is not a recommended first-line agent for **community-acquired pneumonia** unless there is specific concern for aspiration or MRSA, and the patient does not require inpatient care.

Question 194: A 37-year-old woman comes to the physician because of a 2-week history of palpitations and loose stools. She has had a 2.3-kg (5-lb) weight loss over the past month. She has had no change in appetite. She has no history of serious illness. She works in accounting and has been under more stress than usual lately. She takes no medications. She appears pale. Her temperature is 37.8°C (100.1°F), pulse is 110/min, respirations are 20/min, and blood pressure is 126/78 mm Hg. Cardiopulmonary examination shows no abnormalities. The abdomen is soft and nontender. There is a bilateral hand tremor with outstretched arms and a palpable thyroid nodule in the left lobe. Serum laboratory studies show a thyroid stimulating hormone level of 0.03 μU/mL and a thyroxine level of 28 μg/dL. A radioactive iodine uptake scan shows enhancement in a 3-cm encapsulated nodule in the lower left lobe with decreased uptake in the remaining gland. Which of the following is the most likely diagnosis?

A. Graves' disease
B. Thyroid storm
C. Toxic adenoma (Correct Answer)
D. Papillary carcinoma
E. Goiter

Explanation: ***Toxic adenoma*** - The combination of **hyperthyroidism** (low TSH, high thyroxine, palpitations, weight loss, tremor) and a **single, hot nodule** on radioactive iodine uptake scan with suppressed uptake in the surrounding gland is classic for a toxic adenoma. - A **toxic adenoma** is a benign tumor that functions autonomously, producing thyroid hormones independent of TSH regulation. *Graves' disease* - While Graves' disease also causes hyperthyroidism, it typically presents with **diffuse uptake** of radioactive iodine throughout the entire gland, not a single hot nodule. - Classic features like **exophthalmos** or **pretibial myxedema** are also absent in this case. *Thyroid storm* - This is a **life-threatening exacerbation of hyperthyroidism** characterized by fever, marked tachycardia, arrhythmias, altered mental status, and potentially coma. - While the patient has some hyperthyroid symptoms, her presentation is not severe enough to be classified as a thyroid storm. *Papillary carcinoma* - Thyroid cancers, including **papillary carcinoma**, are typically **"cold" nodules** on radioactive iodine uptake scans, meaning they do not take up iodine. - The patient's nodule is "hot" and associated with hyperthyroidism, making carcinoma highly unlikely. *Goiter* - A **goiter** refers to any enlargement of the thyroid gland, which can be diffuse or nodular, and may or may not be associated with functional abnormalities. - While the patient has a palpable nodule, "goiter" is a descriptive term and does not specify the underlying cause of her hyperthyroidism.

Question 195: A 58-year-old woman comes to the physician because of a 3-month history of itching of both legs. She also has swelling and dull pain that are worse at the end of the day and are more severe in her right leg. She has hyperthyroidism, asthma, and type 2 diabetes mellitus. Four years ago, she had basal cell carcinoma of the face that was treated with Mohs surgery. Current medications include methimazole, albuterol, and insulin. She has smoked 3–4 cigarettes a day for the past 29 years. She goes to a local sauna twice a week. Her temperature is 37°C (98.6°F), pulse is 75/min, respirations are 16/min, and blood pressure is 124/76 mm Hg. Physical examination shows fair skin with diffuse freckles. There is 2+ pitting edema of the right leg and 1+ pitting edema of the left leg. There is diffuse reddish-brown discoloration and significant scaling extending from the ankle to the mid-thigh bilaterally. Pedal pulses and sensation are intact bilaterally. Which of the following is the most likely underlying mechanism of this patient's symptoms?

A. Breach of skin barrier by dermatophyte
B. Malignant proliferation of epidermal keratinocytes
C. Dermal accumulation of glycosaminoglycans
D. Venous valve incompetence (Correct Answer)
E. Type IV hypersensitivity reaction

Explanation: **Venous valve incompetence** - The patient's symptoms of **bilateral leg swelling**, **dull pain worse at day's end**, and **reddish-brown discoloration with scaling** are classic signs of **chronic venous insufficiency**, which results from incompetent venous valves. - **Pitting edema**, particularly 2+ in the right leg and 1+ in the left, further supports the diagnosis, indicating fluid accumulation due to impaired venous return. *Breach of skin barrier by dermatophyte* - This typically causes **tinea cruris** or **tinea pedis**, characterized by well-demarcated, erythematous, pruritic, and scaly lesions, often with central clearing. - While itching and scaling are present, the **diffuse reddish-brown discoloration**, **pitting edema**, and distribution from ankle to mid-thigh are not typical of a primary dermatophyte infection. *Malignant proliferation of epidermal keratinocytes* - This describes **squamous cell carcinoma** or **basal cell carcinoma**, which was previously treated on her face. - These conditions usually present as persistent, non-healing sores or plaques, not diffuse bilateral leg swelling, scaling, and discoloration associated with chronic venous stasis. *Dermal accumulation of glycosaminoglycans* - This is characteristic of **pretibial myxedema**, a dermatologic manifestation of **Graves' disease** (hyperthyroidism). - While the patient has hyperthyroidism, pretibial myxedema typically presents as **non-pitting edema** with a "peau d'orange" texture, unlike the pitting edema described. *Type IV hypersensitivity reaction* - This describes **allergic contact dermatitis**, which would present with pruritic, erythematous, vesicular, and papular lesions, often with a clear history of exposure to an allergen. - The chronic, progressive nature of the symptoms, along with diffuse swelling and discoloration, is inconsistent with an acute or subacute type IV hypersensitivity reaction.

Question 196: A 22-year-old woman with a history of type I diabetes mellitus presents to the emergency department with nausea, vomiting, and drowsiness for the past day. Her temperature is 98.3°F (36.8°C), blood pressure is 114/74 mmHg, pulse is 120/min, respirations are 27/min, and oxygen saturation is 100% on room air. Physical exam is notable for a confused and lethargic young woman. Initial laboratory values are notable for the findings below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 2.9 mEq/L HCO3-: 9 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L An initial ECG is notable for sinus tachycardia. Which of the following is the best initial step in management for this patient?

A. Normal saline and insulin
B. Insulin and potassium
C. Normal saline and potassium
D. Normal saline, insulin, and potassium (Correct Answer)
E. Normal saline, insulin, potassium, and sodium bicarbonate

Explanation: ***Normal saline, insulin, and potassium*** - This patient presents with signs and symptoms consistent with **diabetic ketoacidosis (DKA)**, including hyperglycemia (glucose 599 mg/dL), metabolic acidosis (HCO3- 9 mEq/L, respiratory compensation with elevated respiratory rate), and altered mental status. The initial management of DKA involves aggressive **intravenous fluid resuscitation** (normal saline), **insulin administration** to correct hyperglycemia and acidosis, and **potassium replacement** due to total body potassium depletion and anticipated further drop with insulin therapy. - Her **hypokalemia (2.9 mEq/L)**, even before insulin administration, necessitates immediate potassium repletion as insulin drives potassium intracellularly, which could worsen hypokalemia and lead to arrhythmias. *Normal saline and insulin* - While fluid resuscitation and insulin are crucial for DKA management, omitting **potassium replacement** in a patient with initial hypokalemia (K+ 2.9 mEq/L) would be inappropriate and potentially dangerous. - Failure to correct hypokalemia before or with insulin administration can precipitate life-threatening **cardiac arrhythmias**. *Normal saline, insulin, potassium, and sodium bicarbonate* - **Sodium bicarbonate** is generally not recommended for DKA unless pH is extremely low (typically <6.9), as it can worsen cerebral edema and hypokalemia. The patient's bicarbonate of 9 mEq/L and presumably higher pH does not warrant bicarbonate administration. - While fluids, insulin, and potassium are essential, the addition of sodium bicarbonate is usually reserved for severe, life-threatening acidosis (pH < 6.9). *Normal saline and potassium* - Administering only normal saline and potassium would address dehydration and hypokalemia but would fail to correct the underlying **hyperglycemia** and **ketoacidosis**, which are the core pathologies of DKA. - **Insulin** is critical to stop ketogenesis and lower blood glucose. *Insulin and potassium* - Administering insulin and potassium without **fluid resuscitation** would be inadequate. The patient is likely significantly dehydrated due to osmotic diuresis from hyperglycemia and vomiting. - **Fluid administration** is paramount in restoring circulating volume, improving renal perfusion, and reducing hyperglycemia by enhancing glucose excretion.

Question 197: A 72-year-old man presents to the primary care clinic for evaluation of progressive fatigue and weight loss. His past medical history is significant for hypercholesterolemia, type 2 diabetes mellitus, aortic stenosis, and chronic renal insufficiency. He endorses being well-rested after waking from sleep but fatiguing rapidly during the day. In addition, he states that he has lost 15lbs over the previous month. His temperature is 98.3°F (36.8°C), pulse is 100/min, blood pressure is 110/85 mmHg, respirations are 16/min, and oxygen saturation is 96% on room air. Physical exam is notable for conjunctival pallor and scattered areas of ecchymoses. His laboratory results are shown below: Serum: Na+: 140 mEq/L K+: 4.0 mEq/L Cl-: 101 mEq/L HCO3-: 22 mEq/L BUN: 30 mg/dL Glucose: 160 mg/dL Creatinine: 1.9 mg/dL Leukocyte count: 1,100/mm^3 Absolute neutrophil count 920/mm^3 Hemoglobin 8.4 g/dL Platelet count: 45,000/mm^3 Mean corpuscular hemoglobin concentration: 34% Red blood cell distribution width: 12.0% Mean corpuscular volume: 92 µm^3 Lactate dehydrogenase: 456 IU/L Haptoglobin 120 mg/dL Fibrinogen 214 mg/dL A bone marrow biopsy is performed which shows cells that are CD19+, CD20+, CD11c+, and stain with acid phosphatase 5 and tartrate-resistant. Which of the following is the next best step in the treatment of his disorder?

A. Cyclophosphamide
B. Hydroxyurea
C. Cladribine (Correct Answer)
D. Filgrastim
E. Doxorubicin

Explanation: ***Cladribine*** - The patient's blood work (pancytopenia: **leukopenia**, **anemia**, **thrombocytopenia**) along with bone marrow biopsy findings (**CD19+, CD20+, CD11c+, tartrate-resistant acid phosphatase-positive** cells) are highly indicative of **hairy cell leukemia**. - **Cladribine** is a purine analog, which is considered the most effective first-line treatment for hairy cell leukemia, often leading to long-lasting remissions. *Cyclophosphamide* - This is an **alkylating agent** used in various cancers and autoimmune conditions, but it is not the most effective or preferred first-line treatment for hairy cell leukemia. - Cyclophosphamide is associated with significant side effects and would likely be reserved for other hematological malignancies. *Hydroxyurea* - **Hydroxyurea** is a ribonucleotide reductase inhibitor primarily used in myeloproliferative disorders like **chronic myeloid leukemia** or **polycythemia vera** to reduce cell counts. - While it can lower white blood cell counts, it is not curative and not the standard primary therapy for hairy cell leukemia. *Filgrastim* - **Filgrastim** is a **granulocyte colony-stimulating factor (G-CSF)** used to stimulate neutrophil production, often to counter neutropenia caused by chemotherapy. - It would not be used to treat hairy cell leukemia itself, and in some cases, can even paradoxically induce leukocytosis, which may not be desired in a condition characterized by abnormal white blood cells. *Doxorubicin* - **Doxorubicin** is an **anthracycline antibiotic** used in the treatment of many cancers (e.g., lymphomas, breast cancer, sarcomas) but not hairy cell leukemia. - Its mechanism of action involves DNA intercalation and inhibition of topoisomerase II, which is not the primary target for hairy cell leukemia therapy.

Question 198: A 38-year-old woman presents with fever and acute onset chest pain for the past 12 hours. She describes the pain as severe, sharp and stabbing in character, and localized to the retrosternal area. She also says the pain is worse when she breathes deeply or coughs. Past medical history is significant for recently diagnosed systemic lupus erythematosus (SLE). Her vital signs include: blood pressure 110/75 mm Hg, pulse 95/min, and temperature 38.0°C (100.4°F). Physical examination is significant for a friction rub heard best at the lower left sternal border. Which of the following is the most likely diagnosis in this patient?

A. Acute myocardial infarction
B. Septic shock
C. Pericardial tamponade
D. Constrictive pericarditis
E. Acute pericarditis (Correct Answer)

Explanation: ***Acute pericarditis*** - This patient's symptoms of **acute onset, sharp, retrosternal chest pain** that is **worse with deep breathing or coughing**, accompanied by a **pericardial friction rub** and fever, are classic for **acute pericarditis**. - The history of **systemic lupus erythematosus (SLE)** is a significant risk factor for pericarditis, as SLE can cause serositis (inflammation of serous membranes including the pericardium). *Acute myocardial infarction* - While chest pain is present, the description of **sharp, stabbing pain worse with breathing** is more typical of pericarditis than the **crushing, pressure-like pain of an MI** that often radiates to the arm or jaw. - The presence of a **pericardial friction rub** is highly suggestive of pericarditis and not typically found in MI. *Septic shock* - This patient's vital signs, including a blood pressure of **110/75 mmHg**, do not indicate **hypotension** as seen in septic shock. - While fever is present, the primary presentation is **chest pain** and a **friction rub**, not generalized signs of severe infection and organ dysfunction. *Pericardial tamponade* - Pericardial tamponade would present with signs of **hemodynamic compromise** such as **hypotension**, **tachycardia**, **muffled heart sounds**, and **jugular venous distention (Beck's triad)**, which are not described. - The primary symptom is **chest pain** and a **friction rub** indicative of inflammation, not significant fluid accumulation causing cardiac compression. *Constrictive pericarditis* - **Constrictive pericarditis** typically presents with signs of **chronic right-sided heart failure** such as **peripheral edema**, **ascites**, and **jugular venous distention**, often after a prolonged course of pericardial inflammation. - This patient presents with **acute symptoms** and signs of **active inflammation** (fever, friction rub), which is not consistent with the chronic nature of constrictive pericarditis.

Question 199: A 20-year-old man presents to the doctor's office for advice on improving his health. He admits to eating mostly junk food, and he knows that he should lose some weight. His daily physical activity is limited to walking around the college campus between classes. Except for an occasional headache for which he takes acetaminophen, he has no health concerns and takes no other medications. He denies smoking and illicit drug use, but admits to occasional beer binge drinking on weekends. He is sexually active with his current girlfriend and regularly uses condoms. His mother has type 2 diabetes mellitus and obesity, while his father has hypertension and hypercholesterolemia. The pulse is 74/min, the respiratory rate is 16/min, and the blood pressure is 130/76 mm Hg. The body mass index (BMI) is 29 kg/m2. Physical examination reveals an overweight young male, and the rest is otherwise unremarkable. The routine lab test results are as follows: Serum Glucose (fasting) 100 mg/dL Serum Electrolytes: Sodium 141 mEq/L Potassium 4.0 mEq/L Chloride 100 mEq/L Cholesterol, total 190 mg/dL HDL-cholesterol 42 mg/dL LDL-cholesterol 70 mg/dL Triglycerides 184 mg/dL Urinalysis: Glucose Negative Ketones Negative Leukocytes Negative Nitrites Negative RBCs Negative Casts Negative Which of the following lifestyle changes would most likely benefit this patient the most?

A. A low sodium diet
B. Starting a multivitamin
C. Increasing daily water intake
D. Weight reduction (Correct Answer)
E. Increasing dietary fiber

Explanation: ***Weight reduction*** - The patient has a **BMI of 29 kg/m2**, which classifies him as **overweight**, and his diet consists mostly of junk food, making weight reduction a primary and impactful lifestyle change. - Weight loss significantly improves multiple health markers, including **blood pressure**, **lipid profile**, and **insulin sensitivity**, reducing his risk for conditions like **type 2 diabetes** and **hypertension** that run in his family. - The patient shows early signs of **metabolic syndrome** (elevated BP, low HDL 42 mg/dL, triglycerides 184 mg/dL, impaired fasting glucose 100 mg/dL), which weight reduction directly addresses. *A low sodium diet* - While his father has hypertension, this patient's blood pressure is **130/76 mm Hg**, which is in the **elevated range** (120-129/<80 mm Hg), not yet meeting criteria for hypertension (≥130/80 mm Hg). - While a low sodium diet is generally healthy and can help prevent hypertension, addressing his **overweight status** and **poor dietary habits** would yield more comprehensive benefits first. *Starting a multivitamin* - The patient has no symptoms or signs of **nutrient deficiencies**, and his routine lab tests are normal. - There is generally **no strong evidence** to support routine multivitamin supplementation in otherwise healthy individuals with no specific deficiencies. *Increasing daily water intake* - There is no indication that the patient is **dehydrated** or has any conditions that would specifically benefit from a significant increase in water intake. - While adequate hydration is important, it is **not the most impactful intervention** for his current health profile compared to addressing his diet and weight. *Increasing dietary fiber* - Increasing dietary fiber is beneficial for **digestive health** and can help with **satiety** and **cholesterol management**. - However, his primary issue is his overall "junk food" diet and overweight status; tackling these directly through **comprehensive dietary changes** (which would include more fiber) and **weight reduction** would be more beneficial than focusing solely on fiber intake initially.

Question 200: A 53-year-old man comes to the emergency department because of a 1-month history of cough productive of small amounts of blood-tinged sputum. During this time, he has also developed fatigue, myalgia, and shortness of breath on exertion. He has had a 4-lb (2-kg) weight loss over the past 2 months. He has no personal history of serious illness. His mother has systemic lupus erythematosus. His temperature is 37.2°C (99.0 °F), pulse is 98/min, respirations are 22/min, and blood pressure is 152/98 mm Hg. Diffuse rhonchi are heard on auscultation of the chest bilaterally. There are multiple palpable, erythematous, nonblanching lesions on the lower extremities bilaterally. Laboratory studies show: Leukocyte count 12,300 cells/mm3 Platelet count 400,000 cells/mm3 Erythrocyte sedimentation rate 83 mm/hr Serum Creatinine 2.1 mg/dL Antinuclear antibody 1:40 Urine Protein 3+ Blood 2+ RBC casts numerous A biopsy specimen of the skin shows inflammation of the arterioles and capillaries without granuloma formation. Further evaluation of this patient is most likely to show which of the following findings?

A. Hepatitis B surface antigen
B. Increased serum cryoglobulins
C. Myeloperoxidase antineutrophil cytoplasmic antibody (Correct Answer)
D. Anti-glomerular basement membrane antibodies
E. Anti-double stranded DNA antibodies

Explanation: ***Myeloperoxidase antineutrophil cytoplasmic antibody*** - The patient presents with **pulmonary-renal syndrome** and vasculitic skin lesions. - The skin biopsy shows **inflammation of arterioles and capillaries without granuloma formation**, pointing towards a small vessel vasculitis such as **microscopic polyangiitis**, which is commonly associated with **MPO-ANCA (p-ANCA)** positivity. *Hepatitis B surface antigen* - **Polyarteritis nodosa** is a medium-sized vessel vasculitis often associated with **hepatitis B virus infection**. - However, the skin biopsy showing **small vessel vasculitis** (arterioles and capillaries) makes polyarteritis nodosa less likely. *Increased serum cryoglobulins* - **Cryoglobulinemic vasculitis** is associated with **hepatitis C virus infection** and often presents with palpable purpura, arthralgias, and renal involvement. - While the patient has palpable purpura and renal involvement, the absence of **hepatitis C risk factors** and the specific biopsy findings make this less probable than microscopic polyangiitis. *Anti-glomerular basement membrane antibodies* - **Goodpasture syndrome** is characterized by rapidly progressive glomerulonephritis and pulmonary hemorrhage due to **anti-GBM antibodies**. - While the patient has both pulmonary and renal involvement, a skin vasculitis is not typical for Goodpasture syndrome, and the biopsy would show **linear IgG deposition** along the GBM, not inflammation of arterioles and capillaries. *Anti-double stranded DNA antibodies* - **Anti-dsDNA antibodies** are highly specific for **systemic lupus erythematosus (SLE)**, which can cause vasculitis and renal disease. - While the patient's mother has SLE, his clinical presentation, particularly the lung involvement and the specific type of skin vasculitis, is more classic for an **ANCA-associated vasculitis** than for SLE.

Question 201: A 30-year-old woman presents to the emergency department in a state of confusion and disorientation that started this morning. She is accompanied by her husband who says that she has been unwell for about one week. She has been complaining of fatigue. Her husband says that this morning, she also complained that her urine was dark red in color and that there were some red spots over her legs. He did notice some changes in her level of consciousness that worsened over time and he decided to bring her in today. She does not have a significant medical history. Physical examination shows petechiae over her arms and legs. She is conscious but drowsy and disoriented and unable to answer the physician’s questions appropriately. Her temperature is 38.3°C (100.9°F), blood pressure is 160/100 mm Hg, pulse rate is 90/min, and respiratory rate is 20/min. Laboratory studies show: Hemoglobin 10 g/dL Leukocyte count 9,000/mm3 Platelet count 30,000/mm3 Bleeding time 10 min Prothrombin time 12 s Activated partial thromboplastin time 30 s D-dimer 0.4 mg/L (normal < 0.5 mg/L) Serum fibrinogen 350 mg/dL (normal 200–400 mg/dL) Serum bilirubin (indirect) 2.2 mg/dL Serum creatinine 1.5 mg/dL Serum LDH 1,010 U/L Based on her history, and her physical and laboratory findings, which of the following is the most likely pathophysiology for her presentation?

A. GPIIb/IIIa deficiency and failure of platelet aggregation
B. Systemic activation of blood coagulation
C. E. coli-mediated endothelial damage and formation of microthrombi
D. Antiplatelet antibodies
E. Decreased ADAMTS13 causing platelet adhesion and formation of microthrombi (Correct Answer)

Explanation: ***Decreased ADAMTS13 causing platelet adhesion and formation of microthrombi*** * The constellation of **fever, neurologic symptoms (confusion, disorientation), renal dysfunction (creatinine 1.5 mg/dL), microangiopathic hemolytic anemia (indirect bilirubin 2.2 mg/dL, high LDH, dark red urine), and thrombocytopenia (platelet count 30,000/mm3, petechiae)** is characteristic of **Thrombotic Thrombocytopenic Purpura (TTP)**. * **TTP** is caused by a deficiency in the **ADAMTS13 enzyme**, which normally cleaves **large Von Willebrand Factor (vWF) multimers**. A deficiency leads to accumulation of these large vWF multimers, causing **uncontrolled platelet adhesion and aggregation**, forming **microthrombi** in small blood vessels. This results in **hemolytic anemia** (due to fragmentation of red blood cells passing through the partially occluded vessels), **thrombocytopenia** (due to platelet consumption), and **end-organ damage** (kidney, brain). *GPIIb/IIIa deficiency and failure of platelet aggregation* * **GPIIb/IIIa deficiency (Glanzmann thrombasthenia)** is a disorder of **platelet aggregation**, leading to severe bleeding. * Patients typically present with **mucocutaneous bleeding** and **normal platelet counts**. This patient has severe thrombocytopenia and evidence of microangiopathic hemolysis. *Systemic activation of blood coagulation* * This describes **Disseminated Intravascular Coagulation (DIC)**. While DIC involves microthrombi and thrombocytopenia, it is also characterized by **prolonged PT and aPTT**, **decreased fibrinogen**, and **elevated D-dimer** due to widespread activation of the coagulation cascade and subsequent fibrinolysis. * This patient's **PT, aPTT, D-dimer, and fibrinogen levels are normal**, ruling out DIC as the primary etiology. *E. coli-mediated endothelial damage and formation of microthrombi* * This description is suggestive of **Hemolytic Uremic Syndrome (HUS)**, often caused by **Shiga-toxin-producing E. coli (STEC)**. HUS shares features with TTP but typically presents with a prodrome of **bloody diarrhea** and more prominent **renal failure** without significant neurological involvement as seen in TTP. * The patient in this scenario does not report preceding diarrheal illness, making TTP a more likely diagnosis given the prominent neurological symptoms and mild renal dysfunction. *Antiplatelet antibodies* * This mechanism is characteristic of **Immune Thrombocytopenic Purpura (ITP)**, where antibodies destroy platelets, leading to thrombocytopenia and bruising/bleeding. * **ITP** usually presents with isolated **thrombocytopenia** and normal hemoglobin and renal function, without evidence of microangiopathic hemolytic anemia or neurologic symptoms.

Question 202: A 31-year-old woman presents to the clinic with shortness of breath, palpitations, and fatigue. She has had these symptoms over the last several weeks. She had been tolerating these symptoms until last night when she could not fall asleep due to palpitations. She has a past medical history of infective endocarditis 6 months ago that was successfully treated with antibiotics. She does not smoke or drink alcohol. Her blood pressure is 138/89 mm Hg and her pulse is 76/min and regular. The cardiac exam reveals a soft S1, S3 gallop, a hyperdynamic apex beat, and a pansystolic murmur that radiates to the axilla on auscultation. Echocardiography reveals incompetence of one of the valves. Which of the following sites is the best position to auscultate this defect?

A. Medial end of the 2nd intercostal space on the right side
B. 4th intercostal space at the midclavicular line on the left side
C. 5th intercostal space at the midclavicular line on the left side (Correct Answer)
D. Medial end of the 2nd intercostal space on the left side
E. Right lower end of the body of the sternum

Explanation: ***5th intercostal space at the midclavicular line on the left side*** - The patient's symptoms (shortness of breath, palpitations, fatigue, S3 gallop, hyperdynamic apex beat, and a pansystolic murmur radiating to the axilla) following infective endocarditis strongly suggest **mitral regurgitation**. - The **mitral valve** is best auscultated at the **cardiac apex**, which is located at the **5th intercostal space at the midclavicular line on the left side**. *Medial end of the 2nd intercostal space on the right side* - This position is the **aortic area**, where murmurs related to the **aortic valve** (e.g., aortic stenosis or regurgitation) are best heard. - An aortic murmur would not typically radiate to the axilla. *4th intercostal space at the midclavicular line on the left side* - This location is slightly above the typical apex beat and is not the primary auscultation site for any major cardiac valve. - While close to the mitral area, it is not the optimal point for identifying mitral valve pathology. *Medial end of the 2nd intercostal space on the left side* - This position is the **pulmonic area**, where murmurs related to the **pulmonic valve** (e.g., pulmonary stenosis or regurgitation) are best heard. - A pulmonic murmur would not cause a hyperdynamic apex beat or radiate to the axilla. *Right lower end of the body of the sternum* - This location corresponds to the **tricuspid area**, where murmurs related to the **tricuspid valve** (e.g., tricuspid regurgitation or stenosis) are best heard. - Tricuspid murmurs are often amplified with inspiration and typically do not radiate to the axilla.

Question 203: A 43-year-old man presents to a primary care clinic complaining of several months of fatigue and difficulty concentrating at work. He is tired throughout the day and often falls asleep briefly at work. He sleeps for 9 hours per night, falling asleep easily, waking up several times in the middle of the night, and then having trouble waking up in the morning. Physical exam is notable for obesity and a large neck circumference. His temperature is 98°F (36.7°C), blood pressure is 150/90 mmHg, pulse is 75/min, respirations are 22/min, and BMI is 33 kg/m^2. The rest of the physical exam is normal. Which of the following is the most likely cause of his fatigue?

A. Obstructive sleep apnea (Correct Answer)
B. Chronic fatigue syndrome
C. Narcolepsy
D. Circadian rhythm sleep wake disorder
E. Hypothyroidism

Explanation: ***Obstructive sleep apnea*** - The patient's **obesity**, **large neck circumference**, chronic fatigue, daytime sleepiness, and **disrupted nocturnal sleep with multiple awakenings** are all classic symptoms and risk factors for **obstructive sleep apnea (OSA)**. - The nocturnal awakenings occur due to **repeated upper airway obstruction** during sleep, causing brief arousals that fragment sleep architecture despite adequate time in bed. - The high blood pressure and increased respirations are associated with the physiological stress of repeated airway obstruction and arousal during sleep. - **OSA is strongly associated with obesity (BMI >30) and increased neck circumference**, both present in this patient. *Chronic fatigue syndrome* - While fatigue is a primary symptom, chronic fatigue syndrome typically involves **post-exertional malaise** and is not characterized by the specific pattern of sleep disruption and physical risk factors (obesity, large neck circumference) seen here. - Diagnosis requires persistent, unexplained fatigue for at least six months, along with other defining symptoms like cognitive difficulties, but the detailed sleep pattern and physical findings point away from this. *Narcolepsy* - Narcolepsy is characterized by **uncontrollable daytime sleep attacks** and often involves **cataplexy** (sudden loss of muscle tone triggered by strong emotions). - While daytime sleepiness is present, the patient's nocturnal sleep pattern (waking multiple times) and physical risk factors are not typical features of narcolepsy. - Narcolepsy patients typically have **difficulty maintaining nighttime sleep** but do not have the obesity and large neck circumference risk factors. *Circadian rhythm sleep wake disorder* - These disorders involve a misalignment between the **internal sleep-wake clock** and the external environment or work schedule, leading to timing difficulties rather than chronic apnea-related sleep disruption. - The patient's ability to fall asleep easily and the specific physical findings do not align with a primary circadian rhythm disorder. *Hypothyroidism* - Hypothyroidism can cause fatigue, weight gain, and sometimes daytime sleepiness, but it does not typically cause the specific pattern of **nocturnal awakenings** and has no direct link to a **large neck circumference** in the context of sleep quality. - Other classic symptoms like cold intolerance, dry skin, bradycardia, and constipation are not mentioned, and a normal temperature makes severe hypothyroidism less likely.

Question 204: A 23-year-old man presents to his physician's office with increasing breathlessness over the past one month. He was diagnosed with asthma when he was a child and has been able to keep his symptoms under control with a Ventolin inhaler. However, over the past year or so he has found that he gets out of breath on several occasions during the week. He wakes up at least once a week with breathlessness. He finds that he feels out of breath during his weekly football matches, which never used to happen before. He has to sit down and take a couple of puffs of his inhaler to feel better. He has no other pertinent history at this moment, except that he started on a new job painting houses about 5 months ago. His physical examination does not show anything significant. His peak expiratory flow rate during spirometry averages about 85% of the normal value, after conducting the test 3 times. Which of the following would be the next best step in management?

A. Patch test
B. Follow up spirometry in 2 months
C. Arterial blood gas
D. Chest X-ray
E. Methacholine bronchoprovocation test (Correct Answer)

Explanation: ***Methacholine bronchoprovocation test*** - The patient's history, including **worsening asthma symptoms** despite previous control and a new exposure to paint, suggests a potential diagnosis of **occupational asthma**. A methacholine challenge test is indicated to confirm **airway hyperresponsiveness** if spirometry is inconclusive. - Given the history of frequent symptoms, night awakenings, and impact on activity, this points to **uncontrolled asthma** or a new trigger. A positive test to methacholine would confirm **bronchial hyperreactivity**, which is essential for diagnosing asthma when baseline spirometry is near normal. *Patch test* - A patch test is used to identify **contact allergens** that cause **allergic contact dermatitis**, which presents as a rash rather than respiratory symptoms. - It is not indicated for the diagnosis of **occupational asthma**, which involves inhalation of triggers. *Follow up spirometry in 2 months* - Waiting two months for follow-up spirometry would delay diagnosis and potential treatment for a patient with **worsening and uncontrolled asthma symptoms**. - The current spirometry reading of **85% of normal** is not significantly obstructive enough to definitively diagnose asthma without further testing, especially given the history. *Arterial blood gas* - An ABG measures **blood gas levels** and acid-base balance, which is useful in assessing the severity of an acute asthma exacerbation or chronic respiratory failure. - In a patient with partially controlled asthma and near-normal spirometry, an ABG is not typically the next best diagnostic step unless there are signs of severe respiratory distress or hypoxemia. *Chest X-ray* - A chest X-ray is primarily used to rule out other respiratory conditions like **pneumonia**, **pneumothorax**, or structural lung disease, which are not suggested by this patient's history. - It's generally not indicated as a primary diagnostic tool for **asthma**, especially when symptoms are chronic and related to bronchoconstriction.

Question 205: A 40-year-old man presents to a clinic in Michigan in December complaining of painful blue fingers and toes. He also complains of numbness and tingling. The patient’s vital signs are within normal limits, and his symptoms typically disappear when he comes back into a warm room. The patient also notes that he recently moved to the area from Arizona and had recently recovered from a viral infection in which he had a low-grade fever and severe lymphadenopathy. Which of the following tests would most likely be positive in this patient?

A. Direct Coomb’s test with anti-C3 reagent (Correct Answer)
B. Anti-centromere antibody
C. Anti-Ro antibody
D. Indirect Coomb’s test
E. Direct Coomb’s test with anti-IgG reagent

Explanation: ***Direct Coombs test with anti-C3 reagent*** - The patient presents with classic symptoms of **cold agglutinin disease**, characterized by painful blue fingers and toes (acrocyanosis) triggered by cold exposure that resolves with warming. - The recent **viral infection with severe lymphadenopathy** suggests infections such as **Mycoplasma pneumoniae, EBV, or CMV**, which are well-known triggers for cold agglutinin disease. - Cold agglutinins are **IgM antibodies** that bind to red blood cells at cold temperatures, causing **complement activation** (C3d deposition) and **extravascular hemolysis**. - The **direct Coombs test with anti-C3 reagent** detects complement (C3) bound to RBC surfaces and is the diagnostic test of choice for cold agglutinin disease. - The recent move from Arizona to Michigan in December provides the cold exposure trigger needed to manifest symptoms. *Direct Coombs test with anti-IgG reagent* - This test detects **IgG antibodies bound to red blood cells** and is positive in **warm autoimmune hemolytic anemia**, not cold agglutinin disease. - Cold agglutinin disease is mediated by **IgM antibodies and complement (C3)**, not IgG, so this test would be negative. *Indirect Coombs test* - The **indirect Coombs test** detects **free antibodies in serum** against RBCs and is used primarily for blood typing and cross-matching. - While it may detect cold agglutinins in serum, the **direct Coombs with anti-C3** is the more specific and diagnostic test for cold agglutinin disease. *Anti-centromere antibody* - **Anti-centromere antibodies** are highly specific for **limited cutaneous systemic sclerosis (CREST syndrome)**, which can present with Raynaud's phenomenon. - However, the **acute onset** following a viral illness, the **severe lymphadenopathy**, and the **cold-triggered acrocyanosis** are more consistent with cold agglutinin disease rather than a chronic autoimmune connective tissue disease. - Systemic sclerosis typically has a more insidious onset and is not triggered by viral infections. *Anti-Ro antibody* - **Anti-Ro antibodies** are associated with **Sjögren's syndrome** and **systemic lupus erythematosus (SLE)**. - While Raynaud's can occur in these conditions, the clinical presentation with recent viral infection, severe lymphadenopathy, and cold-triggered symptoms points to cold agglutinin disease rather than SLE or Sjögren's syndrome.

Question 206: A 52-year-old woman is accompanied by her husband to the emergency department with a severe occipital headache that started suddenly an hour ago. She is drowsy but able to answer the physician's questions. She describes it as the worst headache she has ever had, 9/10 in intensity. The husband says it was initially localized to the occiput but has now spread all over her head and she also complained of a generalized heaviness. She took an ibuprofen without experiencing any relief. She also complains of blurry vision and nausea and had 1 episode of vomiting. She denies a recent history of fever, chills, numbness, or seizures. Her past medical history is significant for hypertension controlled with lisinopril and metoprolol. On examination, she is drowsy but oriented. Papilledema is seen on ophthalmoscopy. Neck flexion is difficult and painful. The rest of the exam is unremarkable. Her blood pressure is 160/100 mm Hg, heart rate is 100/min, and temperature is 37.0°C (98.6°F). The ECG, cardiac enzymes, and laboratory studies are normal. Lumbar puncture results are as follows: Opening pressure 210 mm H2O RBC 50/mm3, numbers steady over 4 test tubes Cell count 5/mm3 Glucose 60 mg/dL Proteins 100 mg/dL The patient is admitted to the ICU for further management. Which of the following is the most likely pathophysiology based on her history and CSF findings?

A. Rupture of the communicating branches of the cerebral arteries (Correct Answer)
B. Intracerebral bleed
C. Viral infection of the brain parenchyma
D. Bacterial infection of the meninges
E. Trauma during lumbar puncture

Explanation: ***Rupture of the communicating branches of the cerebral arteries*** - This presentation, with a **sudden-onset, severe occipital headache ("thunderclap headache")**, meningeal irritation (stiff neck), blurry vision, papilledema, and elevated intracranial pressure (high opening pressure, nausea, vomiting), is highly classic for a **subarachnoid hemorrhage (SAH)**. - The **CSF findings** of grossly bloody fluid with consistent red blood cells (RBCs) across multiple tubes (indicating true hemorrhage, not traumatic tap), elevated protein, and normal glucose are diagnostic of SAH. The most common cause of spontaneous SAH is the rupture of a **saccular (berry) aneurysm**, frequently found in the communicating branches of cerebral arteries. *Intracerebral bleed* - While an intracerebral bleed can cause severe headache and neurological deficits, it typically presents with **focal neurological signs** corresponding to the brain region affected by the hematoma. - Classic CSF findings in an intracerebral bleed, unless it ruptures into the ventricles or subarachnoid space, would generally be **acellular or mildly pleocytic**, not overtly bloody with high RBC counts. *Viral infection of the brain parenchyma* - **Viral encephalitis** would typically present with fever, altered mental status, and often focal neurological deficits or seizures. - CSF findings for viral encephalitis would show **lymphocytic pleocytosis**, mildly elevated protein, and normal glucose, not significant RBCs. *Bacterial infection of the meninges* - **Bacterial meningitis** is characterized by fever, neck stiffness, and altered mental status. The headache is usually progressive, not thunderclap. - CSF analysis would typically show **neutrophilic pleocytosis**, markedly elevated protein, **low glucose**, and often visible bacteria on gram stain, unlike this patient's findings. *Trauma during lumbar puncture* - A **traumatic lumbar puncture** can cause blood in the CSF, but the RBC count would typically **decrease progressively** in subsequent tubes as less contaminated fluid is collected. - The presence of **xanthochromia** (not explicitly mentioned but usually present in SAH after several hours) and the clinical presentation of a thunderclap headache, papilledema, and meningeal signs prior to the LP make a traumatic tap unlikely as the primary pathology.

Question 207: A 62-year-old man is brought to the emergency department because of progressive shortness of breath, mild chest pain on exertion, and a cough for 2 days. One week ago, he had a low-grade fever and nasal congestion. He has hypertension but does not adhere to his medication regimen. He has smoked one pack of cigarettes daily for 30 years and drinks 3–4 beers daily. His temperature is 37.1°C (98.8°F), pulse is 125/min, respirations are 29/min, and blood pressure is 145/86 mm Hg. He is in moderate respiratory distress while sitting. Pulmonary examination shows reduced breath sounds bilaterally. There is scattered wheezing over all lung fields. There is inward displacement of his abdomen during inspiration. Arterial blood gas analysis shows: pH 7.29 PCO2 63 mm Hg PO2 71 mm Hg HCO3- 29 mEq/L O2 saturation 89% Which of the following is the most likely cause of this patient's symptoms?

A. Acute pulmonary embolism
B. Acute respiratory distress syndrome
C. Acute asthma exacerbation
D. Acute exacerbation of chronic obstructive pulmonary disease (Correct Answer)
E. Acute decompensation of congestive heart failure

Explanation: ***Acute exacerbation of chronic obstructive pulmonary disease*** - The patient's history of heavy smoking, chronic cough, and recent respiratory infection, coupled with acute shortness of breath, wheezing, and hypercapnic respiratory acidosis, is highly suggestive of an **acute exacerbation of COPD**. The inward displacement of the abdomen during inspiration indicates increased work of breathing and **diaphragmatic fatigue**. - The arterial blood gas (ABG) showing **pH 7.29, PCO2 63 mm Hg, PO2 71 mm Hg, and HCO3- 29 mEq/L** points to an uncompensated or partially compensated **respiratory acidosis with hypoxemia**, characteristic of severe COPD exacerbation. *Acute pulmonary embolism* - While pulmonary embolism can cause dyspnea and hypoxemia, the presence of diffuse wheezing, a history of heavy smoking consistent with chronic lung disease, and hypercapnic respiratory acidosis (elevated PCO2) make it less likely. - A **pulmonary embolism** typically presents with sudden onset dyspnea, pleuritic chest pain, and often significant hypoxemia, but usually without diffuse wheezing or hypercapnia unless there is underlying severe lung disease. *Acute respiratory distress syndrome* - ARDS is characterized by severe hypoxemia refractory to oxygen therapy and bilateral pulmonary infiltrates on chest imaging, often in the setting of a direct or indirect lung injury. - The patient's symptoms are more consistent with an obstructive process, and the ABG showing hypercapnia with some bicarbonate compensation is not typical of ARDS, which generally presents with **respiratory alkalosis** early on, due to tachypnea. *Acute asthma exacerbation* - While an asthma exacerbation can cause wheezing and shortness of breath, this patient's long smoking history and chronic cough make COPD a more probable diagnosis, especially given his age. - Although the symptoms are similar, the significant smoking history makes **COPD** more likely, and patients with long-standing asthma often respond well to bronchodilators, which is not mentioned here. *Acute decompensation of congestive heart failure* - **Congestive heart failure** typically presents with orthopnea, paroxysmal nocturnal dyspnea, and bilateral crackles on lung examination, often with peripheral edema. Wheezing, known as "cardiac asthma," can occur but is usually accompanied by other signs of fluid overload. - The primary respiratory findings in this patient are wheezing and reduced breath sounds, with inward abdominal displacement, which point more towards an **obstructive lung process** rather than fluid overload.

Question 208: A 45-year-old woman presents to her primary care physician for an annual checkup. She states that she feels well and has no complaints. She lives alone and works as a banker. She smokes 1 cigarette per day and drinks 2 alcoholic beverages per night. She occasionally gets symmetrical pain in her hands where they change from red to white to blue then return to normal again. Her temperature is 98.7°F (37.1°C), blood pressure is 177/118 mmHg, pulse is 82/min, respirations are 15/min, and oxygen saturation is 99% on room air. The patient's hypertension is treated, and she returns 2 weeks later complaining of weight gain in her legs and arms. On exam, bilateral edema is noted in her extremities. Which of the following is the best next step in management?

A. Metoprolol
B. Lisinopril
C. Furosemide (Correct Answer)
D. Compression stockings
E. Increase current medication dose

Explanation: ***Furosemide*** - The patient developed **bilateral extremity edema** shortly after initiating antihypertensive therapy, presenting 2 weeks after treatment initiation. - While **calcium channel blocker (CCB)-induced edema** is a common cause of peripheral edema developing after starting antihypertensive treatment, the question asks for the "best next step in management" among the given options. - **Furosemide** (a loop diuretic) can provide symptomatic relief of the edema and also helps address the **persistently elevated blood pressure**. - The patient also demonstrates **Raynaud's phenomenon**, which may suggest underlying connective tissue disease that could contribute to renal involvement and secondary hypertension with fluid retention. - In clinical practice, if CCB-induced edema is suspected, the preferred approach would be discontinuing or switching the medication, or adding an ACE inhibitor; however, among the options provided, furosemide addresses both the edema and hypertension. *Lisinopril* - **Lisinopril** (an ACE inhibitor) is an excellent antihypertensive agent and can actually **reduce CCB-induced peripheral edema** when used in combination therapy. - However, ACE inhibitors are not first-line for managing acute bilateral edema and work more slowly than diuretics for symptom resolution. - This would be a reasonable alternative if the edema is medication-induced and additional BP control is needed. *Metoprolol* - **Metoprolol** (a beta-blocker) provides antihypertensive effects but does **not address peripheral edema**. - Beta-blockers can actually worsen peripheral circulation in some patients and may exacerbate Raynaud's phenomenon. - This medication would not resolve the patient's presenting complaint of new-onset edema. *Compression stockings* - Compression stockings are useful for **chronic venous insufficiency** or **mild localized edema**. - They do not address the underlying cause of **acute bilateral edema** developing after medication initiation, nor do they help with hypertension management. - This is a supportive measure, not definitive management for this clinical scenario. *Increase current medication dose* - Simply increasing the dose of the current antihypertensive medication may **worsen the edema** if it is medication-induced (particularly if the patient is on a CCB). - This approach does not address the new symptom of bilateral edema and could potentially exacerbate the problem. - The development of new symptoms after starting therapy suggests the need for a different management approach rather than dose escalation.

Question 209: An 18-year-old Caucasian female presents to your clinic because of a recent increase in thirst and hunger. Urinalysis demonstrates elevated glucose. The patient's BMI is 20. Which of the following is the most common cause of death in persons suffering from this patient's illness?

A. Coma
B. Peripheral neuropathy
C. Infection
D. Renal failure
E. Myocardial infarction (Correct Answer)

Explanation: ***Myocardial infarction*** - **Cardiovascular disease, particularly myocardial infarction, is the leading cause of death in Type 1 Diabetes Mellitus**, accounting for approximately 40% of mortality. - Patients with Type 1 diabetes develop **accelerated atherosclerosis** due to chronic hyperglycemia, dyslipidemia, endothelial dysfunction, and increased oxidative stress. - Even young patients with T1DM have significantly elevated cardiovascular risk compared to age-matched controls, with risk increasing proportionally with disease duration and glycemic control. - While acute complications like DKA are immediately life-threatening, modern medical management has reduced DKA mortality to <1%, making chronic cardiovascular complications the predominant cause of death. *Coma* - **Diabetic ketoacidosis (DKA)** leading to coma is indeed a serious acute complication of Type 1 diabetes. - However, with contemporary medical care and improved access to insulin, DKA mortality is less than 1% in developed countries. - While DKA may be the presenting feature or an immediate threat, it is not the most common cause of death over the lifetime of T1DM patients. *Peripheral neuropathy* - Diabetic peripheral neuropathy is a common chronic complication affecting up to 50% of long-standing diabetics. - While it significantly impacts quality of life and can lead to foot ulcers, infections, and amputations, it is not a direct cause of death. - Autonomic neuropathy can contribute to sudden cardiac death, but this is still categorized under cardiovascular mortality. *Infection* - Diabetes does increase susceptibility to certain infections due to impaired neutrophil function, reduced chemotaxis, and hyperglycemia promoting bacterial growth. - While infections can be serious (e.g., necrotizing fasciitis, mucormycosis), they are not the leading cause of mortality in T1DM. - Infection-related deaths are far less common than cardiovascular deaths. *Renal failure* - **Diabetic nephropathy** is the second most common cause of death in Type 1 diabetes, affecting approximately 20-30% of patients. - End-stage renal disease develops over many years and contributes significantly to mortality. - However, cardiovascular disease remains more common, and many patients with diabetic nephropathy ultimately die from cardiovascular events rather than renal failure alone.

Question 210: A 78-year-old man presents to his primary care physician for persistent back pain. The patient states that he has had back pain for awhile; however, this past weekend he was helping his son move heavy furniture. Since the move, his symptoms have been more severe. The patient states that the pain is constant and occurs throughout the day. On review of systems, the patient endorses a recent 15 pound weight loss and constipation. His temperature is 99.5°F (37.5°C), blood pressure is 137/79 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. Cardiovascular exam is notable for a murmur at the right sternal border that radiates to the carotids. Pulmonary exam reveals mild bibasilar crackles. Musculoskeletal exam is notable for mild midline tenderness of the lower thoracic spine and the upper segment of the lumbar spine. No bruising or signs of external trauma are observable on the back. Symptoms are not exacerbated when the patient is lying down and his straight leg is lifted. Strength is 5/5 in the lower and upper extremities. The patient's sensation is intact bilaterally in his lower and upper extremities. Laboratory values are ordered and return as seen below. Hemoglobin: 11 g/dL Hematocrit: 34% Leukocyte count: 10,500/mm^3 with normal differential Platelet count: 288,000/mm^3 Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 4.3 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 1.6 mg/dL Ca2+: 11.8 mg/dL AST: 12 U/L ALT: 12 U/L Which of the following is the most likely diagnosis?

A. Piriformis muscle inflammation
B. Muscle strain
C. Herniated nucleus pulposus
D. Plasma cell dyscrasia (Correct Answer)
E. Sciatic nerve irritation

Explanation: **Plasma cell dyscrasia** - The patient's presentation with **persistent back pain**, **unexplained weight loss**, and **constipation** are concerning "red flag" symptoms for a serious underlying condition. - The laboratory findings of **anemia (Hb 11 g/dL)**, **elevated calcium (Ca2+ 11.8 mg/dL)**, and **impaired renal function (Creatinine 1.6 mg/dL)** in an older patient strongly suggest a diagnosis of **multiple myeloma**, a type of plasma cell dyscrasia. *Piriformis muscle inflammation* - This condition typically presents with **buttock pain** that can radiate down the leg, often mimicking sciatica. - It is usually associated with **local tenderness** in the piriformis muscle and may be exacerbated by specific movements, none of which are explicitly described as primary features. *Muscle strain* - While the patient's symptoms worsened after moving furniture, a simple muscle strain would typically improve over time and with rest, not cause **persistent, severe pain** with systemic symptoms like **weight loss, anemia, and hypercalcemia**. - Muscle strains do not explain the consistent, constant pain nor the abnormal laboratory findings. *Herniated nucleus pulposus* - A herniated disc usually causes **radicular pain** (sciatica) that radiates down the leg, often accompanied by **neurological deficits** such as weakness, numbness, or diminished reflexes, which are absent in this patient. - The patient's negative straight leg raise test makes a significant disc herniation less likely, and it does not account for the systemic symptoms or lab abnormalities. *Sciatic nerve irritation* - **Sciatica** typically involves radicular pain stemming from compression or irritation of the sciatic nerve, usually characterized by pain radiating below the knee, often with neurological findings. - The absence of **neurological deficits** (normal strength and sensation) and a negative straight leg raise test make primary sciatic nerve irritation less probable, and it does not explain the systemic symptoms of weight loss, anemia, and hypercalcemia.

Question 211: A 55-year-old man with a history of IV drug abuse presents to the emergency department with an altered mental status. He was found unconscious in the park by police. His temperature is 100.0°F (37.8°C), blood pressure is 87/48 mmHg, pulse is 150/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for multiple scars and abscesses in the antecubital fossa. His laboratory studies are ordered as seen below. Serum: Na+: 139 mEq/L Cl-: 105 mEq/L K+: 4.3 mEq/L HCO3-: 19 mEq/L BUN: 20 mg/dL Glucose: 95 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most appropriate treatment for this patient’s blood pressure and acid-base status?

A. Ringer lactate (Correct Answer)
B. Dextrose 5% normal saline
C. Sodium bicarbonate
D. Hypertonic saline
E. Normal saline

Explanation: ***Ringer lactate*** - This patient presents with **hypotension** (BP 87/48 mmHg) and **metabolic acidosis** (HCO3- 19 mEq/L, with an elevated anion gap if calculated). Ringer lactate is a **balanced crystalloid solution** that contains lactate, which is metabolized to bicarbonate in the liver, helping to correct metabolic acidosis while providing fluid resuscitation. - The patient's history of **IV drug abuse**, fever, and altered mental status suggests a possible underlying infection (e.g., sepsis), which often presents with hypotension and metabolic acidosis requiring aggressive fluid resuscitation with a balanced solution. *Dextrose 5% normal saline* - While it provides fluids and some sodium, Dextrose 5% normal saline contains **free water**, which is not ideal for a patient with hypotension and may exacerbate cerebral edema if present. - It does not contain bicarbonate precursors and therefore would not directly address the patient's **metabolic acidosis**. *Sodium bicarbonate* - Administering sodium bicarbonate directly might be considered for severe metabolic acidosis, but **fluid resuscitation with a balanced solution** like Ringer lactate is usually the initial step to address both hypotension and acidosis. - Excessive or rapid administration of sodium bicarbonate can lead to **alkalosis**, worsening intracellular acidosis, and fluid overload. *Hypertonic saline* - **Hypertonic saline** is primarily used to treat severe **hyponatremia** or to reduce intracranial pressure. - It would not be appropriate for a patient with normal sodium levels and hypotension, as it could lead to further dehydration or worsen hypernatremia. *Normal saline* - **Normal saline (0.9% NaCl)** is an isotonic crystalloid often used for fluid resuscitation, but it has a high chloride content. - Large volumes of normal saline can worsen or induce **hyperchloremic metabolic acidosis**, which would be detrimental to a patient who already has metabolic acidosis.

Question 212: An 85-year-old woman otherwise healthy presents with left-sided weakness. Her symptoms started 4 hours ago while she was on the phone with her niece. The patient recalls dropping the phone and not being able to pick it up with her left hand. No significant past medical history. No current medications. Physical examination reveals decreased sensation on the left side, worse in the left face and left upper extremity. There is significant weakness of the left upper extremity and weakness and drooping of the lower half of the left face. Ophthalmic examination reveals conjugate eye deviation to the right. A noncontrast CT of the head is unremarkable. The patient is started on aspirin. A repeat contrast CT of the head a few days later reveals an ischemic stroke involving the lateral convexity of right cerebral hemisphere. Which of the following additional findings would most likely be seen in this patient?

A. Homonymous hemianopsia (Correct Answer)
B. Horner's syndrome
C. Amaurosis fugax
D. Profound lower limb weakness
E. Prosopagnosia

Explanation: ***Homonymous hemianopsia*** - The patient has an ischemic stroke affecting the **right cerebral hemisphere**, specifically the **lateral convexity**. This suggests involvement of the **middle cerebral artery (MCA)** territory. - The **optic radiations** carrying visual information from the contralateral visual field pass through the parietal and temporal lobes to the occipital cortex. Damage to these radiations in the right hemisphere would result in a **left homonymous hemianopsia**. *Horner's syndrome* - Characterized by **ptosis**, **miosis**, and **anhidrosis** on one side of the face. - It results from damage to the **sympathetic pathway**, typically in the brainstem, spinal cord above T1, or sympathetic chain, which is not the primary location of this stroke. *Amaurosis fugax* - This is a **transient monocular vision loss** ("curtain coming down") due to temporary interruption of blood flow to the retina, usually from an **ipsilateral carotid artery embolus**. - It is typically a symptom of impending stroke or TIA, not a direct neurological deficit resulting from a cerebral hemisphere stroke. *Profound lower limb weakness* - The described stroke involves the **lateral convexity of the right cerebral hemisphere**, fed by the **middle cerebral artery (MCA)**. - The MCA primarily supplies the upper limb and facial motor/sensory cortices, leading to more pronounced **upper limb and facial weakness** rather than profound lower limb weakness, which is more characteristic of an **anterior cerebral artery (ACA)** stroke. *Prosopagnosia* - This is the inability to recognize familiar faces, often due to damage to the **fusiform gyrus** in the temporal and occipital lobes, usually on the **right side**. - While it can occur with right hemisphere strokes, it is a specific higher-order cognitive deficit and not the *most likely* additional finding in this presentation focused on motor and sensory deficits and conjugate eye deviation.

Question 213: A 31-year-old woman comes to the physician because of a 2-day history of low-grade intermittent fever, dyspnea, and chest pain that worsens on deep inspiration. Over the past 4 weeks, she has had pain in her wrists and the fingers of both hands. During this period, she has also had difficulties working on her computer due to limited range of motion in her fingers, which tends to be more severe in the morning. Her temperature is 37.7°C (99.8°F). Physical examination shows a high-pitched scratching sound over the left sternal border. Further evaluation of this patient is most likely to reveal which of the following findings?

A. Mutation of the HFE gene
B. Blood urea nitrogen level > 60 mg/dL
C. Increased titer of anti-citrullinated peptide antibodies (Correct Answer)
D. Coxsackie virus RNA
E. Decreased C3 complement levels

Explanation: ***Increased titer of anti-citrullinated peptide antibodies*** - The patient's symptoms, including **polyarthralgia affecting wrists and fingers, morning stiffness, and pericarditis (pericardial friction rub, chest pain, dyspnea)**, are highly suggestive of **rheumatoid arthritis (RA)**. - **Anti-citrullinated peptide antibodies (ACPA)** are specific and sensitive markers for RA, often present early in the disease and associated with more aggressive forms. *Mutation of the HFE gene* - **HFE gene mutations** are associated with **hereditary hemochromatosis**, a disorder of iron overload. - While hemochromatosis can cause arthropathy, it typically affects larger joints and is not associated with pericarditis or rheumatoid-like morning stiffness. *Blood urea nitrogen level > 60 mg/dL* - A **BUN level > 60 mg/dL** indicates significant **renal dysfunction**, often seen in conditions like **uremia**. - While uremia can cause pericarditis (uremic pericarditis) and sometimes arthralgia, the joint symptoms are not typically inflammatory with morning stiffness, and there's no other evidence of kidney disease. *Coxsackie virus RNA* - **Coxsackievirus infection** can cause **myocarditis and pericarditis**, but it less commonly causes chronic inflammatory polyarthralgia with morning stiffness. - While viral infections can trigger reactive arthritis, the specific presentation here points more strongly to an autoimmune connective tissue disease. *Decreased C3 complement levels* - **Decreased C3 complement levels** are typically seen in immune complex-mediated diseases such as **systemic lupus erythematosus (SLE)**, certain **glomerulonephritides**, and some **bacteremias**. - While SLE can cause polyarthralgia and pericarditis, the absence of other SLE features (e.g., malar rash, photosensitivity, renal involvement, cytopenias) makes RA a more likely primary diagnosis given the specific joint and morning stiffness pattern, though SLE can serologically overlap.

Question 214: A 59-year-old man presents to his primary care provider with the complaint of daytime fatigue. He often has a headache that is worse in the morning and feels tired when he awakes. He perpetually feels fatigued even when he sleeps in. The patient lives alone, drinks 2-3 beers daily, drinks coffee regularly, and has a 10 pack-year smoking history. His temperature is 99.0°F (37.2°C), blood pressure is 180/110 mm Hg, pulse is 80/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for a BMI of 39 kg/m^2. The rest of the patient's pulmonary and neurological exams are unremarkable. Which of the following is the best next step in management?

A. Caffeine avoidance
B. Screening for depression
C. Alcohol avoidance in the evening
D. CT head
E. Weight loss (Correct Answer)

Explanation: ***Weight Loss*** - The patient's **BMI of 39 kg/m²** indicates **class III obesity**, which is the strongest modifiable risk factor for **obstructive sleep apnea (OSA)**. The clinical presentation—**daytime fatigue**, morning headaches, unrefreshing sleep despite adequate sleep duration, and hypertension—strongly suggests OSA. - While **polysomnography** is the gold standard for confirming OSA, the clinical diagnosis is evident in this case. **Weight loss** is the most important initial therapeutic intervention, as even modest weight reduction (10% of body weight) can significantly improve or resolve OSA in obese patients. - Weight loss reduces upper airway collapse by decreasing fatty tissue deposition around the pharynx and improving lung volumes. This addresses the underlying pathophysiology rather than just treating symptoms. - This intervention also addresses his **hypertension** (180/110 mm Hg), which is commonly associated with and exacerbated by OSA. *Caffeine avoidance* - While excessive caffeine can disrupt sleep architecture, the patient's symptoms—particularly **morning headaches** and **unrefreshing sleep despite sleeping in**—are not characteristic of caffeine-induced insomnia, which typically presents with difficulty initiating sleep. - These symptoms, combined with obesity and hypertension, point strongly to a sleep-related breathing disorder rather than a stimulant effect. *Screening for depression* - Fatigue is indeed a cardinal symptom of major depressive disorder, but the specific pattern here—**morning headaches** (from nocturnal hypercapnia/hypoxemia), **unrefreshing sleep**, and **obesity with hypertension**—is far more consistent with OSA. - Depression screening could be considered if symptoms persist after addressing the sleep disorder, as untreated OSA can contribute to or worsen mood disorders. *Alcohol avoidance in the evening* - **Alcohol consumption** (2-3 beers daily) does worsen OSA by relaxing upper airway dilator muscles and suppressing arousal responses to hypoxemia. Evening alcohol avoidance would be a beneficial **adjunctive measure**. - However, while helpful, this intervention is less impactful than weight loss. The patient's **severe obesity** (BMI 39 kg/m²) is the predominant and most modifiable risk factor, making weight loss the priority intervention that will have the greatest effect on reducing OSA severity. *CT head* - CT head would be indicated if there were focal neurological deficits, papilledema, or features suggesting increased intracranial pressure or structural brain pathology. - This patient's **neurological exam is unremarkable**, and his headaches are characteristic of OSA (worse in the morning due to nocturnal CO₂ retention, improving throughout the day). Imaging is not warranted.

Question 215: A 45-year-old woman comes to the physician because of a 3-month history of worsening fatigue, loss of appetite, itching of the skin, and progressive leg swelling. Although she has been drinking 2–3 L of water daily, she has been passing only small amounts of urine. She has type 1 diabetes mellitus, chronic kidney disease, hypertension, and diabetic polyneuropathy. Her current medications include insulin, torasemide, lisinopril, and synthetic erythropoietin. Her temperature is 36.7°C (98°F), pulse is 87/min, and blood pressure is 138/89 mm Hg. She appears pale. There is 2+ pitting edema in the lower extremities. Sensation to pinprick and light touch is decreased over the feet and legs bilaterally. Laboratory studies show: Hemoglobin 11.4 g/dL Leukocyte count 6000/mm3 Platelet count 280,000/mm3 Serum Na+ 137 mEq/L K+ 5.3 mEq/L Cl− 100 mEq/L HCO3− 20 mEq/L Urea nitrogen 85 mg/dL Creatinine 8 mg/dL pH 7.25 Which of the following long-term treatments would best improve quality of life and maximize survival in this patient?

A. Peritoneal dialysis
B. Living donor kidney transplant (Correct Answer)
C. Cadaveric kidney transplant
D. Hemofiltration
E. Fluid restriction

Explanation: ***Living donor kidney transplant*** - A **living donor kidney transplant** offers the best outcomes for **quality of life and survival** in eligible patients with end-stage renal disease (ESRD), particularly when compared to dialysis, due to better graft survival rates and reduced complications. - The patient's symptoms (fatigue, itching, leg swelling, oliguria, high urea nitrogen, creatinine, hyperkalemia, metabolic acidosis) are consistent with **ESRD**, and while she has several comorbidities, she is not explicitly stated to have contraindications for transplantation. *Peritoneal dialysis* - While an effective treatment for ESRD, **dialysis generally provides lower quality of life** and survival benefits compared to successful kidney transplantation. - She already has significant fluid overload symptoms and **oliguria**, making adequate fluid removal through peritoneal dialysis potentially challenging without strict management and impacting her overall well-being. *Cadaveric kidney transplant* - A **cadaveric kidney transplant** is a viable option and offers better outcomes than dialysis, but it generally has **poorer graft survival** and a longer wait time compared to a living donor transplant due to delayed graft function and cold ischemia time. - Given the option, a **living donor transplant is superior** in terms of long-term outcomes and reduces the time spent on dialysis. *Hemofiltration* - **Hemofiltration is a form of renal replacement therapy**, similar to hemodialysis, often used in acute settings or for critically ill patients with severe fluid overload or electrolyte imbalances. - While it can manage her symptoms, it is not a long-term treatment that **improves quality of life or maximizes survival** better than transplantation for ESRD. *Fluid restriction* - **Fluid restriction** is a supportive measure to manage fluid overload in patients with ESRD; however, it addresses symptoms rather than the underlying progressive renal failure. - While necessary as part of supportive care, it does not offer a definitive long-term solution or improve survival for ESRD, which requires **renal replacement therapy or transplantation**.

Question 216: A 32-year-old woman is supposed to undergo tooth extraction surgery. Physical examination is unremarkable, and she has a blood pressure of 126/84 mm Hg and regular pulse of 72/min. She takes no medications. Which of the following cardiac conditions would warrant antibiotic prophylaxis to prevent infective endocarditis in this patient?

A. Hypertrophic obstructive cardiomyopathy (HOCM)
B. Mitral regurgitation
C. Past history of infective endocarditis (Correct Answer)
D. Ventricular septal defect (VSD)
E. Implantable cardioverter defibrillator (ICD)

Explanation: ***Past history of infective endocarditis*** - A **history of infective endocarditis** is a definite indication for **antibiotic prophylaxis** before dental procedures that involve manipulation of gingival tissue, periapical region of teeth, or perforation of the oral mucosa due to the high risk of recurrence. - This condition creates a predisposition to subsequent episodes of endocarditis, even with minor bacteremia. *Hypertrophic obstructive cardiomyopathy (HOCM)* - While HOCM is a significant cardiac condition, it is **no longer an indication** for routine infective endocarditis prophylaxis in the absence of other high-risk features like a prosthetic valve. - Current guidelines have narrowed the criteria for prophylaxis due to the low absolute risk and potential for side effects from antibiotics. *Mitral regurgitation* - **Mitral valve regurgitation**, in the absence of a prosthetic valve or a previous history of endocarditis, generally **does not warrant antibiotic prophylaxis** for routine dental procedures. - Only specific types of valvular heart disease with high risk (e.g., prosthetic valves, certain congenital heart diseases) require prophylaxis. *Ventricular septal defect (VSD)* - **Most ventricular septal defects do not require prophylaxis**. Only **unrepaired cyanotic VSD** or **repaired VSD with residual defects adjacent to prosthetic material** would warrant prophylaxis. - Completely repaired VSDs without residual defects do not require prophylaxis after the initial 6 months post-repair. - In this case, with an unremarkable physical examination and normal vital signs, there is no indication of cyanotic heart disease. *Implantable cardioverter defibrillator (ICD)* - An **implantable cardioverter defibrillator (ICD)** itself is a device and does not inherently increase the risk for infective endocarditis to warrant prophylaxis for dental procedures. - The risk of infection is primarily associated with the device insertion procedure itself, not with subsequent dental interventions.

Question 217: A 34-year-old man presents to his primary care provider for evaluation of nocturnal cough and dyspnea. He has been a smoker for the past 15 years with a 7.5-pack-year smoking history. He has no significant medical history and takes no medications. His blood pressure is 118/76 mm Hg, the heart rate is 84/min, the respiratory rate is 15/min, and the temperature is 37.0°C (98.6°F). A sputum sample shows Charcot-Leyden crystals and Curschmann spirals. What is the most likely diagnosis?

A. Chronic obstructive pulmonary disease
B. Pneumonia
C. Atopic asthma (Correct Answer)
D. Bronchiectasis
E. Panacinar emphysema

Explanation: ***Atopic asthma*** - The presence of **Charcot-Leyden crystals** and **Curschmann spirals** in the sputum is pathognomonic for asthma, indicating a chronic inflammatory airway process with eosinophilic infiltration and mucus plugging. - **Nocturnal cough** and **dyspnea** are classic symptoms of asthma, particularly when associated with airway hyper-responsiveness. *Chronic obstructive pulmonary disease* - While a 7.5-pack-year smoking history is notable, **Charcot-Leyden crystals** and **Curschmann spirals** are not typically seen in COPD sputum and are more characteristic of asthma. - COPD usually presents with persistent and progressive dyspnea and cough, which is continuously present in contrast to episodic nocturnal symptoms in asthma. *Pneumonia* - Pneumonia is an **acute infection** of the lungs, typically presenting with fever, productive cough with purulent sputum, and often systemic signs of infection, which are absent here. - Sputum microscopy in pneumonia usually shows bacteria, neutrophils, and inflammatory cells, not Charcot-Leyden crystals or Curschmann spirals. *Bronchiectasis* - Characterized by **permanent dilation of the bronchi** due to chronic inflammation and infection, leading to chronic cough with copious, purulent sputum. - While it can cause dyspnea, the sputum findings of Charcot-Leyden crystals and Curschmann spirals are not typical for bronchiectasis, which often features bacterial cultures. *Panacinar emphysema* - A type of COPD primarily affecting the **respiratory bronchioles and alveolar ducts and sacs**, often associated with alpha-1 antitrypsin deficiency or smoking. - While smoking is a risk factor, the sputum findings in this case are not consistent with emphysema, which primarily involves alveolar destruction and less sputum production, and not these specific crystalline and spiral formations.

Question 218: A 49-year-old woman presents to her primary care physician for a general check up. She has not seen a primary care physician for the past 20 years but states she has been healthy during this time frame. She had breast implants placed when she was 29 years old but otherwise has not had any surgeries. She is concerned about her risk for breast cancer given her friend was recently diagnosed. Her temperature is 97.0°F (36.1°C), blood pressure is 114/64 mmHg, pulse is 70/min, respirations are 12/min, and oxygen saturation is 98% on room air. Physical exam is unremarkable. Which of the following is the most appropriate workup for breast cancer for this patient?

A. No intervention indicated at this time
B. Sentinel node biopsy
C. BRCA genetic testing
D. Mammography (Correct Answer)
E. Ultrasound

Explanation: ***Mammography*** - The patient is 49 years old, making regular screening **mammography** the most appropriate initial workup for breast cancer, as guidelines recommend screening for women over 40. - While breast implants can make mammograms more challenging, specialized techniques like **Eklund views** can be used to visualize breast tissue effectively. *No intervention indicated at this time* - This is incorrect because the patient's age (49) places her in the demographic for routine **breast cancer screening**. - Delaying screening in this age group would increase the risk of detecting cancer at a later, less treatable stage. *Sentinel node biopsy* - **Sentinel node biopsy** is a procedure typically performed after a breast cancer diagnosis to stage the disease and determine lymph node involvement. - It is not a screening tool and is therefore inappropriate as an initial workup in an asymptomatic patient without a known mass. *BRCA genetic testing* - **BRCA genetic testing** is indicated for individuals with a strong family history of breast or ovarian cancer, or those diagnosed with specific types of breast cancer at a young age. - This patient has no such risk factors mentioned, making genetic testing unnecessary as a first-line screening step. *Ultrasound* - **Ultrasound** is often used as a follow-up to an abnormal mammogram or to evaluate specific palpable masses, especially in younger women with dense breasts. - It is not typically recommended as a primary screening tool for breast cancer in a 49-year-old woman, especially without prior mammographic findings.

Question 219: A 31-year-old female presents to the clinic with excessive anxiety and palpitations for a month. She also mentions loss of 2.72 kg (6 lb) of her weight over the last month. Her past medical history is insignificant. She does not smoke nor does she drink alcohol. Her temperature is 37°C (98.6°F), pulse is 81/min, respiratory rate is 23/min, and blood pressure is 129/88 mm Hg. On examination, mild exophthalmos is noted. Heart and lung examination is normal including cardiac auscultation. What is the most likely cause of her symptoms?

A. Thyroid stimulating antibodies (Correct Answer)
B. Inadequate iodine in her diet
C. Lithium use
D. Use of propylthiouracil
E. Medullary carcinoma of the thyroid

Explanation: ***Thyroid stimulating antibodies*** - The patient's symptoms of **anxiety**, **palpitations**, **weight loss**, and **exophthalmos** are characteristic of **hyperthyroidism**, specifically **Graves' disease**. - **Graves' disease** is an autoimmune condition caused by **thyroid-stimulating immunoglobulins (TSI)**, which act as agonists at the TSH receptor, leading to excessive thyroid hormone production. *Inadequate iodine in her diet* - **Iodine deficiency** is a common cause of **hypothyroidism** and **goiter**, where the thyroid gland is unable to produce sufficient thyroid hormones. - This condition presents with symptoms such as **fatigue, weight gain, constipation**, and **cold intolerance**, which are opposite to the patient's presentation. *Lithium use* - **Lithium** is primarily used as a mood stabilizer and is known to cause **hypothyroidism** or, less commonly, euthyroid goiter due to its interference with thyroid hormone synthesis and release. - This would not explain the patient's hyperthyroid symptoms of anxiety, palpitations, and weight loss. *Use of propylthiouracil* - **Propylthiouracil (PTU)** is an **antithyroid medication** used to treat hyperthyroidism by inhibiting thyroid hormone synthesis. - Its use would lead to a reduction in thyroid hormone levels and would not be the cause of the patient's hyperthyroid symptoms. *Medullary carcinoma of the thyroid* - **Medullary thyroid carcinoma** is a neuroendocrine tumor that arises from parafollicular C cells and secretes **calcitonin**. - It typically presents as a thyroid nodule and usually does not cause symptoms of hyperthyroidism unless very advanced and aggressive.

Question 220: A 25-year old man comes to the physician because of fatigue over the past 6 months. He has been to the emergency room several times over the past 3 years for recurrent shoulder and patella dislocations. Physical examination shows abnormal joint hypermobility and skin hyperextensibility. A high-frequency mid-systolic click is heard on auscultation. Which of the following is most likely to result in an earlier onset of this patient’s auscultation finding?

A. Hand grip
B. Rapid squatting
C. Leaning forward
D. Abrupt standing (Correct Answer)
E. Valsalva release phase

Explanation: ***Abrupt standing*** - Abrupt standing reduces **preload** (venous return), leading to a smaller left ventricle and earlier prolapse of the mitral valve, causing an **earlier systolic click**. - This maneuver decreases **left ventricular volume**, thereby reducing the tension on the chordae tendineae and facilitating earlier mitral valve billowing into the atrium. *Hand grip* - Hand grip is an **isometric exercise** that increases **afterload** and **left ventricular volume**. - Increased left ventricular volume would cause the mitral valve leaflets to become taut earlier in systole, thus **delaying** the click rather than making it earlier. *Rapid squatting* - Rapid squatting rapidly increases **venous return** and **systemic vascular resistance**, increasing **preload** and **afterload**. - This leads to increased left ventricular volume, which would **delay** the onset of the systolic click as the mitral valve takes longer to prolapse. *Leaning forward* - Leaning forward is typically used to accentuate the murmur of **aortic regurgitation** or **pericardial friction rubs**, not to alter the timing of a mitral valve prolapse click. - It can sometimes make heart sounds clearer by bringing the heart closer to the chest wall but does not directly affect cardiac preload or afterload significantly to change click timing. *Valsalva release phase* - The release phase of Valsalva maneuver is characterized by an **increase in venous return** and **cardiac output** after the initial decrease during straining. - This increase in left ventricular volume would **delay** the mitral valve prolapse click, as it increases the tension on the mitral valve apparatus.

Question 221: A 41-year-old woman presents to urgent care with complaints of a new rash. On review of systems, she endorses ankle pain bilaterally. Otherwise, she has no additional localized complaints. Physical examination reveals numerous red subcutaneous nodules overlying her shins, bilaterally. Complete blood count shows leukocytes 7,300, Hct 42.0%, Hgb 14.0 g/dL, mean corpuscular volume (MCV) 88 fL, and platelets 209. Chest radiography demonstrates bilateral hilar adenopathy with clear lungs. Which of the following is the most likely diagnosis?

A. Yersiniosis
B. Coccidioidomycosis
C. Histoplasmosis
D. Chlamydophila pneumoniae
E. Sarcoidosis (Correct Answer)

Explanation: ***Sarcoidosis*** - The combination of **erythema nodosum** (red subcutaneous nodules on shins), **bilateral hilar adenopathy**, and **ankle arthralgia** (ankle pain) in a young woman is highly characteristic of **Lofgren's syndrome**, a common acute presentation of sarcoidosis. - While other conditions can cause hilar adenopathy or erythema nodosum, the triad presented makes sarcoidosis the most likely diagnosis. *Yersiniosis* - Can cause **erythema nodosum** and arthralgia, but **bilateral hilar adenopathy** is not a typical feature of *Yersinia* infection. - Often associated with **gastrointestinal symptoms** (e.g., diarrhea) which are not mentioned here. *Coccidioidomycosis* - Can cause **erythema nodosum** and affect the lungs, but typically presents with **pulmonary infiltrates** or **nodules**, not just isolated bilateral hilar adenopathy. - Endemic to specific geographic regions (e.g., southwestern US), which is not specified but relevant for exposure. *Histoplasmosis* - Can cause **hilar adenopathy** and **erythema nodosum**, especially in acute disseminated forms. - However, it's more common in individuals exposed to **bird or bat droppings** (Ohio and Mississippi River valleys), and a fungal infection would likely present with more systemic symptoms or specific lung findings beyond just hilar adenopathy. *Chlamydophila pneumoniae* - This atypical bacterial infection can cause respiratory symptoms and, rarely, reactive arthritis or erythema nodosum. - However, **bilateral hilar adenopathy** is not a typical prominent feature of *Chlamydophila pneumoniae* infection.

Question 222: A 37-year-old man presents to the clinic for evaluation of a chronic cough that has increased in frequency and severity for the past 2 days. His cough began 2 weeks ago but was not as bothersome as now. He states that he can hardly get to sleep because he is coughing all the time. Upon further questioning, he says that he had a low-grade fever, runny nose, and fatigue. However, everything resolved except for his cough. He has a history of hyperlipidemia and takes simvastatin. His vital signs are within normal limits. On physical examination, the patient is in no apparent distress and is alert and oriented. His head is normocephalic with non-tender sinuses. Sclerae are not jaundiced and there are no signs of conjunctivitis. Nares are clear without erythema. Examination of the pharynx shows erythematous mucosa without exudate. Lungs are clear to auscultation bilaterally. Posteroanterior chest X-ray shows no regions of consolidation, hypervascularity or effusion. Which of the following is the next best step in the management of this patient?

A. Azithromycin
B. Amoxicillin
C. Levofloxacin
D. Azithromycin with amoxicillin-clavulanate
E. Supportive treatment (Correct Answer)

Explanation: ***Supportive treatment*** - This patient likely has a **post-viral cough**, which is a self-limiting condition that typically resolves on its own without specific medication. His history of a recent common cold and the absence of bacterial infection signs (normal vital signs, clear chest X-ray, no purulent sputum) support this. - Management involves **symptomatic relief** with measures like cough suppressants, lozenges, and hydration, rather than antibiotics which are ineffective against viral infections. *Azithromycin* - Azithromycin is an **antibiotic** used to treat bacterial infections, particularly atypical respiratory pathogens. - There is no clinical or radiological evidence suggesting a bacterial infection (e.g., fever, crackles, consolidation on X-ray) in this patient, making antibiotic therapy inappropriate. *Amoxicillin* - Amoxicillin is a **beta-lactam antibiotic** primarily used for common bacterial respiratory infections like strep throat or sinusitis. - The patient's symptoms are inconsistent with a bacterial infection requiring amoxicillin; his cough is likely viral in origin and there are no signs of bacterial sinusitis or pneumonia. *Levofloxacin* - Levofloxacin is a **fluoroquinolone antibiotic** typically reserved for more severe bacterial infections or when resistance to other antibiotics is suspected. - Using a broad-spectrum antibiotic like levofloxacin without clear evidence of a bacterial infection is inappropriate and contributes to **antibiotic resistance**. *Azithromycin with amoxicillin-clavulanate* - This combination represents broad-spectrum antibiotic coverage, often indicated for atypical and typical bacterial co-infections. - Prescribing multiple antibiotics without any indication of a bacterial infection is **unnecessary** and carries risks of side effects and promoting antibiotic resistance.

Question 223: A 75-year-old man comes to the physician because of fatigue and decreased urine output for 1 week. He takes ibuprofen as needed for lower back pain and docusate for constipation. Physical examination shows tenderness to palpation over the lumbar spine. There is pedal edema. Laboratory studies show a hemoglobin concentration of 8.7 g/dL, a serum creatinine concentration of 2.3 mg/dL, and a serum calcium concentration of 12.6 mg/dL. Urine dipstick is negative for blood and protein. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Immunoglobulin light chains (Correct Answer)
B. Hypersensitivity reaction
C. Antiglomerular basement membrane antibodies
D. Anti double-stranded DNA antibodies
E. Renal deposition of AL amyloid

Explanation: ***Immunoglobulin light chains*** - The patient's symptoms (fatigue, decreased urine output, **anemia**, **hypercalcemia**, **elevated creatinine**, and **lumbar spine tenderness**) are highly suggestive of **multiple myeloma**. - **Immunoglobulin light chains** (**Bence Jones proteins**) are overproduced in multiple myeloma and are nephrotoxic, leading to **cast nephropathy** and acute kidney injury. *Hypersensitivity reaction* - A hypersensitivity reaction involving the kidneys typically presents as **acute interstitial nephritis** with fever, rash, and eosinophilia, which are absent in this patient. - While NSAIDs can cause interstitial nephritis, the presence of **hypercalcemia** and **anemia** points away from this as the primary cause. *Antiglomerular basement membrane antibodies* - These antibodies cause **Goodpasture syndrome**, characterized by rapidly progressive glomerulonephritis, often with pulmonary hemorrhage. - The urine dipstick negative for blood and protein makes glomerulonephritis less likely, and the co-occurrence of **hypercalcemia** and **anemia** does not fit. *Anti double-stranded DNA antibodies* - These antibodies are characteristic of **systemic lupus erythematosus (SLE)**, which can cause **lupus nephritis**. - While SLE can cause kidney dysfunction and anemia, the prominent **hypercalcemia** and specific bone pain are not typical features of SLE-related kidney disease. *Renal deposition of AL amyloid* - **AL amyloidosis** can present with kidney dysfunction and fatigue. However, significant **hypercalcemia** and a hemoglobin of 8.7 g/dL without other signs of chronic disease are less typical of amyloidosis alone. - The combination of **anemia, hypercalcemia, renal failure**, and bone pain points more specifically to **multiple myeloma**.

Question 224: A 63-year-old man presents to his primary care provider complaining of changes in his vision. He says that he has been having transient episodes of "shimmering lights" and generalized blurring of his vision for the past 3 months. He is disturbed by this development as he worries it may interfere with his job as a bus driver. He additionally reports a 12-pound weight loss over this time unaccompanied by a change in appetite, and his gout flares have grown more frequent despite conforming to his recommended diet and allopurinol. His temperature is 98.0°F (36.7°C), blood pressure is 137/76 mmHg, pulse is 80/min, and respirations are 18/min. Hemoglobin and hematocrit obtained the previous day were 18.1 g/dL and 61%, respectively. Peripheral blood screening for JAK2 V617F mutation is positive. Which of the following findings is most likely expected in this patient?

A. Decreased erythrocyte sedimentation rate (Correct Answer)
B. Schistocytes on peripheral smear
C. Decreased oxygen saturation
D. Thrombocytopenia
E. Increased erythropoietin levels

Explanation: ***Decreased erythrocyte sedimentation rate*** - The patient's presentation is consistent with **polycythemia vera (PV)**, characterized by an **elevated hematocrit (61%)** and **positive JAK2 V617F mutation**. - **Erythrocyte sedimentation rate (ESR)** is **decreased in PV** due to the increased red blood cell mass and elevated hematocrit, which **impairs rouleaux formation** (the stacking of RBCs that normally promotes sedimentation). - The high viscosity and packed RBCs physically hinder the normal settling process, resulting in a characteristically low ESR. *Schistocytes on peripheral smear* - **Schistocytes** are fragmented red blood cells indicating **microangiopathic hemolytic anemia** (MAHA). - This finding is associated with conditions like **thrombotic thrombocytopenic purpura (TTP)** or **disseminated intravascular coagulation (DIC)**, not with polycythemia vera. *Decreased oxygen saturation* - Patients with **polycythemia vera** have **normal or even elevated oxygen saturation** due to the increased red blood cell count and oxygen-carrying capacity. - Decreased oxygen saturation would suggest **hypoxia** or **secondary polycythemia** (compensatory response to chronic hypoxemia), which is ruled out by the positive **JAK2 mutation**. *Thrombocytopenia* - **Polycythemia vera** typically presents with **thrombocytosis** (elevated platelet count), not thrombocytopenia. - The elevated platelet count contributes to the **increased thrombotic risk** in PV, which may explain the patient's visual symptoms (potential retinal vein thrombosis) and worsening gout (hyperuricemia from increased cell turnover). *Increased erythropoietin levels* - In **polycythemia vera**, erythropoietin (EPO) levels are typically **low or inappropriately normal** due to constitutive activation of the **JAK2 pathway**. - The mutation causes erythroid progenitor cells to be hypersensitive to EPO and produce RBCs autonomously, leading to **negative feedback** that suppresses EPO production. - Elevated EPO would suggest **secondary polycythemia** (e.g., from chronic hypoxia, renal tumors), which is excluded by the positive **JAK2 V617F mutation**.

Question 225: A 42-year-old woman presents with complaints of a sharp, stabbing pain in her chest upon coughing and inhalation. She says that the pain started acutely 2 days ago and has progressively worsened. Her past medical history is significant for a rash on her face, joint pains, and fatigue for the past few weeks. The patient is afebrile and her vital signs are within normal limits. On physical examination, there is a malar macular rash that spares the nasolabial folds. There is a friction rub at the cardiac apex that does not vary with respiration. Which of the following additional physical examination signs would most likely be present in this patient?

A. Mid-systolic click
B. Displaced apical impulse
C. Chest pain that improves with leaning forward (Correct Answer)
D. High-pitched diastolic murmur
E. Pain improvement with inspiration

Explanation: ***Chest pain that improves with leaning forward*** - The patient's symptoms (malar rash, joint pains, fatigue, chest pain worse with coughing/inhalation, and an apical friction rub) are highly suggestive of **pericarditis secondary to Systemic Lupus Erythematosus (SLE)**. - Pain from pericarditis is classically **relieved by leaning forward** as this position decreases the pressure on the inflamed pericardium. *Mid-systolic click* - A mid-systolic click is characteristic of **mitral valve prolapse**, which is not directly indicated by the patient's presenting symptoms or primary diagnosis of pericarditis. - While SLE can be associated with various cardiac manifestations, a mid-systolic click is not a direct presentation of acute pericarditis. *Displaced apical impulse* - A displaced apical impulse typically suggests **ventricular enlargement** or conditions that shift the heart, such as a large **pericardial effusion**. - While pericarditis can lead to effusion, the presence of a friction rub and acute onset does not immediately imply a significant enough effusion to displace the apical impulse. *High-pitched diastolic murmur* - A high-pitched diastolic murmur is characteristic of **aortic regurgitation** or, less commonly, **pulmonic regurgitation**. - These are valvular abnormalities not directly linked to the acute pericarditis described in the patient's presentation. *Pain improvement with inspiration* - **Pleuritic chest pain**, often seen in conditions like pleurisy or pulmonary embolism, *worsens* with inspiration, not improves. - The patient's pain worsening with inhalation rules out improvement with inspiration as a likely sign.

Question 226: A 28-year-old woman presents to her physician for follow-up. She was found to be HIV-positive 9 months ago. Currently she is on ART with lamivudine, tenofovir, and efavirenz. She has no complaints and only reports a history of mild respiratory infection since the last follow-up. She is also allergic to egg whites. Her vital signs are as follows: the blood pressure is 120/75 mm Hg, the heart rate is 73/min, the respiratory rate is 13/min, and the temperature is 36.7°C (98.0°F). She weighs 68 kg (150 lb), and there is no change in her weight since the last visit. On physical examination, she appears to be pale, her lymph nodes are not enlarged, her heart sounds are normal, and her lungs are clear to auscultation. Her total blood count shows the following findings: Erythrocytes 3.2 x 106/mm3 Hematocrit 36% Hgb 10 g/dL Total leukocyte count 3,900/mm3 Neutrophils 66% Lymphocytes 24% Eosinophils 3% Basophils 1% Monocytes 7% Platelet count 280,000/mm3 Her CD4+ cell count is 430 cells/µL. The patient tells you she would like to get an influenza vaccination as flu season is coming. Which of the following statements is true regarding influenza vaccination in this patient?

A. As long as the patient is anemic, she should not be vaccinated.
B. Influenza vaccination is contraindicated in HIV-positive patients because of the serious complications they can cause in immunocompromised people.
C. Inactivated or recombinant influenza vaccines fail to induce a sufficient immune response in patients with CD4+ cell counts under 500 cells/µL.
D. Nasal-spray influenza vaccine is the best option for vaccination in this patient.
E. The patient can receive approved recombinant or inactivated influenza vaccines, with egg-free formulations preferred due to her egg allergy. (Correct Answer)

Explanation: **The patient can receive approved recombinant or inactivated influenza vaccines, with egg-free formulations preferred due to her egg allergy.** - Patients with HIV, regardless of their CD4+ count, should receive the **inactivated influenza vaccine** annually due to their increased risk of severe influenza complications. - Given the patient's reported egg allergy, an **egg-free vaccine formulation**, such as a recombinant injectable influenza vaccine (RIV4) or cell-culture-based inactivated influenza vaccine (ccIIV4), is the preferred choice to minimize allergic reactions. *As long as the patient is anemic, she should not be vaccinated.* - **Anemia** is not a contraindication for receiving the influenza vaccine; the benefits of vaccination typically outweigh any risks associated with mild anemia. - While the patient is anemic (Hgb 10 g/dL), this condition does not prevent her from safely receiving an **inactivated influenza vaccine**. *Influenza vaccination is contraindicated in HIV-positive patients because of the serious complications they can cause in immunocompromised people.* - This statement is incorrect; **inactivated influenza vaccines** are recommended for HIV-positive individuals, as they are not live vaccines and cannot cause influenza. - HIV-positive patients are at higher risk for severe influenza complications, making vaccination even more crucial, not contraindicated. *Inactivated or recombinant influenza vaccines fail to induce a sufficient immune response in patients with CD4+ cell counts under 500 cells/µL.* - While the immune response to vaccines can be attenuated in HIV patients with lower CD4+ counts, even a partial response offers some protection and is better than no vaccination. - The **guidelines for HIV patients** recommend influenza vaccination regardless of CD4+ count, emphasizing the importance of any induced immunity. *Nasal-spray influenza vaccine is the best option for vaccination in this patient.* - The **nasal-spray influenza vaccine (LAIV)** is a **live-attenuated vaccine**, which is generally contraindicated in immunocompromised individuals, including those with HIV, due to the risk of active infection. - HIV patients should receive **inactivated or recombinant influenza vaccines**, not live-attenuated formulations.

Question 227: A 23-year-old man presents to the emergency department for altered mental status after a finishing a marathon. He has a past medical history of obesity and anxiety and is not currently taking any medications. His temperature is 104°F (40°C), blood pressure is 147/88 mmHg, pulse is 200/min, respirations are 33/min, and oxygen saturation is 99% on room air. Physical exam reveals dry mucous membranes, hot flushed skin, and inappropriate responses to the physician's questions. Laboratory values are ordered as seen below. Hemoglobin: 15 g/dL Hematocrit: 44% Leukocyte count: 8,500/mm^3 with normal differential Platelet count: 199,000/mm^3 Serum: Na+: 165 mEq/L Cl-: 100 mEq/L K+: 4.0 mEq/L HCO3-: 22 mEq/L BUN: 30 mg/dL Glucose: 133 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following is the best next step in management?

A. Lactated ringer
B. Hypotonic saline
C. 50% normal saline 50% dextrose
D. Normal saline (Correct Answer)
E. Dextrose solution

Explanation: ***Normal saline*** - The patient presents with **heat stroke** (temperature 104°F, altered mental status after marathon) complicated by **severe hypernatremia (Na+ 165 mEq/L)** and **hypovolemia** (elevated BUN/Cr ratio, tachycardia, dry mucous membranes). - In **hypovolemic hypernatremia**, the best initial step is to restore **intravascular volume** with **isotonic crystalloid** (normal saline or lactated Ringer's) to stabilize hemodynamics and organ perfusion. - **Normal saline (0.9% NaCl, 154 mEq/L Na+)** is hypotonic relative to the patient's serum (165 mEq/L), so it will begin **gradual correction** of hypernatremia while providing volume resuscitation. - After volume restoration, hypotonic fluids (0.45% saline or D5W) may be used for further correction, but they should NOT be given initially to a volume-depleted patient due to risk of worsening hypotension. - Correction rate should be **≤10-12 mEq/L per 24 hours** to avoid cerebral edema. *Hypotonic saline* - While hypotonic saline (0.45% NaCl) is used to correct hypernatremia, it should **not** be the first-line choice in a **hypovolemic** patient. - Administering hypotonic fluids to a volume-depleted patient can worsen hypotension and compromise organ perfusion before adequately restoring intravascular volume. - Hypotonic saline is appropriate **after** volume status has been restored with isotonic fluids. *Lactated ringer* - **Lactated Ringer's solution** is an isotonic crystalloid (130 mEq/L Na+) and would be an equally acceptable choice for initial volume resuscitation. - It is slightly more hypotonic than normal saline, which could provide marginally faster correction of hypernatremia. - Either normal saline or lactated Ringer's is appropriate for initial management; normal saline is more commonly cited in USMLE resources for hypernatremia management. *50% normal saline 50% dextrose* - This mixture would create a **hypertonic solution** that could worsen hypernatremia rather than correct it. - The patient's glucose is normal (133 mg/dL), so dextrose supplementation is not indicated. - This option is inappropriate for managing hypernatremia. *Dextrose solution* - **D5W (5% dextrose in water)** provides free water and would correct hypernatremia by diluting serum sodium. - However, in a **volume-depleted** patient, giving free water without adequate sodium can lead to rapid osmotic shifts, worsening hypotension, and potentially causing cerebral edema if correction occurs too rapidly. - D5W is reserved for **euvolemic or hypervolemic hypernatremia**, not hypovolemic hypernatremia.

Question 228: A 65-year-old man presents to his primary-care doctor for a 2-month history of dizziness. He describes feeling unsteady on his feet or like he's swaying from side-to-side; he's also occasionally had a room-spinning sensation. He first noticed it when he was in the front yard playing catch with his grandson, and he now also reliably gets it when throwing the frisbee with his dog. The dizziness only happens during these times, and it goes away after a couple of minutes of rest. His medical history is notable for type 2 diabetes mellitus treated with metformin. His vital signs are within normal limits in the office. The physical exam is unremarkable. Which of the following is the next best test for this patient?

A. Ankle-brachial index
B. Doppler ultrasound (Correct Answer)
C. Transthoracic echocardiogram
D. CT head (noncontrast)
E. Electrocardiogram

Explanation: ***Doppler ultrasound*** - The patient's dizziness occurring specifically during **upper extremity exertion** (playing catch, throwing frisbee) that resolves with rest is classic for **subclavian steal syndrome**. - In subclavian steal, stenosis of the subclavian artery proximal to the vertebral artery origin causes **reversed flow in the vertebral artery** during arm exercise, "stealing" blood from the posterior circulation and causing vertebrobasilar insufficiency symptoms. - **Doppler ultrasound** of the subclavian and vertebral arteries is the appropriate initial test to demonstrate reversed vertebral flow and subclavian stenosis. This can be confirmed with provocative maneuvers (arm exercise during the study). - The patient's diabetes increases his risk for atherosclerotic disease, making this diagnosis more likely. *CT head (noncontrast)* - While CT head can evaluate for stroke or structural brain lesions, it would **not visualize the vascular stenosis** causing subclavian steal syndrome. - The episodic nature triggered by specific arm movements and complete resolution with rest makes an acute structural brain lesion unlikely. - CT head would be appropriate if symptoms were persistent, progressive, or associated with focal neurological deficits. *Ankle-brachial index* - ABI is used to diagnose **peripheral artery disease** affecting the lower extremities, typically presenting with **intermittent claudication** (leg pain with walking). - This does not evaluate the upper extremity or cerebrovascular circulation relevant to this patient's symptoms. *Electrocardiogram* - ECG evaluates cardiac rhythm and ischemia but would not diagnose the **vascular steal phenomenon** causing his symptoms. - Cardiac arrhythmias typically cause syncope or presyncope rather than positional dizziness triggered by specific arm movements. - While arrhythmias should be considered in the differential, the clear association with arm exercise points to a vascular steal phenomenon. *Transthoracic echocardiogram* - TTE assesses cardiac structure and function (valves, chambers, ejection fraction) but does not evaluate the **extracranial vasculature**. - Cardiac causes of dizziness (e.g., severe aortic stenosis) would more likely present with exertional syncope rather than dizziness specifically with arm movements. - The symptom pattern does not suggest primary cardiac pathology.

Question 229: A 35-year-old man presents with pain in his feet during exercise and at rest. He says that his fingers and toes become pale upon exposure to cold temperatures. He has an extensive smoking history, but no history of diabetes mellitus nor hyperlipidemia. He used to exercise frequently but has stopped because of the symptoms. On inspection, a tiny ulcer is found on his toe. On laboratory analysis, his blood sugar, blood pressure, and lipids are all within the normal range. Which is the most probable diagnosis?

A. Buerger's disease (Correct Answer)
B. Peripheral arterial occlusive disease (PAOD)
C. Frostbite
D. Atherosclerosis
E. Popliteal artery entrapment syndrome (PAES)

Explanation: ***Buerger's disease*** - This condition uniquely affects **young male smokers**, causing inflammation and thrombosis in small to medium-sized arteries and veins leading to **ischemic pain**, **Raynaud's phenomenon** (fingers/toes turning pale with cold), and digital **ulcers**. - The absence of typical risk factors for atherosclerosis (normal blood sugar, lipids, blood pressure) in a heavy smoker with these specific symptoms strongly points to Buerger's disease. *Peripheral arterial occlusive disease (PAOD)* - While PAOD can cause exertional pain (claudication) and ulcers, it typically affects older individuals and is primarily caused by **atherosclerosis** and related risk factors (diabetes, hyperlipidemia, hypertension), which are absent here. - The distinct **Raynaud's phenomenon** and the patient's young age are less characteristic of PAOD in the absence of other risk factors. *Frostbite* - Frostbite is tissue damage caused by **extreme cold exposure** and is an acute injury, not a chronic progressive disease like that described. - While it can cause pallor and tissue damage, the patient's symptoms are recurring, involve exercise-induced pain, and occur without clear extreme cold exposure in the history. *Atherosclerosis* - Atherosclerosis is the underlying cause for most PAOD cases and involves plaque buildup in arteries due to risk factors like **dyslipidemia, hypertension, and diabetes**, all of which are explicitly stated as normal in this patient. - In a young patient without these metabolic risk factors, atherosclerosis as the primary diagnosis is less likely, especially with the characteristic Raynaud's phenomenon seen in Buerger's. *Popliteal artery entrapment syndrome (PAES)* - PAES is characterized by **intermittent claudication** due to compression of the popliteal artery by surrounding musculature, typically in young athletes. - However, PAES would not explain the **Raynaud's phenomenon** or the digital ulceration observed, and the pain persists at rest, which is less typical for PAES.

Question 230: A 63-year-old man is brought by his wife to the emergency department after he was found with nausea, headache, and agitation 1 hour ago. When the wife left their lakeside cabin earlier in the day to get more firewood, the patient did not have any symptoms. Vital signs are within normal limits. Pulse oximetry on room air shows an oxygen saturation of 98%. Neurologic examination shows confusion and orientation only to person and place. He recalls only one of three objects after 5 minutes. His gait is unsteady. Which of the following is the most effective intervention for this patient's current condition?

A. Hyperbaric oxygen therapy (Correct Answer)
B. Heliox therapy
C. Intranasal sumatriptan
D. Intravenous hydroxycobalamin
E. Intravenous nitroprusside

Explanation: ***Hyperbaric oxygen therapy*** - **Hyperbaric oxygen therapy** is the most effective intervention for severe **carbon monoxide poisoning**, as it delivers 100% oxygen at increased atmospheric pressure, rapidly displacing carbon monoxide from hemoglobin and improving tissue oxygenation. - The patient's symptoms of nausea, headache, agitation, confusion, and gait instability, developing acutely after being in a lakeside cabin (suggesting potential for a faulty heating system), are highly indicative of **carbon monoxide poisoning**, despite normal pulse oximetry readings. *Heliox therapy* - **Heliox therapy** is a mixture of helium and oxygen used to reduce the work of breathing in patients with **airway obstruction**, such as asthma or croup, by decreasing gas density. - It does not address the underlying pathology of carbon monoxide poisoning, which involves impaired oxygen transport by hemoglobin. *Intranasal sumatriptan* - **Intranasal sumatriptan** is a **triptan derivative** used to treat **migraine headaches** by constricting cranial blood vessels and reducing inflammation. - While the patient has a headache, its acute onset with other neurological symptoms points away from a primary migraine and towards a systemic intoxication. *Intravenous hydroxycobalamin* - **Intravenous hydroxycobalamin** is the primary antidote for **cyanide poisoning**, forming cyanocobalamin (Vitamin B12) and reducing cyanide toxicity. - The patient's symptoms are classic for carbon monoxide poisoning, not cyanide poisoning, which typically presents with severe metabolic acidosis and cardiovascular collapse. *Intravenous nitroprusside* - **Intravenous nitroprusside** is a powerful vasodilator used to treat **hypertensive emergencies** or severe heart failure by rapidly reducing both preload and afterload. - It has no role in the treatment of carbon monoxide poisoning, as it does not address the issue of dysfunctional hemoglobin or tissue hypoxia.

Question 231: A 62-year-old retired professor comes to the clinic with the complaints of back pain and increasing fatigue over the last 4 months. For the past week, his back pain seems to have worsened. It radiates to his legs and is burning in nature, 6/10 in intensity. There is no associated tingling sensation. He has lost 4.0 kg (8.8 lb) in the past 2 months. There is no history of trauma. He has hypertension which is well controlled with medications. Physical examination is normal. Laboratory studies show normocytic normochromic anemia. Serum calcium is 12.2 mg/dL and Serum total proteins is 8.8 gm/dL. A serum protein electrophoresis shows a monoclonal spike. X-ray of the spine shows osteolytic lesions over L2–L5 and right femur. A bone marrow biopsy reveals plasmacytosis. Which of the following is the most preferred treatment option?

A. Renal dialysis
B. Palliative care
C. Chemotherapy and autologous stem cell transplant (Correct Answer)
D. Bisphosphonates
E. Chemotherapy alone

Explanation: ***Chemotherapy and autologous stem cell transplant*** - This patient presents with classic features of **multiple myeloma**, including bone pain with osteolytic lesions, hypercalcemia, normocytic anemia, elevated total protein with a monoclonal spike, and plasmacytosis in the bone marrow. - In a relatively healthy patient with newly diagnosed multiple myeloma who is fit for intensive therapy (as suggested by the absence of significant comorbidities beyond controlled hypertension), **chemotherapy followed by autologous stem cell transplant (ASCT)** is the preferred treatment to achieve deeper and more durable remission. *Renal dialysis* - While **renal impairment** can occur in multiple myeloma due to myeloma kidney, it is not described in this patient, and **dialysis** is a supportive measure for end-stage kidney disease, not the primary treatment for the underlying malignancy. - The patient's symptoms are primarily related to bone involvement and systemic effects of myeloma, not severe renal failure. *Palliative care* - **Palliative care** focuses on symptom relief and quality of life, which is essential at any stage of a serious illness, but it is not the initial primary therapeutic intervention for a newly diagnosed, symptomatic, and treatable cancer like multiple myeloma in a patient who could benefit from curative or remission-inducing therapy. - The goal at this stage is disease control and prolonging survival. *Bisphosphonates* - **Bisphosphonates** (e.g., zoledronic acid) are an important adjunctive therapy in multiple myeloma to manage and prevent **skeletal-related events** by inhibiting osteoclast activity, but they do not treat the underlying plasma cell malignancy itself. - They would be used in conjunction with chemotherapy, not as a standalone primary treatment. *Chemotherapy alone* - While **chemotherapy** (often a combination of proteasome inhibitors, immunomodulatory drugs, and dexamethasone) is central to treating multiple myeloma, **chemotherapy alone** without subsequent ASCT is typically reserved for patients who are not candidates for transplantation due to age, comorbidities, or frailty. - For transplant-eligible patients, ASCT after induction chemotherapy significantly improves progression-free survival and overall survival compared to chemotherapy alone.

Question 232: A 33-year-old man presents to the emergency department because of an episode of bloody emesis. He has had increasing dyspnea over the past 2 days. He was diagnosed with peptic ulcer disease last year. He has been on regular hemodialysis for the past 2 years because of end-stage renal disease. He skipped his last dialysis session because of an unexpected business trip. He has no history of liver disease. His supine blood pressure is 110/80 mm Hg and upright is 90/70, pulse is 110/min, respirations are 22/min, and temperature is 36.2°C (97.2°F). The distal extremities are cold to touch, and the outstretched hand shows flapping tremor. A bloody nasogastric lavage is also noted, which eventually clears after saline irrigation. Intravenous isotonic saline and high-dose proton pump inhibitors are initiated, and the patient is admitted into the intensive care unit. Which of the following is the most appropriate next step in the management of this patient?

A. Observation in the intensive care unit
B. Double-balloon tamponade
C. Hemodialysis (Correct Answer)
D. Transfusion of packed red blood cells
E. Esophagogastroduodenoscopy

Explanation: ***Hemodialysis*** - The patient has **end-stage renal disease** and missed his last dialysis session, leading to **uremic crisis** with **dyspnea** (fluid overload) and **asterixis** (uremic encephalopathy). - **Uremic platelet dysfunction** also contributes to the GI bleeding, making dialysis essential to correct coagulopathy. - Emergency hemodialysis is the most critical intervention to remove accumulated toxins, correct fluid overload, and improve hemostasis before any invasive procedures. *Observation in the intensive care unit* - While ICU admission is appropriate for monitoring, passive observation without addressing the underlying **uremia** will not resolve the critical issues of **fluid overload**, **uremic encephalopathy**, and **uremic coagulopathy**. - The patient's missed dialysis session and severe symptoms necessitate active intervention, not just observation. *Double-balloon tamponade* - This procedure is reserved for **life-threatening variceal bleeding** that is refractory to endoscopic treatment. - The patient's history of **peptic ulcer disease** (not cirrhosis) and the clearing of bloody lavage with saline irrigation suggest non-variceal bleeding, making tamponade inappropriate. *Transfusion of packed red blood cells* - While the patient shows signs of **orthostatic hypotension** and **tachycardia** suggesting hypovolemia, the GI bleeding has **stabilized** (NG lavage cleared with irrigation). - Transfusion may be needed based on hemoglobin levels, but it does not address the **immediately life-threatening uremic crisis** with encephalopathy and platelet dysfunction. - The most urgent priority is dialysis to stabilize the patient for subsequent procedures. *Esophagogastroduodenoscopy* - EGD is indicated to identify and potentially treat the source of **upper GI bleeding** in a patient with **peptic ulcer disease**. - However, the patient's severe **uremic symptoms**, **encephalopathy**, and **coagulopathy** must be addressed first to safely perform this invasive procedure and optimize outcomes.

Question 233: A 47-year-old woman comes to the physician because of body aches for the past 9 months. She also has stiffness of the shoulders and knees that is worse in the morning and tingling in the upper extremities. Examination shows marked tenderness over the posterior neck, bilateral mid trapezius, and medial aspect of the left knee. A complete blood count and erythrocyte sedimentation rate are within the reference ranges. Which of the following is the most likely diagnosis?

A. Systemic lupus erythematosus
B. Fibromyalgia (Correct Answer)
C. Rheumatoid arthritis
D. Polymyositis
E. Major depressive disorder

Explanation: ***Fibromyalgia*** - The patient's presentation of widespread **body aches for 9 months**, morning **stiffness**, and **multiple tender points** (posterior neck, bilateral mid trapezius, medial aspect of the knee) in the absence of inflammatory markers (normal ESR, normal CBC) is highly characteristic of **fibromyalgia**. - **Paresthesias** (tingling in the upper extremities) are a common associated feature in fibromyalgia. - Fibromyalgia is a chronic pain syndrome diagnosed clinically based on widespread pain and tender points, with normal laboratory findings. *Systemic lupus erythematosus* - SLE typically presents with **systemic inflammation**, often involving joints, skin, and kidneys, along with abnormalities in inflammatory markers (e.g., elevated ESR, positive ANA, cytopenias). - The widespread tender points and completely normal inflammatory markers make SLE very unlikely. *Rheumatoid arthritis* - RA primarily affects the **synovial joints** symmetrically, leading to joint swelling, warmth, and morning stiffness, typically accompanied by elevated ESR and CRP. - The examination findings show specific **tender points** rather than objective joint swelling, and the normal ESR rules against active RA. *Polymyositis* - Polymyositis is characterized by **proximal muscle weakness** (not diffuse body aches) and is associated with elevated muscle enzymes (CK, aldolase) and inflammatory changes on muscle biopsy. - This patient has pain and tenderness without weakness, and her laboratory tests are normal. *Major depressive disorder* - While **fatigue**, body aches, and sleep disturbances can be symptoms of major depressive disorder, the presence of specific, well-defined **tender points on examination** points towards a primary pain syndrome. - Fibromyalgia often coexists with depression, but the objective physical findings of multiple tender points are more consistent with fibromyalgia as the primary diagnosis.

Question 234: A laboratory technician processes basic metabolic panels for two patients. Patient A is 18 years old and patient B is 83 years old. Neither patient takes any medications regularly. Serum laboratory studies show: Patient A Patient B Na+ (mEq/L) 145 141 K+ (mEq/L) 3.9 4.4 Cl- (mEq/L) 103 109 HCO3- (mEq/L) 22 21 BUN (mg/dL) 18 12 Cr (mg/dL) 0.8 1.2 Glucose (mg/dL) 105 98 Which of the following most likely accounts for the difference in creatinine seen between these two patients?

A. Volume depletion
B. Low body mass index
C. Insulin resistance
D. Normal aging (Correct Answer)
E. High serum aldosterone levels

Explanation: ***Normal aging*** - **Creatinine** is a byproduct of **muscle metabolism**, and serum levels reflect both production (muscle mass) and clearance (GFR). - In **elderly individuals**, **GFR progressively declines** with age (approximately 1 mL/min/year after age 30). - However, **muscle mass also decreases** with aging (sarcopenia), leading to **reduced creatinine production**. - Patient B's creatinine of 1.2 mg/dL appears only mildly elevated, but this likely **underestimates the true decline in renal function** because decreased muscle mass reduces baseline creatinine production. - This is why **estimated GFR calculations** (using Cockcroft-Gault or MDRD equations) incorporate age and weight to account for this phenomenon. *Volume depletion* - **Volume depletion** typically leads to an increase in both **BUN** and **creatinine**, often with a disproportionately higher **BUN:Cr ratio** (>20:1). - Patient B's BUN is **lower** (12 mg/dL) than Patient A's (18 mg/dL), with a BUN:Cr ratio of 10:1, which argues **against volume depletion**. *Low body mass index* - **Low BMI** generally correlates with lower muscle mass, which would result in a **lower serum creatinine** level, not higher. - Patient B has a **higher creatinine** compared to Patient A, making low BMI an unlikely explanation for the observed difference. *Insulin resistance* - **Insulin resistance** is associated with altered glucose metabolism and can contribute to conditions like diabetes and chronic kidney disease over time. - However, it does not directly explain the **age-related creatinine differences** between these two patients with normal glucose levels and no evidence of diabetic nephropathy. *High serum aldosterone levels* - **High aldosterone levels** primarily affect **sodium and potassium balance** and fluid retention (causing hypokalemia and mild hypernatremia). - Both patients have **normal electrolytes**, and aldosterone does not directly account for **age-related creatinine differences**.

Question 235: A 68-year-old man presents to his primary care physician with pain that started after he visited his daughter as she moved into her new apartment. The patient states that the pain is likely related to all the traveling he has done and helping his daughter move and set up furniture. The patient has a past medical history of obesity, type II diabetes, multiple concussions while he served in the army, and GERD. He is currently taking metformin, lisinopril, omeprazole, and a multivitamin. On physical exam, pain is elicited upon palpation of the patient's lower back. Flexion of the patient's leg results in pain that travels down the patient's lower extremity. The patient's cardiac, pulmonary, and abdominal exam are within normal limits. Rectal exam reveals normal rectal tone. The patient denies any difficulty caring for himself, defecating, or urinating. Which of the following is the best next step in management?

A. NSAIDS and activity as tolerated (Correct Answer)
B. MRI of the spine
C. Oxycodone and bed rest
D. Oxycodone and activity as tolerated
E. NSAIDS and bed rest

Explanation: ***NSAIDS and activity as tolerated*** - The patient presents with classic symptoms of **acute low back pain** with **radicular symptoms** (pain radiating down the leg) following exertion, but without any **red flag symptoms** such as **fever**, **weight loss**, **neurological deficits**, or **cauda equina syndrome**. - Initial management for uncomplicated acute low back pain, including those with radiculopathy, typically involves **NSAIDs or acetaminophen** for pain relief and **maintaining activity as tolerated** to prevent deconditioning and chronicity. *MRI of the spine* - An MRI is generally not indicated as the **initial step** for acute, uncomplicated lower back pain unless **red flag symptoms** or a suspicion of **serious underlying pathology** (e.g., cauda equina syndrome, epidural abscess, malignancy) are present. - Doing an MRI too early in these cases can lead to identifying incidental findings, thus causing **unnecessary investigations** and interventions. *Oxycodone and bed rest* - **Oxycodone** (an opioid) is generally reserved for **severe pain** unresponsive to first-line agents and carries risks of **dependence** and **side effects**; it is not a first-line therapy for this presentation given the lack of severe red flags. - **Bed rest** is **contraindicated** for most cases of acute low back pain as it can worsen symptoms and lead to deconditioning; **activity as tolerated** is preferred. *Oxycodone and activity as tolerated* - While **activity as tolerated** is beneficial, the use of **oxycodone** as a primary treatment for initial, uncomplicated low back pain is generally **inappropriate** due to the risks associated with opioid use. - The patient's symptoms do not suggest a need for strong opioid analgesia at this stage. *NSAIDS and bed rest* - **NSAIDs** are an appropriate initial analgesic, but **bed rest** is **not recommended** for acute low back pain. - Promoting activity helps to prevent stiffness, muscle weakness, and chronicity of pain.

Question 236: A 36-year-old woman comes to the gynecologist because of a 4-month history of irregular menstrual cycles. Menses occur at irregular 15 to 45-day intervals and last 1–2 days with minimal flow. She also reports a milk-like discharge from her nipples for 3 months, as well as a history of fatigue and muscle and joint pain. She does not have abdominal pain, fever, or headache. She has recently gained 2.5 kg (5.5 lb) of weight. She was diagnosed with schizophrenia and started on aripiprazole by a psychiatrist 8 months ago. She has hypothyroidism but has not been taking levothyroxine for 6 months. She does not smoke or consume alcohol. She appears healthy and anxious. Her vital signs are within normal limits. Pelvic examination shows vaginal atrophy. Visual field and skin examination are normal. Laboratory studies show: Hemoglobin 12.7 g/dL Serum Glucose 88 mg/dL Creatinine 0.7 mg/dL Thyroid-stimulating hormone 16.3 μU/mL Cortisol (8AM) 18 μg/dL Prolactin 88 ng/mL Urinalysis is normal. An x-ray of the chest and ultrasound of the pelvis show no abnormalities. Which of the following is the most likely explanation for the nipple discharge in this patient?

A. Prolactinoma
B. Hypothyroidism (Correct Answer)
C. Thyrotropic pituitary adenoma
D. Cushing disease
E. Ectopic prolactin production

Explanation: ***Hypothyroidism*** - The patient has a significantly elevated **TSH (16.3 μU/mL)** and a history of non-compliance with **levothyroxine** for 6 months, strongly indicating uncontrolled hypothyroidism. - **Hypothyroidism** can lead to **increased TRH** (thyrotropin-releasing hormone) from the hypothalamus, which stimulates not only TSH but also **prolactin** release, causing galactorrhea. - Note: **Aripiprazole** is a partial dopamine agonist and typically does **not** cause hyperprolactinemia (unlike typical antipsychotics or risperidone), making hypothyroidism the primary driver here. *Prolactinoma* - While the patient has **hyperprolactinemia (prolactin 88 ng/mL)** and galactorrhea, a prolactinoma usually presents with prolactin levels **significantly higher** (often >200 ng/mL, or >100 ng/mL in microadenomas) than observed here. - The primary driver for the hyperprolactinemia in this case is more likely the **uncorrected hypothyroidism**, which can also cause moderate elevation of prolactin. *Thyrotropic pituitary adenoma* - A **thyrotropic pituitary adenoma** (TSH-secreting adenoma) would cause elevated TSH accompanied by **elevated thyroid hormone levels** (hyperthyroidism), which contradicts this patient's clinical picture of hypothyroidism. - This patient exhibits **hypothyroidism** due to non-adherence to medication, not hyperthyroidism induced by a TSH-secreting tumor. *Cushing disease* - **Cushing disease** is characterized by elevated **cortisol** due to an ACTH-secreting pituitary adenoma, leading to symptoms like central obesity, moon facies, and striae; these are not reported. - While some forms of Cushing syndrome can cause menstrual irregularities, it does not typically cause **galactorrhea** or significantly elevated prolactin levels as seen in this patient. *Ectopic prolactin production* - **Ectopic prolactin production** is a rare cause of hyperprolactinemia, typically associated with large tumors, most commonly **renal cell carcinoma** or other neuroendocrine tumors (e.g., lung carcinoid). - Given the patient's severe **hypothyroidism**, it is a far more common and likely explanation for her hyperprolactinemia and galactorrhea than ectopic production.

Question 237: A 69-year-old male presents to his primary care provider for a general checkup. The patient currently has no complaints. He has a past medical history of diabetes mellitus type II, hypertension, depression, obesity, and a myocardial infarction seven years ago. The patient's prescribed medications are metoprolol, aspirin, lisinopril, hydrochlorothiazide, fluoxetine, metformin, and insulin. The patient states that he has not been filling his prescriptions regularly and that he can not remember what medications he has been taking. His temperature is 99.5°F (37.5°C), pulse is 96/min, blood pressure is 180/120 mmHg, respirations are 18/min, and oxygen saturation is 97% on room air. Serum: Na+: 139 mEq/L K+: 4.3 mEq/L Cl-: 100 mEq/L HCO3-: 24 mEq/L BUN: 7 mg/dL Glucose: 170 mg/dL Creatinine: 1.2 mg/dL On physical exam which of the following cardiac findings would be expected?

A. Heart sound after S2
B. Normal S1 and S2
C. Heart sound prior to S1 (Correct Answer)
D. Holosystolic murmur at the apex
E. Fixed splitting of S1 and S2

Explanation: ***Heart sound prior to S1*** - An S4 heart sound, which occurs **prior to S1**, is common in this patient due to **hypertension** and **diastolic dysfunction**, indicating a stiff and non-compliant ventricle. - The patient's uncontrolled **hypertension (180/120 mmHg)** suggests increased left ventricular afterload, leading to **ventricular hypertrophy** and reduced ventricular compliance. *Heart sound after S2* - A heart sound after S2 typically refers to an **S3 gallop**, which indicates **systolic dysfunction** or **volume overload**. - While the patient has a history of MI, his current presentation does not strongly suggest acute decompensated heart failure with volume overload, and S3 is less specific for the long-standing hypertension indicated here. *Normal S1 and S2* - Given the patient's long-standing, uncontrolled **hypertension** and history of myocardial infarction, it is highly unlikely that he would have entirely normal heart sounds. - The presence of chronic cardiovascular stressors usually leads to **detectable cardiac changes**, such as an S4 gallop, due to ventricular remodeling. *Holosystolic murmur at the apex* - A **holosystolic murmur at the apex** is characteristic of **mitral regurgitation**. - While possible in patients with MI, there is no specific information in the vignette to suggest mitral valve pathology (e.g., progressive shortness of breath, pulmonary edema) as the most expected finding. *Fixed splitting of S1 and S2* - **Fixed splitting of S2** is a classic finding in **atrial septal defect (ASD)**, which is not suggested by this patient's medical history or current presentation. - Fixed splitting refers to the lack of respiratory variation in the splitting of the second heart sound, which is pathognomonic for ASD. - S1 splitting is a normal variant and is not a pathological finding in this context.

Question 238: A 63-year-old woman comes to the physician with a 3-month history of progressively worsening right calf pain. She reports that the pain occurs after walking for about 10 minutes and resolves when she rests. She has hypertension and hyperlipidemia. She takes lisinopril and simvastatin daily. She has smoked two packs of cigarettes daily for 34 years. Her pulse is 78/min and blood pressure is 142/96 mm Hg. Femoral and popliteal pulses are 2+ bilaterally. Left pedal pulses are 1+; right pedal pulses are absent. Remainder of the examination shows no abnormalities. Ankle-brachial index (ABI) is 0.65 in the right leg and 0.9 in the left leg. This patient is at greatest risk of which of the following conditions?

A. Acute myocardial infarction (Correct Answer)
B. Acute mesenteric ischemia
C. Lower extremity lymphedema
D. Deep vein thrombosis
E. Limb amputation

Explanation: ***Acute myocardial infarction*** - The patient has significant risk factors for **atherosclerosis**, including advanced age, hypertension, hyperlipidemia, and a 34-year history of heavy smoking, which significantly increases the risk of **coronary artery disease** and subsequent acute myocardial infarction. - Her presenting symptom of **intermittent claudication** (calf pain with exertion, resolving with rest) with an ABI of 0.65 in the right leg indicates significant peripheral artery disease, which is a strong predictor of systemic atherosclerosis and thus a higher risk for cardiovascular events like MI. *Acute mesenteric ischemia* - While atherosclerosis is a risk factor, acute mesenteric ischemia typically presents with **severe, disproportionate abdominal pain** after eating, not calf pain. - There are no symptoms in the patient's presentation that suggest acute mesenteric ischemia, such as **postprandial pain** or significant changes in bowel habits. *Lower extremity lymphedema* - Lymphedema is characterized by **chronic swelling** of the affected limb, often with skin changes like thickening and hyperpigmentation, and typically does not cause exertional pain that resolves with rest. - The patient's symptoms are classic for vascular insufficiency, not lymphatic obstruction. *Deep vein thrombosis* - DVT presents with **acute onset of unilateral leg pain**, swelling, warmth, and erythema, which is not consistent with this patient's chronic, exertional pain pattern. - The symptoms are relieved with rest, which is characteristic of arterial insufficiency, not venous thrombosis. *Limb amputation* - While severe **peripheral artery disease (PAD)** can eventually lead to limb amputation due to critical limb ischemia, acute myocardial infarction represents a more immediate and life-threatening risk given the patient's constellation of risk factors and systemic atherosclerosis indicated by her PAD. - **Critical limb ischemia** (rest pain, non-healing ulcers, gangrene) typically precedes amputation, and while the patient has PAD, she is not yet at that stage; AMI is a more direct, immediate risk given overall cardiovascular burden.

Question 239: A 53-year-old woman comes to the physician because of pain in her ankle. She twisted her right ankle inward when walking on uneven ground the previous day. She describes the pain as 6 out of 10 in intensity. She is able to bear weight on the ankle and ambulate. Three weeks ago, she had an episode of gastroenteritis that lasted for two days and resolved spontaneously. She has type 2 diabetes mellitus, hypertension, and hyperlipidemia. Her father has type 2 diabetes mellitus and chronic renal failure. Her mother has hypothyroidism and a history of alcohol abuse. The patient drinks 8–10 beers each week and does not smoke or use illicit drugs. She adheres to a strict vegetarian diet. Current medications include metformin, atorvastatin, and lisinopril. Her temperature is 36.9°C (98.4°F), heart rate is 84/min, and blood pressure is 132/80 mm Hg. Examination of the right ankle shows edema along the lateral aspect. She has pain with eversion and tenderness to palpation on the lateral malleolus. The foot is warm to touch and has dry skin. Pedal pulses are palpable. She has decreased sensation to light touch on the plantar and dorsal aspects of the big toe. She has full range of motion with 5/5 strength in flexion and extension of the big toe. Laboratory studies show: Hemoglobin 15.1 g/dL Hemoglobin A1c 8.1% Leukocyte count 7,200/mm3 Mean corpuscular volume 82 μm3 Serum Na+ 135 mEq/L K+ 4.0 mEq/L Cl- 101 mEq/L Urea nitrogen 24 mg/dL Creatinine 1.3 mg/dL Thyroid-stimulating hormone 1.2 μU/mL Which of the following is the most likely cause of the decreased sensation in this patient?

A. Thiamine deficiency
B. Microvascular damage (Correct Answer)
C. Acute inflammatory demyelinating polyradiculopathy
D. Vitamin B12 deficiency
E. Medication side effect

Explanation: ***Microvascular damage*** - The patient's **poorly controlled diabetes mellitus** (HbA1c 8.1%) is a significant risk factor for **diabetic neuropathy**, a common complication caused by chronic hyperglycemia leading to microvascular damage to the nerves. - This damage specifically affects nerve fibers responsible for **sensation**, particularly in a **stocking-glove distribution**, which explains the decreased sensation in her big toe. *Thiamine deficiency* - **Thiamine deficiency** (beriberi) can cause peripheral neuropathy, but it is typically associated with **severe alcohol abuse** or malnutrition. - While the patient drinks beer, her consumption (8-10 beers/week) is moderate and less likely to cause a severe deficiency presenting solely as altered sensation in one toe. *Acute inflammatory demyelinating polyradiculopathy* - **Acute inflammatory demyelinating polyradiculopathy (AIDP)**, also known as **Guillain-Barré syndrome**, typically presents with **progressive, ascending muscle weakness** and paralysis, often following an infection. - The patient solely exhibits sensory changes, and her symptoms are localized and chronic rather than acute and rapidly progressive. *Vitamin B12 deficiency* - **Vitamin B12 deficiency**, often seen in strict vegetarians, can cause **peripheral neuropathy**, sometimes accompanied by **megaloblastic anemia** and **subacute combined degeneration** of the spinal cord. - The patient's **normal hemoglobin** and **mean corpuscular volume (MCV)** make severe B12 deficiency less likely to be the sole cause of her symptoms. *Medication side effect* - While some medications can cause neuropathy, none of the patient's current medications (**metformin, atorvastatin, lisinopril**) are typically associated with causing significant sensory neuropathy as a primary side effect. - Her **poorly controlled diabetes** offers a more direct and prevalent explanation for the sensory findings.

Question 240: A 37-year-old woman comes to the physician because of irregular menses and generalized fatigue for the past 4 months. Menses previously occurred at regular 25- to 29-day intervals and lasted for 5 days but now occur at 45- to 60-day intervals. She has no history of serious illness and takes no medications. She is 155 cm (5 ft 1 in) tall and weighs 89 kg (196 lb); BMI is 37 kg/m2. Her temperature is 37°C (98.6°F), pulse is 90/min, and blood pressure is 146/100 mm Hg. Examination shows facial hair as well as comedones on the face and back. There are multiple ecchymotic patches on the trunk. Neurological examination shows weakness of the iliopsoas and biceps muscles bilaterally. Laboratory studies show: Hemoglobin 13.1 g/dL Leukocyte count 13,500/mm3 Platelet count 510,000/mm3 Serum Na+ 145 mEq/L K+ 3.3 mEq/L Cl- 100 mEq/L Glucose 188 mg/dL Which of the following is the most likely diagnosis?

A. Pheochromocytoma
B. Cushing syndrome (Correct Answer)
C. Primary hyperaldosteronism
D. Polycystic ovarian syndrome
E. Hypothyroidism

Explanation: ***Cushing syndrome*** - The constellation of **obesity**, **hypertension**, **irregular menses**, **hirsutism** (facial hair), **acne** (comedones), **easy bruising** (ecchymotic patches), **proximal muscle weakness** (iliopsoas and biceps), **leukocytosis**, **thrombocytosis**, **hypokalemia**, and **hyperglycemia** is highly characteristic of Cushing syndrome due to chronic glucocorticoid excess. - The patient's **truncal obesity** (BMI 37 kg/m2) and the metabolic derangements further support this diagnosis. *Pheochromocytoma* - While pheochromocytoma can cause **hypertension** and **tachycardia**, it typically presents with **episodic symptoms** like palpitations, sweating, and headaches. - It does not explain the other prominent features such as **hirsutism**, **menstrual irregularities**, **proximal muscle weakness**, or **easy bruising**. *Primary hyperaldosteronism* - This condition is characterized by **hypertension** and **hypokalemia**, often leading to fatigue. - However, it does not account for the patient's **hirsutism**, **menstrual irregularities**, **obesity**, **easy bruising**, **muscle weakness**, **acne**, or **hyperglycemia**. *Polycystic ovarian syndrome* - PCOS causes **irregular menses**, **hirsutism**, **acne**, and **obesity**, which are present in this patient. - However, it typically does not cause **hypertension**, **hypokalemia**, **easy bruising**, or **proximal muscle weakness**, making Cushing syndrome a more encompassing diagnosis. *Hypothyroidism* - Hypothyroidism can lead to **fatigue**, **menstrual irregularities**, and **weight gain**. - However, it typically presents with **bradycardia**, **dry skin**, **constipation**, and **cold intolerance**, not **hypertension**, **hirsutism**, **acne**, **easy bruising**, or **proximal muscle weakness**.

Question 241: A 27-year-old man presents to the emergency department for altered mental status. The patient was found napping in a local market and brought to the hospital. The patient has a past medical history of polysubstance abuse and is homeless. His temperature is 104°F (40.0°C), blood pressure is 100/52 mmHg, pulse is 133/min, respirations are 25/min, and oxygen saturation is 99% on room air. Physical exam is notable for an altered man. Cardiopulmonary exam reveals a murmur over the left lower sternal border. A bedside ultrasound reveals a vegetation on the tricuspid valve. The patient is ultimately started on IV fluids, norepinephrine, vasopressin, vancomycin, and piperacillin-tazobactam. A central line is immediately placed in the internal jugular vein and the femoral vein secondary to poor IV access. Cardiothoracic surgery subsequently intervenes to remove the vegetation. While recovering in the ICU, days 3-5 are notable for an improvement in the patient’s symptoms. Two additional peripheral IVs are placed while in the ICU on day 5, and the femoral line is removed. On day 6, the patient's fever and hemodynamic status worsen. Though he is currently responding and not complaining of any symptoms including headache, photophobia, neck stiffness, or pain, he states he is feeling weak. Jolt accentuation of headache is negative and his abdominal exam is benign. A chest radiograph, urinalysis, and echocardiogram are unremarkable though the patient’s blood cultures are positive when drawn. Which of the following is the best next step in management?

A. Add micafungin to the patient’s antibiotics
B. Perform a lumbar puncture
C. Remove all peripheral IV’s and send for cultures
D. Add cefepime to the patient’s antibiotics
E. Remove the central line and send for cultures (Correct Answer)

Explanation: **Correct: Remove the central line and send for cultures** - The patient's worsening fever and hemodynamic instability on day 6, despite initial improvement, raise suspicion for a **catheter-related bloodstream infection (CRBSI)**, especially given the history of central line placement. - **Prompt removal of the catheter** and sending the tip for culture is crucial for diagnosis and treatment of potential CRBSI, as the source of infection often resides within the biofilm on the catheter. *Incorrect: Remove all peripheral IV's and send for cultures* - While **peripheral IVs** can be a source of infection, the central line was placed earlier and is associated with a much higher risk of serious infection, especially in a critically ill patient. - The patient's initial improvement followed by deterioration points more towards a **central line-associated infection** rather than new peripheral IVs placed only on day 5. *Incorrect: Perform a lumbar puncture* - Although the patient has altered mental status, the absence of focal neurological deficits, headache, photophobia, and neck stiffness, along with a negative **Jolt accentuation of headache**, makes **meningitis** less likely as the primary cause of deterioration. - The more immediate and likely cause of worsening sepsis in this context is a **catheter-related infection**. *Incorrect: Add micafungin to the patient's antibiotics* - Adding an antifungal agent such as **micafungin** would be considered if there was a strong suspicion of a fungal infection, which is not indicated by the current blood cultures or clinical picture. - Empiric antifungal therapy is typically reserved for patients with persistent fever refractory to broad-spectrum antibiotics, known fungal exposure, or specific risk factors. *Incorrect: Add cefepime to the patient's antibiotics* - The patient is already on **vancomycin and piperacillin-tazobactam**, which provides broad-spectrum coverage for both gram-positive and gram-negative bacteria, including *Pseudomonas aeruginosa*. - Adding **cefepime** would broaden gram-negative coverage further but is usually unnecessary unless the current regimen is failing due to specific resistant organisms, and the more likely source of infection should be addressed first.

Question 242: A 42-year-old man presents to the clinic for a several-month history of fatigue, and it is starting to affect his work. He often needs to sneak away in the middle of the day to take naps or else he cannot focus and is at risk of falling asleep at his desk. He has been feeling like this for approximately 1 year. Otherwise, he feels healthy and takes no medications. On further questioning, he also had constipation and thinks he has gained some weight. He denies shortness of breath, chest pain, lightheadedness, or blood in his stool. The vital signs include: pulse 56/min, blood pressure 124/78 mm Hg, and oxygen saturation 99% on room air. The physical exam is notable only for slightly dry skin. The complete blood count (CBC) is within normal limits, and the thyroid-stimulating hormone (TSH) is 8.0 μU/mL. Which of the following is the next best treatment for this patient?

A. Erythropoietin
B. Prednisone
C. Packed red blood cell (RBC) transfusion
D. Levothyroxine (Correct Answer)
E. Inhaled fluticasone plus salmeterol

Explanation: ***Levothyroxine*** - The patient's symptoms of **fatigue**, **weight gain**, **constipation**, **dry skin**, and **bradycardia** are classic for **hypothyroidism**. - A **TSH level of 8.0 μU/mL**, while not extremely high, indicates **subclinical hypothyroidism** in a symptomatic patient, warranting treatment with **thyroid hormone replacement**. *Erythropoietin* - **Erythropoietin** is used to treat **anemia**, particularly in chronic kidney disease, but the patient's **CBC is normal**, making this an inappropriate treatment. - The patient's fatigue is not due to anemia, as evidenced by a normal CBC. *Prednisone* - **Prednisone** is a corticosteroid used for various inflammatory and autoimmune conditions. - There are no signs or symptoms in this patient to suggest an inflammatory or autoimmune process that would require corticosteroid therapy. *Packed red blood cell (RBC) transfusion* - **RBC transfusions** are indicated for severe anemia or acute blood loss. - The patient's **CBC is normal**, indicating no anemia and therefore no need for a transfusion. *Inhaled fluticasone plus salmeterol* - This combination is used to treat **asthma** and **COPD**, which are respiratory conditions. - The patient denies **shortness of breath** or other respiratory symptoms, making this treatment irrelevant.

Question 243: A 22-year-old woman is brought to the physician by her husband because of a gradual 20-kg (45-lb) weight loss and recurrent episodes of vomiting without diarrhea over the past 2 years. Her last menstrual period was 6 months ago. On physical examination, she appears fatigued and emaciated, and there is bilateral swelling of the retromandibular fossa. Laboratory studies show hypokalemia and a hemoglobin concentration of 8 g/dL. Which of the following additional findings is most likely in this patient?

A. Decreased triiodothyronine (Correct Answer)
B. Increased testosterone
C. Decreased growth hormone
D. Increased leptin
E. Increased beta-hCG

Explanation: ***Decreased triiodothyronine*** - This patient presents with signs and symptoms suggestive of **bulimia nervosa** (weight loss, recurrent vomiting, menstrual irregularities, parotid gland swelling, hypokalemia). In bulimia, the body adapts to chronic malnutrition and vomiting by **downregulating metabolism**, which includes decreasing thyroid hormone production, particularly **T3 (triiodothyronine)**. - **Hypothyroidism-like symptoms** (fatigue, bradycardia, cold intolerance) can be seen due to this adaptive metabolic slowing, even in the setting of normal TSH and T4 levels, often referred to as **euthyroid sick syndrome** or non-thyroidal illness syndrome. *Increased testosterone* - **Anorexia nervosa** and conditions involving significant weight loss and malnutrition, as seen in this patient with suspected bulimia, are typically associated with **decreased sex hormone production**, including testosterone in women. - This hormonal dysregulation contributes to features like **amenorrhea** (last menstrual period 6 months ago) and can lead to **osteoporosis**. *Decreased growth hormone* - While **chronic malnutrition** can affect the somatotropic axis, the primary impact is often complex with initial compensatory elevations in **growth hormone (GH)** as the body tries to prevent protein catabolism. - However, the **IGF-1 levels** (insulin-like growth factor 1, a mediator of GH action) are typically decreased in chronic malnutrition, leading to impaired growth and development in younger patients, but not necessarily decreased GH itself. *Increased leptin* - **Leptin** is a hormone primarily produced by adipocytes (fat cells) that signals satiety and energy reserves. In states of **significant weight loss and malnutrition**, like that seen in this patient, leptin levels are typically **decreased**, not increased. - Low leptin levels contribute to the body's adaptive responses to conserve energy and increase appetite, though in eating disorders, psychological factors often override these signals. *Increased beta-hCG* - **Beta-hCG** (human chorionic gonadotropin) is a hormone produced during pregnancy. While **amenorrhea** is present, indicating possible anovulation, the patient's severe malnutrition and weight loss would make pregnancy less likely and even if present, the other symptoms point away from pregnancy as the primary underlying cause of her systemic issues. - The combination of **fatigue, emaciation, hypokalemia, and bilateral retromandibular fossa swelling** (suggestive of parotid gland enlargement from chronic vomiting) is pathognomonic for an eating disorder, not pregnancy.

Question 244: A 54-year-old man is brought to the emergency department after having been hit by a car while riding his bicycle. He was not wearing a helmet. Despite appropriate life-saving measures, he dies 2 hours later because of a severe intracranial hemorrhage. Autopsy of the heart shows general thickening of the left ventricular wall with narrowing of the ventricular chamber. Which of the following conditions is the most likely underlying cause of the described cardiac changes?

A. Sarcoidosis
B. Chronic hypertension (Correct Answer)
C. Chronic heavy drinking
D. Aortic regurgitation
E. Hemochromatosis

Explanation: ***Chronic hypertension*** - **Systemic hypertension** leads to increased **afterload** on the left ventricle, causing **concentric hypertrophy** to normalize wall stress. - This results in a thickened left ventricular wall and a **reduced ventricular chamber size**, which is a classic finding in long-standing untreated hypertension. *Sarcoidosis* - Cardiac sarcoidosis would typically present with **granulomatous inflammation** and could lead to **restrictive cardiomyopathy** or **conduction abnormalities**. - It is less likely to cause isolated, generalized concentric left ventricular hypertrophy. *Chronic heavy drinking* - Chronic heavy alcohol consumption can cause **dilated cardiomyopathy**, characterized by ventricular dilation and systolic dysfunction. - This is distinct from the concentric hypertrophy and narrowed chamber described. *Aortic regurgitation* - **Aortic regurgitation** causes **volume overload** on the left ventricle, leading to **eccentric hypertrophy** (ventricular dilation with increased wall thickness but maintained or increased chamber size). - This is unlike the "narrowing of the ventricular chamber" seen in concentric hypertrophy. *Hemochromatosis* - **Hemochromatosis** causes **iron deposition** in myocardial cells, leading to **restrictive or dilated cardiomyopathy**. - While it can cause heart failure, it typically does not present as isolated concentric hypertrophy with a narrowed chamber.

Question 245: A 39-year-old female with poorly controlled systemic lupus erythematosus (SLE) presents to the emergency room with a cough and pleuritic chest pain. She states that she developed these symptoms 2 days prior. The pain appears to improve when the patient leans forward. She currently takes hydroxychloroquine for her systemic lupus erythematosus but has missed several doses recently. Her temperature is 99°F (37.2°C), blood pressure is 135/80 mmHg, pulse is 115/min, and respirations are 22/min. Physical examination reveals a rise in jugular venous pressure during inspiration. In addition to tachycardia, which of the following EKG patterns is most likely to be seen in this patient?

A. Peaked T waves with flattened P waves
B. Irregularly irregular QRS complexes with no P waves
C. PR depressions and diffuse ST elevations (Correct Answer)
D. ST segment depressions in leads II, III, and aVF
E. Prolonged PR interval with normal QRS complexes

Explanation: ***PR depressions and diffuse ST elevations*** - The patient's symptoms of **pleuritic chest pain** that improves with **leaning forward**, along with a history of **poorly controlled SLE**, are classic for **acute pericarditis**. - **Elevated JVP during inspiration (Kussmaul's sign)** suggests pericardial involvement with possible early effusion, though this sign is more classically associated with constrictive pericarditis or tamponade. However, the **characteristic ECG findings in acute pericarditis** are diffuse **ST segment elevations** (concave upward) and **PR segment depressions**, typically seen in leads II, III, aVF, and V2-V6. - These ECG changes reflect the inflammatory process affecting the pericardium and are the hallmark of acute pericarditis, regardless of whether early effusion is present. *Peaked T waves with flattened P waves* - This pattern is characteristic of **hyperkalemia**, which presents with muscle weakness, fatigue, and cardiac arrhythmias, none of which are present in this case. - The patient's presentation with pleuritic chest pain relieved by leaning forward is not consistent with hyperkalemia. *Irregularly irregular QRS complexes with no P waves* - This EKG pattern is indicative of **atrial fibrillation**, which presents with palpitations and may cause shortness of breath. - While tachycardia is present, the irregular rhythm and absence of P waves characteristic of atrial fibrillation are not typical findings in acute pericarditis. *ST segment depressions in leads II, III, and aVF* - **ST segment depressions** in these leads typically suggest **inferior myocardial ischemia** or infarction, which would cause chest pain that is usually substernal, pressure-like, and not improved by positional changes. - The pleuritic nature of the pain and its relief with leaning forward point away from ischemia. *Prolonged PR interval with normal QRS complexes* - A prolonged PR interval indicates **first-degree atrioventricular (AV) block**, which is usually asymptomatic and not associated with pleuritic chest pain. - While SLE can be associated with conduction abnormalities, first-degree AV block would not explain the acute presentation or the characteristic pericarditis symptoms.

Question 246: A 55-year-old man presents to the internal medicine clinic with complaints of numbness and tingling in his fingers that he first noticed 6 months ago. It has been progressively worsening and has reached the point where it is affecting his normal daily activities, such as brushing his teeth. His past medical history is significant for sinusitis and allergic rhinitis since the age of 18, as well as episodic wheezing and shortness of breath since he was 30. He was diagnosed with asthma when he was 22 years old, and subsequently with gastroesophageal reflux disease (GERD) when he was 40. His current medications include albuterol, loratadine, mometasone, and omeprazole. His blood pressure is 128/86 mm Hg, heart rate is 78/min, and respiratory rate is 16/min. On physical exam, the patient’s skin is mottled and appears to have a diffuse, lace-like, erythematous discoloration of the arms, legs, and trunk. There is also a small papular rash on his right forearm. Bilateral wheezes are heard on auscultation. Which of the following is the most likely diagnosis?

A. CREST syndrome
B. Microscopic polyangiitis
C. Polyarteritis nodosa
D. Eosinophilic granulomatosis with polyangiitis (Correct Answer)
E. Granulomatosis with polyangiitis

Explanation: ***Eosinophilic granulomatosis with polyangiitis (EGPA)*** - This patient presents with **asthma**, **allergic rhinitis**, and **neuropathy** (numbness and tingling), along with **skin findings** (mottled, lace-like discoloration suggesting livedo reticularis, and a papular rash). This constellation of symptoms is highly suggestive of EGPA (formerly Churg-Strauss syndrome). - EGPA is characterized by **eosinophilia**, **asthma**, and **vasculitis** affecting various organs, often leading to mononeuritis multiplex. *CREST syndrome* - CREST syndrome involves **calcinosis**, **Raynaud's phenomenon**, **esophageal dysfunction**, **sclerodactyly**, and **telangiectasias**. - While it can cause some dermatologic manifestations and esophageal issues, it does not typically present with severe asthma, allergic rhinitis, or systemic vasculitic neuropathy. *Microscopic polyangiitis* - Microscopic polyangiitis typically causes **glomerulonephritis** and **pulmonary hemorrhage** and is **pauci-immune** on immunofluorescence for ANCA. - It does not present with a prominent history of asthma, allergic rhinitis, or significant eosinophilia. *Polyarteritis nodosa* - Polyarteritis nodosa (PAN) is a **necrotizing vasculitis** of medium-sized arteries that can cause **neuropathy**, **skin lesions** (such as livedo reticularis and palpable purpura), and **renal involvement**. - However, it typically spares the pulmonary circulation and is **not associated with asthma** or a history of allergic rhinitis and eosinophilia, which are key features in this case. *Granulomatosis with polyangiitis (GPA)* - GPA typically involves the **upper and lower respiratory tracts** and **kidneys**, often presenting with **sinusitis**, **pulmonary infiltrates**, and **glomerulonephritis**. - While sinusitis is present, the prominent history of asthma, allergic rhinitis, and neuropathy with eosinophilic features differentiate this case from GPA.

Question 247: A 42-year-old man presents to his dermatologist with a rash on the extensor surfaces of his elbows and knees which has occurred episodically ever since he was a teenager. The patient was recently diagnosed with essential hypertension and was prescribed lisinopril by his primary care physician. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 128/91 mm Hg, and heart rate 82/min. The physical examination reveals sharply demarcated, erythematous plaques with silvery-white scales on the back of his elbows and front of his knees. He has less than 3% of the total body surface area affected. Which of the following is the best initial therapy for this patient’s condition?

A. Methotrexate
B. Cyclosporine
C. Oral prednisolone
D. Topical clobetasol and/or topical calcipotriol (Correct Answer)
E. Phototherapy

Explanation: ***Topical clobetasol and/or topical calcipotriol*** - This patient presents with **psoriasis**, characterized by sharply demarcated **erythematous plaques with silvery-white scales** on extensor surfaces. Given that less than 3% of the total body surface area is affected, **topical therapies** are the first-line treatment. - **Clobetasol** is a high-potency topical corticosteroid that reduces inflammation, and **calcipotriol** is a vitamin D analog that helps normalize epidermal cell growth; using them in combination or alone is appropriate for limited plaque psoriasis. *Methotrexate* - **Methotrexate** is a systemic agent typically reserved for patients with **moderate to severe psoriasis** (e.g., >10% BSA involvement, psoriatic arthritis, or involvement of critical areas like the face or genitals) or when topical treatments fail. - Its use is associated with potential side effects such as **hepatotoxicity** and **bone marrow suppression**, making it unsuitable as an initial therapy for mild disease. *Cyclosporine* - **Cyclosporine** is a systemic immunosuppressant primarily used for **severe, refractory psoriasis** due to its rapid onset of action. - Significant side effects include **nephrotoxicity** and **hypertension**, making it a second or third-line agent after failure of other systemic treatments. *Oral prednisolone* - **Oral corticosteroids** are generally **avoided in psoriasis** because they can precipitate an unstable form of psoriasis, particularly **pustular psoriasis**, upon withdrawal. - While they can temporarily reduce inflammation, the risk of rebound flares and adverse effects outweighs their benefits for chronic management of plaque psoriasis. *Phototherapy* - **Phototherapy**, such as narrowband ultraviolet B (NB-UVB), is considered for patients with **moderate to severe psoriasis** or those who have significant body surface area involvement (>5% BSA) or failure of topical therapies. - It involves regular clinic visits for light exposure and is not the initial choice for localized, mild plaque psoriasis.

Question 248: A 55-year-old man presents to his primary care physician for a wellness checkup. He states that he generally feels well and has no complaints at this time. The patient consumes alcohol frequently, eats a high sodium diet, and is sedentary. His temperature is 97.5°F (36.4°C), blood pressure is 167/108 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 99% on room air. The patient is 5'10" tall and weighs 220 lbs (BMI 31.5 kg/m²). The patient's blood pressure at his last 2 appointments were 159/100 mmHg and 162/99 mmHg, respectively. His physician wants to intervene to manage his blood pressure. Which of the following is the most effective lifestyle intervention for this patient's hypertension?

A. Exercise
B. DASH diet (Correct Answer)
C. Reduce alcohol consumption
D. Sodium restriction
E. Weight loss

Explanation: ***DASH diet*** - The **DASH (Dietary Approaches to Stop Hypertension) diet** is a comprehensive dietary plan rich in fruits, vegetables, and low-fat dairy, and reduced in saturated and total fats. It is the most effective single lifestyle intervention for reducing **blood pressure (BP)**. - This patient has **stage 2 hypertension** and multiple risk factors including obesity, frequent alcohol consumption, and a high-sodium diet, making a holistic dietary approach crucial for significant BP reduction. *Exercise* - While **regular exercise** is beneficial for overall cardiovascular health and can help manage hypertension, it is generally less effective than the DASH diet for initial, significant **blood pressure reduction** in a patient with stage 2 hypertension. - The patient's **sedentary lifestyle** contributes to his hypertension, but exercise alone may not achieve the desired BP control as effectively as a comprehensive dietary change. *Reduce alcohol consumption* - **Excessive alcohol intake** is a risk factor for hypertension, and reducing consumption can lower blood pressure. However, its effect is typically less pronounced compared to the **DASH diet** in achieving major BP reductions. - The patient's "frequent" alcohol consumption suggests this is an important area for intervention, but it's part of a broader lifestyle modification rather than the single most effective treatment. *Sodium restriction* - A **high sodium diet** is a significant contributor to hypertension, and **sodium restriction** is a key component of managing blood pressure. However, the DASH diet inherently incorporates sodium restriction along with other beneficial dietary changes. - While important, focusing solely on sodium restriction often yields less comprehensive and sustained BP reduction compared to the **multi-faceted approach** of the DASH diet. *Weight loss* - Given the patient's **obesity (BMI 31.5 kg/m²)**, **weight loss** is a critical intervention for blood pressure control and overall health. - However, achieving significant weight loss often requires a combination of dietary changes and increased physical activity, making the **DASH diet** a more direct and often more achievable initial step for BP reduction.

Question 249: A 38-year-old woman is referred to a cardiologist for evaluation of syncope. Over the past year she has experienced 2 syncopal events. The first event occurred while she was standing, and the second when she laid down on her side. She denies bowel or bladder incontinence during the episodes or palpitations. However, she reports the presence of a low-grade fever over the past 3 months and a recent visit to the emergency department for a transient ischemic attack. She has a history of intravenous drug use but reports not having used in over 5 years. Temperature is 100.0°F (37.8°C), blood pressure is 115/72 mmHg, pulse is 90/min, and respirations are 20/min and regular. A detailed neurologic examination reveals no focal deficits. Cardiac auscultation demonstrates a diastolic "plop" at the cardiac apex. Which of the following findings will most likely be demonstrated on transthoracic echocardiography?

A. Flail mitral valve leaflet
B. Left ventricular mass
C. Decreased left ventricular ejection fraction
D. Left atrial pedunculated mass (Correct Answer)
E. Patent foramen ovale

Explanation: ***Left atrial pedunculated mass*** - The patient's presentation with **syncope** in varying positions (standing and lying down), a **low-grade fever**, history of **transient ischemic attack (TIA)**, and a **diastolic "plop"** strongly suggests a **left atrial myxoma**. - A left atrial myxoma is a **pedunculated tumor** that can intermittently obstruct mitral valve flow, leading to syncope, and can embolize, causing TIAs. *Flail mitral valve leaflet* - A flail mitral valve leaflet typically causes severe **mitral regurgitation**, characterized by a **systolic murmur**. - While it can lead to syncope due to reduced cardiac output, it would not typically present with a "diastolic plop" or TIA in this manner. *Decreased left ventricular ejection fraction* - A decreased left ventricular ejection fraction would cause syncope due to **heart failure** or **arrhythmias**, but it does not explain the "diastolic plop" or the TIA, especially with a history of fever. - The "plop" sound is highly specific for an **intracardiac mass** obstructing flow. *Left ventricular mass* - A left ventricular mass, such as a thrombus or tumor, could cause syncope and embolization (TIA). - However, it is unlikely to produce a **diastolic "plop"** sound, which is characteristic of a mass prolapsing into the mitral orifice during diastole. *Patent foramen ovale* - A patent foramen ovale (PFO) can cause **paradoxical emboli** leading to TIA, especially in the context of intravenous drug use history. - However, a PFO does not explain the recurrent syncope in various positions, the **low-grade fever**, or the specific **diastolic "plop"** on auscultation.

Question 250: A 27-year-old woman presents to her primary care physician because of headaches that she has had over the last three weeks. She has not had any significant past medical history though she does recall that various types of cancer run in her family. She has also noticed that she has been gaining some weight, and her feet no longer fit into her favorite shoes. On presentation, her temperature is 98.6°F (37°C), blood pressure is 159/92 mmHg, pulse is 75/min, and respirations are 16/min. Physical exam reveals 1+ edema in her lower extremities bilaterally. She is placed on captopril and presents to the emergency department two weeks later after a minor motor vehicle accident. She is cleared of any serious injuries, and as part of her workup, labs are drawn with the following results: BUN: 47 mg/dL Creatinine: 1.4 mg/dL Which of the following findings would most likely also be seen in this patient?

A. Mass present in adrenal cortex
B. Atherosclerotic plaques blocking blood flow
C. Mass present in adrenal medulla
D. No lesions present
E. String-of-beads appearance on angiography (Correct Answer)

Explanation: ***String-of-beads appearance on angiography*** - The patient's symptoms of **headaches**, **weight gain**, **bilateral lower extremity edema**, and **hypertension** (159/92 mmHg) in a young woman, especially with the presentation of acute kidney injury after beginning an ACE inhibitor (captopril), are highly suggestive of **renovascular hypertension** due to **fibromuscular dysplasia (FMD)**. - FMD characteristically presents as a **"string-of-beads"** appearance on renal angiography due to areas of stenosis alternating with aneurysmal dilations in the renal arteries. *Mass present in adrenal cortex* - A mass in the adrenal cortex typically causes **hyperaldosteronism (Conn syndrome)** or **Cushing's syndrome**. While hyperaldosteronism can cause hypertension and hypokalemia, it does not explain the acute kidney injury with ACE inhibitor treatment. - Cushing's syndrome involves **central obesity**, **moon facies**, and **striae**, which are not described. *Atherosclerotic plaques blocking blood flow* - **Atherosclerotic renovascular disease** typically affects older individuals with a history of cardiovascular risk factors (diabetes, hyperlipidemia, smoking). This patient is young and has no such history. - While it can cause renal artery stenosis and acute kidney injury with ACE inhibitors, the demographic profile does not fit. *Mass present in adrenal medulla* - A mass in the adrenal medulla suggests a **pheochromocytoma**, which causes **episodic hypertension**, **palpitations**, **sweating**, and **anxiety**. - The patient's hypertension is sustained, and she does not present with classic symptoms of a pheochromocytoma. *No lesions present* - The patient's clinical presentation, including the development of acute kidney injury after starting captopril, strongly indicates an underlying renovascular pathology. - The absence of lesions would not explain the severe, sustained hypertension and the adverse reaction to captopril.

Question 251: A 33-year-old man presents with his recent laboratory results. He has no symptoms currently, but he underwent a medical evaluation as a requirement for taking up a new job. His medical history is not significant. His laboratory reports are as follows: Blood hemoglobin 13.7 g/dL Leukocyte count 8,000/mm3 Platelet count 350,000/mm3 Serum creatinine 0.8 mg/dL Serum alanine aminotransferase 16 U/L Serum aspartate aminotransferase 14 U/L Serum cholesterol 450 mg/dL Serum triglyceride 790 mg/dL Serum LDL cholesterol 150 mg/dL Serum HDL cholesterol 55 mg/dL Which of the following findings is most likely to be present on physical examination of this patient?

A. Eruptive xanthomas over back
B. Xanthelasma
C. Palmar xanthomas in flexor creases (Correct Answer)
D. Achilles tendon xanthoma
E. Metacarpophalangeal extensor tendon xanthoma

Explanation: ***Palmar xanthomas in flexor creases*** - This patient presents with significantly elevated **triglycerides (790 mg/dL)** and **total cholesterol (450 mg/dL)** with relatively normal **LDL (150 mg/dL)** and **HDL (55 mg/dL)**. - This lipid profile pattern—**combined elevation of cholesterol and triglycerides with disproportionately normal/low LDL**—is characteristic of **familial dysbetalipoproteinemia (Type III hyperlipoproteinemia)**. - **Palmar xanthomas** appearing in the palmar creases are **pathognomonic** for Type III hyperlipoproteinemia, caused by accumulation of chylomicron and VLDL remnants due to defective apolipoprotein E. - While uncommon even in Type III, palmar xanthomas are the most specific physical finding for this diagnosis. *Eruptive xanthomas over back* - **Eruptive xanthomas** typically occur with **very high triglycerides (>1000 mg/dL)**, presenting as sudden crops of small, yellowish-red papules with erythematous halos. - This patient's triglycerides at 790 mg/dL are elevated but below the threshold that typically produces eruptive xanthomas. - Eruptive xanthomas are more commonly seen in **Type I or Type V hyperlipoproteinemia** with severe hypertriglyceridemia. *Xanthelasma* - **Xanthelasma** are yellowish plaques on the eyelids, the most common type of xanthoma overall. - Can occur with **any lipid disorder** or even with normal lipid levels in some cases. - While possible in this patient, xanthelasma lack the diagnostic specificity of palmar xanthomas for Type III hyperlipoproteinemia. *Achilles tendon xanthoma* - **Achilles tendon xanthomas** are characteristic of **familial hypercholesterolemia (Type IIa)**, which features markedly elevated **LDL cholesterol (typically >190 mg/dL)** due to defective LDL receptors. - This patient's LDL is only 150 mg/dL, making familial hypercholesterolemia unlikely. - The combined cholesterol and triglyceride elevation points away from pure LDL elevation. *Metacarpophalangeal extensor tendon xanthoma* - **Tendon xanthomas** on the extensor tendons are also associated with **familial hypercholesterolemia (Type IIa)**. - Like Achilles tendon xanthomas, these require very high **LDL cholesterol**, which is not the primary abnormality here. - The patient's lipid profile does not support this diagnosis.

Question 252: A 58-year-old patient comes to the physician because of progressive pain and swelling of his left calf for the past 2 days. He has no personal or family history of serious illness. He does not smoke or drink alcohol. His last digital rectal examination and colonoscopy at the age of 50 years were normal. His vital signs are within normal limits. He is 183 cm (6 ft) tall and weighs 80 kg (176 lb); BMI is 24 kg/m2. Physical examination shows redness, warmth, and tenderness of the left calf. The circumference of the left lower leg is 4 cm greater than the right. Dorsiflexion of the left foot elicits pain in the ipsilateral calf. Laboratory studies show: Hemoglobin 15 g/dL Leukocyte count 9000/mm3 Platelet count 190,000/mm3 Erythrocyte sedimentation rate 12 mm/h Serum Urea nitrogen 18 mg/dL Creatinine 1.0 mg/dL Alkaline phosphatase 24 U/L Aspartate aminotransferase (AST, GOT) 12 U/L Alanine aminotransferase (ALT, GPT) 10 U/L Urine Protein negative RBC 1/hpf WBC none Compression ultrasonography with Doppler shows a non-compressible left popliteal vein with a visible 0.5-cm hyperechoic mass and reduced flow. In addition to initiating anticoagulation, which of the following is the most appropriate next step in management?

A. Streptokinase therapy
B. Colonoscopy
C. Inferior vena cava filter
D. X-ray of the chest
E. CT pulmonary angiogram (Correct Answer)

Explanation: ***CT pulmonary angiogram*** - The patient has confirmed **deep vein thrombosis (DVT)** of the left popliteal vein. After initiating anticoagulation, the most appropriate next step is to **evaluate for pulmonary embolism (PE)** with a **CT pulmonary angiogram (CTPA)**. - **Up to 40-50% of patients with proximal DVT have asymptomatic or minimally symptomatic PE**, making screening important for risk stratification and treatment planning. - The presence or absence of PE symptoms does not reliably exclude PE, and detecting PE affects prognosis, treatment duration, and management decisions. - DVT and PE are part of the same disease spectrum (**venous thromboembolism**), and concurrent PE is common enough to warrant investigation. *Streptokinase therapy* - **Thrombolytic therapy** is reserved for **massive PE with hemodynamic instability** or **limb-threatening DVT** (phlegmasia cerulea dolens). - This patient is hemodynamically stable with an uncomplicated DVT, making thrombolysis inappropriate and unnecessarily risky (major bleeding complications). - Standard anticoagulation is the appropriate treatment and has already been initiated. *X-ray of the chest* - While **unprovoked DVT** can be associated with occult malignancy, extensive cancer screening beyond **age-appropriate screening** is **not routinely recommended** by current guidelines. - This patient had a normal colonoscopy 8 years ago (appropriate for his age). - If cancer screening were indicated, **chest X-ray is insensitive for detecting occult malignancy** - low-dose CT would be more appropriate, but even this is not standard practice without other clinical indicators. - The immediate priority is evaluating for PE, not cancer screening. *Colonoscopy* - The patient had a **normal colonoscopy 8 years ago** at age 50, which is within the 10-year screening interval for colorectal cancer. - There are no gastrointestinal symptoms or signs to suggest colorectal pathology. - Repeat colonoscopy is not indicated at this time. *Inferior vena cava filter* - An **IVC filter** is indicated only when there is an **absolute contraindication to anticoagulation** (e.g., active bleeding, recent neurosurgery) or **recurrent PE despite adequate anticoagulation**. - This patient has no contraindication to anticoagulation, and anticoagulation has been successfully initiated. - IVC filters carry risks including filter migration, IVC thrombosis, and filter fracture, so they should only be used when absolutely necessary.

Question 253: A 58-year-old man is diagnosed with right lower lobe pneumonia and has been admitted to a tertiary care hospital. His laboratory investigations suggest that he acquired an infection from the hospital where he underwent an elective abdominal surgery 3 weeks ago. His past medical records reveal a history of deep vein thrombosis and pulmonary embolism one year prior. After a steady clinical improvement over 5 days of inpatient treatment, he develops a cough, breathlessness, and hemoptysis on the 6th day. His temperature is 38.6°C (101.5°F), the pulse is 112/min, the blood pressure is 130/84 mm Hg, and the respiratory rate is 28/min. A general examination shows the presence of edema over the right leg and tenderness over the right calf region. Auscultation of the chest reveals localized crackles over the left mammary region and right infrascapular region. However, his heart sounds are normal, except for the presence of tachycardia, and there are no murmurs. Which of the following is the investigation of choice as the immediate next step in this patient’s management?

A. Ventilation-perfusion scanning
B. Echocardiography
C. Contrast-enhanced computed tomography (CECT) of chest (Correct Answer)
D. Serum brain natriuretic peptide
E. Plasma D-dimer

Explanation: ***Contrast-enhanced computed tomography (CECT) of chest*** - This patient presents with an acute onset of **cough, breathlessness, and hemoptysis** along with signs of **deep vein thrombosis (DVT)**, including leg edema and calf tenderness. This clinical picture, especially with a history of DVT and pulmonary embolism, is highly suggestive of a **pulmonary embolism (PE)**. - **CT pulmonary angiography (CTPA)**, performed as a contrast-enhanced CT of the chest, is the **gold standard** for diagnosing PE, as it directly visualizes thrombi within the pulmonary arteries and provides detailed anatomical information. - Given the **high pre-test probability** (prior DVT/PE, clinical signs of DVT, recent surgery, hemoptysis, tachycardia), immediate imaging with CTPA is indicated without need for D-dimer testing. *Ventilation-perfusion scanning* - **Ventilation-perfusion (V/Q) scanning** is an alternative for diagnosing PE, but it is less sensitive and specific than CTPA, especially in the presence of **pre-existing lung disease** (like the pneumonia this patient has), which can lead to indeterminate results. - It is usually reserved for patients with **renal insufficiency** or **contrast allergy** who cannot undergo CTPA. *Echocardiography* - **Echocardiography** can show signs of **right heart strain** in massive PE, but it is not diagnostic for PE itself, as it cannot directly visualize the emboli in the pulmonary arteries. - It is more useful in assessing **cardiac function** and ruling out other cardiac causes of breathlessness, or for risk stratification in confirmed PE. *Serum brain natriuretic peptide* - **Serum brain natriuretic peptide (BNP)** levels can be elevated in patients with **right heart strain** due to PE, but it is a **non-specific marker** and cannot confirm the diagnosis of PE. - Elevated BNP can also indicate other cardiac conditions, such as **heart failure**. *Plasma D-dimer* - **Plasma D-dimer** is a useful test to **exclude PE** in patients with a **low or intermediate pre-test probability**, but a **positive D-dimer** is non-specific and can be elevated in many conditions, including infection, surgery, and inflammation. - Given the patient's **high clinical probability** for PE (prior DVT/PE, current DVT signs, recent surgery, hemoptysis) and active pneumonia, D-dimer testing is **not indicated** as it would not change management—imaging with CTPA is already warranted regardless of D-dimer result.

Question 254: A 52-year-old man is admitted directly from the clinic for a serum glucose of 980 mg/dL. He has had type 2 diabetes for 16 years, for which he was prescribed metformin and glimepiride; however, he reports not having followed his prescription due to its high cost. For the past 12 days, he has had excess urination, and has lost 6 kg in weight. He has also noted a progressively worsening cough productive of greenish-brown sputum for approximately 20 days. His temperature is 38.9°C (102.02°F), blood pressure is 97/62 mm Hg, pulse is 97/minute and respiratory rate is 26/minute. On physical examination, he is somnolent, his eyes are sunken, and there are crackles at the left lung base. Lab results are shown: Arterial pH: 7.33 Serum sodium: 130 mEq/L Serum potassium: 3 mEq/L Serum osmolality: 325 mOsm/kg Serum beta-hydroxybutyrate: negative Urinalysis: trace ketones Intravenous normal saline infusion is started. Which of the following is the best next step in this patient?

A. Adding sodium bicarbonate infusion
B. Starting basal-bolus insulin
C. Adding dopamine infusion
D. Adding potassium to the intravenous fluids (Correct Answer)
E. Starting regular insulin infusion

Explanation: ***Adding potassium to the intravenous fluids*** - This patient presents with **hypokalemia** (serum potassium 3 mEq/L) and is receiving aggressive fluid resuscitation, which will further dilute his potassium and drive potassium into cells, potentially worsening the hypokalemia. **Potassium replacement** is critical to prevent cardiac arrhythmias. - While fluids and insulin will be necessary, **correcting potassium** should be initiated early, especially with symptoms of hypokalemia or if the level is <3.3 mEq/L, to prevent serious complications and before starting insulin. *Adding sodium bicarbonate infusion* - The patient's arterial pH of 7.33 indicates only **mild acidosis**, likely due to hypovolemic lactic acidosis or other underlying issues, but not severe enough to warrant bicarbonate infusion. - Additionally, his serum beta-hydroxybutyrate is negative and ketones are only trace, ruling out **diabetic ketoacidosis (DKA)**, which is typically the primary indication for bicarbonate in diabetic emergencies. *Starting basal-bolus insulin* - The patient requires insulin for his **hyperglycemia**, but **basal-bolus insulin** is usually started once the patient is stable, able to eat, and out of the acute hyperosmolar state. - In this emergency setting, **intravenous regular insulin infusion** is preferred for precise titration and rapid glucose control. *Adding dopamine infusion* - Dopamine is a **vasopressor** used to support blood pressure in cases of **hypotensive shock** refractory to fluid resuscitation. - While the patient is hypotensive (BP 97/62 mm Hg), his primary problem is severe dehydration, so initial management focuses on **fluid resuscitation** with normal saline rather than immediate pressors. *Starting regular insulin infusion* - While **regular insulin infusion** is appropriate for managing severe hyperglycemia in hyperosmolar hyperglycemic state (HHS), it should be initiated **after initial fluid resuscitation** and after ensuring potassium is ≥3.3 mEq/L. - Administering insulin without adequate potassium replacement could precipitate severe and life-threatening **hypokalemia**, as insulin drives potassium into cells.

Question 255: A 75-year-old woman comes to the physician because of a 6-month history of fatigue. During this period, she has had fever, pain in both shoulders and her hips, and a 5-kg (11-lb) weight loss. She also reports feeling stiff for about an hour after waking up. She has a history of hypertension and hypercholesterolemia. There is no family history of serious illness. She has smoked a pack of cigarettes daily for the past 50 years. Her medications include hydrochlorothiazide and atorvastatin. She appears pale. Her temperature is 38°C (100.4°F), pulse is 90/min, and blood pressure is 135/85 mm Hg. Range of motion of the shoulders and hips is reduced due to pain. Examination shows full muscle strength. The remainder of the examination shows no abnormalities. Laboratory studies show an erythrocyte sedimentation rate of 50 mm/h and a C-reactive protein concentration of 25 mg/dL (N=0–10 mg/dL). Which of the following is the most appropriate next step in management?

A. Chest x-ray
B. Electromyography
C. Muscle biopsy
D. Low-dose of oral prednisone (Correct Answer)
E. Antibody screening

Explanation: ***Low-dose of oral prednisone*** - The patient presents with classic symptoms of **polymyalgia rheumatica (PMR)**, including bilateral shoulder and hip pain, significant morning stiffness (over 1 hour), fatigue, fever, and weight loss, in an elderly individual with elevated **ESR** and **CRP**. - PMR responds dramatically to **low-dose corticosteroids**, making prednisone the most appropriate first-line treatment. *Chest x-ray* - While recommended in patients with unexplained **constitutional symptoms** and **elevated inflammatory markers** to rule out malignancy or infection, it is not the most immediate or specific next step given the clear picture of PMR. - A chest X-ray should be considered during the initial work-up of PMR if there are **pulmonary symptoms** or suspected **malignancy**, but PMR treatment should not be delayed. *Electromyography* - **Electromyography (EMG)** is used to differentiate between **myopathic** and **neuropathic** causes of muscle weakness. - This patient exhibits **painful limitation of range of motion** rather than true muscle weakness, and her muscle strength is full. *Muscle biopsy* - A **muscle biopsy** is useful for diagnosing inflammatory myopathies like **polymyositis** or **dermatomyositis**. - However, the patient's presentation of pain and stiffness without objective muscle weakness, coupled with the age and inflammatory markers, makes PMR much more likely than an inflammatory myopathy. *Antibody screening* - **Autoantibody screening** (e.g., ANA, RF, anti-CCP) is typically performed to evaluate for conditions like **rheumatoid arthritis** or **lupus**. - While these can cause joint symptoms and fatigue, the characteristic **proximal stiffness** and dramatic inflammatory markers in an elderly patient make PMR the more probable diagnosis, and these tests are usually negative in PMR.

Question 256: An otherwise healthy 57-year-old man presents to the emergency department because of progressive shortness of breath and exercise intolerance for the past 5 days. He denies recent travel or illicit habits. His temperature is 36.7°C (98.1°F), the blood pressure is 88/57 mm Hg, and the pulse is 102/min. The radial pulse weakens with inspiration. Physical examination reveals bilateral 1+ pedal edema. There is jugular venous distention at 13 cm and muffled heart sounds. Transthoracic echocardiogram shows reciprocal respiratory ventricular inflow and ventricular diastolic collapse. Which of the following is the best next step in the management of this patient condition?

A. Pericardiectomy
B. Pericardial drainage (Correct Answer)
C. Cardiac catheterization
D. Cardiac MRI
E. Chest X-ray

Explanation: ***Pericardial drainage*** - The clinical presentation, including progressive **shortness of breath**, **hypotension**, **tachycardia**, **pulsus paradoxus** (weak radial pulse with inspiration), **jugular venous distention**, **muffled heart sounds**, and **bilateral pedal edema**, strongly suggests **cardiac tamponade** due to a pericardial effusion. - Prompt **pericardial drainage** (pericardiocentesis) is a life-saving intervention for cardiac tamponade, as it relieves the pressure on the heart and restores cardiac output. *Pericardiectomy* - This is a surgical procedure to remove part or all of the pericardium, typically performed in cases of **constrictive pericarditis** or recurrent effusions that fail conservative management. - It is a more invasive procedure and not the immediate life-saving intervention required for acute cardiac tamponade. *Cardiac catheterization* - This procedure involves inserting a catheter into a blood vessel to measure pressures within the heart chambers and great vessels, often used for diagnosing **coronary artery disease** or valvular heart disease. - While it can provide hemodynamic data, it is not the most immediate or direct therapeutic intervention for cardiac tamponade. *Cardiac MRI* - **Cardiac MRI** provides detailed anatomical imaging of the heart and pericardium, useful for characterizing pericardial effusions or detecting myocardial abnormalities. - Although it could confirm the diagnosis, it takes time and is not the emergent therapeutic step needed for an unstable patient with cardiac tamponade. *Chest X-ray* - A **chest X-ray** might show an enlarged cardiac silhouette (water bottle sign) in cases of large pericardial effusions. - However, it is not sufficiently sensitive or specific for diagnosing cardiac tamponade and does not provide detailed information about ventricular collapse or hemodynamic compromise.

Question 257: A 70-year-old man presents to a physician with a cough and difficulty breathing during the last 7 years. He has smoked since his teenage years and regularly inhales tiotropium, formoterol, and budesonide and takes oral theophylline. The number of exacerbations has been increasing over the last 6 months. His temperature is 37.2°C (99°F), the heart rate is 92/min, the blood pressure is 134/88 mm Hg and the respiratory rate is 26/min. On chest auscultation breath sounds are diffusely decreased and bilateral rhonchi are present. Pulse oximetry shows his resting oxygen saturation to be 88%. Chest radiogram shows a flattened diaphragm, hyperlucency of the lungs, and a long, narrow heart shadow. The physician explains this condition to the patient and emphasizes the importance of smoking cessation. In addition to this, which of the following is most likely to reduce the risk of mortality from the condition?

A. Roflumilast
B. Low-dose oral prednisone
C. Pulmonary rehabilitation
D. Supplemental oxygen (Correct Answer)
E. Prophylactic azithromycin

Explanation: ***Supplemental oxygen*** - The patient's **resting oxygen saturation of 88%** indicates significant hypoxemia, which, if chronic, places a high burden on the cardiovascular system and is a strong predictor of premature mortality in **COPD**. - **Long-term oxygen therapy (LTOT)** for at least 15 hours a day has been shown to improve survival in patients with severe chronic hypoxemia due to COPD. *Roflumilast* - **Roflumilast** is a phosphodiesterase-4 inhibitor that reduces inflammation and is used to decrease exacerbations in severe COPD associated with chronic bronchitis and a history of frequent exacerbations. - While it can improve lung function and reduce exacerbations, it has not been shown to reduce mortality directly. *Low-dose oral prednisone* - **Oral corticosteroids** are primarily used for acute exacerbations of COPD, not for long-term maintenance due to significant systemic side effects like osteoporosis, muscle weakness, and increased infection risk. - While they can temporarily reduce inflammation, chronic low-dose use is not recommended for mortality benefit and may cause harm in the long run. *Pulmonary rehabilitation* - **Pulmonary rehabilitation** is a comprehensive program that improves exercise tolerance, dyspnea, and quality of life in patients with COPD. - It does not directly reduce mortality but significantly improves functional status and potentially reduces hospitalizations. *Prophylactic azithromycin* - **Prophylactic azithromycin** can reduce the frequency of exacerbations in select patients with severe COPD, likely due to its anti-inflammatory and immunomodulatory properties, as well as its bactericidal effect. - Similar to roflumilast, it reduces exacerbations but has not been shown to reduce mortality directly in COPD patients.

Question 258: A 62-year-old man comes to the physician because of a 1-day history of dull pain and stiffness of the right knee. He takes chlorthalidone for hypertension. Physical examination of the right knee shows a large effusion and mild erythema; range of motion is limited by pain. Arthrocentesis of right knee yields a cloudy aspirate. Gram stain is negative. Analysis of the synovial fluid shows a leukocyte count of 15,000/mm3 and 55% neutrophils. Microscopic examination of the synovial fluid under polarized light shows positively birefringent rhomboid crystals. Further evaluation of this patient is most likely to show which of the following findings?

A. Chalky nodules on the external ear
B. Expression of human leukocyte antigen-B27
C. Thickening of the synovia at the metacarpophalangeal joints
D. Calcification of the meniscal cartilage (Correct Answer)
E. Elevation of serum uric acid concentration

Explanation: ***Calcification of the meniscal cartilage*** - The presence of **positively birefringent rods and rhomboid crystals** in synovial fluid is pathognomonic for **calcium pyrophosphate deposition disease (CPPD)**, also known as pseudogout. - **Calcification of articular cartilage (chondrocalcinosis)**, particularly in the meniscal cartilage of the knee, is a characteristic radiographic finding in CPPD and would be expected on further evaluation. *Chalky nodules on the external ear* - **Chalky nodules (tophi)**, often found on the external ear, are characteristic of **gout**, which is caused by monosodium urate crystal deposition. - The synovial fluid crystals described (**positively birefringent rods and rhomboid crystals**) are indicative of CPPD, not gout. *Expression of human leukocyte antigen-B27* - **HLA-B27** is strongly associated with **spondyloarthropathies** such as ankylosing spondylitis and reactive arthritis. - This patient's symptoms and synovial fluid analysis are not consistent with a spondyloarthropathy. *Thickening of the synovia at the metacarpophalangeal joints* - **Synovial thickening and swelling** in the **metacarpophalangeal (MCP) joints** are characteristic features of **rheumatoid arthritis**. - This patient presents with an acute monoarticular arthritis of the knee and synovial fluid findings consistent with CPPD, not rheumatoid arthritis. *Elevation of serum uric acid concentration* - **Elevated serum uric acid** is typically associated with **gout**, indicating hyperuricemia. - While chlorothalidone can increase uric acid, the synovial fluid findings of **positively birefringent rods and rhomboid crystals** specifically point to CPPD, not gout.

Question 259: A 37-year old man is being evaluated due to a recent history of fatigue that started 3 weeks ago. The patient presents with a history of HIV, which was first diagnosed 7 years ago. He has been on an antiretroviral regimen and takes it regularly. His CD4+ count is 350 cells/mm3. According to the patient, his partner passed away from a "blood cancer", and he is worried that his fatigue might be connected to a similar pathology. The physician clarifies that there is an increased risk for HIV patients to develop certain kinds of lymphomas. Which one of the conditions below is the patient more likely to develop based on his medical history?

A. Diffuse large B cell lymphoma (Correct Answer)
B. Follicular lymphoma
C. Burkitt’s lymphoma
D. Extranodal marginal zone lymphoma
E. Small lymphocytic lymphoma

Explanation: ***Diffuse large B cell lymphoma*** - **Diffuse large B-cell lymphoma (DLBCL)** is the most common type of lymphoma diagnosed in HIV-positive patients, accounting for about 50% of cases. - The increased risk of DLBCL in HIV patients is related to chronic immune stimulation and dysregulation, often exacerbated by co-infection with viruses like **Epstein-Barr virus (EBV)**. *Follicular lymphoma* - **Follicular lymphoma** is generally *less common* in HIV-positive patients compared to the general population. - Its incidence does not significantly increase in the context of HIV infection. *Burkitt’s lymphoma* - **Burkitt's lymphoma** is also more common in HIV patients, but typically presents in those with *more severe immunosuppression* (lower CD4 counts) and is specifically associated with **Epstein-Barr virus (EBV)** co-infection. - While a possibility, DLBCL is the *overall most likely* lymphoma. *Extranodal marginal zone lymphoma* - **Extranodal marginal zone lymphoma** is *not typically associated* with an increased incidence in HIV-positive individuals. - It often correlates with chronic inflammation or specific infections (e.g., *H. pylori* in gastric MALT lymphoma). *Small lymphocytic lymphoma* - **Small lymphocytic lymphoma (SLL)**, which is essentially the nodal form of chronic lymphocytic leukemia (CLL), is *not increased* in incidence in HIV-positive patients. - CLL/SLL is generally considered to be *less common* or have no increased risk in HIV-infected individuals.

Question 260: A 67-year-old man presents to the emergency department with acute onset of shortness of breath of 30 minutes' duration. Initially, he felt faint but did not lose consciousness. He is complaining of left-sided chest pain that increases on deep inspiration. He has no history of cardiopulmonary disease. A week ago, he underwent a total left hip replacement and, following discharge, was on bed rest for 5 days due to poorly controlled pain. He subsequently noticed swelling in his right calf, which is tender on examination. His current vital signs reveal a temperature of 38.0°C (100.4°F), heart rate of 112/min, blood pressure of 95/65 mm Hg, and an oxygen saturation on room air of 91%. Computerized tomography pulmonary angiography (CTPA) shows a partial intraluminal filling defect. Which of the following is the mechanism of this patient's illness?

A. Trapped thrombus in the pulmonary vasculature (Correct Answer)
B. Occluding thrombus in a coronary artery
C. Accumulation of fluids in the pericardial sac
D. Inflammation of the lung parenchyma
E. Accumulation of air in the pericardial sac

Explanation: ***Trapped thrombus in the pulmonary vasculature*** - The patient's history of recent hip replacement, prolonged bed rest, and **right calf swelling and tenderness** strongly suggest **deep vein thrombosis (DVT)**, a major risk factor for subsequent **pulmonary embolism (PE)**. - The acute onset of **shortness of breath**, **tachycardia**, **hypoxia**, and **pleuritic chest pain**, combined with **CTPA findings** of a partial intraluminal filling defect, confirms a pulmonary embolism caused by a trapped thrombus. *Occluding thrombus in a coronary artery* - This describes a **myocardial infarction (MI)**, which typically presents with substernal chest pain that may radiate, often associated with risk factors like atherosclerosis, none of which are explicitly highlighted for this patient’s acute presentation. - While MI can cause shortness of breath and faintness, the pleuritic nature of the chest pain (increasing on inspiration) and the CTPA showing a filling defect in the pulmonary arteries point away from a primary cardiac event. *Accumulation of fluids in the pericardial sac* - This describes **pericardial effusion**, which can lead to **cardiac tamponade** if severe, causing hypotension, dyspnea, and muffled heart sounds. - However, the patient's pleuritic chest pain and positive CTPA findings for a pulmonary embolus are not characteristic of pericardial effusion or tamponade. *Inflammation of the lung parenchyma* - This suggests **pneumonia** or **pneumonitis**, which would present with cough, fever, and crackles on lung auscultation, often with infiltrates on chest X-ray. - While the patient has a low-grade fever, the abrupt onset of symptoms, pleuritic chest pain, and particularly the CTPA findings of a vascular filling defect are inconsistent with primary lung parenchymal inflammation. *Accumulation of air in the pericardial sac* - This refers to **pneumopericardium**, a rare condition that can cause chest pain and dyspnea, often associated with trauma, surgery, or barotrauma. - The patient's symptoms and risk factors point clearly to a pulmonary embolism, and pneumopericardium would not typically present with a filling defect in the pulmonary vasculature on CTPA.

Question 261: A 29-year-old woman comes to the office with her husband because she has had 4 spontaneous abortions. Regarding her medical history, she was diagnosed with systemic lupus erythematosus 9 years ago, had a stroke 3 years ago, and was diagnosed with deep vein thrombosis in the same year. She has no relevant family history. Her vital signs include: heart rate 78/min, respiratory rate 14/min, temperature 37.5°C (99.5°F), and blood pressure 120/85 mm Hg. The physical examination is unremarkable. The complete blood count results are as follows: Hemoglobin 12.9 g/dL Hematocrit 40% Leukocyte count 8,500/mm3 Neutrophils 55% Bands 2% Eosinophils 1% Basophils 0% Lymphocytes 29% Monocytes 2% Platelet count 422,000/mm3 Her coagulation test results are as follows: Partial thromboplastin time (activated) 50.9 s Prothrombin time 13.0 s A VDRL test is done, and the result is positive. Mixing studies are performed, and they fail to correct aPTT. What is the most likely cause in this patient?

A. Antithrombin deficiency
B. Protein S deficiency
C. Protein C deficiency
D. Antiphospholipid syndrome (Correct Answer)
E. Factor V Leiden mutation

Explanation: ***Antiphospholipid syndrome*** - The patient's history of **recurrent spontaneous abortions**, **stroke**, **deep vein thrombosis**, and a **positive VDRL** (often falsely positive in APS) in the context of SLE strongly suggests antiphospholipid syndrome. - The **prolonged aPTT** that **fails to correct** with mixing studies indicates the presence of a circulating anticoagulant, such as the lupus anticoagulant, which is characteristic of APS. *Antithrombin deficiency* - Antithrombin deficiency typically presents with a tendency for **thrombosis**, but it would **not cause recurrent abortions** or a **false-positive VDRL**. - It would also **not affect aPTT** in the manner seen here (prolonged and unresponsive to mixing). *Factor V Leiden mutation* - **Factor V Leiden** is a common cause of **thrombophilia** and recurrent thrombosis. However, it is **not associated with recurrent abortions**, **false-positive VDRL**, or **prolonged aPTT**. - This mutation leads to resistance to inactivation by protein C, increasing clot risk, but does not affect coagulation tests like aPTT in this specific way. *Protein S deficiency* - Protein S deficiency, like Factor V Leiden, is associated with an increased risk of **venous thrombosis**. However, it is **not directly linked to recurrent abortions** or a **false-positive VDRL**. - It also does not typically cause a **prolonged aPTT** that fails to correct with mixing studies. *Protein C deficiency* - Protein C deficiency is a risk factor for **venous thrombosis** and can be associated with severe complications like **warfarin-induced skin necrosis**. - Similar to other hereditary thrombophilias, it does **not explain the recurrent abortions**, **false-positive VDRL**, or the **specific aPTT findings** observed in this patient.

Question 262: A 74-year-old woman presents to the clinic for evaluation of an erythematous and edematous skin rash on her right leg that has progressively worsened over the last 2 weeks. The medical history is significant for hypertension and diabetes mellitus type 2. She takes prescribed lisinopril and metformin. The vital signs include: blood pressure 152/92 mm Hg, heart rate 76/min, respiratory rate 12/min, and temperature 37.8°C (100.1°F). On physical exam, the patient appears alert and oriented. Observation of the lesion reveals a poorly demarcated region of erythema and edema along the anterior aspect of the right tibia. Within the region of erythema is a 2–3 millimeter linear break in the skin that does not reveal any serous or purulent discharge. Tenderness to palpation and warmth is associated with the lesion. There are no vesicles, pustules, papules, or nodules present. Ultrasound of the lower extremity is negative for deep vein thrombosis or skin abscess. The blood cultures are pending. Which of the following is the most likely diagnosis based on history and physical examination?

A. Irritant contact dermatitis
B. Gas gangrene
C. Folliculitis
D. Erysipelas
E. Cellulitis (Correct Answer)

Explanation: **Cellulitis** - The patient's presentation with a **poorly demarcated**, erythematous, and edematous rash on the lower leg, accompanied by warmth, tenderness, and a low-grade fever, is highly consistent with **cellulitis**. The linear skin break provides a potential port of entry for bacteria. - Her history of **diabetes mellitus** is a significant risk factor for cellulitis due to impaired immune function and compromised peripheral circulation. The absence of vesicles or pustules further supports this diagnosis. *Irritant contact dermatitis* - This condition is typically characterized by **pruritus (itching)** and a rash that develops after exposure to an irritant, which is not described. - While it can cause redness and edema, contact dermatitis usually does not present with significant **warmth**, tenderness, or fever. *Gas gangrene* - This is a severe, rapidly progressing infection characterized by **crepitus** (gas in the tissues), severe pain, and often a foul-smelling discharge, none of which are noted in the patient's presentation. - The patient's symptoms are localized and do not suggest the systemic toxicity and rapid tissue necrosis associated with gas gangrene. *Folliculitis* - Folliculitis involves inflammation of hair follicles, presenting as small, **pustular lesions centered on hair follicles**, which are explicitly stated to be absent in this case. - The extensive, diffuse erythema and edema described are not typical features of folliculitis. *Erysipelas* - Erysipelas is a superficial skin infection that typically presents with a **sharply demarcated**, raised border, unlike the "poorly demarcated" lesion described. - While it shares some features with cellulitis (erythema, edema), the distinct border is a key differentiator, and erysipelas is also more likely to affect the face.

Question 263: A 42-year-old woman comes to the physician for a routine health maintenance examination. She has generalized fatigue and has had difficulties doing her household duties for the past 3 months. She has eczema and gastroesophageal reflux disease. She has a history of using intravenous methamphetamine in her youth but has not used illicit drugs in 23 years. Her medications include topical clobetasol and pantoprazole. She is 160 cm (5 ft 3 in) tall and weighs 105 kg (231 lb); BMI is 42 kg/m2. Her temperature is 37°C (98.6°F), pulse is 95/min, and blood pressure is 145/90 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no abnormalities. Pelvic examination shows a normal vagina and cervix. Laboratory studies show: Hemoglobin 13.1 g/dL Leukocyte count 7,800/mm3 Platelet count 312,000/mm3 Serum Na+ 141 mEq/L K+ 4.6 mEq/L Cl- 98 mEq/L Urea nitrogen 12 mg/dL Fasting glucose 110 mg/dL Creatinine 0.8 mg/dL Total cholesterol 269 mg/dL HDL-cholesterol 55 mg/dL LDL-cholesterol 160 mg/dL Triglycerides 320 mg/dL Urinalysis is within normal limits. An x-ray of the chest shows no abnormalities. She has not lost any weight over the past year despite following supervised weight loss programs, including various diets and exercise regimens. Which of the following is the most appropriate next step in management of this patient?

A. Phentermine and topiramate therapy and follow-up in 3 months
B. Bariatric surgery (Correct Answer)
C. Liposuction
D. Behavioral therapy
E. Metformin and statin therapy and follow-up in 3 months

Explanation: ***Bariatric surgery*** - This patient has **severe obesity** (BMI of 42 kg/m²) with obesity-related comorbidities including **hypertension** (BP 145/90 mm Hg), **dyslipidemia** (elevated cholesterol and triglycerides), and **pre-diabetes** (fasting glucose 110 mg/dL), and has failed multiple supervised weight loss programs. **Bariatric surgery** is indicated for patients with BMI ≥ 40 kg/m² or BMI ≥ 35 kg/m² with obesity-related comorbidities who have failed at least 6 months of supervised weight loss. - It is the most effective treatment for sustained weight loss in patients with **severe obesity**, leading to significant improvement or resolution of comorbidities. *Phentermine and topiramate therapy and follow-up in 3 months* - While medication can aid weight loss, this patient's **BMI of 42 kg/m²** signifies severe obesity, where medication alone is often insufficient for sustained and significant weight reduction. - **Pharmacotherapy** is typically considered for BMI ≥ 30 kg/m² or BMI ≥ 27 kg/m² with comorbidities, but for class III obesity (BMI ≥ 40 kg/m²), bariatric surgery generally provides superior and more lasting outcomes. *Liposuction* - **Liposuction** is primarily a cosmetic procedure for localized fat removal and is not an effective treatment for generalized severe obesity or weight loss, nor does it address the metabolic complications of obesity. - It does not lead to sustained weight loss or improvement in obesity-related comorbidities like **hypertension** and **dyslipidemia**. *Behavioral therapy* - The patient has already attempted multiple supervised weight loss programs, including various diets and exercise regimens, suggesting that **behavioral therapy** alone has not been effective for sustained weight loss in her case. - While beneficial as part of a comprehensive approach, it is unlikely to achieve the significant and sustained weight loss required for a patient with **severe obesity** that has failed prior conventional methods. *Metformin and statin therapy and follow-up in 3 months* - **Metformin** and **statin therapy** target specific comorbidities (pre-diabetes/insulin resistance and dyslipidemia, respectively) but do not address the underlying **severe obesity**. - While these medications are important for managing aspects of her metabolic syndrome, they are not a primary treatment for weight loss and will not lead to significant weight reduction in a patient with a **BMI of 42 kg/m²**.

Question 264: A 72-year-old man presents to the physician with a 3-month history of severe lower back pain and fatigue. The pain increases with activity. He has no history of any serious illness. He takes ibuprofen for pain relief. He does not smoke. His blood pressure is 105/65 mm Hg, pulse is 86/min, respiratory rate is 16/min, and temperature is 36.7°C (98.1°F). His conjunctivae are pale. Palpation over the 1st lumbar vertebra shows tenderness. Heart, lung, and abdominal examinations show no abnormalities. No lymphadenopathy is noted on palpation. Laboratory studies show: Hemoglobin 9 g/dL Mean corpuscular volume 90 μm3 Leukocyte count 5,500/mm3 with a normal differential Platelet count 350,000/mm3 Serum Calcium 11.5 mg/dL Albumin 3.8 g/dL Urea nitrogen 54 mg/dL Creatinine 2.5 mg/dL Lumbosacral X-ray shows an osteolytic lesion in the 1st lumbar vertebra and several similar lesions in the pelvic bone. Serum immunoelectrophoresis shows an IgG type monoclonal component of 40 g/L. Bone marrow plasma cells levels are at 20%. Which of the following is the most common cause of this patient’s acute renal condition?

A. Recurrent infections
B. Hypercalcemia (Correct Answer)
C. Nonsteroidal antiinflammatory drugs (NSAIDs)
D. Amyloid deposits
E. Infiltration of kidney by malignant cells

Explanation: ***Hypercalcemia*** - The patient exhibits several features of **multiple myeloma**, including osteolytic lesions, monoclonal gammopathy (IgG type, 40 g/L), and increased bone marrow plasma cells (20%). - **Hypercalcemia** is a common complication of multiple myeloma due to increased bone resorption and is a significant cause of **acute kidney injury** through mechanisms like nephrogenic diabetes insipidus and renal vasoconstriction. *Recurrent infections* - While patients with multiple myeloma are prone to **recurrent infections** due to immunodeficiency, infections generally do not directly cause **acute renal failure** unless it is a severe systemic infection leading to sepsis and shock. - There is no clinical evidence of a significant infection in this patient that would explain the acute renal condition. *Nonsteroidal antiinflammatory drugs (NSAIDs)* - **NSAIDs** can cause acute kidney injury, particularly in elderly patients or those with existing renal comorbidities, by inhibiting prostaglandin synthesis, leading to **afferent arteriolar vasoconstriction**. - However, the patient's severe hypercalcemia due to multiple myeloma is a more direct and potent cause of acute renal injury in this context, making NSAID use less likely to be the primary cause. *Amyloid deposits* - **Amyloidosis**, specifically AL amyloidosis, is a known complication of multiple myeloma and can lead to **renal dysfunction** through amyloid deposition in the glomeruli and tubules. - While relevant, amyloidosis typically causes a slower, progressive **chronic kidney disease** rather than an acute renal condition and would present with proteinuria (nephrotic syndrome), which is not mentioned here. *Infiltration of kidney by malignant cells* - Direct **infiltration of the kidneys by plasma cells** in multiple myeloma is a rare cause of renal failure in these patients. - More common renal complications, like cast nephropathy (myeloma kidney) due to light chain deposition, are a more prevalent finding, but the presented data strongly points to hypercalcemia as the acute insult.

Question 265: A 48-year-old woman comes to the physician because of progressively worsening dyspnea on exertion and fatigue for the past 2 months. She had Hodgkin lymphoma as an adolescent, which was treated successfully with chemotherapy and radiation. Her father died from complications related to amyloidosis. She does not smoke or drink alcohol. Her temperature is 36.7°C (98°F), pulse is 124/min, respirations are 20/min, and blood pressure is 98/60 mm Hg. Cardiac examination shows no murmurs. Coarse crackles are heard at the lung bases bilaterally. An ECG shows an irregularly irregular rhythm with absent P waves. An x-ray of the chest shows globular enlargement of the cardiac shadow with prominent hila and bilateral fluffy infiltrates. Transthoracic echocardiography shows a dilated left ventricle with an ejection fraction of 40%. Which of the following is the most likely cause of this patient's condition?

A. Postradiation fibrosis
B. Coronary artery occlusion
C. Amyloid deposition
D. Acute psychological stress
E. Chronic tachycardia (Correct Answer)

Explanation: ***Chronic tachycardia*** - The **irregularly irregular rhythm with absent P waves** on ECG is characteristic of **atrial fibrillation**, which can lead to **tachycardia-induced cardiomyopathy** if sustained. The pulse of 124/min supports this. - A sustained elevated heart rate like 124/min, especially in the context of atrial fibrillation, can cause **ventricular dilation** and reduced ejection fraction, leading to symptoms like dyspnea and fatigue observed in the patient. *Postradiation fibrosis* - While the patient has a history of radiation therapy for Hodgkin lymphoma, **radiation-induced cardiac damage** typically manifests as perivascular **fibrosis**, leading to **restrictive cardiomyopathy** or pericardial disease, not primarily dilated cardiomyopathy with an irregularly irregular rhythm. - This condition is often associated with a **reduced diastolic filling** and **normal systolic function** initially, which contradicts the dilated left ventricle and reduced ejection fraction described. *Amyloid deposition* - The family history of amyloidosis is a red herring in this clinical picture. While **cardiac amyloidosis** can cause heart failure, it typically presents as **restrictive cardiomyopathy** with **thickened ventricular walls** and normal or reduced ventricular cavity size, not a dilated left ventricle. - ECG findings in amyloidosis often include **low voltage QRS complexes** despite thickened walls, which is not described. *Coronary artery occlusion* - **Coronary artery occlusion** (e.g., myocardial infarction) can lead to dilated cardiomyopathy and reduced ejection fraction, but it usually presents with chest pain or specific ECG changes (e.g., ST elevation/depression, Q waves) that are not mentioned. - The **irregularly irregular rhythm** (atrial fibrillation) and absence of murmurs make a primary ischemic event less likely as the sole explanation for the global cardiac changes. *Acute psychological stress* - **Acute psychological stress** can trigger **takotsubo cardiomyopathy** (stress-induced cardiomyopathy), which presents with left ventricular dysfunction and apical ballooning. - However, this is typically an acute event with different ECG patterns (often ST elevation) and would not explain the chronic, sustained tachycardia and atrial fibrillation leading to dilated cardiomyopathy.

Question 266: A 23-year-old woman with no significant past medical history currently on oral contraceptive pills presents to the emergency department with pleuritic chest pain. She states that it started today. Yesterday she had a trip and returned via plane. Her temperature is 98°F (36.7°C), blood pressure is 117/66 mmHg, pulse is 105/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals tachycardia, a normal S1 and S2, and clear breath sounds. The patient’s lower extremities are non-tender and symmetric. Chest pain is not reproducible with position changes or palpation but is worsened with deep breaths. Which of the following is the most appropriate next test for this patient?

A. D-dimer
B. Ultrasound of the lower extremities
C. Ventilation-perfusion scan
D. CT angiogram (Correct Answer)
E. Chest radiograph

Explanation: ***CT angiogram*** - This patient has **HIGH probability for pulmonary embolism (PE)** based on **Wells criteria**: oral contraceptive use (hypercoagulable state), recent long-haul flight (immobilization), pleuritic chest pain, and tachycardia (pulse 105/min). - With a **Wells score ≥4**, the appropriate next step is **definitive imaging with CT pulmonary angiography (CTPA)**, which is the **gold standard** for diagnosing PE. - **D-dimer should be bypassed** in high-probability cases, as a negative result would not adequately rule out PE, and a positive result (expected in high-probability patients) would require CTPA anyway. - CTPA provides direct visualization of pulmonary arterial thrombi and can also identify alternative diagnoses. *D-dimer* - D-dimer is appropriate for **low to moderate probability PE** (Wells score <4) where a negative result can safely rule out PE and avoid unnecessary imaging. - In this **high-probability case**, D-dimer is likely to be positive regardless, making it an unnecessary intermediate step that delays definitive diagnosis. - Using D-dimer in high-probability patients can lead to false reassurance if negative or simply confirms the need for CTPA if positive. *Ultrasound of the lower extremities* - Lower extremity ultrasound diagnoses **deep vein thrombosis (DVT)**, not PE directly. - While finding DVT in a patient with suspected PE would support anticoagulation, **absence of DVT does not rule out PE**, as thrombi may have already embolized. - This would delay appropriate diagnosis and is not the most direct test for suspected PE. *Ventilation-perfusion scan* - V/Q scan is reserved for patients with **contraindications to CT contrast** (severe renal insufficiency, contrast allergy) or pregnant patients where radiation exposure should be minimized. - This young patient has no mentioned contraindications to contrast-enhanced CT. - V/Q scanning is less specific than CTPA and often yields indeterminate results. *Chest radiograph* - Chest X-ray is often **normal in PE** or shows non-specific findings (Westermark sign, Hampton's hump are rare). - While it may help exclude alternative diagnoses like pneumothorax or pneumonia, it cannot definitively diagnose or rule out PE. - In a patient with high clinical suspicion for PE, delaying CTPA to obtain a chest X-ray is not optimal management.

Question 267: A 79-year-old man with aortic stenosis comes to the emergency room because of worsening fatigue for 5 months. During this time, he has also had intermittent bright red blood mixed in with his stool. He has not had any abdominal pain or weight loss. Physical examination shows pale conjunctivae and a crescendo-decrescendo systolic murmur best heard at the second right intercostal space. The abdomen is soft and non-tender. Laboratory studies show a hemoglobin of 8 g/dL and a mean corpuscular volume of 71 μm3. Colonoscopy shows no abnormalities. Which of the following is the most likely underlying mechanism of this patient's bleeding?

A. Thrombus in the superior mesenteric artery
B. Tortuous submucosal blood vessels (Correct Answer)
C. Atherosclerotic narrowing of the mesenteric arteries
D. Inherited factor VIII deficiency
E. Transmural inflammation of the large bowel

Explanation: ***Tortuous submucosal blood vessels*** - This patient's presentation of **aortic stenosis** and **gastrointestinal bleeding** (bright red blood in stool, IDA) is highly suggestive of **Heyde's syndrome**. - Heyde's syndrome is characterized by the association between aortic stenosis and gastrointestinal bleeding due to **angiodysplasia**, which are tortuous submucosal blood vessels prone to bleeding. The pathophysiology involves acquired **von Willebrand factor deficiency** due to high shear stress across the diseased aortic valve, leading to degradation of large von Willebrand factor multimers, which normally help platelet adhesion at sites of bleeding. *Thrombus in the superior mesenteric artery* - A **superior mesenteric artery (SMA) thrombus** typically presents with sudden onset, severe abdominal pain, often disproportionate to physical exam findings, and signs of bowel ischemia (e.g., bloody diarrhea late in the course). - This patient has chronic, intermittent bleeding and fatigue without acute abdominal pain, making SMA thrombosis unlikely. *Atherosclerotic narrowing of the mesenteric arteries* - **Chronic mesenteric ischemia** due to atherosclerotic narrowing often causes **postprandial abdominal pain** (intestinal angina), fear of eating, and weight loss, which are absent here. - While it can lead to ischemic colitis and bleeding, the primary presentation is typically pain related to food intake. *Inherited factor VIII deficiency* - **Hemophilia A** (Factor VIII deficiency) typically causes deep tissue bleeding, hemarthroses, and bleeding after trauma or surgery. It is a congenital disorder, usually presenting much earlier in life. - It is unlikely to present as new-onset, intermittent GI bleeding in an elderly patient without a prior history of bleeding disorders. *Transmural inflammation of the large bowel* - **Transmural inflammation of the large bowel** is characteristic of **Crohn's disease**, which often presents with abdominal pain, diarrhea (sometimes with blood), weight loss, and systemic symptoms. - The patient denies abdominal pain or weight loss, and the colonoscopy showed no abnormalities, ruling out inflammatory bowel disease.

Question 268: A 68-year-old woman presents to the hospital for an elective right hemicolectomy. She is independently mobile and does her own shopping. She has had type 2 diabetes mellitus for 20 years, essential hypertension for 15 years, and angina on exertion for 6 years. She has a 30-pack-year history of smoking. The operation was uncomplicated. On post-op day 5, she becomes confused. She has a temperature of 38.5°C (101.3°F), respiratory rate of 28/min, and oxygen saturation of 92% on 2 L of oxygen. She is tachycardic at 118/min and her blood pressure is 110/65 mm Hg. On chest auscultation, she has coarse crackles in the right lung base. Her surgical wound appears to be healing well, and her abdomen is soft and nontender. Which of the following is the most likely diagnosis?

A. Malignant hyperthermia
B. Drug-induced fever
C. Multiple organ dysfunction syndrome
D. Sepsis (Correct Answer)
E. Non-infectious systemic inflammatory response syndrome (SIRS)

Explanation: ***Sepsis*** - The patient exhibits several signs of **systemic inflammatory response syndrome (SIRS)** (fever, tachycardia, tachypnea) coupled with evidence of infection (coarse crackles in the lung base suggests **pneumonia**). - The combination of **SIRS criteria** and a likely infection source in a postoperative patient strongly points to sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection. *Malignant hyperthermia* - This is a rare, life-threatening condition typically triggered by **volatile anesthetic agents** or **succinylcholine** during surgery. - It usually presents **intraoperatively or immediately postoperatively** with rapid onset of hyperthermia, muscle rigidity, and metabolic acidosis, which is not consistent with a presentation on post-op day 5. *Drug-induced fever* - While drug-induced fever is possible, particularly in polymedicated patients, it would be a **diagnosis of exclusion** when other more likely causes of fever, such as infection, are present. - There are no specific clinical features in this case that strongly suggest a drug as the singular cause of fever and the systemic inflammatory response. *Multiple organ dysfunction syndrome* - **MODS** is the progressive failure of two or more organ systems and is often a **complication of severe sepsis or septic shock**, rather than an initial diagnosis. - While the patient is unwell, her current presentation describes a potential precursor (sepsis) rather than established multi-organ dysfunction. *Non-infectious systemic inflammatory response syndrome (SIRS)* - SIRS caused by non-infectious etiologies (e.g., pancreatitis, trauma, burns) can occur, but the presence of **localized lung crackles** and a **postoperative fever** makes an infectious etiology much more likely. - Postoperative SIRS can occur due to surgical stress, but the signs of infection (especially respiratory) shift the diagnosis towards sepsis.

Question 269: A 54-year-old man comes to the emergency department for nausea and vomiting for the past 2 days. The patient reports that he felt tired and weak for the past week without any obvious precipitating factors. Past medical history is significant for hypertension controlled with hydrochlorothiazide. He denies diarrhea, changes in diet, recent surgery, vision changes, or skin pigmentation but endorses a 10-lb weight loss, headaches, fatigue, and a chronic cough for 2 years. He smokes 2 packs per day for the past 20 years but denies alcohol use. Physical examination demonstrates generalized weakness with no peripheral edema. Laboratory tests are shown below: Serum: Na+: 120 mEq/L Cl-: 97 mEq/L K+: 3.4 mEq/L HCO3-: 24 mEq/L Ca2+: 10 mg/dL Osmolality: 260 mOsm/L Urine: Na+: 25 mEq/L Osmolality: 285 mOsm/L Specific gravity: 1.007 What is the most likely finding in this patient?

A. Antibodies against presynaptic calcium channels
B. Pituitary hypertrophy
C. Chromogranin positive mass in the lung (Correct Answer)
D. Venous congestion at the liver
E. Orphan Annie eyes and psammoma bodies in the thyroid

Explanation: ***Chromogranin positive mass in the lung*** - The patient presents with **hyponatremia**, **low serum osmolality (260 mOsm/L)**, and **inappropriately high urine osmolality (285 mOsm/L)** and urine sodium (25 mEq/L), which are characteristic findings of the **Syndrome of Inappropriate Antidiuretic Hormone (SIADH)**. - While **hydrochlorothiazide can cause hyponatremia**, the patient's **20-pack-year smoking history**, **chronic cough for 2 years**, **weight loss**, and **fatigue** strongly suggest an underlying malignancy rather than simple medication effect. - The most likely cause of SIADH in this patient is **small cell lung carcinoma (SCLC)**, which is a **neuroendocrine tumor** that commonly secretes ADH ectopically and stains positive for **chromogranin A**, a neuroendocrine marker. - SCLC is the most common malignancy associated with SIADH and frequently presents with paraneoplastic syndromes in heavy smokers. *Antibodies against presynaptic calcium channels* - This finding is characteristic of **Lambert-Eaton myasthenic syndrome (LEMS)**, which is a paraneoplastic syndrome associated with small cell lung cancer caused by antibodies against voltage-gated calcium channels. - While LEMS can occur in patients with SCLC, the presented symptoms and laboratory findings (specifically euvolemic hyponatremia consistent with SIADH) point more directly to **ectopic ADH secretion** from the tumor rather than a neuromuscular disorder. - LEMS typically presents with proximal muscle weakness that improves with repeated use, which is not described in this patient. *Pituitary hypertrophy* - **Pituitary adenomas** can cause various endocrine abnormalities, but they do not typically cause SIADH. - SIADH from pituitary pathology is rare and would not explain the **pulmonary symptoms** (chronic cough) or the patient's **significant smoking history**. - This does not fit the overall clinical picture as well as small cell lung carcinoma. *Venous congestion at the liver* - **Hepatic venous congestion** occurs in conditions like right-sided heart failure, constrictive pericarditis, or Budd-Chiari syndrome. - The patient has **no signs of volume overload** (no peripheral edema, and exam shows generalized weakness only). - While heart failure can cause hyponatremia, it typically presents with hypervolemic hyponatremia with signs of fluid overload, which is absent in this case. *Orphan Annie eyes and psammoma bodies in the thyroid* - These are characteristic histological features of **papillary thyroid carcinoma**. - There is **no clinical evidence** of thyroid pathology (e.g., thyroid nodule, neck mass, dysphagia, hoarseness) in this patient. - Papillary thyroid carcinoma is not associated with SIADH or the paraneoplastic syndromes seen in this case.

Question 270: A 27-year-old man comes to the physician because of severe fatigue that started 1 week ago. Ten days ago, he finished a course of oral cephalexin for cellulitis. He does not take any medications. He appears tired. His temperature is 37.5°C (99.5°F), pulse is 95/min, and blood pressure is 120/75 mm Hg. Examination shows scleral icterus and pallor of the skin and oral mucosa. The spleen tip is palpated 1 cm below the left costal margin. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.5 g/dL Hematocrit 32% Reticulocyte count 5% Serum Lactate dehydrogenase 750 IU/L Haptoglobin undetectable Direct antiglobulin test positive for IgG A peripheral blood smear shows spherocytes. Which of the following is the most appropriate next step in treatment?

A. Splenectomy
B. Plasmapheresis
C. Intravenous immune globulin
D. Oral prednisone (Correct Answer)
E. Red blood cell transfusion

Explanation: ***Oral prednisone*** - This patient presents with an acute exacerbation of **autoimmune hemolytic anemia (AIHA)**, as evidenced by fatigue, pallor, scleral icterus, splenomegaly, elevated reticulocyte count, elevated LDH, undetectable haptoglobin, positive direct antiglobulin test (DAT) for IgG, and spherocytes on smear. - **Corticosteroids** like prednisone are the first-line treatment for AIHA, as they suppress the immune system and reduce antibody production against red blood cells. *Splenectomy* - **Splenectomy** is a second-line treatment option considered for AIHA cases that are refractory to corticosteroid therapy or for patients who experience frequent relapses. - It would not be the initial treatment approach for an acute presentation, especially before trying systemic immunosuppression. *Plasmapheresis* - **Plasmapheresis** is rarely indicated for AIHA, unless there is severe, life-threatening hemolysis or concurrent conditions like thrombotic thrombocytopenic purpura (TTP). - It is not a standard first-line treatment for typical AIHA. *Intravenous immune globulin* - **Intravenous immune globulin (IVIG)** can be used in severe cases of AIHA, particularly when a rapid response is needed or when corticosteroids are contraindicated. - However, it is typically used in conjunction with or after corticosteroids, not as the initial sole therapy for an acute AIHA presentation. *Red blood cell transfusion* - While the patient has anemia (Hb 10.5 g/dL), **red blood cell transfusion** is reserved for cases of symptomatic anemia or hemoglobin levels that are critically low (e.g., <7 g/dL) or rapidly falling. - Transfusing red blood cells too early could potentially worsen the hemolytic process by providing more targets for the autoantibodies, although it may be necessary if the anemia becomes severe and life-threatening.

Question 271: A 62-year-old man presents with multiple episodes of hemoptysis for a week. It is associated with generalized weakness, decreased appetite, and a 5.4 kg (12 lb) weight loss in 2 months. He has a smoking history of a pack a day for the last 47 years. Physical examination reveals pallor, while the rest of the results are within normal limits. Laboratory studies reveal decreased hemoglobin and a serum sodium value of 130 mEq/L. Chest X-ray shows a 3 cm rounded opaque shadow. Which of the following conditions is the patient most likely suffering from?

A. Small cell carcinoma of the lung (Correct Answer)
B. Squamous cell carcinoma of the lung
C. Tuberculoma
D. Lung abscess
E. Adenocarcinoma of the lung

Explanation: **Small cell carcinoma of the lung** - The patient's presentation with **hemoptysis**, significant **weight loss**, and a long **smoking history** is highly suggestive of lung cancer. - **Hyponatremia** (130 mEq/L) in this context often indicates **syndrome of inappropriate antidiuretic hormone secretion (SIADH)**, which is a common paraneoplastic syndrome associated with **small cell lung carcinoma**. *Squamous cell carcinoma of the lung* - While squamous cell carcinoma is strongly associated with smoking and can cause hemoptysis, it is less commonly linked to **SIADH and hyponatremia** compared to small cell carcinoma. - This type of cancer is typically **centrally located** and can lead to **hypercalcemia** due to parathyroid hormone-related peptide (PTHrP) production, which is not seen here. *Tuberculoma* - A **tuberculoma** is a localized granuloma that can appear as a rounded opacity on X-ray, but it is less likely to cause significant **systemic symptoms** like profound weight loss and unexplained hyponatremia. - **Hemoptysis** can occur with tuberculosis, but the overall clinical picture, especially the paraneoplastic features, points away from it. *Lung abscess* - A **lung abscess** typically presents with symptoms of infection such as **fever, purulent sputum**, and often a history of aspiration or pneumonia, which are absent here. - The chest X-ray usually shows a **cavitated lesion with an air-fluid level**, and hyponatremia due to SIADH is not a common association. *Adenocarcinoma of the lung* - Although **adenocarcinoma** can cause hemoptysis and weight loss, it is typically more common in **non-smokers** or former smokers and often presents as a peripheral lesion. - While it can be associated with paraneoplastic syndromes, **SIADH** and subsequent hyponatremia are much less frequent with adenocarcinoma compared to small cell lung carcinoma.

Question 272: A 69-year-old woman is brought to the physician by her daughter because of increasing forgetfulness and generalized fatigue over the past 4 months. She is unable to remember recent events and can no longer recognize familiar people. She lives independently, but her daughter has hired a helper in the past month since the patient has found it difficult to shop or drive by herself. She has stopped attending family functions and refuses to visit the neighborhood clubhouse, where she used to conduct game nights for the residents. She has had a 7-kg (15-lb) weight gain over this period. She is alert and oriented to time, place, and person. Her temperature is 36°C (97.6°F), pulse is 54/min, and blood pressure is 122/80 mm Hg. Mental status examination shows impaired attention and concentration; she has difficulty repeating seven digits forward and five in reverse sequence. She cannot recall any of the 3 objects shown to her after 10 minutes. She has no delusions or hallucinations. Further evaluation is most likely to show which of the following?

A. Ventriculomegaly on CT scan of the head
B. Elevated serum WBC count
C. Decreased serum vitamin B12
D. Elevated serum TSH (Correct Answer)
E. Diffuse cortical atrophy on brain MRI

Explanation: ***Elevated serum TSH*** - The patient's symptoms, including **forgetfulness**, generalized **fatigue**, weight gain, and **bradycardia** (pulse 54/min), are highly suggestive of **hypothyroidism**. - **Hypothyroidism** can present with cognitive dysfunction (often mistaken for dementia), depression-like symptoms (withdrawal from social activities), and metabolic changes like weight gain. *Ventriculomegaly on CT scan of the head* - **Ventriculomegaly** is often associated with conditions like **Normal Pressure Hydrocephalus (NPH)**, which presents with a triad of gait disturbance, urinary incontinence, and dementia. - While cognitive impairment is present, the absence of gait issues and incontinence makes NPH less likely, and other symptoms point away from it. *Elevated serum WBC count* - An **elevated WBC count** indicates an **infection** or inflammatory process. - The patient's symptoms are chronic (4 months), subacute, and lack specific signs of infection such as fever (temperature is normal) or acute inflammation. *Decreased serum vitamin B12* - **Vitamin B12 deficiency** can cause cognitive impairment, fatigue, and neurological symptoms. - However, it is typically associated with **anemia** and/or peripheral neuropathy, which are not mentioned in this patient's presentation. *Diffuse cortical atrophy on brain MRI* - **Diffuse cortical atrophy** is a common finding in various forms of **dementia**, such as **Alzheimer's disease**. - While it's a possibility, other more treatable causes of cognitive decline, like hypothyroidism, should be investigated first given the constellation of symptoms.

Question 273: A 30-year-old man is brought into the emergency room for complaints of acute onset chest pain and shortness of breath. He has a history of mental retardation and lives at home with his adoptive parents. His parents inform you that he has not seen a doctor since he was adopted as child and that he currently takes no medications. The patient's temperature is 99.1°F (37.3°C), pulse is 108/min, blood pressure is 125/70 mmHg, respirations are 25/min, and oxygen saturation is 92% on 2L nasal cannula. Physical exam is notable for a tall, thin individual with high-arched feet and mild pectus excavatum. There is mild asymmetry in the lower extremities with discomfort to dorsiflexion of the larger leg. Lung auscultation reveals no abnormalities. What is the most appropriate next step in management?

A. Chest radiograph
B. Serum blood test
C. Genetic testing
D. Angiogram
E. Electrocardiogram (Correct Answer)

Explanation: ***Correct: Electrocardiogram*** - **Acute chest pain** mandates an immediate **ECG** as the first diagnostic test to rule out **ST-elevation myocardial infarction (STEMI)**, which requires emergent intervention (PCI or thrombolysis). - While this patient's presentation is highly suspicious for **pulmonary embolism (PE)** given the **unilateral leg swelling with pain on dorsiflexion** (suggestive of DVT), **tachycardia**, **tachypnea**, and **hypoxemia**, the ECG remains the most appropriate initial step per ACLS protocols for chest pain. - ECG can also show findings suggestive of PE (sinus tachycardia, S1Q3T3 pattern, right heart strain) and help differentiate cardiac from pulmonary etiologies. - The **Marfanoid features** (tall, thin, pectus excavatum, high-arched feet) raise concern for **aortic dissection**, which ECG can help evaluate alongside clinical assessment. *Incorrect: Chest radiograph* - Chest X-ray is critical in the workup and would typically be ordered simultaneously with or immediately after ECG in this patient with suspected PE. - CXR helps exclude pneumothorax, pneumonia, and can show classic PE findings (Westermark sign, Hampton's hump), though it is often normal in PE. - In the context of Marfan syndrome, CXR can reveal a widened mediastinum suggesting aortic dissection. - However, ECG takes precedence as the immediate first step for any acute chest pain presentation. *Incorrect: Serum blood test* - Laboratory tests including **cardiac troponins** (for MI), **D-dimer** (for PE), and **CBC** are important but take time to result. - D-dimer would be useful in this moderate-to-high probability PE case, but imaging (CT pulmonary angiography) would be more appropriate given the high clinical suspicion. - Blood tests do not provide the immediate actionable information needed as the first diagnostic step in acute chest pain. *Incorrect: Genetic testing* - While the patient's phenotype suggests **Marfan syndrome** or another connective tissue disorder, genetic testing is an outpatient diagnostic tool for long-term management. - It provides no immediate utility in the acute management of chest pain and respiratory distress. - Genetic counseling and testing would be appropriate after stabilization and initial workup. *Incorrect: Angiogram* - **CT pulmonary angiography** would be the definitive test for PE diagnosis after initial ECG and CXR, but is not the immediate first step. - **Cardiac catheterization** would be indicated if ECG showed STEMI or if there was high suspicion for ACS after initial workup. - **CT aortography** might be needed if aortic dissection is suspected based on initial findings. - Angiography is an invasive or advanced imaging procedure performed after non-invasive screening tests guide the diagnosis.

Question 274: A 66-year-old man comes to the emergency department because of shortness of breath. His temperature is 37.2°C (99°F) and pulse is 105/min. When the blood pressure cuff is inflated to 140 mm Hg, the patient's pulse is audible and regular. However, upon inspiration, the pulse disappears and does not reappear until expiration. Only when the blood pressure cuff is inflated to 125 mm Hg is the pulse audible throughout the entire respiratory cycle. Which of the following underlying conditions is most likely responsible for this patient's physical examination findings?

A. Congestive heart failure
B. Lobar pneumonia
C. Hypertrophic cardiomyopathy
D. Asthma (Correct Answer)
E. Mitral regurgitation

Explanation: ***Asthma*** - The described phenomenon of a pulsatile arterial blood pressure dropping at least **10 mmHg** during inspiration is known as **pulsus paradoxus**. - **Pulsus paradoxus** is characteristic of conditions that impair cardiac filling during inspiration, such as **severe asthma**, **cardiac tamponade**, and **constrictive pericarditis**. *Congestive heart failure* - While patients with heart failure can experience shortness of breath, they typically do not exhibit **pulsus paradoxus** unless complicated by coexisting conditions like tamponade. - Heart failure is primarily characterized by symptoms of **fluid overload** and **reduced cardiac output**, not by a respiratory-dependent drop in pulse pressure. *Lobar pneumonia* - Lobar pneumonia causes shortness of breath due to **lung consolidation** and impaired gas exchange, often accompanied by fever and productive cough. - It does not typically lead to significant cyclical changes in intrathoracic pressure that would cause **pulsus paradoxus**. *Hypertrophic cardiomyopathy* - **Hypertrophic cardiomyopathy** can cause dyspnea and syncope due to outflow tract obstruction and diastolic dysfunction. - It is not typically associated with **pulsus paradoxus**; instead, it might present with a bifid pulse or other specific cardiac murmurs. *Mitral regurgitation* - **Mitral regurgitation** can present with shortness of breath due to volume overload in the left atrium and pulmonary circulation. - The characteristic finding in severe mitral regurgitation is a **holosystolic murmur** radiating to the axilla, and it does not typically cause **pulsus paradoxus**.

Question 275: A 56-year-old man comes to the emergency department complaining of substernal chest pain that radiates to the left shoulder. Electrocardiogram (EKG) demonstrates ST-elevations in leads II, III, and aVF. The patient subsequently underwent catheterization with drug-eluting stent placement with stabilization of his condition. On post-operative day 3, the patient experiences stabbing chest pain that is worse with inspiration, diaphoresis, and general distress. His temperature is 98.7°F (37.1°C), blood pressure is 145/97mmHg, pulse is 110/min, and respirations are 23/min. EKG demonstrates diffuse ST-elevations. What is the best treatment for this patient?

A. Lisinopril
B. Surgery
C. Needle thoracotomy
D. Atorvastatin
E. Aspirin (Correct Answer)

Explanation: ***Aspirin*** - The patient's symptoms (stabbing chest pain worse with inspiration, diffuse ST-elevations) on **post-operative day 3** following a myocardial infarction and stent placement are highly suggestive of **early post-MI pericarditis** (also called acute pericarditis or epistenocardiac pericarditis). - This occurs within the **first few days** after MI due to direct inflammatory response from myocardial necrosis, distinguished from **Dressler's syndrome** which is a delayed autoimmune phenomenon occurring **1-6 weeks** post-MI. - **Aspirin** is the first-line treatment for post-MI pericarditis (both early and late forms), as it effectively reduces inflammation while being safer than other NSAIDs in the post-MI setting. *Lisinopril* - **Lisinopril** is an ACE inhibitor used for **hypertension**, heart failure, and post-MI remodeling, but it does not address the acute inflammatory process of pericarditis. - While beneficial for long-term cardiac health post-MI, it is not the immediate treatment for these new inflammatory symptoms. *Surgery* - **Surgery** (e.g., pericardiectomy) is reserved for severe, recurrent, or constrictive pericarditis that is refractory to medical therapy. - It is an invasive procedure and not the initial treatment for an acute episode of post-MI pericarditis. *Needle thoracotomy* - A **needle thoracotomy** (needle decompression) is an emergency procedure used to treat a **tension pneumothorax**, which involves air accumulation in the pleural space causing hemodynamic compromise. - The patient's symptoms and EKG findings of diffuse ST-elevations are consistent with pericarditis, not tension pneumothorax. *Atorvastatin* - **Atorvastatin** is a statin used to lower cholesterol and prevent further cardiovascular events. - While important for secondary prevention after an MI, it does not provide acute relief or treatment for the inflammatory chest pain this patient is experiencing.

Question 276: A 62-year-old woman presents with fatigue, night sweats, and a 20-pound weight loss. Examination reveals enlarged lymph nodes. Serum electrophoresis shows an abnormally high concentration of a pentameric protein complex. Which of the following conditions is most likely associated with these findings?

A. Chronic lymphocytic leukemia
B. Non-Hodgkin lymphoma
C. Waldenström macroglobulinemia (Correct Answer)
D. Multiple myeloma
E. Hodgkin lymphoma

Explanation: ***Waldenström macroglobulinemia*** - The combination of **fatigue, night sweats, weight loss (B symptoms)**, enlarged lymph nodes, and a **pentameric protein complex** (IgM paraprotein) on serum electrophoresis is classic for Waldenström macroglobulinemia. - This condition is a **lymphoplasmacytic lymphoma** characterized by the overproduction of monoclonal IgM antibodies. *Chronic lymphocytic leukemia* - While it can manifest with B symptoms and lymphadenopathy, **CLL primarily involves lymphocyte proliferation** and typically does not present with a significant pentameric protein complex on serum electrophoresis. - It is characterized by **monoclonal B-cell lymphocytosis** in the peripheral blood. *Non-Hodgkin lymphoma* - This is a broad category, and while some subtypes can present with B symptoms and lymphadenopathy, the specific finding of a **pentameric protein complex** **(IgM)** on serum electrophoresis is not a typical or defining feature of most NHL subtypes. - The type of monoclonal protein, if any, often differs, and is not usually IgM. *Multiple myeloma* - Characterized by the overproduction of **monoclonal IgG or IgA** antibodies, not IgM, which would appear as a gamma globulin spike on electrophoresis. - Patients typically present with **bone pain, hypercalcemia, renal failure**, and anemia, which are not the primary features described here. *Hodgkin lymphoma* - presents with B symptoms and lymphadenopathy, but the presence of **Reed-Sternberg cells** is pathognomonic, and it typically does **not produce a monoclonal pentameric protein complex** (IgM) in the serum. - Serum protein electrophoresis is usually normal in Hodgkin lymphoma.

Question 277: A 48-year-old man presents with a productive cough and occasional dyspnea on exertion. He has experienced these symptoms for the past 6 years. Patient denies weight loss, night sweats, or hemoptysis. Past medical history is significant for arterial hypertension, diagnosed 3 years ago, and diabetes mellitus type 2, diagnosed 5 years ago. He also has allergic rhinitis with exacerbations in the spring. The current medications include 12.5 mg of lisinopril and 1,000 mg of metformin daily. The patient reports a 30-pack-year smoking history. He works as a financial advisor and is physically inactive. The vital signs are within normal limits. The BMI is 44.9 kg/m2. Upon physical examination, lung auscultation is significant for occasional wheezes over both lungs. The spirometry shows an FEV1 of 59% of predicted. Which of the following interventions would be most useful to slow the progression of this patient’s most likely condition?

A. Discontinuing lisinopril
B. Increasing physical activity
C. Weight reduction
D. Smoking cessation (Correct Answer)
E. Identifying and avoiding contact with an allergen

Explanation: ***Smoking cessation*** - The patient presents with **chronic productive cough**, dyspnea on exertion, and a **30-pack-year smoking history**, along with spirometry showing an **FEV1 of 59% predicted**, all highly suggestive of **Chronic Obstructive Pulmonary Disease (COPD)**. - **Smoking cessation** is the **single most effective intervention** to slow the progression of COPD, as continued smoking causes ongoing inflammation and destruction of lung tissue. *Discontinuing lisinopril* - While **ACE inhibitors like lisinopril can cause a dry cough**, this patient's cough is productive and has lasted for 6 years, predating his 3-year history of hypertension and lisinopril use. - Discontinuing an ACE inhibitor would not address the underlying **COPD** or significantly impact its progression. *Increasing physical activity* - **Physical activity** is beneficial for overall health and can improve exercise tolerance in patients with COPD, but it does **not slow the progression of lung damage**. - It is an important part of pulmonary rehabilitation, but not the primary intervention to halt disease progression. *Weight reduction* - The patient has a **BMI of 44.9 kg/m2**, indicating **severe obesity**, which can exacerbate dyspnea and overall respiratory function. - **Weight reduction** can improve symptoms and quality of life in obese patients with COPD, but it does **not directly slow the progression of the lung disease** itself. *Identifying and avoiding contact with an allergen* - The patient has a history of **allergic rhinitis**, suggesting allergic sensitization, and occasional wheezes, but his primary symptoms of chronic productive cough and significant FEV1 reduction over 6 years are more consistent with **COPD** due to smoking. - While managing allergies is important for symptom control, it will **not slow the progression of COPD**, as chronic tobacco smoke exposure is the main driver.

Question 278: A 47-year-old man presents to his primary care physician for headaches. The patient states that he typically has headaches in the morning that improve as the day progresses. Review of systems reveals that he also experiences trouble focusing and daytime fatigue. The patient drinks 2 to 3 alcoholic beverages daily and smokes 1 to 2 cigarettes per day. His past medical history includes diabetes, hypertension, and hypercholesterolemia. His current medications include insulin, metformin, metoprolol, aspirin, and atorvastatin. His temperature is 98.7°F (37.1°C), blood pressure is 157/98 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 99% on room air. Physical exam reveals a fatigued-appearing obese man with a BMI of 37 kg/m^2. Which of the following is the best initial step in management?

A. CT scan of the head
B. Uvulopalatopharyngoplasty
C. Ibuprofen and follow up in 2 weeks
D. Continuous positive airway pressure
E. Weight loss (Correct Answer)

Explanation: ***Weight loss*** - This patient presents with classic features of **obstructive sleep apnea (OSA)**: **obesity (BMI 37)**, morning headaches that improve during the day, daytime fatigue, trouble focusing, and poorly controlled hypertension. - While **polysomnography (sleep study)** would be the gold standard for confirming OSA diagnosis, among the given therapeutic options, **weight loss is the most appropriate initial conservative management step**. - Even modest weight reduction (5-10% of body weight) can significantly reduce the **apnea-hypopnea index (AHI)**, improve symptoms, and enhance blood pressure control. - Weight loss addresses the underlying pathophysiology and should be initiated regardless of other interventions pursued. *Continuous positive airway pressure* - **CPAP** is highly effective for moderate to severe OSA, but typically requires **formal diagnosis via polysomnography** before initiation and insurance coverage. - While CPAP may ultimately be needed, weight loss can be initiated immediately and may reduce or eliminate the need for CPAP in some patients. - CPAP also requires patient adherence and monitoring, making it less suitable as a first-line approach without confirmed diagnosis. *CT scan of the head* - While headaches are present, the clinical picture strongly suggests **OSA-related morning headaches** (due to nocturnal hypercapnia and hypoxia), not a primary intracranial pathology. - The pattern of morning headaches that improve during the day is highly characteristic of OSA, not brain lesions or masses. - Neuroimaging would be considered if red flags were present (focal neurologic deficits, papilledema, worst headache of life). *Uvulopalatopharyngoplasty* - This **surgical procedure** removes tissue from the soft palate and pharynx to enlarge the airway. - It is reserved for patients who have **failed or cannot tolerate CPAP** and have specific anatomic abnormalities identified on examination. - Surgery is never a first-line approach for OSA - conservative management and CPAP are always attempted first. *Ibuprofen and follow up in 2 weeks* - This approach only treats the **symptom** (headaches) without addressing the underlying **obstructive sleep apnea**. - Delaying appropriate management of OSA leads to persistent symptoms, daytime dysfunction, and increased cardiovascular morbidity and mortality. - Untreated OSA is associated with hypertension, arrhythmias, stroke, and myocardial infarction.

Question 279: A 55-year-old woman presents with fatigue, shortness of breath during ordinary activities, and occasional fluttering in her chest. She denies chest pain or lower extremity edema. She has no prior medical history. She does not smoke but drinks alcohol socially. Her blood pressure is 110/70 mm Hg, her temperature is 36.9°C (98.4°F), and her radial pulse is 95/min and regular. On physical examination, lungs are clear to auscultation, the apical impulse is slightly displaced, and a III/VI holosystolic murmur is audible at the apex and radiates to the axilla. Transthoracic echocardiography shows the presence of mitral regurgitation and an ejection fraction of 60 %. Which of the following is the optimal therapy for this patient?

A. ACE inhibitors, beta-blockers, diuretics, and surgery (Correct Answer)
B. Intra-aortic balloon counterpulsation
C. Observation and echocardiographic followup
D. Emergency surgery
E. Angiotensin-converting enzyme (ACE) inhibitors and beta-blockers

Explanation: ***ACE inhibitors, beta-blockers, diuretics, and surgery*** - This patient has **symptomatic chronic primary mitral regurgitation (MR)** with preserved ejection fraction, presenting with fatigue, dyspnea, and palpitations. - According to **current ACC/AHA guidelines**, the definitive treatment for **symptomatic severe chronic primary MR** is **surgical intervention** (mitral valve repair or replacement). - **Mitral valve repair** is preferred over replacement when feasible, with excellent outcomes in experienced centers. - Medical management with **diuretics** may provide symptomatic relief for volume overload, while surgery addresses the underlying valvular pathology. - **Note:** ACE inhibitors and vasodilators are **not recommended** for chronic primary MR with preserved LV function per current guidelines, but may be initiated if there is concurrent hypertension or as bridge therapy before surgery. *Angiotensin-converting enzyme (ACE) inhibitors and beta-blockers* - **ACE inhibitors and vasodilators have no proven benefit** in chronic primary mitral regurgitation with preserved left ventricular function. - These medications are primarily useful for **secondary (functional) MR** due to LV dysfunction or heart failure with reduced ejection fraction. - Current guidelines **do not recommend** ACE inhibitors as primary therapy for chronic primary MR. *Intra-aortic balloon counterpulsation* - This therapy is used for **acute severe mitral regurgitation** or **cardiogenic shock** to improve cardiac output and reduce afterload. - The patient has **chronic symptoms** and is **hemodynamically stable** with preserved EF, so this aggressive intervention is not indicated. *Observation and echocardiographic followup* - This approach is suitable for **asymptomatic patients with mild to moderate chronic primary MR** and preserved left ventricular function. - However, this patient is experiencing **significant symptoms** (fatigue, dyspnea, palpitations), indicating that observation alone is insufficient. *Emergency surgery* - **Emergency surgery** is reserved for **acute, severe MR** with hemodynamic instability or pulmonary edema. - This patient has **chronic compensated symptoms** with preserved EF, warranting **elective surgical evaluation** rather than emergency intervention.

Question 280: A 19-year-old basketball player unexpectedly collapses on the court. Several minutes later he returns to consciousness and is able to continue playing. This has happened several times before with similar outcomes. He had no significant past medical history. Which of the following is most likely to be found in this patient?

A. Cardiac myxoma
B. Atheromatous plaque rupture
C. Postductal coarctation of the aorta
D. Coagulation necrosis with loss of nuclei and striations
E. Septal hypertrophy (Correct Answer)

Explanation: ***Septal hypertrophy*** - The history of a young, otherwise healthy athlete collapsing during exertion and then recovering suggests a **cardiac arrhythmia** due to **hypertrophic cardiomyopathy (HCM)**. - HCM is characterized by **left ventricular hypertrophy**, especially of the septum, leading to **outflow tract obstruction** and **diastolic dysfunction**, predisposing to arrhythmias. *Cardiac myxoma* - While a myxoma can cause embolic events or obstruction, it typically presents with more insidious symptoms or acute heart failure due to **valvular obstruction**. - Recurrent syncope with immediate recovery is less characteristic of a **primary cardiac tumor**. *Atheromatous plaque rupture* - This is a common cause of **myocardial infarction** or **stroke** in older individuals with risk factors for atherosclerosis. - It is highly unlikely in a 19-year-old athlete without significant medical history. *Postductal coarctation of the aorta* - This congenital heart defect would typically present with **hypertension**, **discrepancy in blood pressure between upper and lower extremities**, or symptoms of heart failure. - It is not a common cause of sudden collapse during sport with rapid recovery. *Coagulation necrosis with loss of nuclei and striations* - This describes the histological changes seen in acute **myocardial infarction**. - While a severe cardiac event, it is unlikely to allow for immediate full recovery and continuation of play, especially in a young, previously healthy individual.

Question 281: A 67-year-old man with a past medical history of poorly-controlled type 2 diabetes mellitus (T2DM) is brought to the emergency department for acute onset nausea and vomiting. According to the patient, he suddenly experienced vertigo and began vomiting 3 hours ago while watching TV. He reports hiking in New Hampshire with his wife 2 days ago. Past medical history is significant for a myocardial infarction (MI) that was treated with cardiac stenting, T2DM, and hypertension. Medications include lisinopril, aspirin, atorvastatin, warfarin, and insulin. Physical examination demonstrates left-sided facial droop and decreased pinprick sensation at the right arm and leg. What is the most likely etiology of this patient’s symptoms?

A. Hypoperfusion of the anterior spinal artery (ASA)
B. Labyrinthitis
C. Early disseminated Lyme disease
D. Thrombotic stroke at the anterior inferior cerebellar artery (AICA)
E. Embolic stroke at the posterior inferior cerebellar artery (PICA) (Correct Answer)

Explanation: ***Embolic stroke at the posterior inferior cerebellar artery (PICA)*** - The constellation of left-sided **facial droop** (cranial nerve impairment) and **contralateral decreased pinprick sensation** (spinothalamic tract deficit) in the context of acute vertigo, nausea, and vomiting is classic for a **lateral medullary syndrome (Wallenberg syndrome)**. - Wallenberg syndrome is most commonly caused by an **ischemic stroke in the PICA territory**, often embolic, especially in patients with risk factors like **atrial fibrillation** (implied by warfarin use) or a history of MI. *Hypoperfusion of the anterior spinal artery (ASA)* - **ASA syndrome** typically presents with sudden onset **flaccid paraplegia, loss of pain and temperature sensation below the level of the lesion**, and preservation of proprioception and vibration sense. - It does not typically cause **facial droop** or **vertigo**, as these are signs of brainstem involvement. *Labyrinthitis* - **Labyrinthitis** is an inflammation of the inner ear, causing acute onset **vertigo, nausea, vomiting**, and sometimes hearing loss or tinnitus. - It would **not cause neurological deficits** like facial droop or contralateral sensory loss in the extremities, which are indicative of a central neurological event. *Early disseminated Lyme disease* - **Early disseminated Lyme disease** can cause neurological symptoms, including **facial nerve palsy** (often bilateral), but it typically presents with other symptoms like **meningitis, radiculopathy, or carditis**. - The **hyperacute onset (3 hours)** strongly favors an acute vascular event over Lyme disease, which takes **days to weeks** to develop neurological manifestations after tick exposure. *Thrombotic stroke at the anterior inferior cerebellar artery (AICA)* - An **AICA stroke** typically presents with **ipsilateral facial paralysis, ipsilateral hearing loss**, vertigo, nystagmus, and sometimes contralateral loss of pain and temperature sensation. - While it can cause vertigo and facial weakness, the specific pattern of **contralateral body sensory loss** combined with facial droop strongly points to a PICA distribution affecting the lateral medulla, not AICA.

Question 282: A 19-year-old woman presents to her gynecologist’s office stating that she has never had a period. She is slightly alarmed because most of her friends in college have been menstruating for years. She is also concerned about her short stature. When she previously visited her family physician during early puberty, she was told that she will gain the appropriate height during her final teenage years. However, over the past few years, she has gained only a couple of inches. On examination, she has a wide chest and short neck. Her breast development is at Tanner stage 1. Her external genitalia is normal with sparse hair distribution over the mons pubis. Her gynecologist suspects a genetic condition and sends her for genetic counseling. Based on her clinical findings, which of the following diseases is she most likely to develop?

A. Cystic medial necrosis
B. Coarctation of aorta (Correct Answer)
C. Supravalvular aortic stenosis
D. Intellectual disability
E. Endocardial cushion defects

Explanation: ***Coarctation of aorta*** - The patient's presentation with **primary amenorrhea**, **short stature**, a **wide chest**, and **short neck** are classic signs of **Turner syndrome (45, XO)**. - **Coarctation of the aorta** is a common cardiovascular anomaly associated with Turner syndrome, occurring in approximately 10-20% of affected individuals. *Cystic medial necrosis* - This condition is associated with conditions like **Marfan syndrome** or **Ehlers-Danlos syndrome**, which present with different physical features, such as tall stature and joint hypermobility. - While it can lead to aortic dissection, it is not a characteristic cardiovascular anomaly of Turner syndrome. *Supravalvular aortic stenosis* - This is a feature more commonly associated with **Williams syndrome**, which involves distinct facial features, intellectual disability, and a cheerful personality, none of which are described in this patient. - It involves narrowing of the ascending aorta above the aortic valve, but is not typically linked to Turner syndrome. *Intelligence disability* - Patients with **Turner syndrome typically have normal intelligence**, although they may experience specific learning difficulties, particularly in visuospatial tasks. - Significant intellectual disability is not a characteristic feature of this syndrome. *Endocardial cushion defects* - These defects, particularly **atrioventricular septal defects**, are classically associated with **Down syndrome (Trisomy 21)**. - They are not a common cardiovascular defect seen in Turner syndrome.

Question 283: A 29-year-old woman presents to the emergency department with joint pain and a notable rash. She has had joint pain for the past 12 months but noticed the rash recently as well as generalized malaise. She states her joint pain is symmetric, in her upper extremities, and is worse in the morning. Her temperature is 97.6°F (36.4°C), blood pressure is 111/74 mmHg, pulse is 83/min, respirations are 14/min, and oxygen saturation is 98% on room air. Laboratory studies are ordered as seen below. Hemoglobin: 10 g/dL Hematocrit: 30% Leukocyte count: 6,800/mm^3 with normal differential Platelet count: 207,000/mm^3 Serum: Na+: 140 mEq/L Cl-: 101 mEq/L K+: 4.9 mEq/L HCO3-: 21 mEq/L BUN: 30 mg/dL Glucose: 120 mg/dL Creatinine: 1.8 mg/dL The patient is ultimately admitted to the hospital. Which of the following is the most appropriate test to monitor her disease progression?

A. Rheumatoid factor
B. Anti-topoisomerase
C. Anti-dsDNA (Correct Answer)
D. Anti-CCP
E. Anti-nuclear antibody

Explanation: ***Anti-dsDNA*** - The patient's presentation with **symmetric polyarthritis**, a **rash**, and **renal involvement** (elevated BUN and creatinine) is highly suggestive of **Systemic Lupus Erythematosus (SLE)**. - **Anti-dsDNA antibodies** correlate well with disease activity, especially **lupus nephritis**, making them an excellent marker for monitoring disease progression and response to therapy in SLE. *Rheumatoid factor* - **Rheumatoid factor** is primarily associated with **Rheumatoid Arthritis** and is generally not used for monitoring SLE activity. - While some SLE patients may test positive for RF, it is not a specific marker for SLE. *Anti-topoisomerase* - **Anti-topoisomerase I (Scl-70) antibodies** are characteristic of **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form. - This antibody is not typically seen in SLE and does not help monitor its progression. *Anti-CCP* - **Anti-cyclic citrullinated peptide (anti-CCP) antibodies** are highly specific for **Rheumatoid Arthritis**. - They are useful for diagnosis and prognosis in RA but have no role in monitoring SLE. *Anti-nuclear antibody* - **Antinuclear antibodies (ANA)** are present in almost all patients with SLE and are essential for diagnosis, but they do not correlate with disease activity. - A positive ANA test is a screening tool but cannot be used to monitor disease progression or response to treatment.

Question 284: A 63-year-old man undergoes workup for nocturnal dyspnea and what he describes as a "choking" sensation while sleeping. He also endorses fatigue and dyspnea on exertion. Physical exam reveals a normal S1, loud P2, and a neck circumference of 17 inches (43 cm) (normal < 14 inches (< 35 cm)). His temperature is 98.8°F (37°C), blood pressure is 128/82 mmHg, pulse is 86/min, and respirations are 19/min. He undergoes spirometry, which is unrevealing, and polysomnography, which shows 16 hypopneic and apneic events per hour. Mean pulmonary arterial pressure is 30 mmHg. Which of the following complications is this patient most at risk for?

A. Left ventricular failure
B. Right ventricular failure (Correct Answer)
C. Pulmonary embolism
D. Aspiration pneumonia
E. Chronic obstructive pulmonary disease

Explanation: ***Right ventricular failure*** - The patient's symptoms (nocturnal dyspnea, choking sensation, fatigue, exertional dyspnea), risk factors (large neck circumference), and polysomnography results (16 hypopneic/apneic events/hour) are consistent with **obstructive sleep apnea (OSA)**. - OSA leads to **chronic intermittent hypoxia** and hypercapnia, causing **pulmonary vasoconstriction** and increased pulmonary arterial pressure (mean PAP 30 mmHg), which can result in **pulmonary hypertension** and eventually **right ventricular failure**. *Left ventricular failure* - While OSA can exacerbate cardiovascular conditions, the primary cardiac complication directly resulting from ongoing pulmonary hypertension due to OSA is typically right-sided, not primarily left-sided, failure. - There are no specific findings in the description (e.g., S3 gallop, crackles) that strongly point to left ventricular dysfunction as the most immediate and direct complication. *Pulmonary embolism* - Although obesity (suggested by large neck circumference) is a risk factor for pulmonary embolism, there are no acute symptoms (e.g., sudden onset dyspnea, pleuritic chest pain, hemoptysis) or signs (e.g., tachycardia, hypoxemia) to suggest a pulmonary embolism. - The patient's symptoms are chronic and related to sleep-disordered breathing and pulmonary hypertension. *Aspiration pneumonia* - While a "choking" sensation could potentially lead to aspiration, there's no evidence of infection (e.g., fever, productive cough, crackles) or recurrent aspiration events. - The primary respiratory pathology is clearly defined by the polysomnography and elevated pulmonary pressures. *Chronic obstructive pulmonary disease* - Spirometry was reported as "unrevealing," which rules out significant airflow limitation characteristic of COPD. - The patient's symptoms are more indicative of sleep-disordered breathing and its cardiovascular consequences rather than an intrinsic obstructive lung disease like COPD.

Question 285: A 22-year-old man comes to the emergency department because of several episodes of blood in his urine and decreased urine output for 5 days. His blood pressure is 158/94 mm Hg. Examination shows bilateral lower extremity edema. Urinalysis shows 3+ protein and red blood cell casts. Mass spectrometry analysis of the urinary protein detects albumin, transferrin, and IgG. Which of the following best describes this type of proteinuria?

A. Tubular
B. Selective glomerular
C. Nonselective glomerular (Correct Answer)
D. Postrenal
E. Overflow

Explanation: ***Nonselective glomerular*** - The presence of **albumin**, **transferrin**, and **IgG** indicates a loss of molecular control by the glomerulus, allowing both small and larger proteins to pass. - This pattern, particularly with significant proteinuria (3+ protein) and **red blood cell casts**, is characteristic of a severe **glomerular injury** leading to nonselective filtration. *Tubular* - **Tubular proteinuria** results from impaired reabsorption of low-molecular-weight proteins by the renal tubules, typically due to **tubulointerstitial damage**. - It would primarily involve smaller proteins like **beta-2 microglobulin** or **retinol-binding protein**, not significant amounts of albumin and IgG. *Selective glomerular* - **Selective glomerular proteinuria** involves the loss of smaller proteins, primarily **albumin**, due to damage to the glomerular charge barrier, while larger proteins like IgG are retained. - The detection of **IgG** in the urine indicates a loss of both charge and size selectivity, ruling out selective proteinuria. *Postrenal* - **Postrenal proteinuria** is due to inflammation or bleeding in the urinary tract below the kidneys, such as the ureters, bladder, or urethra. - It is typically associated with conditions like **urinary tract infections** or **stones** and would not cause the significant systemic symptoms (hypertension, edema) or protein profile seen here. *Overflow* - **Overflow proteinuria** occurs when there is an overproduction of low-molecular-weight proteins (e.g., **Bence Jones proteins** in multiple myeloma) that overwhelm the reabsorptive capacity of the tubules. - This patient presents with **glomerular injury** features (red blood cell casts, hypertension, edema) and the presence of albumin and IgG, not an overproduction of single-type low-molecular-weight proteins.

Question 286: A 28-year-old woman comes to the emergency department for a rash that began 3 days ago. She has low-grade fever and muscle aches. She has no history of serious illness and takes no medications. She has had 5 male sexual partners over the past year and uses condoms inconsistently. Her temperature is 38.1°C (100.6° F), pulse is 85/min, and blood pressure is 126/89 mm Hg. Examination shows a diffuse maculopapular rash that includes the palms and soles. The remainder of the examination shows no abnormalities. A venereal disease research laboratory (VDRL) test is positive. Which of the following is the next appropriate step in management?

A. Intravenous penicillin G
B. Dark field microscopy
C. Treponemal culture
D. Oral doxycycline
E. Fluorescent treponemal antibody absorption test (Correct Answer)

Explanation: ***Fluorescent treponemal antibody absorption test*** - A positive **VDRL** (a non-treponemal test) should be confirmed with a **treponemal-specific test** like the **fluorescent treponemal antibody absorption (FTA-ABS)** test or **Treponema pallidum particle agglutination (TPPA)** assay to definitively diagnose syphilis. - This confirmatory step helps differentiate true syphilis from false-positive VDRL results, which can occur in autoimmune diseases (SLE, antiphospholipid syndrome), other infections (malaria, mononucleosis), pregnancy, or recent vaccination. - While this patient's presentation is highly suggestive of **secondary syphilis** (diffuse maculopapular rash involving palms and soles, fever, myalgias, positive VDRL), confirmatory testing is the standard next step before initiating treatment. - Note: In some clinical settings with classic secondary syphilis, immediate treatment may be initiated, but confirmatory testing remains the most appropriate next diagnostic step. *Intravenous penicillin G* - IV aqueous penicillin G is the treatment for **neurosyphilis**, not uncomplicated secondary syphilis. - **Secondary syphilis** is treated with **intramuscular benzathine penicillin G 2.4 million units** as a single dose. - Treatment should follow confirmed diagnosis with treponemal-specific testing. *Dark field microscopy* - This technique visualizes spirochetes directly from **primary lesions** (chancres) or moist secondary lesions (condyloma lata, mucous patches). - It is not practical for this patient who has a diffuse maculopapular rash without obvious mucosal or genital lesions. - Dark-field microscopy requires specialized equipment and expertise not readily available in most emergency departments. *Treponemal culture* - **Treponema pallidum** cannot be cultured on artificial media because it is an **obligate pathogen** that requires living host cells. - Culture is not a diagnostic option for syphilis. *Oral doxycycline* - **Doxycycline 100 mg twice daily for 14 days** is an alternative treatment for early syphilis in **penicillin-allergic patients**. - Treatment should only be initiated after diagnosis is confirmed with treponemal-specific testing. - This is not the next appropriate step; confirmatory testing comes first.

Question 287: A 34-year-old man with a 2-year history of rheumatoid arthritis is being evaluated on a follow-up visit. He is currently on methotrexate and celecoxib for pain management and has shown a good response until now. However, on this visit, he mentions that the morning stiffness has been getting progressively worse. On physical examination, both his wrists are erythematous and swollen, nodules on his elbows are also noted. Rheumatoid factor is 30 (normal reference values: < 15 IU/mL), ESR is 50 mm/h, anti-citrullinated protein antibodies is 55 (normal reference values: < 20). What is the next best step in the management of this patient?

A. Sulfasalazine
B. Adalimumab monotherapy
C. Methotrexate and Corticosteroids
D. Methotrexate and Infliximab (Correct Answer)
E. Infliximab monotherapy

Explanation: **Methotrexate and Infliximab** - The patient is experiencing a **flare-up of rheumatoid arthritis** despite being on methotrexate, indicated by worsening morning stiffness, active synovitis (erythematous and swollen wrists), elevated ESR, and positive rheumatoid factor and anti-CCP. This suggests a need for more aggressive therapy, and adding a **biologic agent like infliximab (an anti-TNF agent)** to methotrexate is a standard approach for moderate to severe RA that is not adequately controlled by methotrexate monotherapy. - Combination therapy with **methotrexate and a biologic DMARD** (e.g., TNF inhibitors like infliximab) has been shown to be more effective than monotherapy for controlling disease activity and preventing joint damage in refractory RA. *Sulfasalazine* - **Sulfasalazine** is a conventional synthetic DMARD that is generally used as a **first-line agent or in combination therapy** for mild to moderate RA. - Given the patient's ongoing active disease despite methotrexate and the severity of his symptoms, sulfasalazine is unlikely to be sufficient to achieve disease control. *Adalimumab monotherapy* - While adalimumab (another anti-TNF biologic) is an effective treatment for RA, **biologic monotherapy is generally less effective** than combination therapy with methotrexate. - Current guidelines and clinical practice favor combining biologic DMARDs with methotrexate for optimal outcomes in RA management, especially in patients with active disease. *Methotrexate and Corticosteroids* - **Corticosteroids** are effective in rapidly reducing inflammation and can be used for **short-term management of RA flares**. - However, corticosteroids are not recommended for long-term use due to significant side effects and do not address the underlying disease progression as comprehensively as biologic DMARDs in patients refractory to methotrexate. *Infliximab monotherapy* - Similar to adalimumab monotherapy, **infliximab is typically more effective when combined with methotrexate**. - Using infliximab alone would be a less optimal choice for this patient whose disease is clearly not controlled by methotrexate, as it may lead to a suboptimal response and potentially increase the risk of developing anti-drug antibodies.

Question 288: A 62-year-old man comes to the physician in May for a routine health maintenance examination. He feels well. He underwent a right inguinal hernia repair 6 months ago. He has hypertension and type 2 diabetes mellitus. There is no family history of serious illness. Current medications include metformin, sitagliptin, enalapril, and metoprolol. He received the zoster vaccine 1 year ago. He received the PPSV23 vaccine 4 years ago. His last colonoscopy was 7 years ago and was normal. He smoked a pack of cigarettes a day for 20 years but quit 17 years ago. He drinks two to three alcoholic beverages on weekends. He is allergic to amoxicillin. He is scheduled to visit Australia and New Zealand in 2 weeks to celebrate his 25th wedding anniversary. He appears healthy. Vital signs are within normal limits. An S4 is heard at the apex. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate recommendation at this time?

A. Colonoscopy
B. Influenza vaccine (Correct Answer)
C. Pneumococcal conjugate vaccine 13
D. Cardiac stress test
E. Abdominal ultrasound

Explanation: ***Influenza vaccine*** - Current guidelines recommend annual **influenza vaccination** for all adults, particularly those over 60 years old and those with chronic medical conditions like diabetes and hypertension. - **Critical timing consideration**: The patient is traveling to Australia and New Zealand (Southern Hemisphere) in 2 weeks, where it will be **winter season** (May-September) with peak influenza activity. - He is a **high-risk patient** (age >60, diabetes, hypertension, cardiovascular disease) who should receive influenza vaccine before travel to areas experiencing influenza season. - This is the **most appropriate and time-sensitive recommendation** at this visit. *Colonoscopy* - The patient had a normal colonoscopy 7 years ago; current guidelines suggest a repeat colonoscopy every **10 years** for average-risk individuals. - There are no new symptoms, family history, or risk factors that would necessitate an earlier repeat colonoscopy at this time. *Pneumococcal conjugate vaccine 13* - The patient received **PPSV23** four years ago at approximately age 58. - Per **current CDC guidelines (2019+)**, PCV13 is **no longer routinely recommended** for immunocompetent adults ≥65 years old. - PPSV23 alone is now the standard recommendation for adults ≥65, which this patient has already received. - PCV13 may be considered through **shared decision-making** in specific circumstances, but is not a routine or urgent recommendation. *Cardiac stress test* - Although the patient has risk factors for cardiovascular disease (hypertension, diabetes, former smoker) and an **S4 heart sound** (indicating **left ventricular hypertrophy**), he is asymptomatic. - Routine **screening stress tests** are not recommended for asymptomatic individuals without signs of active cardiac ischemia. *Abdominal ultrasound* - There are **no symptoms** or specific indications (e.g., abdominal aortic aneurysm screening criteria not met - would need age 65-75 with smoking history). - The patient is 62 years old and quit smoking 17 years ago, so AAA screening criteria are not yet met. - Routine screening abdominal ultrasounds are not indicated.

Question 289: A 62-year-old man is brought to the emergency department with a sudden onset of severe chest pain, that he describes as tearing. The pain started 90 minutes back and is now referring to the upper back. There is a history of essential hypertension for the past 17 years. The patient has smoked 20–30 cigarettes daily for the past 27 years. Vital signs reveal: temperature 36.8°C (98.2°F), heart rate 105/min, and blood pressure 192/91 mm Hg in the right arm and 159/81 mm Hg in the left arm. Pulses are absent in the right leg and diminished in the left. ECG shows sinus tachycardia, and chest X-ray shows a widened mediastinum. Transthoracic echocardiography shows an intimal flap arising from the ascending aorta and extended to the left subclavian artery. Intravenous morphine sulfate is started. Which of the following is the best next step in the management of this patient condition?

A. Intravenous metoprolol (Correct Answer)
B. Intravenous hydralazine
C. Chest magnetic resonance imaging
D. Oral aspirin
E. D-dimer

Explanation: ***Intravenous metoprolol*** - This patient presents with an **acute aortic dissection** (type A given the involvement of the ascending aorta), which is a medical emergency requiring immediate management to reduce stress on the aorta and prevent rupture. - **Beta-blockers** like metoprolol are the **first-line therapy** to rapidly **lower heart rate** and **blood pressure**, thereby reducing the shear stress on the aortic wall and limiting the propagation of the dissection. *Intravenous hydralazine* - Hydralazine is a direct **vasodilator** that can cause **reflex tachycardia**, which would increase the shear stress on the dissected aorta and worsen the condition. - While it lowers blood pressure, it does not address the crucial need to reduce heart rate and myocardial contractility in aortic dissection. *Chest magnetic resonance imaging* - While MRI can provide detailed imaging of aortic dissection, the **diagnosis is already confirmed** by transthoracic echocardiography showing the intimal flap. - Further diagnostic imaging is **not the priority**; immediate **medical stabilization** with beta-blockade to reduce aortic stress is the essential next step before considering definitive surgical management. - MRI is also **time-consuming** and generally avoided in unstable patients requiring urgent intervention. *Oral aspirin* - Aspirin is an **antiplatelet agent** primarily used to prevent arterial thrombosis in conditions like myocardial infarction or stroke. - It is **not indicated** for the acute management of aortic dissection and would not address the immediate hemodynamic goals of reducing heart rate and blood pressure. *D-dimer* - **D-dimer** is a marker of fibrin degradation products used as a screening tool for conditions like **pulmonary embolism** or deep vein thrombosis. - While an elevated D-dimer can be seen in aortic dissection, it is a **non-specific test** and is not the best next step in immediate management, especially when the **diagnosis is already confirmed** by echocardiography.

Question 290: A 34-year-old G3P3 woman with a history of migraines presents with several weeks of headaches. The headaches are unlike her usual migraines and are worse in the morning. This morning she had an episode of emesis prompting her to seek medical care. She also has some right sided weakness which she believes is related to a new exercise routine. Her mother is a breast cancer survivor. Her medications include oral contraceptives and ibuprofen as needed, which has not helped her current headaches. She drinks 2-3 alcoholic drinks on the weekends and does not smoke. Physical examination is remarkable for bilateral papilledema. Motor exam is notable for upper and lower extremity strength 4/5 on the right and 5/5 on the left. Magnetic resonance venography demonstrates absent flow in the left venous sinuses. Which of the following predisposed this patient to her current condition?

A. Oral contraceptive use (Correct Answer)
B. Alcohol use
C. Family history
D. Ibuprofen use
E. History of migraines

Explanation: ***Oral contraceptive use*** - **Oral contraceptives** increase the risk of **venous thromboembolism**, including **cerebral venous thrombosis (CVT)**, which is strongly suggested by the patient's symptoms (headaches, papilledema, focal weakness) and the MRI finding of absent flow in the left venous sinuses. - The combination of **oral contraceptive use** and **migraines with aura** can further elevate the risk of CVT, as both are independent risk factors. *Alcohol use* - Moderate alcohol consumption, as described (2-3 drinks on weekends), is generally **not considered a direct risk factor** for cerebral venous thrombosis. - While chronic heavy alcohol use can indirectly affect coagulation, the patient's intake is not indicative of this. *Family history* - A family history of **breast cancer** (mother as a survivor) is not a direct predisposing factor for **cerebral venous thrombosis**. - While some cancers can increase thrombotic risk, it is the active cancer and associated treatments, rather than a past family history, that are typically relevant. *Ibuprofen use* - **Ibuprofen**, a non-steroidal anti-inflammatory drug (NSAID), is not known to directly predispose to **cerebral venous thrombosis**. - It works by inhibiting prostaglandin synthesis and is not associated with a prothrombotic state. *History of migraines* - A history of **migraines, particularly migraines with aura**, can be a **weak independent risk factor** for stroke, including some forms of thrombosis. - However, in this specific case, the presence of oral contraceptive use is a much stronger and more direct predisposing factor for cerebral venous thrombosis, making it the primary predisposing condition.

Question 291: A 52-year-old man presents to the emergency department with sudden-onset dyspnea, tachypnea, and chest pain. He works as a long-haul truck driver, and he informs you that he recently returned to the west coast from a trip to Tennessee. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type 2, and mild intellectual disability. He currently smokes 2 packs of cigarettes/day, drinks a 6-pack of beer/day, and he endorses a past history of injection drug use but currently denies any illicit drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 23/min. His physical examination shows minimal bibasilar rales, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, and a benign abdominal physical examination. A computed tomography angiography (CTA) demonstrates a segmental pulmonary embolism (PE). Which of the following is the most appropriate treatment plan for this patient?

A. Consult interventional radiologist (IR) for IVC filter placement
B. Initiate heparin
C. Tissue plasminogen activator (tPA)
D. Initiate heparin with a bridge to warfarin (Correct Answer)
E. Initiate warfarin anticoagulation

Explanation: ***Initiate heparin with a bridge to warfarin*** - This patient presents with a **segmental pulmonary embolism (PE)** and is hemodynamically stable (BP 126/74 mmHg, HR 87/min), making initial anticoagulation with **heparin** followed by a bridge to **warfarin** the most appropriate treatment. - Heparin provides rapid anticoagulation, while warfarin is initiated concurrently and takes several days to reach therapeutic levels, requiring overlap until the **International Normalized Ratio (INR)** is within the therapeutic range (2.0-3.0). *Consult interventional radiologist (IR) for IVC filter placement* - **Inferior vena cava (IVC) filters** are typically reserved for patients with a **contraindication to anticoagulation** or those who experience **recurrent PE despite adequate anticoagulation**. - This patient has no stated contraindications to anticoagulation and has not failed initial therapy, so an IVC filter is not indicated at this time. *Initiate heparin* - While initiating **heparin** is the correct first step, it is incomplete as a long-term treatment strategy for PE. - Patients with PE require **long-term anticoagulation** (typically 3-6 months or longer), for which warfarin or novel oral anticoagulants (NOACs) are used, following an initial period of rapid-acting anticoagulation. *Tissue plasminogen activator (tPA)* - **Thrombolytic therapy with tPA** is indicated for patients with **massive PE** who are **hemodynamically unstable** (e.g., hypotension, shock). - This patient is hemodynamically stable, and his PE is segmental, so thrombolysis carries a higher risk of bleeding complications than benefits in this case. *Initiate warfarin anticoagulation* - **Warfarin** has a slow onset of action (3-5 days to achieve therapeutic INR) and therefore should not be used as monotherapy for initial management of acute PE. - Initial management requires a **rapid-acting anticoagulant** like heparin or low molecular weight heparin (LMWH) to prevent further clot propagation and embolization.

Question 292: A 65-year-old male engineer presents to the office with shortness of breath on exertion and a dry cough that he has had for about a year. He is a heavy smoker with a 25-pack-years history. His vitals include: heart rate 95/min, respiratory rate 26/min, and blood pressure 110/75 mm Hg. On examination, he presents with nail clubbing and bilateral and persistent crackling rales. The chest radiograph shows basal reticulonodular symmetric images, with decreased lung fields. The pulmonary function tests show the following: diffusing capacity of the lungs for carbon monoxide (DLCO) is 43% and reference SaO2 is 94% and 72%, at rest and with exercise, respectively. What is the most likely diagnosis?

A. Chronic hypersensitivity pneumonitis
B. Pulmonary Langerhans cell histiocytosis
C. Pleuropulmonary fibroelastosis
D. Asbestosis
E. Idiopathic pulmonary fibrosis (Correct Answer)

Explanation: ***Idiopathic pulmonary fibrosis*** - This patient's presentation with **progressive dyspnea**, **dry cough**, **clubbing**, and **basal crackles (rales)**, combined with restrictive lung physiology (low **DLCO**) and **basal reticulonodular infiltrates** on CXR, is highly characteristic of **idiopathic pulmonary fibrosis**. The marked **desaturation with exercise** further supports this diagnosis. - While smoking is a risk factor, the pattern of lung disease is consistent with IPF, a chronic, progressive, fibrosing interstitial pneumonia of unknown cause. *Chronic hypersensitivity pneumonitis* - This condition is caused by **chronic exposure to inhaled antigens** and typically presents with symptoms that link back to the exposure, potentially resolving with avoidance. - While it can cause interstitial lung disease, the absence of an identifiable antigen exposure and the typical fibrotic pattern with subpleural honeycombing would make IPF more likely. *Pulmonary Langerhans cells histiocytosis* - This disease is strongly associated with **smoking** but typically presents with **cysts and nodules** predominantly in the **upper and middle lung fields** on imaging. - The patient's **basal reticulonodular pattern** with decreased lung fields on CXR, rather than cysts, makes this diagnosis less likely. *Pleuropulmonary fibroelastosis* - This is a rare interstitial lung disease characterized by **fibrosis predominantly affecting the upper lobes** and pleura. - The patient's **basal predominant findings** on chest radiograph and crackles make this diagnosis less consistent. *Asbestosis* - Although the patient's occupation as an engineer could suggest **asbestos exposure**, the description lacks specific features like **pleural plaques** or calcifications. - While asbestosis can cause diffuse interstitial fibrosis and similar symptoms, the clinical and radiological picture, especially the extent of **DLCO reduction** for the given findings, more strongly points to IPF.

Question 293: A 51-year-old woman is brought into the emergency department following a motor vehicle accident. She is unconscious and was intubated in the field. Past medical history is unknown. Upon arrival, she is hypotensive and tachycardic. Her temperature is 37.2°C (99.1°F), the pulse is 110/min, the respiratory rate is 22/min, and the blood pressure is 85/60 mm Hg. There is no evidence of head trauma, she withdraws to pain and her pupils are 2mm and reactive to light. Her heart has a regular rhythm without any murmurs or rubs and her lungs are clear to auscultation. Her abdomen is firm and distended with decreased bowel sounds. Her extremities are cool and clammy with weak, thready pulses. There is no peripheral edema. Of the following, what is the likely cause of her presentation?

A. Septic shock
B. Neurogenic shock
C. Obstructive shock
D. Hypovolemic shock (Correct Answer)
E. Cardiogenic shock

Explanation: ***Hypovolemic shock*** - The patient's presentation with ***hypotension*** (BP 85/60 mm Hg), ***tachycardia*** (pulse 110/min), ***cool and clammy extremities***, ***weak peripheral pulses***, and a ***firm, distended abdomen*** after a motor vehicle accident strongly suggests internal hemorrhage leading to hypovolemic shock. - The ***firm and distended abdomen*** is a key indicator of potential intra-abdominal bleeding, significantly contributing to the loss of intravascular volume. *Septic shock* - Septic shock is characterized by signs of infection along with organ dysfunction and circulatory compromise, often presenting with **fever** or **hypothermia**, and sometimes **warm extremities** initially due to vasodilation. This patient's temperature is normal, and extremities are cool. - While hypotension and tachycardia are present, the absence of clear signs of infection and the presence of a firm, distended abdomen make hypovolemia a more immediate concern following trauma. *Neurogenic shock* - Neurogenic shock typically follows severe spinal cord injury above T6, leading to a loss of sympathetic tone. This results in **hypotension with bradycardia** and **warm, dry skin** due to widespread vasodilation. - This patient is tachycardic and has cool, clammy extremities, which contradicts the classic presentation of neurogenic shock. *Obstructive shock* - Obstructive shock occurs due to a physical obstruction to central circulation, such as **tension pneumothorax**, **cardiac tamponade**, or **pulmonary embolism**. - There is no mention of absent breath sounds, jugular venous distention, muffled heart sounds, or other specific signs pointing to an obstructive cause. Lungs are clear to auscultation and heart rhythm is regular. *Cardiogenic shock* - Cardiogenic shock results from primary cardiac dysfunction, often presenting with signs of **heart failure**, such as **pulmonary edema** (rales), **jugular venous distention**, gallop rhythms, or new murmurs. - The patient has clear lungs, a regular heart rhythm, and no murmurs, which makes primary cardiac dysfunction less likely as the immediate cause of shock in this trauma setting.

Question 294: A 25-year-old previously healthy woman is admitted to the hospital with progressively worsening shortness of breath. She reports a mild fever. Her vital signs at the admission are as follows: blood pressure 100/70 mm Hg, heart rate 111/min, respiratory rate 20/min, and temperature 38.1℃ (100.6℉); blood saturation on room air is 90%. Examination reveals a bilateral decrease of vesicular breath sounds and rales in the lower lobes. Plain chest radiograph demonstrates bilateral opacification of the lower lobes. Despite appropriate treatment, her respiratory status worsens. The patient is transferred to the intensive care unit and put on mechanical ventilation. Adjustment of which of the following ventilator settings will only affect the patient’s oxygenation?

A. Tidal volume and respiratory rate
B. FiO2 and PEEP (Correct Answer)
C. Respiratory rate and PEEP
D. Tidal volume and FiO2
E. FiO2 and respiratory rate

Explanation: ***FiO2 and PEEP*** - **FiO2 (fraction of inspired oxygen)** directly controls the oxygen concentration delivered to the patient, thus solely impacting **oxygenation**. - **PEEP (positive end-expiratory pressure)** prevents alveolar collapse and recruits collapsed alveoli, improving the **functional residual capacity** and thus **oxygenation** without significantly altering CO2 removal (ventilation). *Tidal volume and respiratory rate* - **Tidal volume (Vt)** directly impacts the amount of air moved with each breath, primarily affecting **ventilation** (CO2 removal). - **Respiratory rate (RR)** also directly determines the total minute ventilation, thus influencing **ventilation** more than oxygenation. *Respiratory rate and PEEP* - As mentioned, **respiratory rate** significantly affects **ventilation** by altering minute ventilation (Vt x RR). - While **PEEP** primarily affects oxygenation, the combination with respiratory rate means it's not exclusively targeting oxygenation. *Tidal volume and FiO2* - **Tidal volume** is a key determinant of **ventilation** (CO2 removal), not solely oxygenation. - **FiO2** does affect oxygenation, but its combination with tidal volume makes this option incorrect for *only* affecting oxygenation. *FiO2 and respiratory rate* - **FiO2** directly impacts **oxygenation**. - **Respiratory rate** primarily affects **ventilation** (CO2 removal), thereby influencing carbonic acid levels and pH.

Question 295: A 76-year-old woman with hypertension and coronary artery disease is brought to the emergency department after the sudden onset of right-sided weakness. Her pulse is 83/min and blood pressure is 156/90 mm Hg. Neurological examination shows right-sided facial drooping and complete paralysis of the right upper and lower extremities. Tongue position is normal and she is able to swallow liquids without difficulty. Knee and ankle deep tendon reflexes are exaggerated on the right. Sensation to vibration, position, and light touch is normal bilaterally. She is oriented to person, place, and time, and is able to speak normally. Occlusion of which of the following vessels is the most likely cause of this patient's current symptoms?

A. Ipsilateral anterior cerebral artery
B. Contralateral middle cerebral artery
C. Anterior spinal artery
D. Contralateral lenticulostriate artery (Correct Answer)
E. Ipsilateral posterior inferior cerebellar artery

Explanation: ***Contralateral lenticulostriate artery*** - The patient presents with **pure motor hemiparesis** affecting the face, arm, and leg equally on the right side, with **no sensory deficits, aphasia, or cognitive impairment**. - This clinical pattern is classic for a **lacunar stroke** affecting the **internal capsule**, which is supplied by the **lenticulostriate arteries** (branches of the middle cerebral artery). - The internal capsule contains tightly packed corticospinal and corticobulbar fibers; a small infarct here causes complete contralateral motor deficits without cortical signs. - The **absence of cortical findings** (normal speech, cognition, and sensation) distinguishes this from cortical MCA stroke. *Contralateral middle cerebral artery* - A **cortical MCA stroke** would typically present with **cortical signs** such as aphasia (if left hemisphere), neglect (if right hemisphere), sensory loss, and visual field defects. - MCA strokes usually show **arm and face > leg** weakness (the leg area is supplied by ACA). - This patient's **pure motor syndrome** without cortical signs points to a subcortical lesion, not cortical MCA occlusion. *Ipsilateral anterior cerebral artery* - First, the lateralization is incorrect - symptoms are right-sided, indicating left hemisphere pathology, so it would be **contralateral** ACA. - ACA occlusion causes weakness predominantly in the **contralateral leg > arm**, with relative sparing of the face. - This patient has equal involvement of face, arm, and leg, which is inconsistent with ACA territory. *Anterior spinal artery* - The **anterior spinal artery** supplies the anterior two-thirds of the spinal cord, including the corticospinal tracts and anterior horn cells. - Occlusion causes **bilateral** motor weakness below the lesion level and bilateral loss of pain/temperature sensation. - It does not cause **unilateral facial weakness** or the distribution of deficits seen in this patient. *Ipsilateral posterior inferior cerebellar artery* - Again, lateralization is incorrect - symptoms would be from **contralateral** PICA for motor findings, but PICA supplies the lateral medulla and inferior cerebellum. - PICA occlusion causes **lateral medullary syndrome (Wallenberg syndrome)**: ataxia, vertigo, dysphagia, dysarthria, Horner syndrome, and contralateral pain/temperature loss. - The patient's **pure motor hemiparesis** without cerebellar or brainstem signs is incompatible with PICA occlusion.

Question 296: A 57-year-old woman presents to her primary care physician with a concern for joint pain. She states that she often feels minor joint pain and morning stiffness in both of her hands every day, particularly in the joints of her fingers. Her symptoms tend to improve as the day goes on and she states they are not impacting the quality of her life. She lives alone as her partner recently died. She smokes 1 pack of cigarettes per day and drinks 2-3 alcoholic drinks per day. Her last menses was at age 45 and she works at a library. The patient has a history of diabetes and chronic kidney disease with her last GFR at 45 mL/min. Her temperature is 97.5°F (36.4°C), blood pressure is 117/58 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical examination is within normal limits. Which of the following interventions is appropriate management of future complications in this patient?

A. Methotrexate
B. Ibuprofen
C. Prednisone
D. Alendronate (Correct Answer)
E. Infliximab

Explanation: ***Alendronate*** - This patient, a 57-year-old postmenopausal woman with **early menopause (age 45)**, **smoking**, **alcohol use**, and **chronic kidney disease**, is at **significantly increased risk for osteoporosis**. Alendronate, a **bisphosphonate**, is an appropriate intervention to prevent future osteoporotic fractures. - While her joint pain is likely **osteoarthritis** and currently mild, the question targets **future complication management**, highlighting her significant risk factors for bone density loss. - Her **GFR of 45 mL/min** (Stage 3a CKD) is at the lower acceptable range for bisphosphonate use; alendronate is generally avoided when GFR < 30-35 mL/min, but can be used with monitoring at GFR 45 mL/min given her high fracture risk. *Methotrexate* - Methotrexate is a **disease-modifying antirheumatic drug (DMARD)** typically used for inflammatory arthropathies like **rheumatoid arthritis** or **psoriatic arthritis**. - The patient's symptoms (mild, improving with activity, no significant exam findings) are not consistent with an inflammatory arthritis requiring methotrexate, and her **chronic kidney disease** makes its use more complex due to renal elimination and toxicity risk. *Ibuprofen* - Ibuprofen, a **nonsteroidal anti-inflammatory drug (NSAID)**, could be used for symptomatic relief of her mild osteoarthritis. - However, the question asks about **"future complications"** and her history of **chronic kidney disease** makes long-term NSAID use potentially harmful due to the risk of worsening renal function and increased cardiovascular risk. *Prednisone* - Prednisone is a powerful **corticosteroid** used for acute flares of inflammatory conditions or severe autoimmune diseases. - Her current joint pain is mild and not indicative of an inflammatory process requiring prednisone; furthermore, long-term corticosteroid use is a significant **risk factor for osteoporosis**, which would worsen her already elevated fracture risk. *Infliximab* - Infliximab is a **biologic agent** (TNF-alpha inhibitor) used for severe, refractory inflammatory conditions such as **rheumatoid arthritis**, **ankylosing spondylitis**, or **inflammatory bowel disease**. - Her symptoms are mild and do not suggest a severe inflammatory arthropathy that would warrant the use of a high-risk biologic medication, which also carries risks like increased infection susceptibility and significant cost.

Question 297: A 70-year-old woman presents to her primary care doctor complaining of left knee pain. She states that she has noticed this more during the past several months after a fall at home. Previously, she was without pain and has no history of trauma to her knees. The patient states that the majority of her pain starts in the afternoon after she has been active for some time, and that the pain resolves with rest and over-the-counter analgesics. Aside from the left knee, she has no other symptoms and no other joint findings. On exam, her temperature is 98.8°F (37.1°C), blood pressure is 124/76 mmHg, pulse is 70/min, and respirations are 12/min. The patient has no limitations in her range of motion and no changes in strength on motor testing. However, there is tenderness along the medial joint line. What finding is most likely seen in this patient?

A. Association with HLA-DR4
B. Heberden nodes
C. Increased synovial fluid
D. Marginal sclerosis (Correct Answer)
E. Joint pannus

Explanation: ***Marginal sclerosis*** - The patient's symptoms (age, knee pain worsening with activity and relieved by rest, tenderness on the medial joint line) are highly suggestive of **osteoarthritis**. - **Marginal sclerosis** (increased bone density at the joint margins) is a characteristic radiological finding in osteoarthritis, resulting from increased stress on the subchondral bone. *Association with HLA-DR4* - **HLA-DR4** is strongly associated with **rheumatoid arthritis**, an autoimmune inflammatory condition. - The patient's symptoms (pain worsening with activity, relief with rest, absence of systemic inflammation) do not align with rheumatoid arthritis. *Heberden nodes* - **Heberden nodes** are bony enlargements of the **distal interphalangeal (DIP)** joints of the fingers, characteristic of osteoarthritis. - While frequently seen in osteoarthritis, the question describes knee pain and does not mention findings in the hands, so this is not the most direct finding for the described locale of pain. *Increased synovial fluid* - While some mild effusion can occur in osteoarthritis, significant **increased synovial fluid** (effusion or swelling) is more typical of **inflammatory arthropathies** or acute injuries. - The patient's exam notes no limitations in range of motion and only tenderness, not overt swelling. *Joint pannus* - A **pannus** is an abnormal layer of fibrovascular tissue that invades and erodes cartilage and bone, a hallmark of **rheumatoid arthritis**. - This finding is specific to inflammatory arthritides and not characteristic of osteoarthritis.

Question 298: A 57-year-old woman is brought to the emergency department by her husband with complaints of sudden-onset slurring for the past hour. She is also having difficulty holding things with her right hand. She denies fever, head trauma, diplopia, vertigo, walking difficulties, nausea, and vomiting. Past medical history is significant for type 2 diabetes mellitus, hypertension, and hypercholesterolemia for which she takes a baby aspirin, metformin, ramipril, and simvastatin. She has a 23-pack-year cigarette smoking history. Her blood pressure is 148/96 mm Hg, the heart rate is 84/min, and the temperature is 37.1°C (98.8°F). On physical examination, extraocular movements are intact. The patient is dysarthric, but her higher mental functions are intact. There is a right-sided facial weakness with preserved forehead wrinkling. Her gag reflex is weak. Muscle strength is mildly reduced in the right hand. She has difficulty performing skilled movements with her right hand, especially writing, and has difficulty touching far objects with her index finger. She is able to walk without difficulty. Pinprick and proprioception sensation is intact. A head CT scan is within normal limits. What is the most likely diagnosis?

A. Locked in syndrome
B. Pure motor syndrome
C. Parinaud’s syndrome
D. Dysarthria-clumsy hand syndrome (Correct Answer)
E. Lateral medullary syndrome

Explanation: ***Dysarthria-clumsy hand syndrome*** - This syndrome is characterized by **dysarthria**, **facial weakness**, and **clumsiness of the hand** (especially with fine motor movements), often affecting the contralateral side to the lesion. - The patient's presentation with slurred speech (dysarthria), mild right-hand weakness, difficulty with skilled movements, and preserved forehead wrinkling (indicating an upper motor neuron lesion in the facial nerve distribution) is highly consistent and points to a **lacunar stroke** typically affecting the pons or internal capsule. *Locked-in syndrome* - This severe condition involves **complete paralysis** of nearly all voluntary muscles except for vertical eye movements and blinking, which is not described here. - Patients are fully conscious but unable to communicate verbally or with body movements, a much more extensive deficit than presented. *Pure motor syndrome* - This syndrome primarily involves **weakness** without significant sensory, cerebellar, or cranial nerve involvement. - While the patient has motor symptoms, the presence of **dysarthria** and **facial weakness** suggests more than just pure motor deficits of the limbs, differentiating it from pure motor hemiparesis. *Parinaud’s syndrome* - This syndrome, resulting from a lesion in the **dorsal midbrain**, presents with **vertical gaze palsy**, pupillary abnormalities, and lid retraction (Collier's sign). - The patient's intact extraocular movements and lack of these specific eye signs rule out Parinaud's syndrome. *Lateral medullary syndrome* - Also known as **Wallenberg's syndrome**, it results from an infarct of the lateral medulla and is characterized by a constellation of symptoms including **vertigo**, nystagmus, ipsilateral facial numbness, contralateral body numbness, and ataxia. - The patient explicitly denies vertigo and walking difficulties, and her sensory examination is intact, making lateral medullary syndrome unlikely.

Question 299: A 56-year-old man comes to the physician because of worsening double vision and drooping of the right eyelid for 2 days. He has also had frequent headaches over the past month. Physical examination shows right eye deviation laterally and inferiorly at rest. The right pupil is dilated and does not react to light or with accommodation. The patient's diplopia improves slightly on looking to the right. Which of the following is the most likely cause of this patient’s findings?

A. Demyelination of the medial longitudinal fasciculus
B. Aneurysm of the posterior communicating artery (Correct Answer)
C. Infarction of the midbrain
D. Enlarging pituitary adenoma
E. Thrombosis of the cavernous sinus

Explanation: ***Aneurysm of the posterior communicating artery*** - The combination of **third nerve palsy** (drooping eyelid, dilated pupil, eye deviated down and out) with **pupillary involvement** (dilated and unreactive) is a hallmark of **compressive lesions** affecting the oculomotor nerve, such as a PComm artery aneurysm. - Frequent headaches over the past month can suggest a progressively enlarging lesion that is starting to exert pressure. *Demyelination of the medial longitudinal fasciculus* - This would cause **internuclear ophthalmoplegia (INO)**, characterized by impaired adduction of one eye and nystagmus of the abducting eye on attempted lateral gaze. - It does not typically cause **pupillary dilation** or **ptosis** as seen in this patient. *Infarction of the midbrain* - A midbrain infarction could cause an **ischemic third nerve palsy**, but this usually **spares the pupil** because the parasympathetic fibers are located peripherally on the nerve and are more susceptible to compression than ischemia. - The patient's **mydriasis** (dilated pupil) is a key feature pointing away from an ischemic cause. *Enlarging pituitary adenoma* - While a large pituitary adenoma can cause **vision changes** or **headaches**, it typically compresses the **optic chiasm** leading to **bitemporal hemianopsia**. - Direct third nerve palsy with pupillary involvement is **uncommon** unless the mass is unusually large and extends significantly laterally. *Thrombosis of the cavernous sinus* - Cavernous sinus thrombosis presents more acutely with severe headache, fever, and involves **multiple cranial nerves** (**III, IV, V1, V2, VI**), often unilaterally. - This patient's symptoms are primarily localized to the third nerve, and there are no signs of widespread cranial nerve involvement or systemic infection.

Question 300: A 76-year-old female with a past medical history of obesity, coronary artery disease status post stent placement, hypertension, hyperlipidemia, and insulin dependent diabetes comes to your outpatient clinic for regular checkup. She has not been very adherent to her diabetes treatment regimen. She has not been checking her sugars regularly and frequently forgets to administer her mealtime insulin. Her Hemoglobin A1c three months ago was 14.1%. As a result of her diabetes, she has developed worsening diabetic retinopathy and neuropathy. Based on her clinical presentation, which of the following is the patient most at risk for developing?

A. Stress incontinence
B. Hemorrhoids
C. Rectal prolapse
D. Overflow incontinence (Correct Answer)
E. Uterine prolapse

Explanation: ***Overflow incontinence*** - The patient's **poorly controlled diabetes** can lead to **diabetic autonomic neuropathy**, affecting bladder function and causing **neurogenic bladder**. - This results in the bladder not emptying completely, leading to **urinary retention** and leakage as the bladder overfills, which defines **overflow incontinence**. *Stress incontinence* - This type of incontinence is typically caused by **weakening of pelvic floor muscles** and **urethral sphincter**, leading to leakage with increased abdominal pressure (e.g., coughing, sneezing). - While obesity is a risk factor, the patient's severe, uncontrolled diabetes points more strongly to neuropathy affecting bladder emptying rather than just sphincter weakness. *Hemorrhoids* - Hemorrhoids are **swollen veins in the rectum or anus**, often associated with straining during bowel movements, chronic constipation, or obesity. - While common in this demographic, there is no direct link between uncontrolled diabetes and the development of hemorrhoids. *Rectal prolapse* - Rectal prolapse involves the **protrusion of the rectum through the anus**, often due to weakened pelvic floor muscles or chronic straining. - Although the patient's age and obesity could be contributing factors, poorly controlled diabetes does not directly cause rectal prolapse. *Uterine prolapse* - Uterine prolapse occurs when the **uterus descends into the vagina**, typically due to weakened pelvic floor muscles, often following childbirth or with age and obesity. - Uncontrolled diabetes does not directly cause uterine prolapse, although shared risk factors like obesity might be present.

Question 301: A 37-year-old-man presents to the clinic for a 2-month follow-up. He is relatively healthy except for a 5-year history of hypertension. He is currently on lisinopril, amlodipine, and hydrochlorothiazide. The patient has no concerns and denies headaches, weight changes, fever, chest pain, palpitations, vision changes, or abdominal pain. His temperature is 98.9°F (37.2°C), blood pressure is 157/108 mmHg, pulse is 87/min, respirations are 15/min, and oxygen saturation is 98% on room air. Laboratory testing demonstrates elevated plasma aldosterone concentration and low renin concentration. What is the most likely explanation for this patient’s presentation?

A. Increased activity of the epithelial sodium channel at the kidney
B. Renin-secreting tumor
C. Ectopic secretion of anti-diuretic hormone (ADH)
D. Mutation of the Na-K-2Cl cotransporter at the thick ascending limb
E. Aldosterone-producing adenoma (Correct Answer)

Explanation: ***Aldosterone-producing adenoma*** - The patient's **hypertension**, elevated plasma **aldosterone** concentration, and suppressed **renin** concentration ("high aldosterone, low renin") are classic findings for **primary hyperaldosteronism**, often caused by an **aldosterone-producing adenoma**. - This condition is also resistant to multiple antihypertensive medications, as seen in this patient, which is another hallmark presentation of **primary hyperaldosteronism**. *Increased activity of the epithelial sodium channel at the kidney* - This describes **Liddle's syndrome**, a rare genetic disorder leading to severe hypertension. - While it also causes hypertension and suppressed renin, Liddle's syndrome presents with **low aldosterone levels**, not elevated, because the enhanced sodium reabsorption is independent of aldosterone. *Renin-secreting tumor* - A **renin-secreting tumor** would cause **elevated renin** levels, leading to increased angiotensin II and subsequently increased aldosterone. - The patient's presentation of **low renin** concentrations makes this diagnosis unlikely. *Ectopic secretion of anti-diuretic hormone (ADH)* - **Ectopic ADH secretion**, as seen in **SIADH**, causes **hyponatremia** and often low plasma osmolality. - This condition does not directly cause hypertension with elevated aldosterone and suppressed renin. *Mutation of the Na-K-2Cl cotransporter at the thick ascending limb* - This mutation is characteristic of **Bartter's syndrome** or can be induced by **loop diuretics**. - It leads to **hypokalemia**, **metabolic alkalosis**, and **hyperreninemic hyperaldosteronism**, often with **hypotension** or normal blood pressure, not hypertension with low renin.

Question 302: Please refer to the summary above to answer this question. Further evaluation of this patient is most likely to show which of the following findings? Patient Information Age: 28 years Gender: F, self-identified Ethnicity: unspecified Site of Care: office History Reason for Visit/Chief Concern: "I'm not making breast milk anymore." History of Present Illness: 1-week history of failure to lactate; has previously been able to breastfeed her twins, who were born 12 months ago menses resumed 4 months ago but have been infrequent feels generally weak and tired has had a 6.8-kg (15-lb) weight gain over the past 2 months despite having a decreased appetite Past Medical History: vaginal delivery of twins 12 months ago, complicated by severe postpartum hemorrhage requiring multiple blood transfusions atopic dermatitis Social History: does not smoke, drink alcohol, or use illicit drugs is not sexually active Medications: topical triamcinolone, multivitamin Allergies: no known drug allergies Physical Examination Temp Pulse Resp BP O2 Sat Ht Wt BMI 37°C (98.6°F) 54/min 16/min 101/57 mm Hg – 160 cm (5 ft 3 in) 70 kg (154 lb) 27 kg/m2 Appearance: tired-appearing HEENT: soft, nontender thyroid gland without nodularity Pulmonary: clear to auscultation Cardiac: bradycardic but regular rhythm; normal S1 and S2; no murmurs, rubs, or gallops Breast: no nodules, masses, or tenderness; no nipple discharge Abdominal: overweight; no tenderness, guarding, masses, bruits, or hepatosplenomegaly; normal bowel sounds Extremities: mild edema of the ankles bilaterally Skin: diffusely dry Neurologic: alert and oriented; cranial nerves grossly intact; no focal neurologic deficits; prolonged relaxation phase of multiple deep tendon reflexes

A. Decreased serum cortisol concentration (Correct Answer)
B. Decreased serum aldosterone concentration
C. Increased serum FSH concentration
D. Increased serum sodium concentration
E. Decreased serum oxytocin concentration

Explanation: **Decreased serum cortisol concentration** - The patient's history of **postpartum hemorrhage**, subsequent failure to lactate, infrequent menses, fatigue, weight gain, and bradycardia are all highly suggestive of **Sheehan's syndrome**, which is postpartum pituitary necrosis. - Sheehan's syndrome typically results in a deficiency of multiple pituitary hormones, including **ACTH**, leading to secondary adrenal insufficiency and consequently, **decreased serum cortisol**. *Decreased serum aldosterone concentration* - Aldosterone production is primarily regulated by the **renin-angiotensin-aldosterone system (RAAS)**, not directly by the pituitary gland. - While severe secondary adrenal insufficiency can indirectly affect aldosterone in some contexts, a direct and significant decrease in serum aldosterone is more characteristic of **primary adrenal insufficiency (Addison's disease)**, which is not indicated here. *Increased serum FSH concentration* - In Sheehan's syndrome, the pituitary gland's ability to produce **gonadotropins (FSH and LH)** is impaired, leading to **decreased or normal-low FSH and LH levels** and subsequent infrequent menses or amenorrhea. - An **increased FSH concentration** would typically be seen in **primary ovarian failure**, where the pituitary is attempting to stimulate non-responsive ovaries. *Increased serum sodium concentration* - Patients with Sheehan's syndrome and subsequent hypocortisolism often experience **hyponatremia** (decreased serum sodium) due to impaired water excretion and increased ADH secretion, not hypernatremia. - The symptoms described (fatigue, weight gain) are also not consistent with **increased serum sodium** (hypernatremia), which would typically present with symptoms like thirst and dehydration. *Decreased serum oxytocin concentration* - While oxytocin is produced by the posterior pituitary, the **failure to lactate** in Sheehan's syndrome is primarily due to **prolactin deficiency**, as prolactin is essential for milk production. - Although oxytocin is crucial for milk ejection ("let-down") and can be affected in pituitary damage, the initial and prominent lactation failure points more strongly to **prolactin deficiency**, and a specific test for oxytocin is not a routine diagnostic for Sheehan's.

Question 303: A 59-year-old man presents to his primary care physician complaining of leg pain with exertion for the last 6 months. He has cramping in his calves when walking. He states that the cramping is worse on the right than the left and that the cramping resolves when he stops walking. He has had type 2 diabetes mellitus for 15 years and is not compliant with his medications. He has smoked 20–30 cigarettes daily for the past 30 years. On examination, the femoral pulses are diminished on both sides. Which of the following is the most likely cause of this patient’s condition?

A. Segmental arterial occlusions due to non-atherosclerotic vasculitis
B. Narrowing of the spinal canal
C. Joint degeneration
D. Venous thrombosis
E. Atherosclerosis (Correct Answer)

Explanation: ***Atherosclerosis*** - The patient's presentation of **intermittent claudication** (leg pain with exertion, resolving with rest), history of **type 2 diabetes mellitus**, and **heavy smoking** are classic risk factors for atherosclerosis leading to peripheral artery disease (PAD). - **Diminished femoral pulses** further support the diagnosis of arterial insufficiency caused by atherosclerotic plaque buildup. *Segmental arterial occlusions due to non-atherosclerotic vasculitis* - While vasculitis can cause arterial occlusions, conditions like **Takayasu arteritis** or **Buerger's disease** are less common in this age group and typically have different risk factors and clinical presentations compared to the patient's strong atherosclerotic risk profile. - The patient's long-standing diabetes and smoking history strongly favor atherosclerosis over non-atherosclerotic vasculitis as the primary pathology. *Narrowing of the spinal canal* - This describes **neurogenic claudication**, which typically presents with leg pain that is often **position-dependent** (e.g., exacerbated by standing or extension of the spine) and may be relieved by leaning forward, rather than strictly by rest from walking. - Neurogenic claudication usually involves **neurological symptoms** like numbness or weakness and does not typically present with diminished peripheral pulses. *Joint degeneration* - **Osteoarthritis** or joint degeneration would typically cause pain localized to the affected joint, which would worsen with joint movement and improve with rest from that movement, but it would not explain the **cramping nature** of the pain in the calves or the **diminished pulses**. - Joint degeneration does not explain the systemic risk factors like diabetes and smoking contributing to vascular compromise. *Venous thrombosis* - A **venous thrombosis** (deep vein thrombosis) would typically cause acute onset leg pain, swelling, warmth, and erythema, often constant rather than exertional and resolving with rest. - It would not lead to **diminished arterial pulses**; in fact, arterial pulses would typically be preserved.

Question 304: A 55-year-old man comes to the physician for a follow-up examination. For the past 6 months, he has had fatigue, headaches, and several episodes of dizziness. Three months ago, he was diagnosed with hypertension and started on medications. Since the diagnosis was made, his medications have been adjusted several times because of persistently high blood pressure readings. He also has hypercholesterolemia and peripheral arterial disease. He smoked one pack of cigarettes daily for 34 years but quit two months ago. His current medications include aspirin, atorvastatin, losartan, felodipine, and hydrochlorothiazide. He is 188 cm (6 ft 2 in) tall and weighs 109 kg (240 lb); BMI is 31 kg/m2. His pulse is 82/min and blood pressure is 158/98 mm Hg. Physical examination shows bilateral carotid bruits and normal heart sounds. Serum potassium concentration is 3.2 mEq/L, plasma renin activity is 4.5 ng/mL/h (N = 0.3–4.2 ng/mL/h), and serum creatinine concentration is 1.5 mg/dL. Further evaluation of this patient is most likely to show which of the following findings?

A. Pituitary mass
B. Unilateral parathyroid mass
C. Unilateral kidney atrophy (Correct Answer)
D. Bilateral kidney enlargement
E. Diffuse thyroid enlargement

Explanation: ***Unilateral kidney atrophy*** - The patient's **refractory hypertension**, **hypokalemia**, elevated **plasma renin activity**, and developing **renal insufficiency** with normal heart sounds despite multiple antihypertensive medications strongly suggest **renovascular hypertension**. - In adults, the most common cause of renovascular hypertension is **atherosclerotic renal artery stenosis**, which typically leads to **atrophy of the affected kidney** due to chronic hypoperfusion. *Pituitary mass* - A pituitary mass could cause secondary hypertension if it leads to **Cushing's disease** (ACTH-producing adenoma) or **acromegaly** (growth hormone-producing adenoma). - However, the patient's symptoms (headaches, dizziness, hypertension, hypokalemia) and laboratory findings (elevated renin, renal insufficiency) are more consistent with **renovascular disease**, and there are no specific signs of Cushing's or acromegaly. *Unilateral parathyroid mass* - A unilateral parathyroid mass would typically cause **primary hyperparathyroidism**, characterized by **hypercalcemia** and potentially hypertension. - This patient presents with **hypokalemia**, not hypercalcemia, and his symptoms are not typical for hyperparathyroidism. *Bilateral kidney enlargement* - Bilateral kidney enlargement is seen in conditions such as **autosomal dominant polycystic kidney disease** or **diabetic nephropathy**. - While both can cause hypertension and renal insufficiency, the patient's elevated **plasma renin activity** and **hypokalemia** point more specifically to renovascular hypertension, which often causes **unilateral atrophy** rather than bilateral enlargement. *Diffuse thyroid enlargement* - Diffuse thyroid enlargement (goiter) could be associated with **hyperthyroidism** or **hypothyroidism**. Hyperthyroidism can cause hypertension, but typically it presents with **tachycardia**, weight loss, and other specific symptoms. - This patient's clinical picture, particularly the **hypokalemia** and high renin, is not characteristic of thyroid dysfunction.

Question 305: A 45-year-old male is presenting for routine health maintenance. He has no complaints. His pulse is 75/min, blood pressure is 155/90 mm Hg, and respiratory rate is 15/min. His body mass index is 25 kg/m2. The physical exam is within normal limits. He denies any shortness of breath, daytime sleepiness, headaches, sweating, or palpitations. He does not recall having an elevated blood pressure measurement before. Which of the following is the best next step?

A. Treat with thiazide diuretic
B. Repeat the blood pressure measurement (Correct Answer)
C. Refer patient to cardiologist
D. Provide reassurance
E. Obtain computed tomography scan

Explanation: ***Repeat the blood pressure measurement*** - A single elevated blood pressure reading, especially in an **asymptomatic patient** with no prior history of hypertension, requires confirmation. - According to guidelines, a diagnosis of **hypertension** is typically based on the average of two or more readings taken on two or more separate occasions. *Treat with thiazide diuretic* - Initiating antihypertensive medication on the basis of a **single elevated reading** is premature and not recommended. - Treatment should follow **confirmed hypertension** diagnosis and evaluation of cardiovascular risk factors. *Refer patient to cardiologist* - Referral to a specialist like a cardiologist is not indicated until **hypertension is confirmed** and standard initial management strategies have been considered or failed. - The patient is **asymptomatic** and presents with a borderline elevated reading, not an emergency. *Provide reassurance* - While reassurance is part of patient care, simply reassuring the patient without **further assessment** of the elevated blood pressure would be neglecting a potentially important health concern. - Further action is required to either confirm or rule out **hypertension**. *Obtain computed tomography scan* - A CT scan is an **invasive and expensive** procedure that is not indicated for an initial elevated blood pressure reading in an asymptomatic patient. - It would only be considered if there were strong suspicions of **secondary hypertension** causes after thorough workup.

Question 306: A 20-year-old woman visits the clinic for her annual physical examination. She does not have any complaints during this visit. The past medical history is insignificant. She follows a healthy lifestyle with a balanced diet and moderate exercise schedule. She does not smoke or drink alcohol. She does not take any medications currently. The family history is significant for her grandfather and uncle who had their parathyroid glands removed. The vital signs include: blood pressure:122/88 mm Hg, pulse 88/min, respirations 17/min, and temperature 36.7°C (98.0°F). The physical exam is within normal limits. The lab test results are as follows: Blood Urea Nitrogen 12 mg/dL Serum Creatinine 1.1 mg/dL Serum Glucose (Random) 88 mg/dL Serum chloride 107 mmol/L Serum potassium 4.5 mEq/L Serum sodium 140 mEq/L Serum calcium 14.5 mg/dL Serum albumin 4.4 gm/dL Parathyroid Hormone (PTH) 70 pg/mL (Normal: 10-65 pg/mL) 24-Hr urinary calcium 85 mg/day (Normal: 100–300 mg/day) Which of the following is the next best step in the management of this patient?

A. No treatment is necessary (Correct Answer)
B. Start IV fluids to keep her hydrated
C. Start her on pamidronate
D. Give glucocorticoids
E. Parathyroidectomy

Explanation: ***No treatment is necessary*** - This patient has **familial hypocalciuric hypercalcemia (FHH)**, a benign autosomal dominant condition caused by inactivating mutations in the calcium-sensing receptor (CaSR). - The key diagnostic triad is: **elevated serum calcium** (14.5 mg/dL), **mildly elevated or inappropriately normal PTH** (70 pg/mL), and **LOW 24-hour urinary calcium** (<100 mg/day). - The family history of parathyroid surgery in relatives suggests they may have been misdiagnosed with primary hyperparathyroidism. - **FHH is a benign condition that requires no treatment**. Patients are typically asymptomatic and do not develop complications of hypercalcemia. - The calcium-creatinine clearance ratio (CCCR) is typically <0.01 in FHH, which helps distinguish it from primary hyperparathyroidism (CCCR >0.02). *Parathyroidectomy* - **Parathyroidectomy is contraindicated in FHH** and is a common error in management. - Surgery does not correct the hypercalcemia in FHH because the defect is in the calcium-sensing receptor throughout the body, not in the parathyroid glands. - Parathyroidectomy can lead to **permanent hypoparathyroidism** without resolving the underlying condition. - Surgery is indicated for **primary hyperparathyroidism**, which differs from FHH by having normal or elevated urinary calcium excretion. *Start IV fluids to keep her hydrated* - IV fluids are used for **acute symptomatic hypercalcemia** or hypercalcemic crisis. - This patient is **asymptomatic** with stable vital signs and does not require acute intervention. - Fluids do not address the underlying pathophysiology of FHH and are unnecessary in this benign condition. *Start her on pamidronate* - Bisphosphonates like pamidronate are used for **hypercalcemia of malignancy** or severe symptomatic primary hyperparathyroidism. - They are **ineffective in FHH** because the hypercalcemia is due to altered calcium sensing, not increased bone resorption. - Pamidronate is not indicated for chronic management of asymptomatic hypercalcemia due to FHH. *Give glucocorticoids* - Glucocorticoids treat hypercalcemia from **granulomatous diseases** (sarcoidosis), **vitamin D intoxication**, or **hematologic malignancies** (lymphoma, multiple myeloma). - They work by decreasing intestinal calcium absorption and are ineffective in FHH. - This patient's clinical presentation and laboratory findings do not suggest any of these conditions.

Question 307: A 74-year-old woman is brought to the physician by her daughter for worsening memory for the past 1 month. She can no longer manage her bills and frequently forgets the names of her children. Her daughter is also concerned that her mother has a urinary tract infection because she has had increased urinary urgency and several episodes of urinary incontinence. Vital signs are within normal limits. Physical examination shows poor short-term memory recall and a slow gait with wide, short steps. Which of the following is most likely to improve this patient's condition?

A. Bromocriptine therapy
B. Vaginal pessary placement
C. Cerebral shunt placement (Correct Answer)
D. Donepezil therapy
E. Ciprofloxacin therapy

Explanation: ***Cerebral shunt placement*** - This patient presents with a classic triad of **dementia**, **urinary incontinence**, and **gait disturbance (ataxia)**, highly suggestive of **normal pressure hydrocephalus (NPH)**. - **Cerebral shunt placement** (e.g., ventriculoperitoneal shunt) is the definitive treatment for NPH, rerouting excess CSF and often leading to significant improvement in symptoms, especially gait and incontinence. *Bromocriptine therapy* - **Bromocriptine** is a **dopamine agonist** primarily used in the treatment of **Parkinson's disease** and **hyperprolactinemia**. - There is no evidence to support its use in improving cognitive or gait symptoms related to normal pressure hydrocephalus. *Vaginal pessary placement* - A **vaginal pessary** is used to support pelvic organs and treat **pelvic organ prolapse** or **stress urinary incontinence**. - While the patient has urinary incontinence, her other symptoms of dementia and gait disturbance point to a central neurological cause rather than a purely gynecological issue. *Donepezil therapy* - **Donepezil** is an **acetylcholinesterase inhibitor** used to treat the cognitive symptoms of **Alzheimer's disease** and other dementias. - While the patient has dementia, the combination of gait disturbance and urinary incontinence makes NPH a more likely diagnosis than Alzheimer's, and donepezil would not address the underlying pathology of NPH. *Ciprofloxacin therapy* - **Ciprofloxacin** is an antibiotic used to treat bacterial infections, including **urinary tract infections (UTIs)**. - Although the patient has urinary symptoms, the presence of dementia and gait disturbance suggests a systemic neurological cause (NPH) rather than just an isolated UTI, and antibiotics would not address these broader issues.

Question 308: A 48-year-old woman comes to the physician because of an increasingly painful swelling behind her right knee for the past 2 months. During this time, she has also had intermittent low-grade fever and she has been more fatigued than usual. She has not had any trauma to the knee. Over the past year, she has had occasional pain in her hands and wrists bilaterally. She has hypertension and type 2 diabetes mellitus. She drinks 1–2 glasses of wine daily and occasionally more on weekends. Current medications include enalapril, metformin, and glimepiride. Her mother and older brother have osteoarthritis. She is 165 cm (5 ft 5 in) tall and weighs 68 kg (150 lb); BMI is 25 kg/m2. Vital signs are within normal limits. Examination shows a 3-cm nontender mass in the right popliteal fossa that becomes prominent when the knee is extended. There is mild swelling and redness of her right knee joint. Which of the following is the most likely diagnosis?

A. Rheumatoid arthritis (Correct Answer)
B. Systemic lupus erythematosus
C. Popliteal artery aneurysm
D. Osteoarthritis
E. Psoriatic arthritis

Explanation: ***Rheumatoid arthritis*** - The patient's presentation with **bilateral hand and wrist pain**, along with **fatigue**, **low-grade fever**, and a **Baker's cyst** (swelling in the popliteal fossa) is highly suggestive of **rheumatoid arthritis (RA)**. The mild swelling and redness of the knee further support an inflammatory arthropathy. - While a Baker's cyst can appear in other conditions, its presence in combination with symmetrical small joint pain and systemic symptoms points towards the chronic inflammation seen in RA. *Systemic lupus erythematosus* - Although SLE can cause **arthralgias** and fatigue, it typically presents with other classic features such as a **malar rash**, photosensitivity, serositis, and renal involvement, none of which are described. - A Baker's cyst is not a common primary manifestation of SLE, and the predominant focus on joint inflammation with systemic symptoms makes RA a more fitting diagnosis. *Popliteal artery aneurysm* - A popliteal artery aneurysm would typically present as a **pulsatile mass** behind the knee, often associated with symptoms of **ischemia** in the lower limb. - The patient's mass is described as "nontender" and becomes prominent on knee extension, which is characteristic of a Baker's cyst, not a vascular aneurysm. *Osteoarthritis* - Osteoarthritis usually causes **deep, aching joint pain** that **worsens with activity** and improves with rest, and is often asymmetrical. - The patient's symptoms of **inflammatory arthritis**, including low-grade fever and fatigue, along with bilateral small joint involvement, are not typical of osteoarthritis despite a family history. *Psoriatic arthritis* - Psoriatic arthritis is associated with **psoriasis** (skin lesions) or a family history of psoriasis, and often presents with **enthesitis**, dactylitis, or distinctive nail changes. - The patient has no history or clinical signs suggesting psoriasis, making psoriatic arthritis less likely than RA, given the symmetrical small joint pain and systemic inflammatory features.

Question 309: A 24-year-old woman presents with episodic shortness of breath, chest tightness, and wheezing. She has noticed an increased frequency of such episodes in the spring season. She also has a history of urticaria. She has smoked a half pack of cigarettes per day over the last 5 years. Her mother also has similar symptoms. The physical exam is within normal limits. Which of the following findings is characteristic of her condition?

A. Increased oxygen saturation
B. Decrease in forced expiratory volume in 1 second (FEV1) after methacholine (Correct Answer)
C. Decreased forced vital capacity (FVC) on pulmonary tests
D. Paroxysmal nocturnal dyspnea
E. Chest X-ray showing hyperinflation

Explanation: ***Decrease in forced expiratory volume in 1 second (FEV1) after methacholine*** - The patient's symptoms of **episodic shortness of breath, chest tightness, and wheezing**, especially with seasonal variability and a history of **urticaria** and maternal history of similar symptoms, are highly suggestive of **asthma**. - A significant **decrease in FEV1 after methacholine challenge** is a hallmark of bronchial hyperresponsiveness, which is diagnostic for asthma. *Increased oxygen saturation* - While a patient with asthma might have normal oxygen saturation during an asymptomatic period, during an **acute asthma exacerbation**, oxygen saturation would likely be decreased, not increased. - Increased oxygen saturation is not a characteristic finding and does not help diagnose asthma. *Decreased forced vital capacity (FVC) on pulmonary tests* - Although **FVC can be reduced in severe asthma** due to air trapping, it is not the primary or most characteristic pulmonary function test finding. - The hallmark of asthma is **airflow obstruction**, specifically a reduced FEV1/FVC ratio and reduced FEV1, which is reversible. *Paroxysmal nocturnal dyspnea* - **Paroxysmal nocturnal dyspnea (PND)** is typically associated with **heart failure**, where fluid accumulation in the lungs worsens when lying flat, causing shortness of breath that awakens the patient from sleep. - While some asthmatics may experience nocturnal symptoms, PND is not a defining characteristic of asthma. *Chest X-ray showing hyperinflation* - A **chest X-ray is typically normal in asthma** unless there is an exacerbation or complications like pneumonia or pneumothorax. - **Hyperinflation** can be seen in severe, prolonged asthma or during an acute attack due to air trapping, but it is not a *characteristic diagnostic feature* during asymptomatic periods or generally for diagnosis.

Question 310: A 55-year-old man with a BMI of 34 kg/m² presents to his primary care physician for knee pain. The patient has had left knee pain, which has been steadily worsening for the past year. He states that ice and rest has led to minor improvement in his symptoms. He recently bumped his knee; however, he says that it has not altered his baseline pain when ambulating. The patient is a butcher and lives with his wife. His current medications include insulin, metformin, hydrochlorothiazide, and lisinopril. He is attending Alcoholics Anonymous with little success. Physical exam reveals a left knee that is mildly erythematous with some bruising. There is no pain upon palpation of the joint or with passive range of motion. The patient exhibits a mildly antalgic gait. Which of the following is the best initial step in management?

A. Rest for 1-2 weeks
B. Colchicine
C. Aspirin
D. MRI
E. Weight loss (Correct Answer)

Explanation: ***Weight loss*** - The patient has **obesity (BMI 34 kg/m²)** and several risk factors for **osteoarthritis**, including age (55), chronic knee pain, occupational stress (butcher), and an antalgic gait. - **Weight reduction** is the most important initial conservative management for osteoarthritis in obese patients, as it significantly reduces mechanical stress on weight-bearing joints like the knee, improves pain, and slows disease progression. - Every pound of weight lost reduces knee joint load by approximately 4 pounds, making weight loss one of the most effective interventions for symptomatic relief and disease modification. - Given the patient's diabetes and cardiovascular risk factors, weight loss also addresses multiple comorbidities simultaneously. *Rest for 1-2 weeks* - While rest can temporarily alleviate symptoms in acute exacerbations, prolonged rest for 1-2 weeks is generally **not the best long-term initial management** for chronic knee pain caused by osteoarthritis, and it may lead to deconditioning and muscle atrophy. - The patient's pain has been steadily worsening for a year, suggesting a chronic issue where activity modification and weight loss are more beneficial than complete immobility. *Colchicine* - **Colchicine** is primarily used for diagnosing and treating **gout**, which is not strongly indicated here despite the patient's alcohol use and diabetes (risk factors for gout). - Although the patient has mild erythema and bruising, the bruising is explained by recent trauma, and there are no classic signs of an acute gout attack, such as severe pain, rapid onset, or specific joint involvement like the first metatarsophalangeal joint. - The absence of pain on palpation makes gout unlikely. *Aspirin* - **Aspirin** is an NSAID and can provide symptomatic pain relief, but it does not address the underlying mechanical cause of osteoarthritis in an obese patient. - Given the patient's existing medications (lisinopril, HCTZ) and diabetes, adding NSAIDs like aspirin could increase the risk of adverse effects such as **renal dysfunction**, gastrointestinal bleeding, and fluid retention. - NSAIDs are better used as adjunctive therapy after addressing fundamental issues like excess weight. *MRI* - While an MRI can provide detailed images of knee structures, it is generally **not the initial step** for chronic knee pain suggestive of osteoarthritis. - Clinical diagnosis and plain radiographs are usually sufficient for initial evaluation of osteoarthritis, and an MRI would typically be reserved for cases where other pathologies (meniscal tears, ligamentous injuries) are suspected or when surgery is being considered. - Imaging does not change the initial management recommendation of weight loss in this obese patient with clinical osteoarthritis.

Question 311: A 25-year-old woman presents to her primary care clinic for a general checkup. She states she's been a bit more fatigued lately during finals season but is otherwise well. Her mother and sister have hypothyroidism. She denies weight gain, cold intolerance, constipation, heavy or irregular menses, or changes in the quality of her hair, skin, or nails. Physical exam is unremarkable. Laboratory studies are ordered as seen below. Hemoglobin: 14 g/dL Hematocrit: 40% Leukocyte count: 5,500/mm^3 with normal differential Platelet count: 188,000/mm^3 Serum: Na+: 139 mEq/L Cl-: 102 mEq/L K+: 4.4 mEq/L HCO3-: 24 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 0.8 mg/dL Ca2+: 10.2 mg/dL Antithyroid peroxidase Ab: Positive AST: 12 U/L ALT: 10 U/L Which of the following laboratory values is most likely in this patient?

A. Elevated TSH and low T4
B. Elevated TSH and elevated T4
C. Normal TSH and low T4
D. Normal TSH and normal T4 (Correct Answer)
E. Low TSH and elevated T4

Explanation: ***Normal TSH and normal T4*** - The patient has a **positive antithyroid peroxidase antibody**, indicating **Hashimoto's thyroiditis**, but she is currently **euthyroid** as evidenced by the absence of typical hypothyroid symptoms. - In the initial stages of Hashimoto's thyroiditis, the thyroid gland often functions normally, leading to **normal TSH and T4 levels**, even with positive antibodies. *Elevated TSH and low T4* - This pattern indicates **overt hypothyroidism**, which would be expected to cause symptoms like **weight gain, cold intolerance, and constipation**, none of which are present in this patient. - While Hashimoto's thyroiditis can progress to this stage, the patient's current presentation is subclinical, without biochemical evidence of hypofunction. *Elevated TSH and elevated T4* - This combination is rare and typically suggests **TSH-producing pituitary adenoma** or **thyroid hormone resistance**, neither of which is indicated by the patient's symptoms or family history. - An elevated TSH would normally stimulate the thyroid to produce more T4, but if TSH is also elevated, it points to a problem at the pituitary level. *Normal TSH and low T4* - This pattern is highly suggestive of **central (secondary) hypothyroidism**, where the pituitary gland is not producing enough TSH to stimulate the thyroid. - Given the patient's family history of hypothyroidism and positive antithyroid peroxidase antibodies (suggesting a primary thyroid issue), central hypothyroidism is less likely. *Low TSH and elevated T4* - This indicates **hyperthyroidism** (e.g., Graves' disease or toxic goiter), which would present with symptoms like **weight loss, heat intolerance, and tachycardia**, which are absent in this patient. - While positive antithyroid antibodies can sometimes be seen in Graves' disease, the patient's lack of hyperthyroid symptoms rules out this state.

Question 312: A 43-year-old woman presents to her primary care physician with complaints of mild shortness of breath and right-sided chest pain for three days. She reports that lately she has had a nagging nonproductive cough and low-grade fevers. On examination, her vital signs are: temperature 99.1 deg F (37.3 deg C), blood pressure is 115/70 mmHg, pulse is 91/min, respirations are 17/min, and oxygen saturation 97% on room air. She is well-appearing, with normal work of breathing, and no leg swelling. She is otherwise healthy, with no prior medical or surgical history, currently taking no medications. The attending has a low suspicion for the most concerning diagnosis and would like to exclude it with a very sensitive though non-specific test. Which of the following should this physician order?

A. Obtain chest radiograph
B. Obtain spiral CT chest with IV contrast
C. Order a lower extremity ultrasound
D. Order a D-dimer (Correct Answer)
E. Obtain ventilation-perfusion scan

Explanation: ***Order a D-dimer*** - The physician has a **low suspicion based on clinical assessment** and wants to **exclude** a concerning diagnosis (likely **pulmonary embolism** or PE) using a **sensitive test**. A negative D-dimer test can effectively rule out PE in patients with a low pre-test probability. - The D-dimer is a product of **fibrin degradation** and its elevation indicates recent or ongoing **thrombus formation** and lysis. It is highly sensitive for PE but has low specificity. *Obtain chest radiograph* - A chest radiograph is often **normal in pulmonary embolism** or may show non-specific findings, making it unsuitable for ruling out PE. - While useful for diagnosing other conditions like pneumonia or pleural effusions, it is **not sensitive enough to exclude PE**. *Obtain spiral CT chest with IV contrast* - A **spiral CT chest with IV contrast (CT pulmonary angiography)** is the gold standard for diagnosing PE, but it is **not a sensitive rule-out test** for low-probability cases. - It involves **radiation exposure** and **contrast administration**, which are generally avoided if a less invasive, equally effective rule-out test is available for low-risk patients. *Order a lower extremity ultrasound* - Lower extremity ultrasound is used to diagnose **deep vein thrombosis (DVT)**, which is a common source of PE. - While DVT can lead to PE, a negative lower extremity ultrasound **does not rule out PE** itself, as the clot may have already embolized or originated from elsewhere. *Obtain ventilation-perfusion scan* - A **ventilation-perfusion (V/Q) scan** is an alternative to CT angiography for diagnosing PE, particularly in patients with contraindications to contrast. - However, it is **less definitive than CTPA** and is typically used when suspicion for PE is moderate or higher, rather than as a primary rule-out test for low-probability patients.

Question 313: A 75-year-old woman presents with sudden loss of vision. She says that she was reading when suddenly she was not able to see the print on half of the page. Her symptoms started 4 hours ago and are accompanied by a severe posterior headache. Vital signs reveal the following: blood pressure 119/76 mm Hg, pulse 89/min, SpO2 98% on room air. The patient was unable to recognize her niece when she arrived to see her. A noncontrast CT of the head shows no evidence of hemorrhagic stroke. What is the most likely diagnosis in this patient?

A. Lacunar stroke
B. Middle cerebral artery stroke
C. Vertebrobasilar stroke
D. Subarachnoid hemorrhage
E. Posterior cerebral artery stroke (Correct Answer)

Explanation: ***Posterior cerebral artery stroke*** - The sudden severe posterior headache along with **unilateral vision loss** and **prosopagnosia** (inability to recognize familiar faces) are characteristic signs of a **posterior cerebral artery (PCA) stroke**. - PCA occlusion often affects the **occipital lobe** (vision) and can extend to the **temporal lobe** (facial recognition). *Lacunar stroke* - This type of stroke results from the occlusion of small penetrating arteries and typically causes **pure motor** or **pure sensory deficits**, not complex visual or recognition problems. - While headache can occur, the specific combination of symptoms points away from a lacunar infarct. *Middle cerebral artery stroke* - MCA stroke commonly presents with **contralateral hemiparesis**, **aphasia** (if dominant hemisphere), and **hemianopia** but usually not isolated unilateral vision loss or severe posterior headache with prosopagnosia. - The symptoms are more consistent with involvement of the posterior circulation. *Vertebrobasilar stroke* - A vertebrobasilar stroke can cause **visual disturbances**, but it is typically associated with other **brainstem symptoms** like vertigo, ataxia, or cranial nerve deficits, which are not described here. - The specific presentation of unilateral vision loss and prosopagnosia is less typical for a vertebrobasilar stroke affecting widespread brainstem structures. *Subarachnoid hemorrhage* - While a **sudden severe headache (thunderclap headache)** is a hallmark of SAH, it usually presents with meningeal irritation symptoms like **neck stiffness** and often altered mental status, and the visual deficits are usually different (e.g., oculomotor nerve palsy). - The patient's focal neurological deficits, specifically prosopagnosia and unilateral visual field loss, are more indicative of an ischemic event in a specific vascular territory.

Question 314: A 49-year-old man is referred to a cardiologist by his primary care provider (PCP) for a new heart murmur. He otherwise feels well and has no complaints. He had not seen a doctor in the last 15 years but finally went to his PCP for a check-up at the urging of his girlfriend. His past medical history is notable for gastroesophageal reflux disease, hypertension, and hepatitis B. He takes omeprazole and lisinopril. He has a prior history of intravenous drug abuse and a 50-pack-year smoking history. He has had many prior sexual partners and uses protection intermittently. He reports that he may have had a sore on his penis many years ago, but it went away without treatment. His temperature is 99°F (37.2°C), blood pressure is 141/91 mmHg, pulse is 89/min, and respirations are 18/min. On exam, S1 is normal and S2 has a tambour-like quality. There is a visible and palpable pulsation in the suprasternal notch and a diastolic decrescendo murmur over the right upper sternal border. A chest radiograph demonstrates calcification of the aortic root. Which of the following is the most likely cause of this patient's condition?

A. Tricuspid valve inflammation
B. Pericardial inflammation
C. Fibrinous plaque formation in the arterial intima
D. Neoplastic growth in the cardiac atria
E. Vasa vasorum destruction (Correct Answer)

Explanation: ***Vasa vasorum destruction*** - The patient's presentation with a **diastolic decrescendo murmur** over the right upper sternal border, pulsatile suprasternal notch, and **aortic root calcification** is highly suggestive of **aortic regurgitation** due to a dilated aortic root. This, coupled with a history of a penile sore that resolved spontaneously, raises strong suspicion for **tertiary syphilis**. - **Tertiary syphilis** can lead to **aortitis**, an inflammation of the **aorta's vasa vasorum**, causing their obliteration and subsequently weakening the aortic wall, leading to **aneurysm formation** and **aortic valve insufficiency**. This can result in the "tambour-like" S2 sound due to aortic root dilation. *Fibrinous plaque formation in the arterial intima* - This description is characteristic of **atherosclerosis**, which can affect the aorta but typically causes **stenotic lesions** or aneurysms that are not primarily associated with the specific murmur and tambour S2 described here in the context of this patient's risk factors. - While **atherosclerosis** can contribute to aortic stiffness and calcification, it is less likely to directly cause the specific constellation of findings (particularly the "tambour-like" S2 and historical penile sore suggestive of syphilis) compared to syphilitic aortitis. *Neoplastic growth in the cardiac atria* - **Cardiac tumors**, such as **atrial myxomas**, can cause murmurs and systemic symptoms, but they typically obstruct blood flow or cause embolic phenomena and would not explain the **diastolic decrescendo murmur** at the right upper sternal border, **aortic root calcification**, or the tambour-like S2. - These tumors are not directly linked to a history of a penile sore or intravenous drug use in a way that explains the cardiovascular findings in this case. *Tricuspid valve inflammation* - **Tricuspid valve inflammation** or endocarditis is common in intravenous drug users and would typically cause a **systolic murmur** (regurgitation) or **diastolic murmur** (stenosis) best heard at the left sternal border and would not explain the aortic root calcification or the tambour S2. - While the patient has a history of IV drug abuse, the physical exam findings strongly point to aortic valve pathology rather than tricuspid valve issues. *Pericardial inflammation* - **Pericardial inflammation (pericarditis)** can cause chest pain, a pericardial friction rub, and sometimes effusions, but it does not cause a **diastolic decrescendo murmur** indicative of aortic regurgitation or a tambour S2. - While it can be a manifestation of systemic diseases, the specific murmur and imaging findings are not characteristic of pericarditis.

Question 315: A 22-year-old man presents with lower limb weakness for the past 2 days. The patient says that the weakness started in both his feet, manifesting as difficulty walking, but it has progressed to where he cannot move his legs completely and has become bedbound. He also has experienced a recent history of numbness and tingling sensations in both his feet. He denies any recent history of fever, backache, urinary or bowel incontinence, trauma, shortness of breath, or diplopia. His past medical history is remarkable for a viral flu-like illness 2 weeks ago. The patient is afebrile, and his vital signs are within normal limits. On physical examination, muscle strength in both lower limbs is 1/5. The muscle strength in the upper limbs is ⅘ bilaterally. Sensation to pinprick is decreased in both lower limbs in a stocking distribution. The sensation is intact in the upper limbs bilaterally. Knee and ankle reflexes are absent bilaterally. The laboratory findings are significant for the following: Hemoglobin 14.2 g/dL White blood cell count 8,250/mm3 Platelet count 258,000/mm3 BUN 14 mg/dL Creatinine 0.9 mg/dL Serum sodium 144 mEq/L Serum potassium 3.9 mEq/L Which of the following tests would most likely confirm the diagnosis in this patient?

A. Acetylcholine receptor antibodies
B. Muscle biopsy
C. Nerve conduction studies (Correct Answer)
D. Serum creatine kinase
E. MRI of the lumbosacral spine

Explanation: ***Nerve conduction studies*** - This patient presents with **progressive, ascending weakness** and **areflexia** following a recent viral illness, highly suggestive of **Guillain-Barré Syndrome (GBS)**. Nerve conduction studies (NCS) will show evidence of **demyelination** (e.g., prolonged distal latencies, reduced conduction velocities, conduction block) or axonal damage, which is characteristic of GBS. - NCS are crucial for confirming the diagnosis of GBS by demonstrating the typical electrophysiological abnormalities in peripheral nerves. *Acetylcholine receptor antibodies* - **Acetylcholine receptor antibodies** are elevated in **myasthenia gravis**, an autoimmune disorder characterized by fluctuating muscle weakness that worsens with activity and improves with rest. - The patient's symptoms of **progressive ascending paralysis** and **areflexia**, are inconsistent with myasthenia gravis, which typically presents with ocular, bulbar, or generalized weakness without prominent sensory deficits. *Muscle biopsy* - A **muscle biopsy** is generally used to diagnose **myopathies** or muscular dystrophies, which would show characteristic muscle fiber degeneration or inflammatory changes. - This patient's presentation with **ascending weakness**, **sensory changes**, and **areflexia** points towards a peripheral neuropathy rather than a primary muscle disorder. *Serum creatine kinase* - **Serum creatine kinase (CK)** levels are typically elevated in **muscle damage** or inflammatory myopathies. - While GBS can rarely cause a mild elevation, it is not a primary diagnostic marker, and a normal CK level does not rule out the condition. *MRI of the lumbosacral spine* - An **MRI of the lumbosacral spine** would be indicated if **spinal cord compression** or other spinal pathology were suspected, such as in cases of significant back pain, bladder/bowel dysfunction, or a distinct sensory level. - The patient's presentation of **ascending weakness**, **symmetrical sensory deficits in a stocking distribution**, and **areflexia** without signs of spinal cord compression makes spinal MRI less likely to be the diagnostic test for the presenting illness.

Question 316: A 62-year-old man comes to the physician for decreased exercise tolerance. Over the past four months, he has noticed progressively worsening shortness of breath while walking his dog. He also becomes short of breath when lying in bed at night. His temperature is 36.4°C (97.5°F), pulse is 82/min, respirations are 19/min, and blood pressure is 155/53 mm Hg. Cardiac examination shows a high-pitch, decrescendo murmur that occurs immediately after S2 and is heard best along the left sternal border. There is an S3 gallop. Carotid pulses are strong. Which of the following is the most likely diagnosis?

A. Aortic valve regurgitation (Correct Answer)
B. Tricuspid valve regurgitation
C. Mitral valve prolapse
D. Mitral valve regurgitation
E. Mitral valve stenosis

Explanation: ***Aortic valve regurgitation*** - A **high-pitch, decrescendo murmur immediately after S2** and heard best along the **left sternal border** is characteristic of **aortic regurgitation**. - Symptoms like **dyspnea on exertion** and **orthopnea**, an **S3 gallop**, and a **wide pulse pressure** (155/53 mmHg) further support heart failure due to chronic aortic regurgitation. *Tricuspid valve regurgitation* - This typically presents with a **holosystolic murmur** best heard at the **left lower sternal border** that increases with inspiration. - Clinical signs often include **jugular venous distension** and **peripheral edema**, not primarily a decrescendo diastolic murmur. *Mitral valve prolapse* - Characterized by a **mid-systolic click** followed by a **late systolic murmur**, and symptomatically may be asymptomatic or cause palpitations. - The described diastolic murmur and symptoms of heart failure do not align with mitral valve prolapse. *Mitral valve regurgitation* - Typically presents as a **holosystolic murmur** heard best at the **apex** and often radiating to the axilla. - While it can cause dyspnea and an S3, the character and timing of the murmur reported (decrescendo, immediately after S2) are inconsistent with mitral regurgitation. *Mitral valve stenosis* - This condition presents with a **diastolic rumble** heard best at the **apex** with an opening snap. - The murmur described is a high-pitch decrescendo murmur, which is distinct from the low-pitched rumble of mitral stenosis.

Question 317: A 38-year-old female presents to the emergency room with fevers, fatigue, and anorexia for over a month. Past medical history includes mild mitral valve prolapse. She underwent an uncomplicated tooth extraction approximately 6 weeks ago. Her vital signs include a temperature of 100.8 F, pulse of 83, blood pressure of 110/77, and SpO2 of 97% on room air. On exam, you note a grade III/VI holosystolic murmur at the apex radiating to the axilla as well as several red, painful nodules on her fingers. Which of the following is the next best course of action?

A. Blood cultures are not needed. Start empiric antibiotics
B. Start anticoagulation with heparin
C. Consult cardiothoracic surgery for mitral valve replacement
D. Obtain blood cultures x3 sites over 24 hours and start antibiotics after culture results are available
E. Obtain blood cultures x3 sites over 1 hour and start empiric antibiotics (Correct Answer)

Explanation: ***Obtain blood cultures x3 sites over 1 hour and start empiric antibiotics*** - The patient's presentation with **fever, fatigue, anorexia, new murmur, and painful finger nodules (Osler's nodes)** after a recent dental procedure strongly suggests **infective endocarditis**. Prompt initiation of **empiric antibiotics** after obtaining adequate blood cultures is crucial to improve outcomes and prevent further complications like septic emboli or valvular damage. - Obtaining **multiple blood cultures rapidly (e.g., three sets over 1 hour)** from different sites maximizes the chance of isolating the causative organism before antibiotics are given, enabling targeted therapy later, while minimizing delay to treatment. *Blood cultures are not needed. Start empiric antibiotics* - **Blood cultures are essential** for diagnosing infective endocarditis, identifying the causative organism, and guiding appropriate antibiotic therapy. Skipping blood cultures could lead to inappropriate antibiotic selection and treatment failure. - While empiric antibiotics are warranted, they should always be initiated **after blood cultures** have been drawn to avoid sterilizing the blood and making microbial identification difficult. *Start anticoagulation with heparin* - **Anticoagulation is generally contraindicated** in infective endocarditis due to the increased risk of hemorrhagic complications, especially in cases of septic emboli to the brain. - While patients with endocarditis can form vegetations that may embolize, the risks of **bleeding outweigh the benefits** of routine anticoagulation. *Consult cardiothoracic surgery for mitral valve replacement* - While **mitral valve prolapse** is a risk factor for endocarditis and severe valvular damage may eventually require surgery, primary management involves **antibiotic therapy**. - Surgical intervention is typically reserved for cases with **severe valvular regurgitation/stenosis leading to heart failure**, uncontrolled infection despite antibiotics, or recurrent emboli, and is not the immediate next step. *Obtain blood cultures x3 sites over 24 hours and start antibiotics after culture results are available* - Waiting for **24 hours to collect blood cultures** would significantly delay the initiation of antibiotics, which is dangerous in a potentially life-threatening infection like endocarditis. - Delaying antibiotics until **culture results are available** could take several days, leading to worsening infection, organ damage, and increased mortality. **Empiric antibiotics** must be started promptly after initial blood collection.

Question 318: A 45-year-old woman comes to the physician for a 3-week history of intermittent episodes of dizziness. The episodes last for hours at a time and are characterized by the sensation that the room is spinning. The patient also reports that she has started using her cell phone with her left ear because she hears better on that side. She has experienced intermittent ringing and fullness in her right ear. She has no history of serious medical conditions. She does not smoke or drink alcohol. She takes no medications. Her temperature is 37.1°C (98.8°F) pulse is 76/min respirations are 18/min, and blood pressure is 130/76 mm Hg. Cardiopulmonary examination shows no abnormalities. There is horizontal nystagmus to the right. Motor strength is 5/5 in all extremities, and sensory examination shows no abnormalities. Finger-to-nose and heel-to-shin testing are normal bilaterally. Weber test shows lateralization to the left ear. The Rinne test is positive bilaterally. Which of the following is the most likely cause of this patient's symptoms?

A. Obstruction of the anterior inferior cerebellar artery
B. Cerebellopontine angle tumor
C. Reduced resorption of endolymph (Correct Answer)
D. Demyelinating plaques
E. Occlusion of the posterior inferior cerebellar artery

Explanation: ***Reduced resorption of endolymph*** - The triad of **intermittent vertigo**, **sensorineural hearing loss** (lateralization to the unaffected ear in Weber and positive Rinne tests), and **tinnitus/aural fullness** is characteristic of **Ménière's disease**. - This condition is caused by **excessive endolymphatic fluid** pressure due to reduced resorption, leading to distension of the endolymphatic sac. *Obstruction of the anterior inferior cerebellar artery* - Leads to a **lateral pontine syndrome** which would present with symptoms like **ipsilateral facial paralysis**, **ataxia**, and **contralateral body deficits**, none of which are described. - While it can cause hearing loss and vertigo, the **intermittent nature** and specific combination of symptoms point away from an acute stroke. *Cerebellopontine angle tumor* - A tumor in this location would typically cause more **slowly progressive** symptoms, including persistent, rather than intermittent, hearing loss, vertigo, and potentially **cranial nerve VII and V deficits**. - The patient's symptoms are episodic and fluctuating, which is less consistent with a continuously growing mass. *Demyelinating plaques* - Demyelinating diseases like **multiple sclerosis** can cause neurological symptoms, including vertigo and hearing deficits, but these are often accompanied by other **widespread neurological signs** like motor weakness, sensory disturbances, or optic neuritis. - The patient's neurological examination is largely normal aside from the nystagmus and hearing issues, and the symptoms are typically **episodic but without the consistent aural fullness** and hearing loss pattern seen here. *Occlusion of the posterior inferior cerebellar artery* - This causes **Wallenberg syndrome** (lateral medullary syndrome), characterized by **ipsilateral ataxia**, **loss of pain/temperature sensation on the ipsilateral face** and **contralateral body**, and dysphagia/hoarseness. - While vertigo can occur, the specific pattern of hearing loss, tinnitus, and aural fullness is not typical for this condition.

Question 319: A 63-year-old woman presents to your outpatient clinic complaining of headaches, blurred vision, and fatigue. She has a blood pressure of 171/91 mm Hg and heart rate of 84/min. Physical examination is unremarkable. Her lab results include K+ of 3.1mEq/L and a serum pH of 7.51. Of the following, which is the most likely diagnosis for this patient?

A. Pheochromocytoma
B. Renal artery stenosis
C. Cushing’s syndrome
D. Primary hyperaldosteronism (Conn’s syndrome) (Correct Answer)
E. Addison’s disease

Explanation: ***Primary hyperaldosteronism (Conn’s syndrome)*** - The combination of **hypertension**, **hypokalemia (K+ 3.1 mEq/L)**, and **metabolic alkalosis (pH 7.51)** is highly characteristic of primary hyperaldosteronism. - Excess aldosterone leads to increased sodium reabsorption and potassium/hydrogen ion excretion, causing these electrolyte imbalances. *Pheochromocytoma* - This condition involves episodic **hypertension**, palpitations, sweating, and anxiety due to catecholamine excess. - While hypertension is present, the absence of paroxysmal symptoms and the specific electrolyte abnormalities (hypokalemia, alkalosis) make it less likely. *Renal artery stenosis* - This can cause **secondary hypertension** and occasionally hypokalemia, but it typically presents with **renal bruits**, and the metabolic alkalosis is not a direct or prominent feature. - The elevated renin-angiotensin-aldosterone axis would lead to secondary hyperaldosteronism, but primary hyperaldosteronism is suggested by the overall clinical picture. *Cushing’s syndrome* - Cushing's syndrome is characterized by **central obesity**, striae, moon facies, and **hyperglycemia**, among other symptoms. - While hypertension and hypokalemia can occur in severe cases, the predominant clinical features are not aligned with this patient's presentation. *Addison’s disease* - This condition is characterized by **adrenal insufficiency**, leading to hypoglycemia, **hyponatremia**, **hyperkalemia**, and **hypotension**. - The patient's hypertension and hypokalemia directly contradict the typical presentation of Addison’s disease.

Question 320: A 26-year-old man presents with a 2-day history of worsening right lower leg pain. He states that he believes his right leg is swollen when compared to his left leg. Past medical history is significant for generalized anxiety disorder, managed effectively with psychotherapy. He smokes a pack of cigarettes daily but denies alcohol and illicit drug use. His father died of a pulmonary embolism at the age of 43. His vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, respiratory rate 14/min. On physical examination, the right lower leg is warmer than the left, and dorsiflexion of the right foot produces pain. Which of the following conditions is most likely responsible for this patient’s presentation?

A. Vitamin K deficiency
B. Hemophilia A
C. von Willebrand disease
D. Factor V Leiden (Correct Answer)
E. Factor XI deficiency

Explanation: ***Factor V Leiden*** - The patient presents with classic symptoms of a **deep vein thrombosis (DVT)** in the right lower leg: pain, swelling, warmth, and pain on dorsiflexion (**Homans' sign**). His history of smoking and a family history of **pulmonary embolism (PE)** in a young father strongly suggest an underlying **thrombophilia**. - **Factor V Leiden** is the most common inherited thrombophilia, predisposing individuals to venous thromboembolism. The constellation of symptoms and risk factors points directly to this condition. *Vitamin K deficiency* - **Vitamin K deficiency** primarily leads to impaired production of clotting factors II, VII, IX, and X, resulting in a **bleeding diathesis**, not thrombotic events. - Patients would typically present with **bruising, petechiae, gastrointestinal bleeding, or hematuria**, which are not seen here. *Hemophilia A* - **Hemophilia A** is an X-linked recessive disorder characterized by a deficiency of **Factor VIII**, leading to severe **bleeding**. - Symptoms include **spontaneous or prolonged bleeding** into joints (hemarthrosis), muscles, or following trauma, which is the opposite of the patient's presentation. *von Willebrand disease* - **Von Willebrand disease (vWD)** is the most common inherited bleeding disorder, caused by a deficiency or defect in **von Willebrand factor**. - It primarily causes **mucocutaneous bleeding**, such as epistaxis, menorrhagia, and easy bruising, not thrombotic episodes. *Factor XI deficiency* - **Factor XI deficiency** is a rare inherited bleeding disorder that typically causes **mild to moderate bleeding**, often associated with trauma or surgery. - It is not associated with an increased risk of thrombosis and would present with bleeding, not a DVT.

Question 321: A 70-year-old man presents with a complaint of progressive dyspnea on minimal exertion. The patient reports being quite active and able to climb 3 flights of stairs in his building 10 years ago, whereas now he feels extremely winded when climbing a single flight. At first, he attributed this to old age but has more recently begun noticing that he feels similarly short of breath when lying down. He denies any recent fevers, cough, chest pain, nausea, vomiting, or diarrhea. He denies any past medical history except for two hospitalizations over the past 10 years for "the shakes." Family history is negative for any heart conditions. Social history is significant for a 10 pack-year smoking history. He currently drinks "a few" drinks per night. On exam, his vitals are: BP 120/80, HR 85, RR 14, and SpO2 97%. He is a mildly obese man who appears his stated age. Physical exam is significant for a normal heart exam with a few crackles heard at the bases of both lungs. Abdominal exam is significant for an obese abdomen and a liver edge palpated 2-3 cm below the costal margin. He has 2+ edema present in both lower extremities. Lab results reveal a metabolic panel significant for a sodium of 130 mEq/L but otherwise normal. Complete blood count, liver function tests, and coagulation studies are normal as well. An EKG reveals signs of left ventricular enlargement with a first degree AV block. A cardiac catheterization report from 5 years ago reveals a moderately enlarged heart but patent coronary arteries. Which of the following is the most likely cause of this individual's symptoms?

A. Nephrotic syndrome
B. Diastolic heart failure
C. Ischemic cardiomyopathy
D. Toxic cardiomyopathy (Correct Answer)
E. Liver failure

Explanation: ***Toxic cardiomyopathy*** - The patient's history of heavy alcohol consumption ("a few drinks per night") and two past hospitalizations for "**the shakes**" (suggesting **alcohol withdrawal**) are strong indicators of **alcoholic cardiomyopathy**. - **Alcoholic cardiomyopathy** causes progressive left ventricular enlargement and dysfunction, leading to symptoms like **dyspnea on exertion**, **orthopnea**, **peripheral edema**, and **hepatomegaly**, all of which are present. *Diastolic heart failure* - While dyspnea and orthopnea are present, the EKG showing **left ventricular enlargement** and the cardiac catheterization reporting a **moderately enlarged heart** suggest **systolic dysfunction** rather than isolated diastolic dysfunction. - **Diastolic heart failure** typically presents with preserved ejection fraction and abnormalities in ventricular relaxation or filling, which are not explicitly described or directly implied as the primary issue here. *Ischemic cardiomyopathy* - The **cardiac catheterization from 5 years ago** reported **patent coronary arteries**, making **ischemic heart disease** an unlikely primary cause of the current cardiac enlargement and symptoms. - Although smoking is a risk factor for ischemia, the absence of coronary artery disease on prior catherization and the prominent history of alcohol abuse point elsewhere. *Nephrotic syndrome* - Although the patient has **edema** and **hyponatremia**, there is no mention of **significant proteinuria** (a hallmark of nephrotic syndrome) or elevated creatinine, and renal function tests are otherwise normal. - **Nephrotic syndrome** would not explain the **left ventricular enlargement**, **dyspnea**, or the marked history of alcohol abuse and its cardiotoxic effects. *Liver failure* - While the patient has **peripheral edema** and **hepatomegaly**, his **liver function tests are normal**, arguing against significant **cirrhosis or liver failure** as the primary cause of his symptoms. - The primary symptoms of **dyspnea**, **orthopnea**, and **left ventricular enlargement** point more directly to a cardiac origin rather than liver failure.

Question 322: A 58-year-old female presents to her primary care physician with complaints of chest pain and palpitations. A thorough past medical history reveals a diagnosis of rheumatic fever during childhood. Echocardiography is conducted and shows enlargement of the left atrium and narrowing of the mitral valve opening. Which of the following should the physician expect to hear on cardiac auscultation?

A. Continuous, machine-like murmur
B. Holosystolic murmur that radiates to the axilla
C. Opening snap following S2 (Correct Answer)
D. High-pitched, blowing decrescendo murmur in early diastole
E. Mid-systolic click

Explanation: ***Opening snap following S2*** - The patient's history of **rheumatic fever** and echocardiographic findings of **left atrial enlargement** and **mitral valve narrowing** (mitral stenosis) are classic for this condition. - An **opening snap** is a high-pitched, sharp sound that occurs shortly after **S2** (the second heart sound) and is pathognomonic for **mitral stenosis**, caused by the sudden tensing of the stenotic mitral valve leaflets as they open during diastole. - The **S2-OS interval** indicates severity: a shorter interval suggests more severe stenosis. *Continuous, machine-like murmur* - This type of murmur is characteristic of a **patent ductus arteriosus (PDA)**, which is a congenital heart defect. - The patient's symptoms and echocardiographic findings are not consistent with PDA. *Holosystolic murmur that radiates to the axilla* - This murmur describes **mitral regurgitation**, which is a leaky mitral valve. While rheumatic fever can cause mitral regurgitation, the echocardiogram shows **narrowing** of the mitral valve, not leakage. - The radiation to the axilla is classical for the regurgitant jet flowing into the left atrium during systole. *High-pitched, blowing decrescendo murmur in early diastole* - This murmur is typical for **aortic regurgitation**, indicating a leaky aortic valve. - The patient's presentation and echocardiogram findings specifically point to **mitral valve involvement** rather than aortic valve issues. *Mid-systolic click* - A **mid-systolic click** is characteristic of **mitral valve prolapse**, often followed by a late systolic murmur. - The echocardiogram findings of **mitral valve narrowing** are not consistent with mitral valve prolapse.

Question 323: A 47-year-old man presents for a routine physical examination as part of an insurance medical assessment. He has no complaints and has no family history of cardiac disease or sudden cardiac death. His blood pressure is 120/80 mm Hg, temperature is 36.7°C (98.1°F), and pulse is 75/min and is regular. On physical examination, he appears slim and his cardiac apex beat is of normal character and non-displaced. On auscultation, he has a midsystolic click followed by a late-systolic high-pitched murmur over the cardiac apex. On standing, the click and murmur occur earlier in systole, and the murmur is of increased intensity. While squatting, the click and murmur occur later in systole, and the murmur is softer in intensity. Echocardiography of this patient will most likely show which of the following findings?

A. Left atrial mass arising from the region of the septal fossa ovalis
B. Doming of the mitral valve leaflets in diastole
C. Prolapse of a mitral valve leaflet of ≥2 mm above the level of the annulus in systole (Correct Answer)
D. Retrograde blood flow into the right atrium
E. High pressure gradient across the aortic valve

Explanation: ***Prolapse of a mitral valve leaflet of ≥2 mm above the level of the annulus in systole*** - The clinical presentation with a **midsystolic click** followed by a **late-systolic high-pitched murmur over the cardiac apex** is characteristic of **mitral valve prolapse (MVP)**. - The changes in the click and murmur timing and intensity with **standing (earlier, louder)** and **squatting (later, softer)** are classic findings, reflecting changes in left ventricular volume that affect the onset of valve prolapse. *Left atrial mass arising from the region of the septal fossa ovalis* - This description is highly suggestive of a **myxoma**, typically found in the left atrium, which can cause symptoms of **obstructive heart failure** or **embolism**. - A myxoma would not typically present with the characteristic **midsystolic click** and **late-systolic murmur** that changes with position. *Doming of the mitral valve leaflets in diastole* - **Doming of the mitral valve leaflets in diastole** is characteristic of **mitral stenosis**, where the valve fails to open properly. - Mitral stenosis would present with a **diastolic murmur**, not a midsystolic click and late-systolic murmur. *Retrograde blood flow into the right atrium* - **Retrograde blood flow into the right atrium** indicates **tricuspid regurgitation**, which would typically manifest as a **holosystolic murmur** best heard at the lower left sternal border, often with prominent jugular venous pulsations. - This finding is inconsistent with the patient's auscultatory findings at the cardiac apex. *High pressure gradient across the aortic valve* - A **high pressure gradient across the aortic valve** signifies **aortic stenosis**, which is characterized by a **systolic ejection murmur** best heard at the right upper sternal border with radiation to the carotids. - This condition would not produce a midsystolic click or a late-systolic murmur at the apex.

Question 324: A 44-year-old male immigrant presents to his primary care physician for a new patient visit. The patient reports chronic fatigue but states that he otherwise feels well. His past medical history is not known, and he is not currently taking any medications. The patient admits to drinking 7 alcoholic beverages per day and smoking 1 pack of cigarettes per day. His temperature is 99.4°F (37.4°C), blood pressure is 157/98 mmHg, pulse is 99/min, respirations are 18/min, and oxygen saturation is 100% on room air. Physical exam demonstrates mild pallor but is otherwise not remarkable. Laboratory studies are ordered as seen below. Hemoglobin: 9 g/dL Hematocrit: 33% Leukocyte count: 6,500/mm^3 with normal differential Platelet count: 190,000/mm^3 Mean corpuscular volume (MCV): 60 femtoliters Free iron: 272 mcg/dL Total iron binding capacity (TIBC): 175 mcg/dL Ferritin: 526 ng/mL Reticulocyte count: 2.8% Which of the following is the most likely diagnosis?

A. Folate deficiency
B. Beta-thalassemia (Correct Answer)
C. Iron deficiency
D. B12 deficiency
E. Hemolytic anemia

Explanation: ***Beta-thalassemia*** - The patient presents with **microcytic anemia** (MCV 60 fL) and **elevated ferritin**, **high free iron**, and **low TIBC**, which are characteristic of thalassemia due to ineffective erythropoiesis and iron overload. - A **reticulocyte count of 2.8%** (elevated for the degree of anemia) indicates the bone marrow is attempting to compensate, consistent with a hemolytic process like thalassemia. *Folate deficiency* - Folate deficiency typically causes **macrocytic anemia** (elevated MCV), which is not seen here; the patient has microcytic anemia. - Alcohol abuse can cause folate deficiency, but the lab values for iron studies and MCV are inconsistent with this diagnosis. *Iron deficiency* - Iron deficiency anemia would present with **low ferritin**, **low free iron**, and **high TIBC**, which are opposite to the patient's lab results. - Although the patient has microcytic anemia, the iron study profile rules out iron deficiency. *B12 deficiency* - Vitamin B12 deficiency also causes **macrocytic anemia** (elevated MCV), often with neurological symptoms, neither of which are observed in this patient. - The patient's microcytic anemia and iron study results contradict a diagnosis of B12 deficiency. *Hemolytic anemia* - While beta-thalassemia is a form of hemolytic anemia, the term "hemolytic anemia" alone is too broad and does not specify the underlying cause, especially with the provided iron studies and MCV. - Other common causes of hemolytic anemia, like autoimmune hemolytic anemia or G6PD deficiency, would require different diagnostic presentations or specific tests not consistent with the given lab values.

Question 325: A 46-year-old male was found unconscious in the field and brought to the emergency department by EMS. The patient was intubated in transit and given a 2 liter bolus of normal saline. On arrival, the patient's blood pressure is 80/60 mmHg and temperature is 37.5°C. Jugular veins are flat and capillary refill time is 4 seconds. Vascular parameters are measured and are as follows: Cardiac index - Low Pulmonary capillary wedge pressure (PCWP) - Low Systemic vascular resistance - High Which of the following is the most likely diagnosis?

A. Septic shock
B. Anaphylactic shock
C. Cardiogenic shock
D. Hypovolemic shock (Correct Answer)
E. Neurogenic shock

Explanation: ***Hypovolemic shock*** - The patient presents with **hypotension**, **flat jugular veins**, **prolonged capillary refill**, and a **low cardiac index** and **low pulmonary capillary wedge pressure (PCWP)**, all indicative of inadequate intravascular volume. - The **high systemic vascular resistance** is a compensatory mechanism to maintain blood pressure in the setting of decreased circulating volume. *Septic shock* - Septic shock typically presents with **vasodilation**, leading to a **low systemic vascular resistance**, which contradicts the findings in this patient. - While patients can be hypotensive, the vascular parameters, especially SVR, do not align with septic shock. *Anaphylactic shock* - This type of shock is characterized by widespread **vasodilation** and increased capillary permeability, leading to a **low systemic vascular resistance** and often significant **edema** or **urticaria**, none of which are suggested here. - While it can cause hypotension and low PCWP due to fluid shifts, the high SVR makes it less likely. *Cardiogenic shock* - Cardiogenic shock is characterized by **pump failure**, leading to a **low cardiac index** but a **high PCWP** due to fluid backup in the pulmonary circulation. - This directly contrasts the patient's low PCWP. *Neurogenic shock* - Neurogenic shock involves a loss of **sympathetic tone**, resulting in widespread **vasodilation** and a **low systemic vascular resistance**, often accompanied by **bradycardia**. - The high SVR in this patient rules out neurogenic shock.

Question 326: A 59-year-old man presents with the persistent right-sided facial droop and slurred speech for the past 2 hours. He says he had similar symptoms 6 months ago which resolved within 1 hour. His past medical history is significant for long-standing hypertension, managed with hydrochlorothiazide. He reports a 10-pack-year smoking history but denies any alcohol or recreational drug use. The vital signs include: blood pressure 145/95 mm Hg, pulse 95/min, and respiratory rate 18/min. On physical examination, the patient has an asymmetric smile and right-sided weakness of his lower facial muscles. There is a deviation of his tongue towards the right. Dysarthria is noted. His muscle strength in the upper extremities is 4/5 on the right and 5/5 on the left. The remainder of the physical exam is unremarkable. Which of the following is the next most appropriate step in the management of this patient?

A. T1/T2 MRI of the head
B. CT of the head without contrast (Correct Answer)
C. CT of the head with contrast
D. IV tPA
E. CT angiography of the brain

Explanation: ***CT of the head without contrast*** - This patient presents with acute neurological deficits suggestive of a **stroke**, and a rapid **CT scan without contrast** is the **initial imaging modality** of choice to differentiate between **ischemic stroke** and **hemorrhagic stroke**. - A non-contrast CT can quickly rule out a hemorrhage, which is crucial for determining eligibility for **thrombolytic therapy** like IV tPA. *T1/T2 MRI of the head* - While an MRI can provide more detailed imaging of brain tissue and is better for detecting smaller or older ischemic strokes, it is typically **more time-consuming** and **less readily available** in an emergency setting compared to CT. - It is not the initial go-to for acute stroke evaluation because the priority is to rule out hemorrhage quickly. *CT of the head with contrast* - A CT scan with contrast is not indicated for the initial evaluation of acute stroke as it primarily helps visualize **vascular structures** or **brain tumors** and could potentially obscure a subtle hemorrhage in the hyperacute phase. - Contrast administration can also delay the imaging process and potentially cause **nephrotoxicity**, which is undesirable in an emergency. *IV tPA* - **Intravenous tissue plasminogen activator (IV tPA)** is a treatment for **ischemic stroke**, but it can only be administered **after a hemorrhagic stroke has been ruled out** by imaging. - Administering tPA in the presence of hemorrhage would be catastrophic. *CT angiography of the brain* - CT angiography (CTA) is useful for identifying **large vessel occlusions** in the brain, which can guide treatment options like **endovascular thrombectomy**. - However, it is not the very first step; a non-contrast CT is performed initially to rule out hemorrhage before proceeding with CTA or other advanced imaging.

Question 327: A 62-year-old female presents with complaint of chronic productive cough for the last 4 months. She states that she has had 4-5 month periods of similar symptoms over the past several years. She has never smoked, but she reports significant exposure to second-hand smoke in her home. She denies any fevers, reporting only occasional shortness of breath and a persistent cough where she frequently expectorates thick, white sputum. Vital signs are as follows: T 37.1 C, HR 88, BP 136/88, RR 18, O2 sat 94% on room air. Physical exam is significant for bilateral end-expiratory wheezes, a blue tint to the patient's lips and mucous membranes of the mouth, and a barrel chest. Which of the following sets of results would be expected on pulmonary function testing in this patient?

A. Normal FEV1, Normal FEV1/FVC, Normal TLC, Normal DLCO
B. Decreased FEV1, Normal FEV1/FVC, Decreased TLC, Decreased DLCO
C. Decreased FEV1, Decreased FEV1/FVC ratio, Increased TLC, Normal DLCO (Correct Answer)
D. Decreased FEV1, Increased FEV1/FVC ratio, Decreased TLC, Normal DLCO
E. Decreased FEV1, Decreased FEV1/FVC ratio, Increased TLC, Decreased DLCO

Explanation: ***Decreased FEV1, Decreased FEV1/FVC ratio, Increased TLC, Normal DLCO*** - This patient presents with **chronic bronchitis**, a form of COPD characterized by **chronic productive cough** with sputum production for at least 3 months in 2 consecutive years. The clinical picture of **cyanosis** ("blue bloater"), **productive cough with thick white sputum**, and **wheezing** points to chronic bronchitis as the predominant pathology. - COPD is an **obstructive lung disease**, characterized by **decreased FEV1** and **decreased FEV1/FVC ratio** (<0.70). - **Increased TLC** occurs due to **air trapping** seen in obstructive diseases. - **Normal DLCO** is characteristic of **chronic bronchitis** where the alveolar-capillary membrane remains relatively intact, unlike in emphysema. Although the patient has a barrel chest (suggesting some hyperinflation), the predominant clinical features favor chronic bronchitis, making normal DLCO the expected finding. *Normal FEV1, Normal FEV1/FVC, Normal TLC, Normal DLCO* - This represents **normal pulmonary function**, which is inconsistent with the patient's clinical presentation. - The **chronic productive cough**, **cyanosis**, **wheezes**, and **barrel chest** clearly indicate underlying obstructive pulmonary disease. *Decreased FEV1, Normal FEV1/FVC, Decreased TLC, Decreased DLCO* - This pattern is characteristic of **restrictive lung disease** (decreased TLC with preserved or increased FEV1/FVC ratio). - A **normal FEV1/FVC ratio** excludes obstructive disease, which is clearly present in this patient based on clinical findings. - Does not match the obstructive picture presented. *Decreased FEV1, Increased FEV1/FVC ratio, Decreased TLC, Normal DLCO* - An **increased FEV1/FVC ratio** with decreased FEV1 is physiologically implausible and not seen in any standard lung disease pattern. - This would require FVC to be disproportionately more reduced than FEV1, which doesn't occur in typical disease states. *Decreased FEV1, Decreased FEV1/FVC ratio, Increased TLC, Decreased DLCO* - This pattern is most consistent with **emphysema-predominant COPD**, where destruction of alveolar-capillary membranes causes **decreased DLCO**. - While this patient has some features suggestive of emphysema (barrel chest, air trapping), the **predominant clinical picture** of **chronic productive cough**, **cyanosis** ("blue bloater"), and **thick sputum production** points to **chronic bronchitis** as the primary pathology, where DLCO is typically preserved. - Emphysema patients ("pink puffers") typically present with minimal cough, dyspnea on exertion, and pursed-lip breathing, which are not prominent in this case.

Question 328: A 32-year-old man is brought into the emergency department by his friends. The patient was playing soccer when he suddenly became short of breath. The patient used his albuterol inhaler with minimal improvement in his symptoms. He is currently struggling to breathe. The patient has a past medical history of asthma and a 25 pack-year smoking history. His current medications include albuterol, fluticasone, and oral prednisone. His temperature is 99.5°F (37.5°C), blood pressure is 137/78 mmHg, pulse is 120/min, respirations are 27/min, and oxygen saturation is 88% on room air. On pulmonary exam, the patient exhibits no wheezing with bilateral minimal air movement. The patient’s laboratory values are ordered as seen below. Hemoglobin: 15 g/dL Hematocrit: 43% Leukocyte count: 5,500/mm^3 with normal differential Platelet count: 194,000/mm^3 Serum: Na+: 138 mEq/L Cl-: 102 mEq/L K+: 4.4 mEq/L HCO3-: 24 mEq/L BUN: 20 mg/dL Glucose: 120 mg/dL Creatinine: 1.0 mg/dL Ca2+: 10.2 mg/dL pH: 7.44 PaCO2: 10 mmHg PaO2: 60 mmHg AST: 12 U/L ALT: 10 U/L The patient is started on an albuterol nebulizer, magnesium sulfate, and tiotropium bromide. Repeat vitals reveal an oxygen saturation of 90% with a pulse of 115/min. Laboratory values are repeated as seen below. pH: 7.40 PaCO2: 44 mmHg PaO2: 64 mmHg Which of the following is the next best step in management of this patient?

A. Continue current management with close observation
B. Begin IV steroids
C. Intubation (Correct Answer)
D. Begin oral steroids
E. Terbutaline

Explanation: ***Intubation*** - The patient presents with **severe asthma exacerbation** indicated by minimal air movement despite no wheezing, **hypoxia (SpO2 88%)**, and respiratory distress (RR 27/min, HR 120/min). - The initial **PaCO2 of 10 mmHg** suggests hyperventilation due to severe distress; the subsequent rise to **44 mmHg** after treatment, despite clinical deterioration, indicates **impending respiratory failure** and exhaustion, necessitating intubation. *Continue current management with close observation* - The patient's **oxygen saturation remains low (90%)** and **PaCO2 has dangerously normalized from 10 to 44 mmHg**, indicating worsening respiratory failure, not improvement. - **Close observation without escalation** is inappropriate given the signs of treatment failure and impending decompensation. *Begin IV steroids* - The patient is already on **oral prednisone** and is likely receiving IV steroids in the ED; however, steroids have a **delayed onset of action** and will not acutely address the respiratory failure. - While important for managing asthma exacerbation, **steroids alone are insufficient** to prevent immediate respiratory collapse in this critical scenario. *Begin oral steroids* - The patient is already on **oral prednisone**, and in an acute, severe exacerbation requiring hospitalization, **IV steroids are preferred** for faster absorption if steroids haven't been initiated. - **Oral steroids will not provide the rapid therapeutic effect** needed to reverse acute respiratory failure and may lead to aspiration in a patient with respiratory distress. *Terbutaline* - **Terbutaline is a beta-2 agonist** similar to albuterol, and the patient has already shown **minimal improvement with albuterol and other bronchodilators**. - While it can be considered, it is **unlikely to provide significant additional benefit** or resolve impending respiratory failure when conventional bronchodilators have failed.

Question 329: A 71-year-old man comes to the physician for routine health maintenance examination. He feels well. He has hypertension and gastroesophageal reflux disease. Current medications include metoprolol and pantoprazole. He does not smoke or drink alcohol. Temperature is 37.3°C (99.1°F), pulse is 75/min, and blood pressure 135/87 mm Hg. Examination shows no abnormalities. Laboratory studies show: Hematocrit 43% Leukocyte count 32,000/mm3 Segmented neutrophils 22% Basophils 1% Eosinophils 2% Lymphocytes 74% Monocytes 1% Platelet count 190,000/mm3 Blood smear shows small, mature lymphocytes and several smudge cells. Immunophenotypic analysis with flow cytometry shows B-cells that express CD19, CD20 and CD23. Which of the following is the most appropriate next step in management?

A. Stem cell transplantation
B. Fludarabine, cyclophosphamide, and rituximab
C. All-trans retinoic acid
D. Imatinib
E. Observation and follow-up (Correct Answer)

Explanation: ***Observation and follow-up*** - The patient's presentation, including marked **lymphocytosis** (leukocyte count 32,000/mm³ with 74% lymphocytes), **small mature lymphocytes** and **smudge cells** on blood smear, and **CD19, CD20, CD23 expression** on B-cells, is highly suggestive of **Chronic Lymphocytic Leukemia (CLL)**. - Given the patient is **asymptomatic** and has **no signs of end-organ damage** or disease progression, the most appropriate initial management for CLL is "watch and wait" or observation. Treatment is typically initiated only when symptoms develop or there are signs of advanced disease. *Stem cell transplantation* - **Stem cell transplantation** is a highly intensive treatment, usually reserved for young, fit patients with **high-risk CLL refractory to conventional chemotherapy** or for those with transformation to aggressive lymphoma. - It is not indicated for an asymptomatic 71-year-old man with newly diagnosed, likely early-stage CLL. *Fludarabine, cyclophosphamide, and rituximab* - This combination, known as **FCR regimen**, is a common and effective first-line chemotherapy for **symptomatic CLL** patients who require treatment. - However, for asymptomatic patients fulfilling the diagnostic criteria for CLL but without indications for treatment (e.g., progressive lymphadenopathy, splenomegaly, anemia, thrombocytopenia, B symptoms), initiating chemotherapy is not recommended. *All-trans retinoic acid* - **All-trans retinoic acid (ATRA)** is a specific differentiating agent used primarily in the treatment of **Acute Promyelocytic Leukemia (APL)**, a subtype of acute myeloid leukemia. - It has no role in the management of Chronic Lymphocytic Leukemia (CLL). *Imatinib* - **Imatinib** is a tyrosine kinase inhibitor used primarily in the treatment of **Chronic Myeloid Leukemia (CML)**, which is characterized by the Philadelphia chromosome (BCR-ABL fusion gene). - While sometimes used in other malignancies with specific kinase mutations, it is not indicated for CLL.

Question 330: A 24-year-old man comes to the physician for a 1-week history of a painless swelling on the right side of his neck that he noticed while showering. He is 203 cm (6 ft 8 in) tall and weighs 85 kg (187 lb); BMI is 21 kg/m2. Physical examination shows long, thin fingers and an increased arm-length to body-height ratio. Examination of the neck shows a single 2-cm firm nodule. Ultrasonography of the neck shows a hypoechoic thyroid lesion with irregular margins. A core needle biopsy of the thyroid lesion shows sheets of polygonal cells surrounded by Congo red-stained amorphous tissue. Which of the following additional findings is most likely in this patient?

A. Gastric ulcers
B. Kidney stones
C. Oral tumors (Correct Answer)
D. Recurrent hypoglycemia
E. Breast enlargement

Explanation: **Oral tumors** - The patient's presentation with a **painless thyroid nodule**, tall stature, **long, thin fingers**, and a **hypoechoic thyroid lesion with irregular margins** suggests **multiple endocrine neoplasia type 2B (MEN2B)**. - **MEN2B** is characterized by **medullary thyroid carcinoma**, **pheochromocytoma**, and **mucosal neuromas (oral tumors)** and a **Marfanoid habitus**. *Gastric ulcers* - **Gastric ulcers** are more commonly associated with **Zollinger-Ellison syndrome**, often seen in **MEN1**, which presents with pituitary tumors, parathyroid hyperplasia, and pancreatic islet cell tumors (e.g., gastrinomas). - The patient's morphologic features and thyroid pathology are not consistent with **MEN1** or typical causes of gastric ulcers. *Kidney stones* - **Kidney stones** are often associated with **hyperparathyroidism**, which is characteristic of **MEN1** and sometimes **MEN2A**. - The patient's specific presentation, particularly the **Marfanoid habitus** and evidence of **medullary thyroid carcinoma** with amyloid deposition, points more strongly to **MEN2B**. *Recurrent hypoglycemia* - **Recurrent hypoglycemia** can occur with **insulinomas**, often part of **MEN1**. - This patient's findings, including the **thyroid lesion** with **amyloid** and **Marfanoid features**, are not consistent with an insulinoma or **MEN1**. *Breast enlargement* - **Breast enlargement (gynecomastia)** can be associated with various hormonal imbalances, including certain tumors, but it is not a primary component of **MEN2B** or suggested by the patient's other symptoms. - While some endocrine disorders can lead to gynecomastia, it is not a characteristic feature that helps differentiate this patient's underlying condition from the given choices.

Question 331: A 14-year-old boy presents with his mother complaining of a swollen, red, painful left knee. His physician aspirates the joint and discovers frank blood. The patient denies a recent history of trauma to the knee. Upon further discussion, the mother describes that her son has had multiple swollen painful joints before, often without evidence of trauma. She also mentions a history of frequent nosebleeds and gum bleeding following visits to the dentist. Which of the following is the most likely underlying diagnosis?

A. Factor VII deficiency
B. Hemophilia C
C. Child abuse
D. Hemophilia B
E. Hemophilia A (Correct Answer)

Explanation: ***Hemophilia A*** - The presentation of recurrent **hemarthroses** (swollen, red, painful joints with frank blood on aspiration) without trauma, along with a history of spontaneous bleeding (nosebleeds, gum bleeding), is highly characteristic of hemophilia. - **Hemophilia A**, caused by a deficiency in factor VIII, is the most common type of severe hemophilia and often presents in childhood with these bleeding manifestations, particularly in joints. *Factor VII deficiency* - Factor VII deficiency primarily affects the **extrinsic pathway** of coagulation and typically presents with a prolonged **prothrombin time (PT)**, while the activated partial thromboplastin time (aPTT) would be normal. - Clinical manifestations are usually milder than hemophilia A, but can include epistaxis, menorrhagia, and occasionally hemarthroses, but not with the classic severity and frequency seen here. *Hemophilia C* - Hemophilia C, caused by **factor XI deficiency**, is a milder bleeding disorder, often presenting with bleeding after trauma or surgery rather than spontaneous joint bleeding. - It mainly affects Ashkenazi Jews and typically causes a prolonged **aPTT**, but usually less severe symptoms than hemophilia A or B. *Child abuse* - While child abuse should always be considered in cases of unexplained trauma, the detailed history of **recurrent, spontaneous bleeding events** (hemarthroses, nosebleeds, gum bleeding post-dental work) without a clear traumatic cause is more indicative of a systemic bleeding disorder. - The pattern of bleeding is consistent with a coagulation defect rather than isolated traumatic injuries. *Hemophilia B* - Hemophilia B, or Christmas disease, is caused by **factor IX deficiency** and presents with symptoms clinically indistinguishable from hemophilia A (i.e., spontaneous joint and deep tissue bleeding). - However, Hemophilia A is significantly more common than Hemophilia B (affecting about 1 in 5,000 to 10,000 live male births, compared to 1 in 25,000 to 30,000 for Hemophilia B). Therefore, Hemophilia A is the most likely diagnosis.

Question 332: A 50-year-old woman comes to the emergency department because of fever and productive cough with blood in the sputum for 1 day. She also reports a sharp pain under her ribs that is worsened on taking deep breaths. Over the past 2 years, she has had repeated episodes of sinusitis, for which she used over the counter medication. She has recently started a new job at a wire-mesh factory. Her temperature is 38.3°C (100.9 °F), pulse is 72/min, respirations are 16/min, and blood pressure is 120/80 mm Hg. Physical examination shows palpable nonblanching skin lesions over her hands and feet. Examination of the nasal cavity shows ulcerations of the nasopharyngeal mucosa and a small septal perforation. Pulmonary examination shows stridor on inspiration. Laboratory studies show: Hemoglobin 13.2 g/dL Leukocyte count 10,300/mm3 Platelet count 205,000/mm3 Serum Urea nitrogen 24 mg/dL Creatinine 2.4 mg/dL Urine Protein 2+ RBC 70/hpf RBC casts numerous WBC 1–2/hpf A chest x-ray shows multiple cavitating, nodular lesions bilaterally. Which of the following additional findings is most likely to be present in this patient?

A. Increased p-ANCA titers
B. Increased anti-Smith titers
C. Increased anti-GBM titers
D. Increased c-ANCA titers (Correct Answer)
E. Decreased ADAMTS13 activity

Explanation: ### ***Increased c-ANCA titers*** - The patient's presentation with **sinusitis**, **nasal ulcerations**, **pulmonary cavitating nodules** with hemoptysis, and **rapidly progressive glomerulonephritis** (elevated creatinine, proteinuria, RBC casts) is highly indicative of **Granulomatosis with Polyangiitis (GPA)**. - **c-ANCA (cytoplasmic antineutrophil cytoplasmic antibodies)**, primarily targeting **proteinase 3 (PR3)**, are serological markers commonly elevated in GPA and help confirm the diagnosis. ### *Increased p-ANCA titers* - **p-ANCA (perinuclear antineutrophil cytoplasmic antibodies)**, typically targeting **myeloperoxidase (MPO)**, are more commonly associated with **microscopic polyangiitis** or **eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)**. - While both GPA and microscopic polyangiitis can present with kidney and lung involvement, the prominent upper airway disease (sinusitis, nasal ulcerations, septal perforation) in this patient points more strongly towards GPA and c-ANCA positivity. ### *Increased anti-Smith titers* - **Anti-Smith antibodies** are highly specific for **Systemic Lupus Erythematosus (SLE)**. - The clinical presentation of **upper airway destruction**, **cavitating lung lesions**, and **glomerulonephritis with RBC casts** is not typical for SLE, which more commonly presents with malar rash, arthritis, serositis, and other systemic symptoms. ### *Increased anti-GBM titers* - **Anti-GBM (anti-glomerular basement membrane) antibodies** are characteristic of **Goodpasture syndrome**, which causes a **rapidly progressive glomerulonephritis** and often **pulmonary hemorrhage**. - However, Goodpasture syndrome does not typically involve **upper airway disease** (sinusitis, nasal ulcerations, septal perforation) or **palpable skin lesions**, which are prominent features in this patient. ### *Decreased ADAMTS13 activity* - **Decreased ADAMTS13 activity** is diagnostic of **Thrombotic Thrombocytopenic Purpura (TTP)**. - TTP is characterized by the pentad of **thrombocytopenia**, **microangiopathic hemolytic anemia**, **neurological symptoms**, **renal insufficiency**, and **fever**, but it does not involve the prominent **destructive upper airway disease** or **cavitating lung lesions** seen in this patient.

Question 333: A 42-year-old man comes to the physician because of a 2-month history of fatigue and increased urination. The patient reports that he has been drinking more than usual because he is constantly thirsty. He has avoided driving for the past 8 weeks because of intermittent episodes of blurred vision. He had elevated blood pressure at his previous visit but is otherwise healthy. Because of his busy work schedule, his diet consists primarily of fast food. He does not smoke or drink alcohol. He is 178 cm (5 ft 10 in) tall and weighs 109 kg (240 lb); BMI is 34 kg/m2. His pulse is 75/min and his blood pressure is 148/95 mm Hg. Cardiopulmonary examination shows no abnormalities. Laboratory studies show: Hemoglobin A1c 6.8% Serum Glucose 180 mg/dL Creatinine 1.0 mg/dL Total cholesterol 220 mg/dL HDL cholesterol 50 mg/dL Triglycerides 140 mg/dL Urine Blood negative Glucose 2+ Protein 1+ Ketones negative Which of the following is the most appropriate next step in management?

A. Metformin therapy (Correct Answer)
B. Low-carbohydrate diet
C. Aspirin therapy
D. ACE inhibitor therapy
E. Insulin therapy

Explanation: ***Metformin therapy*** - This patient has **newly diagnosed type 2 diabetes mellitus** with classic symptoms (polyuria, polydipsia, blurred vision) and laboratory confirmation (HbA1c 6.8%, glucose 180 mg/dL, glucosuria). - **Metformin is the first-line pharmacologic therapy** for type 2 diabetes according to current guidelines (ADA, AACE) due to its efficacy, safety profile, cardiovascular benefits, and low risk of hypoglycemia. - The patient's creatinine is normal (1.0 mg/dL), so metformin is not contraindicated. - Addressing the **symptomatic hyperglycemia** is the most appropriate next step in management. *ACE inhibitor therapy* - ACE inhibitors are indicated for diabetic patients with **hypertension and albuminuria** to provide renoprotection and slow progression of diabetic nephropathy. - While this patient has both hypertension (148/95 mm Hg) and proteinuria (1+), ACE inhibitor therapy should be initiated **after or concurrent with diabetes management**, not as the sole initial intervention. - The patient needs **glycemic control first** given symptomatic hyperglycemia, though ACE inhibitor would be an appropriate addition to the treatment regimen. *Low-carbohydrate diet* - **Lifestyle modifications** including medical nutrition therapy and exercise are foundational for managing type 2 diabetes and should be recommended. - However, given the patient's **symptomatic hyperglycemia** (HbA1c 6.8%, glucose 180 mg/dL with classic symptoms), lifestyle changes alone are **insufficient as the initial management**. - Pharmacologic therapy with metformin should be initiated immediately alongside lifestyle counseling. *Insulin therapy* - Insulin therapy is indicated for patients with **very high HbA1c** (typically >9-10%), **severe symptoms of hyperglycemia**, evidence of catabolism, or failure of oral agents. - This patient's HbA1c of 6.8% represents **relatively mild hyperglycemia** that is appropriately managed with metformin as first-line therapy. - Insulin is **not indicated** at this stage of disease. *Aspirin therapy* - **Aspirin for primary prevention** in diabetes is controversial; current guidelines suggest shared decision-making for patients at increased cardiovascular risk without high bleeding risk. - While this patient has cardiovascular risk factors (diabetes, hypertension, obesity, dyslipidemia), aspirin would be a **secondary priority** after addressing the acute metabolic derangements. - **Glycemic control takes precedence** over aspirin initiation in newly diagnosed diabetes.

Question 334: A 35-year-old patient with a history of diabetes presents to the ED with a myriad of systemic complaints. An arterial blood gas shows serum pH = 7.3, HCO3- = 13 mEq/L, PCO2 = 27 mmHg. Which of the following would you LEAST expect to observe in this patient?

A. Increased anion gap
B. Increased urine output
C. Increased serum potassium
D. Decreased respiratory rate (Correct Answer)
E. Increased serum ketones

Explanation: ***Decreased respiratory rate*** - This patient has **diabetic ketoacidosis (DKA)**, which causes a metabolic acidosis. The body compensates for acidosis by increasing the respiratory rate (**Kussmaul respirations**) to blow off CO2, thus decreasing serum acidity. - A decreased respiratory rate would worsen the acidosis by retaining CO2, which is contrary to the body's compensatory mechanism in DKA. - This is what you would **LEAST expect** to observe in a patient with DKA. *Increased anion gap* - The patient's **pH of 7.3** and **HCO3- of 13 mEq/L** indicate a metabolic acidosis with a PCO2 of 27 mmHg showing respiratory compensation. - DKA is characterized by the accumulation of **ketoacids** (acetoacetate, beta-hydroxybutyrate), which are unmeasured anions, leading to an **elevated anion gap**. - This is an **expected finding** in DKA. *Increased urine output* - In DKA, **hyperglycemia** leads to an osmotic diuresis as excess glucose is filtered by the kidneys and draws water out, resulting in **polyuria** (increased urine output). - This excessive urination contributes to **dehydration**, a common finding in DKA. - This is an **expected finding** in DKA. *Increased serum potassium* - Despite total body potassium depletion, patients in DKA often present with **normal or elevated serum potassium** due to intracellular potassium shifting out of cells in exchange for hydrogen ions (to buffer acidosis). - **Insulin deficiency** also contributes to this shift by impairing potassium uptake into cells. - This is an **expected finding** in DKA, though potassium will drop with insulin treatment. *Increased serum ketones* - **Diabetic ketoacidosis (DKA)** is fundamentally caused by insulin deficiency, leading to increased **lipolysis** and subsequent overproduction of **ketone bodies** (acetoacetate, beta-hydroxybutyrate) by the liver. - These ketones accumulate in the blood, causing the characteristic metabolic acidosis and are measurable in serum and urine. - This is an **expected finding** and diagnostic of DKA.

Question 335: A 74-year-old man presents to the emergency department with shortness of breath that started about 30 minutes ago. He is also experiencing chest pain on deep inspiration. He has several significant medical conditions including chronic obstructive pulmonary disease, hypertension, and dyslipidemia. He used to smoke about 3 packs of cigarettes every day until last year when he quit. He was in the emergency room 2 weeks ago for a hemorrhagic stroke which was promptly treated. He currently weighs 97.5 kg (215 lb). His respirations are 20/min, the blood pressure is 110/80 mm Hg, and the pulse is 105/min. On physical examination, Homan's sign is positive. An ECG and chest X-ray are performed. His current oxygen saturation is at 87% and D-dimer results are positive. He is wheeled in for a CT scan. What is the most appropriate initial treatment for this patient?

A. Subcutaneous fondaparinux
B. Greenfield filter (Correct Answer)
C. Surgical thrombectomy
D. Unfractionated heparin
E. Warfarin

Explanation: ***Greenfield filter (IVC filter)*** - This patient presents with **acute pulmonary embolism (PE)** evidenced by sudden **shortness of breath**, **pleuritic chest pain**, **tachycardia (105/min)**, **hypoxemia (87%)**, and **positive D-dimer**. The positive **Homan's sign** suggests deep vein thrombosis as the source. - The critical factor is his **recent hemorrhagic stroke 2 weeks ago**, which represents an **absolute contraindication to anticoagulation** in the acute/subacute period due to the high risk of re-bleeding. - **IVC filter placement** is specifically indicated for patients with **venous thromboembolism (VTE) who have contraindications to anticoagulation**, which precisely describes this clinical scenario. - The filter prevents further emboli from reaching the lungs while avoiding the bleeding risks associated with anticoagulants. *Subcutaneous fondaparinux* - While **fondaparinux** is a factor Xa inhibitor commonly used for PE treatment, it is still an **anticoagulant** that significantly increases bleeding risk. - A **recent hemorrhagic stroke (2 weeks ago)** is an **absolute contraindication** to any form of anticoagulation, including fondaparinux, due to the substantial risk of intracranial re-bleeding. - Standard guidelines recommend avoiding anticoagulation for at least 2-4 weeks (often longer) after intracranial hemorrhage. *Unfractionated heparin* - **Unfractionated heparin (UFH)** is a standard treatment for acute PE but is absolutely **contraindicated** in this patient due to the **recent hemorrhagic stroke**. - UFH would carry an unacceptable risk of causing recurrent intracranial bleeding in the subacute post-stroke period. *Surgical thrombectomy* - **Surgical embolectomy** is reserved for patients with **massive PE causing hemodynamic instability** (cardiogenic shock, persistent hypotension) who have failed or have contraindications to thrombolysis. - This patient is **hemodynamically stable** with a blood pressure of 110/80 mmHg, making surgical intervention unnecessarily invasive and inappropriate as initial management. *Warfarin* - **Warfarin** is an oral anticoagulant used for long-term VTE management but has a **slow onset of action** (requires 5-7 days to reach therapeutic levels), making it unsuitable for acute PE treatment. - More importantly, like all anticoagulants, warfarin is **absolutely contraindicated** in this patient due to the recent hemorrhagic stroke and high re-bleeding risk.

Question 336: A 64-year-old woman presents to the physician with fever and sore throat for 2 days. She was diagnosed with rheumatoid arthritis 15 years ago. She has had several flares necessitating admission to the hospital in recent years. She has developed deformity in her joints despite aggressive therapy. She is a candidate for surgical correction. Her temperature is 38.2°C (100.9°F), and the rest of her vital signs are stable. Physical examination of the hands reveals multiple swan-neck, boutonniere, and Z-line deformities. Ulnar deviation is evident in both hands. She has flat feet. There are 3 firm, nontender nodules palpated around the right elbow and one on the left Achilles tendon. The spleen is palpated 5 cm below the costal margin with a percussion span of 15 cm. Lymphadenopathy is absent on exam. The laboratory test results show: Hemoglobin 11 g/dL Mean corpuscular volume 90 μm3 Leukocyte count 3,500/mm3 Segmented neutrophils 20% Lymphocytes 70% Platelet count 240,000/mm3 Erythrocyte sedimentation rate 65 mm/hour Rheumatoid factor 85 IU/mL (Normal: up to 14 IU/mL) Which of the following is the most likely cause of this patient’s current condition?

A. Sarcoidosis
B. Diffuse large B cell lymphoma
C. Secondary amyloidosis
D. Felty syndrome (Correct Answer)
E. T cell large granular lymphocytic leukemia

Explanation: ***Felty syndrome*** - This patient presents with a long history of severe, progressive **rheumatoid arthritis (RA)**, characteristic deformities (**swan-neck, boutonniere, Z-line, ulnar deviation**), **splenomegaly**, and **neutropenia** (leukocyte count 3,500/mm3 with 20% neutrophils, meaning an absolute neutrophil count of 700/mm3). This triad defines **Felty syndrome**. - **Felty syndrome** is a rare, severe complication of chronic RA, often associated with a high **rheumatoid factor (RF)**, and increased risk of infections due to neutropenia. *Sarcoidosis* - While sarcoidosis can cause **lymphadenopathy** and occasionally **splenomegaly**, it does not typically present with the specific joint deformities and positive **RF** seen in severe RA. - The elevated **RF** and characteristic joint changes are not features of sarcoidosis. *Diffuse large B cell lymphoma* - This condition can cause **splenomegaly** and systemic symptoms but is not primarily associated with the specific joint deformities and highly positive **RF** characteristic of longstanding, severe **rheumatoid arthritis**. - While patients with RA have an increased risk of lymphoma, the constellation of neutropenia and splenomegaly in the context of severe RA points more strongly to Felty syndrome. *Secondary amyloidosis* - **Secondary amyloidosis** can occur in chronic inflammatory conditions like **rheumatoid arthritis** and can cause **splenomegaly**. - However, it does not explain the **neutropenia** or the specific pattern of hematologic abnormalities (lymphocytosis with neutropenia) seen in this patient. *T cell large granular lymphocytic leukemia* - This leukemia can cause **neutropenia** and **splenomegaly** and is sometimes associated with **rheumatoid arthritis**. - However, the patient's lymphocyte count is 70% of 3,500, which is 2,450/mm3. While this is absolute lymphocytosis, the diagnosis is confirmed by immunophenotyping to detect abnormal clonal T cells, which is not provided. The classic presentation of severe RA with splenomegaly and neutropenia strongly aligns with Felty syndrome.

Question 337: A 49-year-old man presents to his primary care physician for leg pain. He states that when he goes for walks with his dog, he starts feeling calf pain. He either has to stop or sit down before the pain resolves. He used to be able to walk at least a mile, and now he starts feeling the pain after 8 blocks. His medical history includes hyperlipidemia and hypertension. He takes lisinopril, amlodipine, and atorvastatin, but he admits that he takes them inconsistently. His blood pressure is 161/82 mmHg, pulse is 87/min, and respirations are 16/min. On physical exam, his skin is cool to touch and distal pulses are faint. His bilateral calves are smooth and hairless. There are no open wounds or ulcers. Dorsi- and plantarflexion of bilateral ankles are 5/5 in strength. Ankle-brachial indices are obtained, which are 0.8 on the left and 0.6 on the right. In addition to lifestyle modifications, which of the following is the next best step in management?

A. Angioplasty
B. Bed rest
C. Arteriography
D. Electromyography
E. Clopidogrel (Correct Answer)

Explanation: ***Clopidogrel*** - This patient presents with **claudication** consistent with peripheral artery disease (PAD), evidenced by cramping leg pain with exertion, faint pulses, cool and hairless skin, and **abnormal ankle-brachial indices (ABI)**. Antiplatelet therapy with medications like **clopidogrel** is a cornerstone of PAD management to reduce cardiovascular event risk. - While lifestyle modifications are crucial, medications that improve arterial blood flow and reduce thrombotic events, such as **antiplatelets** (e.g., clopidogrel, aspirin) and **phosphodiesterase inhibitors** (e.g., cilostazol), are often the next step in medical management for symptomatic PAD. *Angioplasty* - **Angioplasty** is an invasive procedure generally reserved for patients with severe claudication that significantly impacts their quality of life, limb-threatening ischemia, or those who have failed medical therapy. - Given that this patient's symptoms are new and he has not yet optimized medical management, an **invasive procedure** is premature. *Bed rest* - **Bed rest** is contraindicated in PAD as it can worsen symptoms and lead to deconditioning. - **Supervised exercise programs** are a key component of conservative management for PAD, improving walking distance and reducing symptoms. *Arteriography* - **Arteriography** (angiography) is an invasive diagnostic procedure that uses contrast dye and X-rays to visualize arterial blockages. It is typically performed when revascularization (e.g., angioplasty, bypass surgery) is being considered to map the exact location and extent of the disease. - While it can confirm the diagnosis, it's not the next best step in initial management after confirming PAD with ABI; rather, it’s a precursor to **interventional procedures**. *Electromyography* - **Electromyography (EMG)** measures the electrical activity of muscles in response to nerve stimulation and is primarily used to diagnose neuromuscular disorders like neuropathy or myopathy. - The patient's symptoms are classic for **vascular claudication**, not a neuromuscular condition, making EMG an inappropriate diagnostic step here.

Question 338: A 35-year-old man presents to pulmonary function clinic for preoperative evaluation for a right pneumonectomy. His arterial blood gas at room air is as follows: pH: 7.34 PaCO2: 68 mmHg PaO2: 56 mmHg Base excess: +1 O2 saturation: 89% What underlying condition most likely explains these findings?

A. Cystic fibrosis
B. Bronchiectasis
C. Chronic obstructive pulmonary disease (Correct Answer)
D. Obesity
E. Acute respiratory distress syndrome

Explanation: ***Chronic obstructive pulmonary disease*** - This patient exhibits **compensated respiratory acidosis** (low pH, high PaCO2, slightly elevated base excess) and **hypoxemia** (low PaO2), which are characteristic findings in chronic obstructive pulmonary disease (COPD) with underlying respiratory failure. - The history of a planned **pneumonectomy** also suggests a significant pre-existing lung pathology often seen in patients with severe COPD. *Cystic fibrosis* - While cystic fibrosis can lead to chronic lung disease, it typically presents at a younger age and is associated with a history of recurrent infections and exocrine gland dysfunction. - While it can manifest similarly in ABG, the age and the planned pneumonectomy make COPD a more likely primary cause in this context. *Bronchiectasis* - Bronchiectasis involves permanent dilation of the bronchi, often leading to chronic cough, sputum production, and recurrent infections. - While it can cause respiratory compromise, the ABG findings are more classically associated with the widespread air trapping and V/Q mismatch seen in COPD. *Obesity* - Severe obesity can lead to **obesity hypoventilation syndrome**, presenting with hypercapnia and hypoxemia. - However, the patient's age and the context of a planned pneumonectomy make an underlying primary lung disease like COPD a more focused explanation for the ABG pattern. *Acute respiratory distress syndrome* - Acute respiratory distress syndrome (ARDS) is an **acute** and severe form of respiratory failure characterized by severe hypoxemia and bilateral opacities on chest imaging. - The ABG findings in ARDS typically show **severe hypoxemia** with **respiratory alkalosis** early on, evolving to acidosis, and it is an acute process, not a chronic pre-existing condition suitable for elective surgery.

Question 339: A 62-year-old man comes to the physician for the evaluation of lower back pain and tingling and numbness in his legs for the past 6 months. The pain radiates bilaterally to his buttocks and legs gets worse while standing or walking downhill. Two weeks ago, he had an upper respiratory tract infection that resolved spontaneously. He has hypertension and hypercholesterolemia. His son has ankylosing spondylitis. The patient does not smoke. He drinks 2–3 beers on the weekends. Current medications include enalapril and atorvastatin. He is 180 cm (5 ft 11 in) tall and weighs 90 kg (198 lb); BMI is 27.8 kg/m2. His temperature is 37°C (98.6°F), pulse is 70/min, and blood pressure is 135/85 mm Hg. There is no tenderness to palpation over the lumbar spine. Sensation to pinprick and light touch is decreased over the lower extremities. The patient's gait is unsteady and wide based. Muscle strength is normal. Deep tendon reflexes are 1+ bilaterally. Babinski's sign is absent bilaterally. Further evaluation is most likely to reveal which of the following findings?

A. Increased hemoglobin A1c
B. Albuminocytologic dissociation on CSF analysis
C. Decreased ankle-brachial index
D. Positive HLA-B27
E. Leaning forward relieves the pain (Correct Answer)

Explanation: ***Leaning forward relieves the pain*** - The patient's symptoms of **lower back pain** and **tingling/numbness in the legs** that worsen with **standing or walking downhill** and are relieved by **leaning forward** are classic signs of **spinal stenosis**. - Leaning forward (flexion) increases the spinal canal's cross-sectional area, temporarily decompressing the neural structures. *Increased hemoglobin A1c* - While the patient has risk factors like **obesity** and **hypercholesterolemia**, there are no specific symptoms pointing towards **diabetes mellitus** exacerbating his current neurological symptoms. - Although diabetes can cause neuropathy, the **positional nature of the pain** (worsening with extension, improving with flexion) suggests a mechanical rather than metabolic cause for the neurological symptoms. *Albuminocytologic dissociation on CSF analysis* - This finding is characteristic of **Guillain-Barré syndrome**, which typically presents with **rapidly progressive ascending paralysis** following an infection. - The patient's symptoms are chronic (6 months), primarily sensory, and related to posture, which is inconsistent with acute demyelinating polyneuropathy. *Decreased ankle-brachial index* - A decreased **ankle-brachial index (ABI)** indicates **peripheral artery disease (PAD)**, which can cause **claudication** (leg pain with exertion). - While PAD causes leg pain that improves with rest, the patient's symptoms are specifically exacerbated by spinal extension (standing, walking downhill) and relieved by flexion, which is more typical of neurogenic claudication. *Positive HLA-B27* - A positive **HLA-B27** is associated with **spondyloarthropathies** like **ankylosing spondylitis**, which his son has. - However, the patient's age of onset and the *nature* of his pain (relieved by leaning forward, worsening with standing/walking downhill) are not typical for inflammatory back pain seen in ankylosing spondylitis, which usually improves with activity and is worse in the morning.

Question 340: A 62-year-old woman comes to the physician because of a 2-month history of a rash on her ankles with intermittent itching. After the rash developed, she started applying a new scented lotion to her legs daily. She works as a cashier at a grocery store. She has type 2 diabetes mellitus and hypertension. Current medications include metformin and enalapril. Examination shows enlarged superficial veins of the right lower extremity and red-brown discoloration with indistinct margins over the medial ankles. There is 1+ edema in the lower extremities. Which of the following is the most likely cause of this patient’s skin findings?

A. Bacterial spread through the superficial dermis
B. Dermal deposition of hemosiderin (Correct Answer)
C. Intracellular accumulation of sorbitol
D. Contact of antigen with pre-sensitized T lymphocytes
E. Infection with dermatophyte

Explanation: ***Dermal deposition of hemosiderin*** - The patient presents with **enlarged superficial veins**, **red-brown discoloration** with indistinct margins over the medial ankles, and **1+ edema**, which are classic signs of **venous stasis dermatitis**. - Chronic venous insufficiency leads to increased hydrostatic pressure in capillaries, causing extravasation of red blood cells and subsequent breakdown into **hemosiderin**, which deposits in the dermis, causing the characteristic discoloration. *Bacterial spread through the superficial dermis* - This description is characteristic of **erysipelas** or **cellulitis**, which typically present with rapidly spreading, tender, warm, and erythematous skin lesions, often with fever and systemic symptoms. - The patient's chronic, discolored rash with edema is more indicative of a circulatory issue rather than an acute bacterial infection. *Intracellular accumulation of sorbitol* - This mechanism is associated with **diabetic complications** such as retinopathy, neuropathy, and nephropathy due to the polyol pathway in hyperglycemia. - It does not explain the **cutaneous findings** of red-brown discoloration and edema on the ankles, which are specifically linked to venous insufficiency. *Contact of antigen with pre-sensitized T lymphocytes* - This describes **allergic contact dermatitis**, which would typically present with pruritic, erythematous, and possibly vesicular or weeping lesions, often sharply demarcated to the area of contact with the allergen (e.g., the scented lotion). - While the patient used a new lotion, the primary skin findings of **red-brown discoloration** and **enlarged veins** point away from a simple allergic reaction and towards a chronic vascular issue. *Infection with dermatophyte* - A dermatophyte infection (e.g., tinea pedis, tinea cruris) typically presents as a fungal rash, often with **scaling**, **itching**, **erythema**, and sometimes blisters, occurring in specific patterns like ringworm. - The red-brown discoloration and indistinct margins, along with enlarged superficial veins, are not characteristic features of a dermatophyte infection.

Question 341: A 65-year-old man comes to the physician because of increasing swelling of the legs and face over the past 2 months. He has a history of diastolic heart dysfunction. The liver and spleen are palpable 4 cm below the costal margin. On physical examination, both lower limbs show significant pitting edema extending above the knees and to the pelvic area. Laboratory studies show: Serum Cholesterol 350 mg/dL (<200 mg/dL) Triglycerides 290 mg/dL (35–160 mg/dL) Calcium 8 mg/dL Albumin 2.8 g/dL Urea nitrogen 54 mg/dL Creatinine 2.5 mg/dL Urine Blood 3+ Protein 4+ RBC 15–17/hpf WBC 1–2/hpf RBC casts Many Echocardiography shows concentrically thickened ventricles with diastolic dysfunction. Skeletal survey shows no osteolytic lesions. Which of the following best explains these findings?

A. Smoldering multiple myeloma
B. Monoclonal gammopathy of undetermined significance
C. Waldenstrom’s macroglobulinemia
D. AL amyloidosis (Correct Answer)
E. Symptomatic multiple myeloma

Explanation: ***AL amyloidosis*** - The combination of **nephrotic syndrome** (edema, proteinuria, hypoalbuminemia, hyperlipidemia) with **renal failure** (elevated BUN and creatinine, RBC casts) and **restrictive cardiomyopathy** (diastolic dysfunction, concentrically thickened ventricles) is highly suggestive of **AL (light chain) amyloidosis**. - **Hepatomegaly** (palpable liver) further supports the diagnosis of systemic amyloidosis due to amyloid deposition in the liver. *Smoldering multiple myeloma* - Characterized by high levels of **monoclonal protein** and **plasma cells in the bone marrow** but **without CRAB features** (HyperCalcemia, Renal failure, Anemia, Bone lesions). - This patient presents with **renal failure** and **cardiac involvement**, which are symptomatic and thus inconsistent with smoldering multiple myeloma. *Monoclonal gammopathy of undetermined significance* - Defined by the presence of a **monoclonal protein** in the serum or urine but **without evidence of multiple myeloma, amyloidosis, or related disorders**. - This patient exhibits significant **organ damage** indicative of systemic disease, ruling out MGUS. *Waldenstrom's macroglobulinemia* - A low-grade lymphoma characterized by **IgM monoclonal gammopathy** and **lymphoplasmacytic infiltration of the bone marrow**. - It often causes **hyperviscosity syndrome**, lymphadenopathy, and peripheral neuropathy, which are not the primary features in this case. *Symptomatic multiple myeloma* - Requires evidence of **CRAB features** (HyperCalcemia, Renal failure, Anemia, Bone lesions) in addition to monoclonal protein and bone marrow plasma cells. - While **renal failure** is present, the prominent **cardiac involvement** (restrictive cardiomyopathy) and the specific nature of the renal disease (nephrotic range proteinuria, RBC casts suggesting glomerular involvement) are more characteristic of AL amyloidosis rather than typical multiple myeloma kidney.

Question 342: A 45-year-old woman from Mexico comes to your office due to recent shortness of breath. The patient states that she has recently started having trouble breathing when she is working out, but this resolves when she rests for a while. She states that she has no history of diabetes, heart disease, or hypertension, but does state that she had several colds when she was growing up that weren't treated with antibiotics. Furthermore, she has arthritis in one of her knees and both wrists. On exam, her vitals are normal, but there is a mid-diastolic rumble present at the apex. What is the best definitive treatment for this patient?

A. Diuretics
B. Open valve commissurotomy
C. Valve replacement
D. Beta-blockers
E. Percutaneous valve commissurotomy (Correct Answer)

Explanation: ***Percutaneous valve commissurotomy*** - The patient's symptoms, history of untreated childhood infections (suggesting **rheumatic fever**), and the finding of a **mid-diastolic rumble at the apex** are highly indicative of **mitral stenosis**. - **Percutaneous mitral commissurotomy (PMC)** is generally the preferred definitive treatment for isolated, symptomatic mitral stenosis when valve anatomy is favorable (non-calcified, pliable leaflets) as it is less invasive than surgical options. *Diuretics* - Diuretics help manage symptoms of **fluid overload** and pulmonary congestion associated with mitral stenosis by reducing preload. - However, they do not address the underlying **structural valve defect** and are therefore not a definitive treatment. *Open valve commissurotomy* - This is a surgical option to widen the mitral valve opening and is considered when PMC is not feasible or fails, or when other cardiac issues require concomitant surgery. - It is more invasive than PMC and thus not the first-line definitive treatment unless PMC cannot be performed. *Valve replacement* - **Mitral valve replacement** is generally reserved for severe cases of mitral stenosis with significant valve calcification, severe regurgitation, or when repairs (PMC or surgical commissurotomy) are not possible or have failed. - It is a more extensive procedure than commissurotomy and is typically not the initial definitive treatment for primary mitral stenosis. *Beta-blockers* - Beta-blockers can help slow the heart rate, prolonging diastolic filling time and potentially improving symptoms in patients with mitral stenosis. - However, they also do not address the **anatomical narrowing** of the mitral valve and are considered symptomatic management, not a definitive cure.

Question 343: A 76-year-old woman presents to the physician for a follow-up examination. She had a hemoglobin level of 10.5 g/dL last month. She complains of mild dyspnea with exercise. She reports exercising daily for the past 30 years. She is relatively healthy without any significant past medical history. She occasionally takes ibuprofen for knee pain. She denies a prior history of alcohol or tobacco use. Her temperature is 37.1°C (98.8°F), the pulse is 65/min, the respiratory rate is 13/min, and the blood pressure is 115/65 mm Hg. The examination shows no abnormalities. Laboratory studies show: Laboratory test Hemoglobin 10.5 g/dL Mean corpuscular volume 75 μm3 Leukocyte count 6500/mm3 with a normal differential Platelet 400,000/mm3 Serum Iron 35 Total iron-binding capacity 450 μg/dL Ferritin 8 Ca+ 9.0 mg/dL Albumin 3.9 g/dL Urea nitrogen 10 mg/dL Creatinine 0.9 mg/dL Serum protein electrophoresis and immunofixation show a monoclonal protein of 20 g/L (non-IgM). Marrow plasmacytosis is 5%. A skeletal survey shows no abnormalities. In addition to the workup of iron deficiency anemia, which of the following is the most appropriate next step in management?

A. Referral for radiation therapy
B. Check beta-2 microglobulin
C. No further steps are required at this time
D. Annual follow-up with laboratory tests (Correct Answer)
E. Referral for induction therapy

Explanation: ***Annual follow-up with laboratory tests*** - This patient's presentation, with a **monoclonal protein (non-IgM) of 20 g/L** and **5% marrow plasmacytosis**, along with the absence of bone lesions and hypercalcemia, aligns with the diagnostic criteria for **Monoclonal Gammopathy of Undetermined Significance (MGUS)**. - MGUS is a **pre-malignant condition** with a low annual risk of progression to multiple myeloma or related disorders, justifying annual monitoring rather than immediate aggressive intervention. *Referral for radiation therapy* - **Radiation therapy** is typically reserved for patients with localized complications of multiple myeloma, such as **painful bone lesions** or **spinal cord compression**, which are absent in this case. - This patient's skeletal survey shows **no abnormalities**, ruling out the need for radiation therapy at this stage. *Check beta-2 microglobulin* - **Beta-2 microglobulin** is a marker used for staging **multiple myeloma**, indicating tumor burden and prognosis. - While it's a helpful marker in confirmed myeloma, it is **not diagnostic for MGUS** and does not change the management of an asymptomatic patient with MGUS. *No further steps are required at this time* - While the patient does not need immediate aggressive treatment, **regular monitoring** is crucial due to the small but definite risk of progression of MGUS to multiple myeloma or related disorders. - Doing nothing would be inappropriate, as missing the **progression of MGUS** could delay essential treatment. *Referral for induction therapy* - **Induction therapy** (e.g., chemotherapy, immunomodulatory drugs, proteasome inhibitors) is the primary treatment for **symptomatic multiple myeloma**. - Since this patient has **MGUS** (asymptomatic monoclonal gammopathy without end-organ damage), induction therapy is **not indicated** and could expose her to unnecessary toxicity.

Question 344: A 23-year-old woman presents to the emergency department after fainting at a baseball game. The patient was using the bathroom and upon standing up, felt a warm and tingling sensation followed by an episode of syncope that lasted for about 5 seconds. While the patient was unconscious, bystanders observed twitching and contractile motions of her upper extremities. When the patient awoke, she recalled falling and the events leading up to her fainting and was not confused. The patient has no other medical diagnoses. Her temperature is 97.7°F (36.5°C), blood pressure is 124/84 mmHg, pulse is 80/min, respirations are 12/min, and oxygen saturation is 98% on room air. Physical exam is notable for a healthy young woman. Cranial nerves II-XII are grossly intact, and cerebellar function and gait are unremarkable. She has normal strength of her upper and lower extremities. An ECG is notable for normal sinus rhythm with a normal axis and normal voltages. Which of the following is the best next step in management for this patient?

A. Serum toxicology
B. EEG
C. Discharge the patient with reassurance (Correct Answer)
D. Echocardiography
E. CT head

Explanation: ***Discharge the patient with reassurance*** - The patient's presentation is highly consistent with **vasovagal syncope**, characterized by a **prodrome** (warmth, tingling), short duration of unconsciousness, and rapid, full recovery without **postictal confusion**. - Given her young age, lack of medical history, normal vital signs, normal physical exam, and normal ECG, further extensive workup is unlikely to yield significant findings. *Serum toxicology* - While drug use can cause syncope, the clear **vasovagal prodrome** and complete recovery make toxicology screening less immediately necessary. - There are no other signs or symptoms (e.g., altered mental status, track marks) to suggest drug intoxication. *EEG* - An EEG is used to evaluate for seizure activity, but the patient's symptoms are more consistent with syncope than a seizure. - The **brief twitching** can occur during syncope due to cerebral hypoxia, and the **absence of postictal confusion** argues against a generalized seizure. *Echocardiography* - This test evaluates cardiac structure and function. While cardiac issues can cause syncope, her **normal ECG** and classic vasovagal presentation make a primary cardiac cause less likely. - There are no symptoms such as chest pain, dyspnea on exertion, or family history of sudden cardiac death to suggest a cardiac pathology. *CT head* - A CT head is typically used to evaluate for acute neurological events like stroke or hemorrhage, which are not suggested by this patient's presentation. - The patient's rapid and complete recovery, along with a normal neurological exam, makes an acute intracranial pathology highly improbable.

Question 345: A 34-year-old man presents to the neurology clinic for an appointment after having been referred by his family physician. Four months earlier, he presented with worsening upper limb weakness. His primary complaint at that time was that he was unable to play badminton because of increasing difficulty in moving his shoulders and arms. The weakness later progressed, and he now has spontaneous twitching of his leg and thigh muscles throughout the day. He also feels increasingly fatigued. On physical examination, there is significant atrophy of his arm and thigh muscles. Cranial nerves testing is unremarkable. The pupillary light and accommodation reflexes are both normal. Swallowing, speech, and eye movements are all normal. His cousin had similar symptoms at the age of 19 years old. Which of the following is most likely to also be seen in this patient?

A. Spastic paralysis (Correct Answer)
B. Positive Romberg sign
C. Bowel incontinence
D. Cape-like sensory loss
E. Paresthesia

Explanation: ***Spastic paralysis*** - The combination of **progressive muscle weakness**, **atrophy**, and **spontaneous muscle twitching (fasciculations)**, with normal cranial nerves except for muscle weakness, points towards a diagnosis of **Amyotrophic Lateral Sclerosis (ALS)**. - In ALS, there is degeneration of both **upper motor neurons** (leading to spasticity and hyperreflexia) and **lower motor neurons** (leading to weakness, atrophy, and fasciculations), so **spastic paralysis** (due to upper motor neuron involvement) would be expected. *Positive Romberg sign* - A **positive Romberg sign** indicates dysfunction in **proprioception** (dorsal columns) or **cerebellar function**, neither of which is characteristic of ALS in its early to mid-stages. - ALS primarily affects motor neurons, and sensory pathways are typically spared, meaning proprioceptive deficits are not a common feature. *Bowel incontinence* - **Bowel and bladder control** are generally preserved in ALS, as the **sphincter muscles** are often spared until very late stages, distinguishing it from conditions like spinal cord injury. - Incontinence would suggest damage to the **autonomic nervous system** or specific spinal cord segments not primarily affected in ALS. *Cape-like sensory loss* - **Cape-like sensory loss** (loss of pain and temperature sensation in a shawl-like distribution over the shoulders and upper trunk) is characteristic of **syringomyelia**, a condition involving a fluid-filled cyst within the spinal cord. - This symptom pattern is due to damage to the **spinothalamic tracts** as they cross in the spinal cord, and it is not typically seen in ALS, which spares sensory pathways. *Paresthesia* - **Paresthesias** (e.g., tingling, numbness) indicate **sensory nerve involvement** or **dorsal column dysfunction**. - ALS is predominantly a **motor neuron disease**, and sensory symptoms like paresthesia are generally absent or minor, serving as a key differentiating factor from sensory neuropathies.

Question 346: A 43-year-old gentleman with a history of intravenous drug use presents with general fatigue and weakness accompanied by swelling in his ankles and lower legs. Further questions elicit that he has had many infections due to his drug use but has not previously had any cardiac or pulmonary issues. Upon physical examination you notice a holosystolic blowing murmur radiating to the right sternal border, which the patient denies being told about previously. Based on this presentation, what is the most likely cause of the murmur?

A. Tricuspid regurgitation (Correct Answer)
B. Tricuspid stenosis
C. Ventricular septal defect
D. Mitral regurgitation
E. Mitral stenosis

Explanation: ***Tricuspid regurgitation*** - The patient's history of **intravenous drug use** significantly increases the risk of **infective endocarditis** affecting the tricuspid valve due to bacteria introduced through injection. - A **holosystolic blowing murmur radiating to the right sternal border** is a classic finding for tricuspid regurgitation, especially in the context of right-sided heart involvement often seen in IV drug users. *Tricuspid stenosis* - This condition typically presents with a **diastolic murmur** and is less common in the setting of endocarditis from intravenous drug use. - While it can cause right heart failure symptoms, the murmur quality (**diastolic rumbling**) is inconsistent with the described holosystolic murmur. *Ventricular septal defect* - A VSD typically presents with a **holosystolic murmur** best heard at the **left sternal border**, which can be harsh rather than blowing. - While it is a holosystolic murmur, it is usually congenital and not typically acquired in adulthood due to IV drug use or infection in the same manner as tricuspid regurgitation. *Mitral regurgitation* - Would present with a **holosystolic murmur** that radiates to the **axilla** or left sternal border, not the right sternal border. - Though possible in endocarditis, it is less common than tricuspid involvement in IV drug users and the radiation pattern is incorrect. *Mitral stenosis* - This condition is characterized by a **diastolic rumble** with an opening snap, which is inconsistent with a holosystolic blowing murmur. - Symptoms would include dyspnea and pulmonary hypertension, but the murmur description does not fit.

Question 347: A 72-year-old man presents to his physician’s office with complaints of a cough and painful breathing for the last 2 months. He says that he has also observed a 5 kg (11 lb) weight loss during the past month. He is relatively healthy but the sudden change in his health worries him. Another problem that he has been facing is the swelling of his face and arms at unusual times of the day. He says that the swelling is more prominent when he is supine. He has also lately been experiencing difficulty with his vision. He consumes alcohol occasionally and quit smoking last year following a 25-year history of smoking. On examination, the patient is noted to have distended veins in the chest and arms. His jugular veins are distended. Physical examination shows ptosis of the right eye and miosis of the right pupil. His lungs are clear to auscultation. He is sent for an X-ray for further evaluation of his condition. Which of the following is the most likely site for the detection of the nodule on CT scan?

A. Right upper lobe (Correct Answer)
B. Brain stem metastasis
C. Left upper lobe
D. Central hilar region
E. Peripheral bronchial region

Explanation: ***Right upper lobe*** - The patient's symptoms, including **Ptosis**, **Miosis**, and **Anhidrosis** of the right side of the face, are indicative of **Horner's syndrome**. - **Horner's syndrome** in a patient with a smoking history, cough, weight loss, and edema of the face and arms (suggesting **SVC syndrome**) points strongly to a **Pancoast tumor** (superior sulcus tumor). - The tumor is located in the **right upper lobe** specifically because the **Horner's syndrome is right-sided** (right ptosis, right miosis). Pancoast tumors cause **ipsilateral** Horner's syndrome by invading the sympathetic chain on the same side as the tumor. *Brain stem metastasis* - While a brain stem lesion could cause vision difficulties and neurological deficits, it does not explain the **SVC syndrome** (facial/arm swelling, distended veins) or the pulmonary symptoms like cough and weight loss. - **Pancoast tumors** can cause vision changes due to **Horner's syndrome**, not necessarily brain metastasis. *Left upper lobe* - Although a tumor in the left upper lobe could cause similar symptoms to a right upper lobe tumor, the examination findings of **ptosis** and **miosis** on the **right side** localize the lesion to the **right apex**. - **Horner's syndrome** develops on the **ipsilateral side** of the sympathetic chain disruption. *Central hilar region* - A tumor in the central hilar region would typically cause symptoms related to bronchial obstruction or compression of central structures, such as a persistent cough, hemoptysis, or SVC syndrome if it's large enough. - However, it is less likely to directly cause **Horner's syndrome** with ptosis and miosis localized to one eye, which is a hallmark of an apical (Pancoast) tumor affecting the sympathetic chain. *Peripheral bronchial region* - A peripheral bronchial nodule would usually present with a cough, possibly hemoptysis, or be asymptomatic until it grows large enough to cause obstructive symptoms or pleural involvement. - It is unlikely to cause both **SVC syndrome** and **Horner's syndrome** simultaneously, which are characteristic of an apical lung tumor.

Question 348: A 62-year-old woman is brought to the physician because of 6 months of progressive weakness in her arms and legs. During this time, she has also had difficulty swallowing and holding her head up. Examination shows pooling of oral secretions. Muscle strength and tone are decreased in the upper extremities. Deep tendon reflexes are 1+ in the right upper and lower extremities, 3+ in the left upper extremity, and 4+ in the left lower extremity. Sensation to light touch, pinprick, and vibration are intact. Which of the following is the most likely diagnosis?

A. Guillain-Barré syndrome
B. Amyotrophic lateral sclerosis (Correct Answer)
C. Spinal muscular atrophy
D. Myasthenia gravis
E. Syringomyelia

Explanation: ***Amyotrophic lateral sclerosis*** - The patient presents with a combination of **upper motor neuron (UMN)** signs (hyperreflexia at 3+ and 4+, possibly stiffness contributing to difficulty holding head up) and **lower motor neuron (LMN)** signs (progressive weakness, decreased muscle tone, pooling of oral secretions due to bulbar involvement). This coexistence is pathognomonic for **ALS**. - The **progressive nature** of the weakness in arms and legs, encompassing both UMN and LMN features without sensory deficits, is characteristic of ALS. *Guillain-Barré syndrome* - Typically presents with **acute or subacute onset (days to weeks)** of ascending weakness, often post-infectious, and characteristically causes **areflexia** or severely diminished deep tendon reflexes. - This patient's symptoms have been progressive over **6 months**, and she exhibits significantly **increased reflexes** in some limbs, which is inconsistent with GBS. *Spinal muscular atrophy* - This is a group of **autosomal recessive disorders** that primarily affect **lower motor neurons**, leading to progressive muscle weakness and atrophy, usually presenting in infancy or childhood. - The patient's age of presentation (62 years old) and the presence of **upper motor neuron signs** (hyperreflexia) rule out SMA. *Myasthenia gravis* - Presents with **fluctuating muscle weakness** that worsens with activity and improves with rest, often affecting ocular, bulbar, and limb muscles. It does not typically cause hyperreflexia or sustained upper motor neuron signs. - While the patient has difficulty swallowing and pooling oral secretions, the **progressive, sustained weakness** and varied deep tendon reflexes (hypo to hyper) are not typical of myasthenia gravis without specific triggers like exertion. *Syringomyelia* - Characterized by a **syrinx (cyst) within the spinal cord**, leading to sensory deficits (often **"cape-like" loss of pain and temperature sensation**) and weakness/atrophy due to LMN damage, usually affecting the upper extremities. - This patient's **intact sensation** and the presence of widespread UMN signs (hyperreflexia in lower limb) make syringomyelia an unlikely diagnosis.

Question 349: A 48-year-old woman comes to the physician for the evaluation of 24-hour blood pressure monitoring results. Over the last 3 months, she has had intermittent nausea, decreased appetite, and increasing weakness and fatigue during the day. She has been treated twice for kidney stones within the past year. Her current medications include lisinopril, amlodipine, and furosemide. She is 178 cm (5 ft 10 in) tall and weighs 97 kg (214 lb); BMI is 31 kg/m2. Her blood pressure is 152/98 mm Hg. Physical examination shows no abnormalities. Serum studies show: Na+ 141 mEq/L Cl− 101 mEq/L K+ 4.5 mEq/L HCO3− 24 mEq/L Calcium 12.9 mg/dL Creatinine 1.0 mg/dL Twenty-four-hour blood pressure monitoring indicates elevated nocturnal blood pressure. Further evaluation is most likely to show which of the following findings?

A. Increased serum parathyroid hormone (Correct Answer)
B. Decreased nocturnal oxygen saturation
C. Decreased serum thyroid-stimulating hormone
D. Decreased renal blood flow
E. Increased serum aldosterone-to-renin ratio

Explanation: ***Increased serum parathyroid hormone*** - The patient presents with **hypercalcemia** (12.9 mg/dL), a history of recurrent **kidney stones**, and non-specific symptoms like nausea, fatigue, and weakness, which are classic signs of **primary hyperparathyroidism**. - **Primary hyperparathyroidism** is characterized by autonomous overproduction of parathyroid hormone (PTH), leading to increased serum calcium and often bone and kidney complications. *Decreased nocturnal oxygen saturation* - While **obstructive sleep apnea (OSA)** is common in obese patients and can cause **nocturnal hypertension**, there is no direct evidence (e.g., snoring history, daytime sleepiness) in this case to suggest OSA is the primary issue. - The patient's prominent symptoms (hypercalcemia, kidney stones) point more strongly towards an endocrine disorder than sleep-disordered breathing. *Decreased serum thyroid-stimulating hormone* - **Hyperthyroidism** typically presents with symptoms like weight loss, heat intolerance, tremor, and palpitations, which are not described. Elevated calcium is not a primary feature of hyperthyroidism. - While hyperthyroidism can affect blood pressure, it does not explain the recurrent kidney stones or the profound hypercalcemia seen here. *Decreased renal blood flow* - **Renal artery stenosis** can cause **hypertension** and might eventually lead to elevated creatinine, but it does not directly explain the hypercalcemia or recurrent kidney stones. - The patient's creatinine (1.0 mg/dL) is normal, making significant renal impairment due to reduced renal blood flow less likely at this stage. *Increased serum aldosterone-to-renin ratio* - An **increased aldosterone-to-renin ratio** suggests **primary aldosteronism**, which presents with **hypertension** and often **hypokalemia**, neither of which are present here (K+ is normal at 4.5 mEq/L). - Primary aldosteronism does not cause hypercalcemia or kidney stones.

Question 350: A 67-year-old woman comes to the physician for chest tightness, shortness of breath, and lightheadedness. She has experienced these symptoms during the past 2 weeks while climbing stairs but feels better when she sits down. She had a cold 2 weeks ago but has otherwise been well. She appears short of breath. Her respirations are 21/min and blood pressure is 131/85 mmHg. On cardiovascular examination, a systolic ejection murmur is heard best in the third right intercostal space. The lungs are clear to auscultation. Which of the following mechanisms is the most likely cause of this patient's current condition?

A. Narrowing of the coronary arterial lumen
B. Inflammatory constriction of the bronchioles
C. Cellular injury of the esophageal epithelium
D. Critical transmural hypoperfusion of the myocardium
E. Increased left ventricular oxygen demand (Correct Answer)

Explanation: ***Increased left ventricular oxygen demand*** - The patient's symptoms of chest tightness, shortness of breath, and lightheadedness exacerbated by exertion (climbing stairs) and relieved by rest are classic signs of **angina pectoris**. - The **systolic ejection murmur** in the third right intercostal space suggests **aortic stenosis**, which increases the **afterload** on the left ventricle, leading to increased oxygen demand to maintain cardiac output, especially during exertion. *Narrowing of the coronary arterial lumen* - While narrowing of the coronary arterial lumen (coronary artery disease) can cause similar exertional symptoms, the presence of a **systolic ejection murmur** points more specifically to a valvular issue like **aortic stenosis** as the primary driver of symptoms. - Though coronary artery disease could coexist, the murmur provides a more direct pathophysiological link to the described symptoms of high left ventricular stress. *Inflammatory constriction of the bronchioles* - This mechanism would typically present with wheezing and diffuse crackles on lung auscultation, not a **cardiac murmur**, and would likely involve more persistent respiratory distress rather than exertional and rapidly relievable symptoms. - The patient's **clear lungs to auscultation** makes bronchoconstriction less likely. *Cellular injury of the esophageal epithelium* - **Esophageal pain** (e.g., from reflux or spasm) can sometimes mimic cardiac pain, but it is not typically associated with a **systolic ejection murmur** or relief with rest from a cardiac perspective. - The symptoms of lightheadedness and exertional dyspnea are also not typical of esophageal pathology. *Critical transmural hypoperfusion of the myocardium* - This refers to severe ischemia, often seen in acute coronary syndromes, which might cause similar symptoms but typically presents as more severe and less easily relieved pain than classic stable angina. - While potential with severe coronary artery disease, the specific murmur points to **aortic stenosis** being a major contributor, where hypoperfusion is secondary to increased demand rather than solely primary arterial occlusion.

Question 351: A 42-year-old woman comes to the physician because of a 2-week history of joint pain and fatigue. She has a history of multiple unprovoked deep vein thromboses. Physical examination shows small bilateral knee effusions and erythematous raised patches with scaling and follicular plugging over the ears and scalp. Oral examination shows several small ulcers. Laboratory evaluation of this patient is most likely to show which of the following?

A. Decreased activated partial thromboplastin time
B. Negative anti-double-stranded DNA antibodies
C. Negative antinuclear antibodies
D. Positive anti-citrullinated peptide antibodies
E. Positive rapid plasma reagin test (Correct Answer)

Explanation: ***Positive rapid plasma reagin test*** - The constellation of **joint pain**, **fatigue**, **thromboses**, **skin lesions** (reminiscent of **discoid lupus**), and **oral ulcers** is highly suggestive of **systemic lupus erythematosus (SLE)**. - Approximately 10-20% of SLE patients have a **false-positive rapid plasma reagin (RPR)** or **Venereal Disease Research Laboratory (VDRL)** test due to the presence of **anticardiolipin antibodies**, which also contribute to the thrombotic events seen in **antiphospholipid syndrome (APS)**, often co-occurring with SLE. *Decreased activated partial thromboplastin time* - Patients with APS, a common comorbidity with SLE, often have **antiphospholipid antibodies** (e.g., **lupus anticoagulant**), which can paradoxically prolong the **activated partial thromboplastin time (aPTT)** in vitro, although they are associated with a **prothrombotic state** in vivo. - A decreased aPTT would indicate a **hypercoagulable state** but is not typically associated with the specific antibody profile seen in APS and SLE. *Negative anti-double-stranded DNA antibodies* - **Anti-double-stranded DNA (anti-dsDNA) antibodies** are **highly specific for SLE** and are present in 60-80% of patients, particularly during active disease. - Given the strong clinical picture of SLE, it is **unlikely** that these antibodies would be negative. *Negative antinuclear antibodies* - **Antinuclear antibodies (ANAs)** are present in over 95% of SLE patients and are a **highly sensitive screening test**; a negative result makes the diagnosis of SLE extremely unlikely. - The diverse systemic symptoms described, including joint pain, fatigue, thromboses, skin lesions, and oral ulcers, are classic features of SLE, suggesting a positive ANA would be expected. *Positive anti-citrullinated peptide antibodies* - **Anti-citrullinated peptide antibodies (ACPA)**, such as anti-CCP, are highly specific for **rheumatoid arthritis (RA)**. - While both SLE and RA can cause joint pain, the additional features of **thrombosis**, **skin rash with follicular plugging**, and **oral ulcers** are not characteristic of RA and point away from this diagnosis.

Question 352: A 74-year-old man comes to the physician for a 6-month history of progressively worsening fatigue and shortness of breath on exertion. He immigrated to the United States 35 years ago from India. His pulse is 89/min and blood pressure is 145/60 mm Hg. Crackles are heard at the lung bases. Cardiac examination shows a grade 3/6 early diastolic murmur loudest at the third left intercostal space. Further evaluation of this patient is most likely to show which of the following?

A. Paradoxical splitting of S2
B. Pulsus paradoxus
C. Pulsus parvus et tardus
D. Fixed splitting of S2
E. Water hammer pulse (Correct Answer)

Explanation: ***Water hammer pulse*** - The patient's presentation with **fatigue**, **dyspnea**, **crackles**, and a **grade 3/6 early diastolic murmur** loudest at the **third left intercostal space** is highly suggestive of **aortic regurgitation (AR)**. - A **water hammer pulse** (also known as a **Corrigan's pulse**) is a **bounding**, **collapsing pulse** characteristic of severe AR due to the rapid runoff of blood from the aorta into the left ventricle during diastole, causing a widened pulse pressure (145/60 mmHg in this case). *Paradoxical splitting of S2* - **Paradoxical splitting of S2** occurs when the aortic valve closes *after* the pulmonic valve, typically due to **left bundle branch block** or **severe aortic stenosis**, which are not indicated here. - In such cases, the split narrows or disappears during inspiration. *Pulsus paradoxus* - **Pulsus paradoxus** is an exaggerated drop in systolic blood pressure (>10 mmHg) during inspiration, commonly seen in **cardiac tamponade**, **severe asthma**, or **constrictive pericarditis**. - There are no features in the patient's history or examination to suggest these conditions. *Pulsus parvus et tardus* - **Pulsus parvus et tardus** (small and delayed pulse) is characteristic of **severe aortic stenosis**, where the pulse is weak and slow to rise due to obstruction of left ventricular outflow. - The murmur described, an **early diastolic murmur**, is indicative of **aortic regurgitation**, not stenosis. *Fixed splitting of S2* - **Fixed splitting of S2** is typically associated with an **atrial septal defect (ASD)**, where the split between the aortic and pulmonic components of S2 remains constant during respiration. - There is no clinical evidence to suggest an ASD in this patient.

Question 353: A 55-year-old woman complains of daytime somnolence. Her BMI is 32 kg/m² and her husband says she snores frequently during the night. Polysomnography test reveals the patient experiences more than 5 obstructive events an hour. The patient is at increased risk of developing which of the following?

A. Pulmonary hypertension (Correct Answer)
B. Hypersensitivity pneumonitis
C. Emphysema
D. Idiopathic pulmonary fibrosis
E. Pleural effusion

Explanation: ***Pulmonary hypertension*** - The patient's symptoms (daytime **somnolence**, **snoring**, **BMI** of 32 kg/m3 with more than 5 obstructive events an hour as per **polysomnography**) are highly suggestive of **obstructive sleep apnea (OSA)**. - OSA leads to **intermittent hypoxia** and **hypercapnia**, causing **pulmonary vasoconstriction** and remodeling of pulmonary arteries, ultimately resulting in **pulmonary hypertension**. *Hypersensitivity pneumonitis* - This is an **immunological lung disease** caused by repeated inhalation of **antigenic particles**, leading to inflammation of the alveoli and small airways. - It is not directly associated with OSA or obesity, and there are no signs of environmental allergen exposure in this case. *Emphysema* - **Emphysema** is a type of **COPD** characterized by the destruction of alveolar walls and enlargement of airspaces, primarily caused by **smoking**. - While patients with OSA may also smoke, OSA itself does not directly cause emphysema. *Idiopathic pulmonary fibrosis* - This is a chronic, progressive **fibrotic lung disease** of unknown etiology, characterized by progressive scarring of the lung tissue. - While its cause is unknown, it is not directly linked to OSA or obesity in the manner that pulmonary hypertension is. *Pleural effusion* - A **pleural effusion** is an accumulation of fluid in the **pleural space**, which can be caused by various conditions like heart failure, pneumonia, or malignancy. - OSA does not directly cause pleural effusion; it is a separate pathology.

Question 354: A 61-year-old man presents to the emergency department with new-onset dizziness. He reports associated symptoms of confusion, headaches, and loss of coordination. The patient’s wife also mentions he has had recent frequent nosebleeds. Physical examination demonstrates a double vision. Routine blood work is significant for a slightly reduced platelet count. A noncontrast CT of the head is normal. A serum protein electrophoresis is performed and shows an elevated IgM spike. The consulting hematologist strongly suspects Waldenström’s macroglobulinemia. Which of the following is the best course of treatment for this patient?

A. Plasmapheresis (Correct Answer)
B. Vincristine
C. Cyclophosphamide
D. Rituximab
E. Prednisone

Explanation: ***Plasmapheresis*** - This patient presents with symptoms of **hyperviscosity syndrome** (dizziness, confusion, headaches, loss of coordination, double vision, nosebleeds) due to high levels of IgM, which is characteristic of Waldenström's macroglobulinemia. - **Plasmapheresis** is the most effective initial treatment to rapidly reduce the IgM level and relieve these acute neurological and hemorrhagic symptoms by removing the excess globulins from the plasma. *Vincristine* - **Vincristine** is a chemotherapy agent used in the treatment of Waldenström's macroglobulinemia, but it is typically used as part of a multi-drug regimen for long-term disease control, not for acute management of hyperviscosity. - Its mechanism involves inhibiting microtubule formation, which is a slower process and would not provide immediate relief for the crisis. *Cyclophosphamide* - **Cyclophosphamide** is an alkylating agent, often part of chemotherapy regimens for Waldenström's macroglobulinemia, especially for long-term disease control to reduce IgM production. - Like vincristine, it works by damaging DNA in cancer cells, a process that is too slow to address the immediate, life-threatening symptoms of hyperviscosity syndrome. *Rituximab* - **Rituximab** is an anti-CD20 monoclonal antibody that targets B-cells, often used in Waldenström's macroglobulinemia to reduce the malignant B-cell clone and subsequent IgM production. - While effective for disease control, its therapeutic effects take weeks to materialize and would not provide rapid relief for acute hyperviscosity. *Prednisone* - **Prednisone** is a corticosteroid that can be used in some hematologic malignancies to reduce inflammation or induce apoptosis in certain cell types. - However, in Waldenström's macroglobulinemia, corticosteroids alone are not effective in rapidly reducing the large IgM burden causing hyperviscosity, and their role is often supportive or part of combination chemotherapy.

Question 355: A previously healthy 20-year-old man is brought to the emergency department 15 minutes after collapsing while playing basketball. He has no history of serious illness. On arrival, there is no palpable pulse or respiratory effort observed. He is declared dead. The family agrees to an autopsy. Cardiac workup prior to this patient's death would most likely have shown which of the following findings?

A. Systolic anterior motion of the mitral valve (Correct Answer)
B. Narrowing of the left main coronary artery
C. Bicuspid aortic valve
D. Asymmetric septal hypertrophy
E. Ventricular septal defect

Explanation: ***Systolic anterior motion of the mitral valve*** - This finding is characteristic of **hypertrophic cardiomyopathy (HCM)**, the most common cause of sudden cardiac death in young athletes. - **Systolic anterior motion (SAM)** of the mitral valve leads to **left ventricular outflow tract (LVOT) obstruction**, which can precipitate fatal arrhythmias during exertion. - While asymmetric septal hypertrophy is the underlying anatomical abnormality in HCM, **SAM is the dynamic functional finding** on echocardiography that directly explains the mechanism of sudden death during exercise due to LVOT obstruction. *Ventricular septal defect* - A **ventricular septal defect (VSD)** is a congenital heart defect that typically presents with a **murmur** and may lead to heart failure or pulmonary hypertension if large. - While VSDs can cause complications, they are not typically associated with sudden cardiac death in a previously healthy young adult collapsing during exertion without prior symptoms. *Narrowing of the left main coronary artery* - Significant **coronary artery disease (CAD)**, especially of the left main, is a common cause of sudden cardiac death but is rare in a **20-year-old** without significant risk factors. - When coronary anomalies occur in young individuals causing sudden death, it's typically due to **anomalous coronary artery origin** rather than atherosclerotic narrowing. *Bicuspid aortic valve* - A **bicuspid aortic valve** is a congenital malformation that can lead to **aortic stenosis** or **regurgitation**, or an increased risk of aortic dissection. - While it can be associated with sudden cardiac events, it is less commonly implicated in sudden cardiac death in an otherwise healthy young athlete during exertion compared to HCM. *Asymmetric septal hypertrophy* - This describes the **morphological hallmark** of **hypertrophic cardiomyopathy (HCM)** where the **interventricular septum** is disproportionately thickened (≥15 mm or septal-to-free wall ratio ≥1.3). - While this is the diagnostic anatomical finding for HCM, **systolic anterior motion (SAM) of the mitral valve** is the specific *dynamic functional abnormality* seen on cardiac workup that directly causes LVOT obstruction and explains the mechanism of sudden death during exercise in this clinical scenario.

Question 356: A 51-year-old man presents to his physician with increased thirst, frequent urination, and fatigue. These symptoms have increased gradually over the past 3 years. He has no past medical history or current medications. Also, he has no family history of endocrinological or cardiovascular diseases. The blood pressure is 140/90 mm Hg, and the heart rate is 71/min. The patient is afebrile. The BMI is 35.4 kg/m2. On physical examination, there is an increased adipose tissue over the back of the neck, and hyperpigmentation of the axilla and inguinal folds. Which of the following laboratory results is diagnostic of this patient’s most likely condition?

A. Random plasma glucose 167 mg/dL
B. Serum insulin level of 10 μU/mL
C. Plasma glucose of 209 mg/dL 2 hours after the oral glucose load (Correct Answer)
D. HbA1c 5.9%
E. Fasting plasma glucose 123 mg/dL

Explanation: ***Plasma glucose of 209 mg/dL 2 hours after the oral glucose load*** - This value indicates **diabetes mellitus** if the 2-hour plasma glucose is ≥200 mg/dL after a 75-g oral glucose tolerance test (OGTT). The patient's symptoms (thirst, frequent urination, fatigue) and risk factors (obesity, hypertension, acanthosis nigricans) are highly suggestive of type 2 diabetes. - The elevated BMI, increased adipose tissue in the neck, and **hyperpigmentation** of the axilla and inguinal folds (**acanthosis nigricans**) are strong indicators of **insulin resistance**, a hallmark of type 2 diabetes. *Random plasma glucose 167 mg/dL* - A random plasma glucose ≥200 mg/dL with classic symptoms of hyperglycemia (polyuria, polydipsia, unexplained weight loss) is diagnostic of diabetes. A value of 167 mg/dL is **elevated** but, in isolation, without meeting the ≥200 mg/dL threshold for a random test, is **not definitively diagnostic** of diabetes. - This result would typically warrant further confirmatory testing, such as a fasting plasma glucose or an oral glucose tolerance test. *Serum insulin level of 10 μU/mL* - A serum insulin level of 10 μU/mL is within the normal range (typically 2-25 μU/mL). In the setting of **insulin resistance**, patients with type 2 diabetes often have **elevated insulin levels** initially as the pancreas tries to compensate, or normal levels if beta-cell function has declined. - An isolated insulin level is **not a diagnostic criterion** for diabetes. *HbA1c 5.9%* - An HbA1c value between 5.7% and 6.4% indicates **prediabetes**. An HbA1c of ≥6.5% is diagnostic of diabetes. - While this value suggests impaired glucose regulation, it is **below the diagnostic threshold** for diabetes. *Fasting plasma glucose 123 mg/dL* - A fasting plasma glucose between 100 mg/dL and 125 mg/dL indicates **prediabetes** (impaired fasting glucose). A fasting plasma glucose of ≥126 mg/dL is diagnostic of diabetes. - This value is **below the diagnostic threshold** for diabetes, similar to the HbA1c result, and would indicate prediabetes rather than confirmed diabetes.

Question 357: A 12-year-old girl is brought to the physician by her mother because she has been waking up multiple times at night to go to the bathroom even though she avoids drinking large amounts of water close to bedtime. She has no significant medical history apart from 3 episodes of lower urinary tract infections treated with nitrofurantoin in the past 2 years. Her family emigrated from Nigeria 10 years ago. Physical examination shows no abnormalities. Laboratory studies show: Hemoglobin 14.2 g/dL MCV 92 fL Reticulocytes 1.5% Serum Osmolality 290 mOsmol/kg H2O Urine Leukocytes negative Nitrite negative Glucose negative Osmolality 130 mOsmol/kg H2O Hemoglobin electrophoresis shows: HbA 56% HbS 43% HbF 1% This patient is at greatest risk for which of the following conditions?

A. Transient arrest of erythropoiesis
B. Necrosis of the renal papillae (Correct Answer)
C. Sickling in the cerebral vessels
D. Autoinfarction of the spleen
E. Pigment stones in the biliary tract

Explanation: ***Necrosis of the renal papillae*** - This patient has **sickle cell trait (HbAS)**, indicated by HbA 56% and HbS 43%. Individuals with sickle cell trait are particularly susceptible to **renal papillary necrosis** due to sickling in the renal medulla, which is a hypoxic and hyperosmolar environment. - The symptoms of **nocturia** and **polyuria** (frequent nighttime urination despite avoiding fluids) along with a **low urine osmolality** (130 mOsmol/kg H2O) despite normal serum osmolality (290 mOsmol/kg H2O) suggest impaired concentrating ability of the kidneys, a common finding in early renal damage associated with sickle cell trait. *Transient arrest of erythropoiesis* - **Transient aplastic crisis** or erythropoiesis arrest is primarily associated with **sickle cell disease (HbSS)**, often triggered by parvovirus B19 infection, leading to a precipitous drop in hemoglobin. - This patient's hemoglobin is within the normal range, and her reticulocyte count is not suggestive of acute aplasia. *Sickling in the cerebral vessels* - **Cerebral vessel sickling** leading to stroke is a severe complication predominantly associated with **homozygous sickle cell disease (HbSS)**, where a much higher percentage of HbS leads to widespread vaso-occlusive crises. - While individuals with sickle cell trait have a very small, albeit increased, risk of stroke compared to the general population, it is not the *greatest risk* among the options for their specific genotype and given clinical presentation. *Autoinfarction of the spleen* - **Splenic autoinfarction** (autosplenectomy) is a hallmark complication of **sickle cell anemia (HbSS)**, occurring due to repeated vaso-occlusive episodes in the splenic microcirculation. - Patients with sickle cell trait typically have a normal-sized spleen and do not experience autoinfarction. *Pigment stones in the biliary tract* - **Pigment gallstones** are a common complication of **chronic hemolytic anemia**, such as that seen in **sickle cell disease (HbSS)**, due to increased bilirubin production from red blood cell breakdown. - Patients with sickle cell trait do not typically experience chronic hemolysis and therefore have no increased risk of pigment gallstones compared to the general population.

Question 358: A 55-year-old man presents to the family medicine clinic after noticing a gradually enlarging smooth and symmetrical bump on his left forearm at the site of his PPD placement 2 days ago. The patient takes lisinopril for hypertension and metformin for diabetes mellitus type 2. He was screened for tuberculosis 2 days ago as a requirement for work. He works as a guard at the county prison. He smokes a half-pack of cigarettes per day and has done so for the last 5 years. His heart rate is 88/min, respiratory rate is 16/min, temperature is 37.3°C (99.2°F), and blood pressure is 142/86 mm Hg. The patient appears clean and overweight. The bleb from the screening test is measured at 12 mm. Acid-fast smear of a sputum sample is negative. Which of the following is recommended for the patient at this time?

A. No treatment
B. Isoniazid for 9 months (Correct Answer)
C. Isoniazid for 6 months
D. Isoniazid for 3 months
E. Rifampin, isoniazid, pyrazinamide, ethambutol

Explanation: ***Isoniazid for 9 months*** - A **PPD induration of 12 mm** in a prison guard (high-risk occupational exposure) indicates **latent tuberculosis infection (LTBI)**, even with a negative sputum smear. - **Isoniazid for 9 months** is a standard and highly effective treatment regimen for LTBI, offering optimal efficacy in preventing progression to active disease. - This remains a preferred option for LTBI treatment in guidelines. *No treatment* - Leaving **latent tuberculosis infection (LTBI)** untreated in a high-risk individual like a prison guard carries a significant risk of progression to active tuberculosis. - The 12 mm induration in a high-risk setting necessitates treatment to prevent future active disease. *Isoniazid for 6 months* - While **isoniazid for 6 months** is an acceptable alternative regimen for **latent tuberculosis infection (LTBI)**, the **9-month course offers superior efficacy** in preventing progression to active disease. - Both durations are recognized in guidelines, but 9 months is generally preferred for adults when treatment completion is expected. *Isoniazid for 3 months* - A 3-month course of **isoniazid monotherapy** is insufficient for treating **latent tuberculosis infection (LTBI)** and would not provide adequate protection against progression to active disease. - This duration is generally not recommended for LTBI treatment (though 3-month combination regimens with rifamycins exist). *Rifampin, isoniazid, pyrazinamide, ethambutol* - This four-drug regimen is used for treating **active tuberculosis disease**, not **latent tuberculosis infection (LTBI)**. - The patient's presentation with a positive PPD but negative acid-fast smear indicates LTBI rather than active disease, which does not require multi-drug therapy.

Question 359: A 50-year-old man presents to his primary care physician for management of a lung nodule. The nodule was discovered incidentally when a chest radiograph was performed to rule out pneumonia. The nodule is 8.5 mm in size and was confirmed by CT. The patient is otherwise healthy, has never smoked, and exercises regularly. The patient works in a dairy factory. He has had no symptoms during this time. His temperature is 97.6°F (36.4°C), blood pressure is 122/81 mmHg, pulse is 83/min, respirations are 12/min, and oxygen saturation is 98% on room air. Physical exam including auscultation of the lungs is unremarkable. Which of the following is the most appropriate next step in management?

A. Biopsy and lymph node dissection
B. PET scan
C. No further workup indicated
D. Surgical excision
E. CT scan in 6 months (Correct Answer)

Explanation: ***CT scan in 6 months*** - The patient has an **incidental lung nodule** that is **8.5 mm** in size in a **low-risk** individual (non-smoker, otherwise healthy). According to the **Fleischner Society guidelines**, for solid nodules between 6-8 mm in low-risk individuals, follow-up CT at 6-12 months is recommended, and for those >8 mm, a CT at 3 months and then depending on findings. Given the patient's low-risk profile and the nodule size, monitoring with a follow-up CT is the most appropriate initial management to assess for growth. - This approach aims to reduce unnecessary invasive procedures while ensuring early detection of potential malignancy through serial imaging. *Biopsy and lymph node dissection* - **Invasive procedures** like biopsy and lymph node dissection are typically reserved for larger nodules, those with suspicious features (e.g., spiculated margins, growth on follow-up), or in high-risk patients. - Performing these procedures on an 8.5 mm nodule in a low-risk patient without any concerning features would expose the patient to **unnecessary risks** and complications. *PET scan* - A **PET scan** is useful for assessing the metabolic activity of a lung nodule and is more commonly used for nodules > 8-10 mm or in patients with a higher pre-test probability of malignancy. - For this 8.5 mm nodule in a low-risk patient, initial observation with serial CT is preferred over immediate PET given the potential for **false positives** and cost. *No further workup indicated* - Although the patient is low-risk and the nodule is relatively small, an 8.5 mm nodule still warrants **some follow-up** to ensure it is benign. - Complete cessation of workup without any follow-up could miss a potentially evolving malignancy, especially since malignancy risk increases with nodule size. *Surgical excision* - **Surgical excision** is a definitive and invasive procedure usually undertaken after a nodule is highly suspected of being malignant based on imaging, biopsy results, or rapid growth. - Recommending immediate surgical excision for an asymptomatic 8.5 mm nodule in a low-risk patient without prior follow-up imaging or further characterization is **premature** and overly aggressive.

Question 360: A 42-year-old man who is employed as a construction worker presents to his primary care physician with complaints of moderate headaches and profuse sweating. He reports the need to carry up to 3 additional shirt changes to work because they drench quickly even with tasks of low physical exertion. His coworkers have commented about his changing glove and boot sizes, which have increased at least 4 times since he joined the company 10 years ago. Physical examination is unremarkable except for blood pressure of 160/95 mm Hg, hyperhidrosis, noticeably large pores, hypertrichosis, widely spaced teeth, and prognathism. Which of the following best explains the patient’s clinical manifestations?

A. Increased serum cortisol
B. Increased thyroid-stimulating hormone
C. Increased serum metanephrines
D. Increased serum insulin-like growth factor 1 (IGF-1) (Correct Answer)
E. Increased serum testosterone

Explanation: ***Increased serum insulin-like growth factor 1 (IGF-1)*** - Elevated **IGF-1** levels are indicative of **acromegaly**, a condition caused by excess growth hormone (GH) secretion, which explains the gradual changes in glove and boot sizes, prognathism, widely spaced teeth, and large pores. - The symptoms of **profuse sweating**, **hypertrichosis**, **headaches**, and **hypertension** are common clinical manifestations of acromegaly due to the systemic effects of chronic GH excess. *Increased serum cortisol* - **Increased cortisol** (Cushing's syndrome) would present with central obesity, moon facies, buffalo hump, and striae, which are not described in the patient. - While hypertension and hyperhidrosis can occur in Cushing's, the characteristic physical changes related to growth are absent. *Increased thyroid-stimulating hormone* - Elevated **TSH** suggests **hypothyroidism**, which would typically cause fatigue, weight gain, cold intolerance, and bradycardia, rather than profuse sweating and hypertension. - **Hyperthyroidism** (low TSH, high thyroid hormones) can cause sweating and hypertension, but it would not explain the gradual increase in body and appendage size. *Increased serum metanephrines* - Elevated **metanephrines** are a hallmark of **pheochromocytoma**, which typically presents with paroxysmal episodes of hypertension, palpitations, and sweating. - While sweating and hypertension are present, the absence of episodic symptoms and the long-term changes in body size make pheochromocytoma less likely. *Increased serum testosterone* - **Increased testosterone** in a male would typically lead to increased muscle mass, acne, and potentially male-pattern baldness, but not the specific skeletal and soft tissue growth patterns observed, such as increased shoe and glove size or prognathism. - While some skin changes might occur, **hyperhidrosis** and the dramatic facial and extremity changes are not characteristic features of testosterone excess.

Question 361: A 50-year-old man comes to the physician for the evaluation of recurrent episodes of chest pain, difficulty breathing, and rapid heart beating over the past two months. During this period, he has had a 4-kg (8.8-lb) weight loss, malaise, pain in both knees, and diffuse muscle pain. Five years ago, he was diagnosed with chronic hepatitis B infection and was started on tenofovir. His temperature is 38°C (100.4°F), pulse is 110/min, and blood pressure is 150/90 mm Hg. Cardiopulmonary examination shows no abnormalities except for tachycardia. There are several ulcerations around the ankle and calves bilaterally. Laboratory studies show: Hemoglobin 11 g/dL Leukocyte count 14,000/mm3 Erythrocyte sedimentation rate 80 mm/h Serum Perinuclear anti-neutrophil cytoplasmic antibodies negative Hepatitis B surface antigen positive Urine Protein +2 RBC 6-7/hpf Which of the following is the most likely diagnosis?

A. Granulomatosis with polyangiitis
B. Giant cell arteritis
C. Thromboangiitis obliterans
D. Polyarteritis nodosa (Correct Answer)
E. Takayasu arteritis

Explanation: ***Polyarteritis nodosa (PAN)*** - This patient presents with **fever**, **weight loss**, **myalgia**, and **arthralgia** along with **skin ulcerations** and **renal involvement** (proteinuria, hematuria), signs of systemic inflammation, and **medium-sized vessel vasculitis**. The history of **chronic Hepatitis B infection** is strongly associated with PAN. - The elevated **ESR** and **leukocytosis** indicate ongoing inflammation, and the chest pain/rapid heart beating could be signs of cardiac involvement, which is common in PAN. The negative p-ANCA also helps rule out other vasculitides. *Granulomatosis with polyangiitis* - This condition is typically associated with **upper and lower respiratory tract involvement**, **glomerulonephritis**, and **c-ANCA positivity** (anti-PR3 antibodies). - The patient's symptoms do not primarily involve sinusitis, pulmonary nodules, or other upper/lower airway disease, and p-ANCA is negative, rather than c-ANCA positive. *Giant cell arteritis* - This is a vasculitis affecting primarily **large-sized arteries**, especially the carotid artery branches, and typically occurs in patients **older than 50 years** (though this patient is 50, other symptoms rule it out). - Key symptoms include **new-onset headache**, **jaw claudication**, **scalp tenderness**, and potential vision loss, none of which are reported here. *Thromboangiitis obliterans* - This condition is strongly linked to **heavy tobacco use** and results in **segmental thrombosis and inflammation of small and medium-sized arteries and veins** in the extremities. - It primarily causes **ischemia of the digits** (fingers and toes), leading to pain, ulcerations, and gangrene, which is not fully consistent with the patient's widespread systemic symptoms and organ involvement. *Takayasu arteritis* - This is a **large-vessel vasculitis** primarily affecting the **aorta and its major branches**, typically seen in **younger women**. - Symptoms often include **claudication**, **absent or diminished pulses**, and **discrepancies in blood pressure between limbs**, which are not described in this patient.

Question 362: A 35-year-old woman presents to the emergency department for evaluation of severe central chest pain for 2 hours. She says the pain is heavy in nature and radiates to her jaw. She has no relevant past medical history. The vital signs and physical examination are non-contributory. Echocardiography is performed. Mitral valve leaflet thickening is observed with several masses attached to both surfaces of the valve leaflets. The coronary arteries appear normal on coronary angiography. Which of the following is most likely associated with this patient's condition?

A. Dermatomyositis
B. Churg-Strauss syndrome
C. Systemic lupus erythematosus (Correct Answer)
D. Fibromyalgia
E. Temporal arteritis

Explanation: ***Systemic lupus erythematosus*** - **Libman-Sacks endocarditis**, characterized by **sterile vegetations on both surfaces of the heart valve leaflets** (often the mitral valve), is a classic cardiac manifestation of SLE. - The key diagnostic feature is the presence of vegetations on **both the atrial and ventricular surfaces** of the valve, distinguishing it from infectious endocarditis. - The patient's presentation with **chest pain radiating to the jaw** (possibly due to embolic phenomena or associated pericarditis) and the echocardiographic finding of **mitral valve leaflet thickening** and **masses (vegetations)** without evidence of coronary artery disease strongly point to this condition. *Dermatomyositis* - This is an inflammatory myopathy primarily affecting the **skin and muscles**, leading to weakness and characteristic rashes (heliotrope rash, Gottron's papules). - While it can have cardiac involvement (e.g., myocarditis, arrhythmias), **valvular vegetations** like those described are not a typical feature. *Churg-Strauss syndrome* - Also known as **Eosinophilic Granulomatosis with Polyangiitis (EGPA)**, this is a rare systemic vasculitis primarily affecting the respiratory tract. - It involves **asthma, eosinophilia, and granulomatous inflammation**, but valvular heart disease with vegetations is not its hallmark cardiac manifestation. *Fibromyalgia* - This is a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and tenderness. - It is a **functional pain syndrome** and does not involve structural heart abnormalities like valvular vegetations. *Temporal arteritis* - This is a **large-vessel vasculitis** (Giant Cell Arteritis) primarily affecting the arteries of the head and neck, typically presenting with headache, jaw claudication, and visual disturbances. - It does not cause valvular vegetations or the type of chest pain described in this case.

Question 363: A 40-year-old woman comes to the physician with a 5-day history of mild shortness of breath with exertion. She has also had a cough for 5 days that became productive of whitish non-bloody sputum 3 days ago. Initially, she had a runny nose, mild headaches, and diffuse muscle aches. She has not had fevers or chills. Three weeks ago, her 9-year-old son had a febrile illness with a cough and an exanthematous rash that resolved without treatment 1 week later. The patient has occasional migraine headaches. Her sister was diagnosed with antiphospholipid syndrome 12 years ago. The patient does not smoke; she drinks 3–4 glasses of wine per week. Her current medications include zolmitriptan as needed. Her temperature is 37.1°C (99°F), pulse is 84/min, respirations are 17/min, and blood pressure is 135/82 mm Hg. Scattered wheezes are heard at both lung bases. There are no rales. Egophony is negative. Which of the following is the most appropriate next step in management?

A. Supportive treatment only (Correct Answer)
B. Obtain D-dimer
C. Perform Bordetella pertussis PCR
D. Administer clarithromycin
E. Conduct a high-resolution chest CT

Explanation: ***Supportive treatment only*** - This patient presents with symptoms highly suggestive of an **acute viral bronchitis**, characterized by an antecedent upper respiratory infection, **non-bloody productive cough**, mild shortness of breath, and scattered wheezes without signs of bacterial pneumonia (e.g., fever, rales, egophony). Acute bronchitis is typically **self-limiting** and managed with symptomatic care. - The history of her son's **febrile illness with cough and rash** (possibly a viral infection) supports a viral etiology for her current respiratory symptoms. *Obtain D-dimer* - A D-dimer test is used to rule out **venous thromboembolism (VTE)**, such as **pulmonary embolism (PE)**. While shortness of breath is a PE symptom, the patient's presentation with a prominent cough, preceding viral symptoms, and absence of high-risk features for PE makes acute viral bronchitis much more likely. - Although the patient's sister has **antiphospholipid syndrome** (which increases risk for both arterial and venous thrombosis), the patient herself has no personal history of thrombosis, and her clinical presentation with gradual onset dyspnea, prominent cough, wheezes, and preceding URI symptoms is typical for **viral bronchitis** rather than PE. - A PE typically causes **acute onset dyspnea** and pleuritic chest pain, which differs from the gradual onset and prominent cough seen here. *Perform Bordetella pertussis PCR* - While *Bordetella pertussis* can cause a prolonged cough (whooping cough), the patient's symptoms are inconsistent with typical pertussis. Pertussis is characterized by **paroxysmal cough** followed by an inspiratory "whoop" and **post-tussive emesis**, which are not reported. - The illness has only been present for 5 days, whereas pertussis often involves a **catarrhal stage** followed by several weeks of paroxysmal cough. *Administer clarithromycin* - **Clarithromycin is an antibiotic** usually prescribed for bacterial infections. Given the patient's likely viral bronchitis, antibiotics are **not indicated** and could contribute to **antibiotic resistance** and adverse effects. - The absence of fever, normal vital signs, and lack of signs of bacterial pneumonia (e.g., rales, egophony, purulent sputum) rule out the immediate need for antibiotic therapy. *Conduct a high-resolution chest CT* - A **high-resolution chest CT (HRCT)** is typically used for diagnosing **interstitial lung diseases** or evaluating persistent, unexplained respiratory symptoms. - In this case, the patient's symptoms are acute and consistent with a **viral respiratory infection**, making an HRCT an **overly aggressive and unnecessary diagnostic step** at this time.

Question 364: A 76-year-old woman presents to the primary care physician for a regular check-up. History reveals that she has had episodes of mild urinary incontinence over the past 2 years precipitated by sneezing or laughing. However, over the past week, her urinary incontinence has occurred during regular activities. Her blood pressure is 140/90 mm Hg, heart rate is 86/min, respiratory rate is 22/min, and temperature is 37.7°C (99.9°F). Physical examination is remarkable for suprapubic tenderness. Urinalysis reveals 15 WBCs/HPF, positive nitrites, and positive leukocyte esterase. Which of the following is the best next step for this patient?

A. Pelvic floor muscle training
B. Ultrasound scan of the kidneys, urinary tract, and bladder
C. Cystoscopy
D. Urine culture (Correct Answer)
E. Start empirical antibiotic therapy

Explanation: ***Urine culture*** - The patient presents with classic **signs of a urinary tract infection (UTI)**: new onset urinary incontinence worsening, suprapubic tenderness, and urinalysis positive for **WBCs, nitrites, and leukocyte esterase**. - A urine culture is essential to **confirm the diagnosis of UTI**, identify the causative organism, and determine antibiotic sensitivity before initiating targeted treatment. *Pelvic floor muscle training* - This intervention is appropriate for **stress urinary incontinence (SUI)**, which the patient initially experienced, but it will not address the acute infection. - While it may be considered after UTI treatment for managing chronic incontinence, it's NOT the immediate priority given the acute infectious symptoms. *Ultrasound scan of the kidneys, urinary tract, and bladder* - An ultrasound might be considered if there were concerns for **obstruction**, **pyelonephritis**, or recurrent UTIs after treatment, but it is not the immediate diagnostic step for an acute, uncomplicated UTI. - The primary goal is to identify and treat the infection first. *Cystoscopy* - **Cystoscopy** is an invasive procedure generally reserved for investigating causes of recurrent UTIs, hematuria, or bladder abnormalities after initial treatment failures or in specific clinical scenarios, not for initial diagnosis of an apparent UTI. - It would be premature and unnecessary at this stage without ruling out a simple infection. *Start empirical antibiotic therapy* - While antibiotics are indeed needed, starting empirical therapy without a culture could lead to **antibiotic resistance** or ineffective treatment if the causative organism is not susceptible to the chosen antibiotic. - Given the suprapubic tenderness and urinalysis findings, a UTI is highly likely, but **culture and sensitivity guided therapy** is the best practice for optimal patient outcomes and to prevent resistance, especially in an elderly patient.

Question 365: In a routine medical examination, a young man is noted to be tall with slight scoliosis and pectus excavatum. He had been told that he was over the 95% percentile for height as a child. Auscultation reveals a heart murmur, and transthoracic echocardiography shows an enlarged aortic root and mitral valve prolapse. Blood screening for fibrillin-1 (FBN1) gene mutation is positive and plasma homocysteine is normal. This patient is at high risk for which of the following complications?

A. Intravascular thrombosis
B. Infertility
C. Aortic dissection (Correct Answer)
D. Spontaneous pneumothorax
E. Mucosal neuromas

Explanation: ***Aortic dissection*** - The constellation of **tall stature**, **scoliosis**, **pectus excavatum**, **enlarged aortic root**, **mitral valve prolapse**, and a **positive FBN1 gene mutation** is highly indicative of **Marfan syndrome**. - **Aortic dissection** is the most life-threatening complication of Marfan syndrome due to the weakened connective tissue in the aortic wall, a direct consequence of the FBN1 mutation affecting fibrillin-1 protein. - Patients with Marfan syndrome require regular cardiovascular surveillance and prophylactic beta-blocker therapy to reduce aortic wall stress. *Intravascular thrombosis* - This complication is more characteristic of conditions like **homocystinuria**, which is ruled out by the **normal plasma homocysteine** level. - Marfan syndrome primarily affects connective tissue strength, not coagulation pathways or endothelial function. *Infertility* - Marfan syndrome does not inherently cause **infertility** in males or females. - The primary health risks for Marfan patients are cardiovascular, musculoskeletal, and ophthalmologic (lens dislocation). *Spontaneous pneumothorax* - While **spontaneous pneumothorax** can occur in Marfan syndrome due to apical blebs and weakened pleural tissue, it is far less immediately life-threatening than aortic dissection. - The question asks for the "high risk" complication, and cardiovascular complications (particularly aortic dissection and rupture) are the leading cause of mortality in Marfan syndrome. *Mucosal neuromas* - **Mucosal neuromas** are characteristic of **Multiple Endocrine Neoplasia type 2B (MEN2B)**, not Marfan syndrome. - MEN2B involves RET proto-oncogene mutations and is associated with medullary thyroid cancer, pheochromocytoma, and a marfanoid habitus, which can be mistaken for Marfan syndrome.

Question 366: A 58-year-old man presents to the emergency department following a motor vehicle accident where he was an unrestrained passenger. On initial presentation in the field, he had diffuse abdominal tenderness and his blood pressure is 70/50 mmHg and pulse is 129/min. Following administration of 2 L of normal saline, his blood pressure is 74/58 mmHg. He undergoes emergency laparotomy and the source of the bleeding is controlled. On the second post-operative day, his blood pressure is 110/71 mmHg and pulse is 90/min. There is a midline abdominal scar with no erythema and mild tenderness. Cardiopulmonary examination is unremarkable. He has had 300 mL of urine output over the last 24 hours. Urinalysis shows 12-15 RBC/hpf, 2-5 WBC/hpf, and trace protein. What additional finding would you expect to see on urinalysis?

A. WBC casts
B. RBC casts
C. Fatty casts
D. Hyaline casts
E. Muddy brown casts (Correct Answer)

Explanation: ***Muddy brown casts*** - The patient's history of **post-traumatic hypovolemic shock** leading to prolonged hypotension, coupled with **oliguria** and an elevated blood pressure on post-operative day 2, are highly suggestive of **acute tubular necrosis (ATN)**. - **Muddy brown granular casts** are a hallmark finding of ATN, representing sloughed renal tubular cells and heme pigments. *WBC casts* - **WBC casts** are characteristic of **pyelonephritis** or **interstitial nephritis**, often accompanied by fever, flank pain, and significant pyuria, none of which are the primary presentation here. - While there are some WBCs in the urine, the overall clinical picture does not point towards an infectious or inflammatory renal process as the primary cause of renal dysfunction. *RBC casts* - **RBC casts** indicate **glomerulonephritis** or severe tubular damage with hemorrhage, suggesting glomerular inflammation or a vasculitic process. - While the urinalysis shows 12-15 RBC/hpf, the absence of other strong indicators of glomerular disease and the prominent history of shock make ATN a more likely diagnosis than glomerulonephritis. *Fatty casts* - **Fatty casts** are typically seen in **nephrotic syndrome**, associated with significant proteinuria (>3.5g/day), hyperlipidemia, and edema. - The patient's trace proteinuria and the absence of other nephrotic syndrome features make this finding unlikely. *Hyaline casts* - **Hyaline casts** are composed of Tamm-Horsfall mucoprotein and can be found in **healthy individuals** as well as in states of **dehydration** or mild renal injury. - While the patient was likely dehydrated, hyaline casts are non-specific and do not explain the degree of renal dysfunction and oliguria observed in this case.

Question 367: A 34-year-old man presents to a clinic with complaints of abdominal discomfort and blood in the urine for 2 days. He has had similar abdominal discomfort during the past 5 years, although he does not remember passing blood in the urine. He has had hypertension for the past 2 years, for which he has been prescribed medication. There is no history of weight loss, skin rashes, joint pain, vomiting, change in bowel habits, and smoking. On physical examination, there are ballotable flank masses bilaterally. The bowel sounds are normal. Renal function tests are as follows: Urea 50 mg/dL Creatinine 1.4 mg/dL Protein Negative RBC Numerous The patient underwent ultrasonography of the abdomen, which revealed enlarged kidneys and multiple anechoic cysts with well-defined walls. A CT scan confirmed the presence of multiple cysts in the kidneys. What is the most likely diagnosis?

A. Simple renal cysts
B. Acquired cystic kidney disease
C. Autosomal recessive polycystic kidney disease (ARPKD)
D. Medullary cystic disease
E. Autosomal dominant polycystic kidney disease (ADPKD) (Correct Answer)

Explanation: ***Autosomal dominant polycystic kidney disease (ADPKD)*** - The patient's presentation with **bilateral ballotable flank masses**, **hypertension**, **recurrent abdominal discomfort**, **hematuria**, and imaging findings of **enlarged kidneys with multiple anechoic cysts** are highly characteristic of ADPKD. - ADPKD is a **heritable systemic disorder** characterized by the progressive development and enlargement of cysts in the kidneys and other organs, often leading to chronic kidney disease and hypertension in adulthood. *Simple renal cysts* - **Simple renal cysts** are typically solitary or few in number and usually do not cause symptoms or significant kidney enlargement. - They are generally **benign** and do not explain the patient's extensive cystic burden, hypertension, or progressive symptoms. *Acquired cystic kidney disease* - **Acquired cystic kidney disease** typically develops in patients with **long-standing end-stage renal disease** or on dialysis, which is not indicated by the patient's current renal function tests (Urea 50 mg/dL, Creatinine 1.4 mg/dL). - The cysts are usually smaller and less numerous than in ADPKD and are not associated with the extensive systemic manifestations seen here. *Autosomal recessive polycystic kidney disease (ARPKD)* - **ARPKD** is a rare and severe form of polycystic kidney disease that usually presents in **infancy or childhood** with significant renal impairment, liver involvement, and often pulmonary hypoplasia. - The patient's age and clinical history, including the onset of symptoms in adulthood, do not align with the typical presentation of ARPKD. *Medullary cystic disease* - **Medullary cystic disease** is a group of inherited kidney disorders characterized by the presence of **cysts primarily in the renal medulla** and tubules, leading to progressive renal failure and salt wasting. - It does not typically present with the striking bilateral flank masses or the large, numerous cortical cysts observed on imaging in this patient.

Question 368: A 76-year-old man comes to the emergency department because of an episode of seeing jagged edges followed by loss of central vision in his right eye. The episode occurred 6 hours ago and lasted approximately 5 minutes. The patient has no pain. He has a 3-month history of intermittent blurriness out of his right eye and reports a 10-minute episode of slurred speech and left-sided facial droop that occurred 2 months ago. He has hypercholesterolemia, stable angina pectoris, hypertension, and a 5-year history of type 2 diabetes mellitus. Medications include glyburide, atorvastatin, labetalol, isosorbide, lisinopril, and aspirin. He feels well. He is oriented to person, place, and time. His temperature is 37°C (98.6°F), pulse is 76/min, respirations are 12/min, and blood pressure is 154/78 mm Hg. The extremities are well perfused with strong peripheral pulses. Ophthalmologic examination shows visual acuity of 20/30 in the left eye and 20/40 in the right eye. Visual fields are normal. Fundoscopic examination shows two pale spots along the supratemporal and inferotemporal arcade. Neurologic examination shows no focal findings. Cardiopulmonary examination shows systolic rumbling at the right carotid artery. The remainder of the examination shows no abnormalities. An ECG shows normal sinus rhythm with no evidence of ischemia. Which of the following is the most appropriate next step in management?

A. Echocardiography
B. Fluorescein angiography
C. Temporal artery biopsy
D. Reassurance and follow-up
E. Carotid duplex ultrasonography (Correct Answer)

Explanation: ***Carotid duplex ultrasonography*** - The patient's presentation with **transient monocular vision loss** (**amaurosis fugax**), transient ischemic attack (TIA) symptoms (**slurred speech, facial droop**), and a **carotid bruit** strongly suggests carotid artery stenosis as the source of emboli. - **Carotid duplex ultrasonography** is the gold standard initial non-invasive imaging test to assess for **carotid artery stenosis** in symptomatic patients. *Echocardiography* - While echocardiography can identify cardiac sources of emboli (e.g., atrial fibrillation, valvular vegetations, PFO), the presence of a **carotid bruit** and prior TIA symptoms points more directly to carotid disease as the cause of transient visual and neurological deficits. - This would be a reasonable next step if carotid studies were negative or if there were strong cardiac risk factors without carotid ones. *Fluorescein angiography* - **Fluorescein angiography** is used to evaluate the retinal circulation and can identify areas of ischemia or neovascularization, but it is not the primary diagnostic tool for determining the **etiology of amaurosis fugax** in a patient with a carotid bruit. - It would be considered if a primary retinal vascular disease, rather than embolic phenomenon, were suspected. *Temporal artery biopsy* - **Temporal artery biopsy** is used to diagnose **giant cell arteritis (temporal arteritis)**, which can cause amaurosis fugax. - However, this patient lacks typical symptoms of giant cell arteritis such as headache, jaw claudication, scalp tenderness, or an elevated ESR/CRP, making it less likely given the prominent carotid bruit and other embolic symptoms. *Reassurance and follow-up* - Given the patient's history of multiple transient ischemic events (amaurosis fugax, TIA) and clear signs of potential atherosclerotic disease (**carotid bruit**, multiple cardiovascular risk factors), **reassurance alone is inappropriate**. - These are warning signs of impending stroke, and prompt investigation and management are crucial to prevent further, potentially permanent, neurological damage.

Question 369: A 69-year-old man is scheduled to undergo radical retropubic prostatectomy for prostate cancer in 2 weeks. He had a myocardial infarction at the age of 54 years. He has a history of GERD, unstable angina, hyperlipidemia, and severe osteoarthritis in the left hip. He is unable to climb up stairs or walk fast because of pain in his left hip. He had smoked one pack of cigarettes daily for 30 years but quit 25 years ago. He drinks one glass of wine daily. Current medications include aspirin, metoprolol, lisinopril, rosuvastatin, omeprazole, and ibuprofen as needed. His temperature is 36.4°C (97.5°F), pulse is 90/min, and blood pressure is 136/88 mm Hg. Physical examination shows no abnormalities. A 12-lead ECG shows Q waves and inverted T waves in leads II, III, and aVF. His B-type natriuretic protein is 84 pg/mL (N < 125). Which of the following is the most appropriate next step in management to assess this patient's perioperative cardiac risk?

A. No further testing
B. 24-hour ambulatory ECG monitoring
C. Radionuclide myocardial perfusion imaging (Correct Answer)
D. Treadmill stress test
E. Resting echocardiography

Explanation: ***Radionuclide myocardial perfusion imaging*** - This patient requires **perioperative cardiac risk assessment** before intermediate-risk surgery (radical prostatectomy). - Key factors include: history of **myocardial infarction**, current cardiac risk factors, and **inability to exercise** due to severe osteoarthritis. - Since he cannot perform exercise stress testing, **pharmacologic stress testing** with radionuclide myocardial perfusion imaging (using agents like adenosine, dipyridamole, or regadenoson) is the most appropriate test to assess for **inducible myocardial ischemia**. - This provides functional assessment of coronary perfusion under pharmacologic stress, helping guide perioperative risk stratification and management. - *Note: The presence of unstable angina would typically require cardiac stabilization first; this question focuses on selecting the appropriate stress test modality for a patient unable to exercise.* *No further testing* - This patient has significant cardiac risk factors including **prior MI**, ongoing cardiac medications, and ECG changes suggesting old infarction. - Proceeding directly to surgery without functional cardiac assessment would be **inappropriate** given his risk profile and the intermediate-risk nature of the planned surgery. *24-hour ambulatory ECG monitoring* - Holter monitoring detects arrhythmias and silent ischemic episodes but does not provide **functional capacity assessment** or evaluation of inducible ischemia under stress conditions. - It is not the primary tool for **perioperative cardiac risk stratification** before major surgery. *Treadmill stress test* - The patient's **severe osteoarthritis** prevents him from climbing stairs or walking fast, making him unable to achieve adequate exercise workload for a treadmill stress test. - This functional limitation makes **exercise stress testing contraindicated**; pharmacologic stress testing is required instead. *Resting echocardiography* - Resting echocardiography assesses **baseline left ventricular function**, wall motion abnormalities from prior infarction, and valvular disease. - While useful for structural assessment, it does **not evaluate for exercise-induced or stress-induced ischemia**, which is critical for perioperative risk assessment in patients with coronary artery disease. - His normal BNP (84 pg/mL) suggests adequate baseline ventricular function, making functional ischemia assessment more relevant than structural evaluation alone.

Question 370: A 53-year-old woman presents to the physician with palpitations and increasing swelling of the legs over the past 3 months. During this time, she has also had generalized pruritus. She has dyspnea on exertion. She has no history of asthma. She occasionally takes ibuprofen for chronic headaches she has had for several years. She does not smoke or drink alcohol. The pulse is 92/min and irregular, blood pressure is 115/65 mm Hg, temperature is 36.7°C (98.1°F), and respiratory rate are 16/min. On physical examination, the skin shows papules and linear scratch marks on the limbs and trunk. She has 2+ pitting edema. Auscultation of the heart shows irregular heartbeats. Examination of the lungs shows no abnormalities. The spleen is palpated 5 cm (1.9 in) below the costal margin. No lymphadenopathy is palpated. The results of the laboratory studies show: Hemoglobin 14 g/dL Leukocyte count 17,500/mm3 Percent segmented neutrophils 25.5% Lymphocytes 16.5% Eosinophils 52% Basophils 2% Platelet count 285,000/mm3 Echocardiography is consistent with restrictive-pattern cardiomyopathy and shows thickening of the mitral valve and a thrombus in the left ventricular apex. Abdominal ultrasound confirms splenomegaly and shows ascites. Which of the following best explains these findings?

A. Eosinophilic granulomatosis with polyangiitis
B. Hodgkin’s lymphoma
C. Drug rash with eosinophilia and systemic symptoms (DRESS)
D. Hypereosinophilic syndrome (Correct Answer)
E. Strongyloidiasis eosinophilia

Explanation: ***Hypereosinophilic syndrome*** - The patient presents with **persistent eosinophilia** (52% eosinophils, absolute count ~9,100/mm³) and systemic involvement affecting multiple organs, including the **heart (restrictive cardiomyopathy, mitral valve thickening, LV thrombus)** and **spleen (splenomegaly)**. - **Pruritus and skin lesions** (papules, scratch marks) along with symptoms like palpitations, dyspnea, and leg swelling further support the diagnosis of hypereosinophilic syndrome. - Classic endomyocardial involvement with **restrictive physiology and thrombus formation** is pathognomonic for cardiac complications of this condition. *Eosinophilic granulomatosis with polyangiitis* - This condition typically involves **asthma or allergic rhinitis**, and often presents with **pulmonary infiltrates** and **neuropathy**, which are not described in this patient. - While it features eosinophilia and systemic manifestations, the **lack of respiratory symptoms** like asthma and specific organ involvement patterns makes it less likely. *Hodgkin's lymphoma* - Although Hodgkin's lymphoma can cause **splenomegaly and systemic symptoms** (like pruritus), it is not typically associated with such profound and isolated **eosinophilia** (52%) or the specific cardiac manifestations described. - **Lymphadenopathy is a hallmark** of Hodgkin's, but is explicitly stated to be absent in this patient. *Drug rash with eosinophilia and systemic symptoms (DRESS)* - DRESS syndrome is characterized by a **skin rash, fever, lymphadenopathy, and internal organ involvement**, typically occurring 2-8 weeks after exposure to a culprit drug. - The patient's long-term use of ibuprofen for chronic headaches makes it an unlikely trigger, and the **absence of a clear recent drug initiation** or a prominent rash with fever makes DRESS less probable. *Strongyloidiasis eosinophilia* - While parasitic infections like strongyloidiasis can cause **significant eosinophilia**, they typically present with **gastrointestinal or pulmonary symptoms** and are less commonly associated with **restrictive cardiomyopathy and mitral valve thickening**. - The clinical picture of specific cardiac and splenic involvement, without typical parasitic infection symptoms, points away from strongyloidiasis.

Question 371: A 78-year-old woman is brought to the physician by her son because of progressive memory loss for the past year. She feels tired and can no longer concentrate on her morning crossword puzzles. She has gained 11.3 kg (25 lb) in the last year. Her father died from complications of Alzheimer disease. She has a history of drinking alcohol excessively but has not consumed alcohol for the past 10 years. Vital signs are within normal limits. She is oriented but has short-term memory deficits. Examination shows a normal gait and delayed relaxation of the achilles reflex bilaterally. Her skin is dry and she has brittle nails. Which of the following is the most likely underlying etiology of this woman’s memory loss?

A. Thiamine deficiency
B. Autoimmune thyroid disease (Correct Answer)
C. Alzheimer disease
D. Vitamin B12 deficiency
E. Normal pressure hydrocephalus

Explanation: ***Autoimmune thyroid disease*** - The patient exhibits classic symptoms of **hypothyroidism**, including **fatigue**, **difficulty concentrating**, **weight gain**, **dry skin**, **brittle nails**, and **delayed relaxation of the Achilles reflex**. - **Hypothyroidism** can lead to cognitive impairment, including memory loss, which may be reversible with treatment. *Thiamine deficiency* - While thiamine deficiency can cause memory loss (Wernicke-Korsakoff syndrome), it typically presents with **ataxia**, **ophthalmoplegia**, and severe global amnesia, often in the context of active alcohol abuse. - The patient's **alcohol consumption** ceased 10 years ago, and she does not exhibit other characteristic symptoms of Wernicke-Korsakoff syndrome. *Alzheimer disease* - Although the patient's father had Alzheimer disease and she has progressive memory loss, her additional symptoms like **weight gain**, **fatigue**, **dry skin**, **brittle nails**, and **delayed reflexes** are not typical for Alzheimer disease. - While Alzheimer's cannot be entirely ruled out, the constellation of symptoms points strongly towards a more immediately treatable cause. *Vitamin B12 deficiency* - Vitamin B12 deficiency can cause **memory loss**, **fatigue**, and neurologic symptoms, but it is not typically associated with **weight gain**, **dry skin**, **brittle nails**, or **delayed deep tendon reflexes**. - Neurologic symptoms often include **peripheral neuropathy** and **paresthesias**. *Normal pressure hydrocephalus* - **Normal pressure hydrocephalus (NPH)** is characterized by the triad of **gait disturbance**, **urinary incontinence**, and **dementia**. - While the patient has memory loss, her gait is described as normal, and there is no mention of urinary incontinence, making NPH less likely.

Question 372: You are called to a hemodialysis suite. The patient is a 61-year-old man with a history of hypertension, hypercholesterolemia, and type-2 diabetes mellitus-induced end-stage renal disease who has required hemodialysis for the past year. His current hemodialysis session is nearing the end when the nurse notices that his blood pressure has dropped to 88/60 mm Hg from his normal of 142/90 mm Hg. The patient denies any shortness of breath or chest pain. He took his daily bisoprolol, metformin, and insulin this morning before coming to the hospital. On examination, the patient’s blood pressure is 92/60 mm Hg, and his heart rate is 119/min. Chest auscultation is unremarkable. What is the most appropriate next management step?

A. Infuse 1 liter of 0.9% saline
B. Administer intravenous calcium gluconate
C. Transfuse the patient with 1 unit of packed red blood cells
D. Stop ultrafiltration and decrease blood flow into the machine (Correct Answer)
E. Start the patient on an epinephrine drip

Explanation: ***Stop ultrafiltration and decrease blood flow into the machine*** - The patient's **hypotension** and **tachycardia** during hemodialysis strongly suggest **intradialytic hypotension**, which is often caused by excessive fluid removal (ultrafiltration) or rapid fluid shifts. - **Stopping ultrafiltration** and **reducing blood flow** allows for gradual re-equilibration of fluid and helps stabilize blood pressure without adding more fluid to a patient with end-stage renal disease. *Infuse 1 liter of 0.9% saline* - Administering a large volume of saline is generally **contraindicated in ESRD patients** given their inability to excrete fluid, which could lead to **fluid overload** and pulmonary edema. - While fluid resuscitation might be considered for severe hypotension, the initial step in intradialytic hypotension is to adjust the dialysis settings. *Administer intravenous calcium gluconate* - **Calcium gluconate** is primarily used to stabilize the cardiac membrane in cases of **severe hyperkalemia**, which is not indicated by the current clinical picture. - There is no mention of ECG changes or lab results to suggest hyperkalemia. *Transfuse the patient with 1 unit of packed red blood cells* - There is no clinical evidence of **acute blood loss** or **severe anemia** presenting with hypovolemic shock. - Transfusion is an intervention for significant blood loss or severe anemia, not for intradialytic hypotension caused by fluid shifts. *Start the patient on an epinephrine drip* - **Vasopressors** like epinephrine are typically reserved for **refractory hypotension** after more conservative measures have failed, or in cases of **septic shock** or **anaphylaxis**. - Initiating a powerful vasopressor as a first step without addressing the potential underlying cause related to dialysis is inappropriate.

Question 373: A 14-year-old boy who has been otherwise healthy presents to his doctor complaining of feeling easily winded and light-headed at basketball practice. He has never felt this way before and is frustrated because he is good enough to make varsity this year. He denies smoking, alcohol, or recreational drug use. His mother is very worried because her oldest son and brother had both died suddenly while playing sports despite being otherwise healthy. The transthoracic echocardiogram confirms the suspected diagnosis, which demonstrates a preserved ejection fraction and systolic anterior motion of the mitral valve. The patient is advised that he will need to stay hydrated and avoid intense exercise, and he will likely need an ICD due to his family history. Which of the following physical exam findings is consistent with this patient’s most likely diagnosis?

A. Tricuspid regurgitation
B. Systolic ejection murmur that radiates to the carotids
C. S3 heart sound
D. Mitral regurgitation
E. Systolic ejection murmur that worsens with the Valsalva maneuver (Correct Answer)

Explanation: ***Systolic ejection murmur that worsens with the Valsalva maneuver*** - The patient's presentation with **syncope/lightheadedness during exertion**, family history of **sudden cardiac death in athletes**, and echocardiogram findings of **systolic anterior motion (SAM) of the mitral valve** are classic for **hypertrophic cardiomyopathy (HCM)**. - The murmur of HCM is typically a **systolic ejection murmur** that **worsens with maneuvers that decrease preload**, such as the **Valsalva maneuver** or standing, because this reduction in ventricular volume exacerbates the left ventricular outflow tract (LVOT) obstruction. *Tricuspid regurgitation* - This is typically associated with **right heart failure** or **pulmonary hypertension**, which are not indicated by the patient's symptoms or echo findings. - While it can be heard as a **systolic murmur**, it usually accentuates with inspiration (Carvallo's sign) and does not worsen with the Valsalva maneuver in the context of hypertrophic cardiomyopathy. *Systolic ejection murmur that radiates to the carotids* - A systolic ejection murmur radiating to the carotids is characteristic of **aortic stenosis**, which involves a fixed obstruction of the aortic valve. - While both HCM and aortic stenosis cause systolic murmurs, HCM's murmur has different auscultatory behavior with preload-altering maneuvers (worsening with Valsalva) compared to aortic stenosis (which often softens or is unchanged). *S3 heart sound* - An **S3 heart sound** is typically a low-pitched diastolic sound associated with **volume overload** and **heart failure with reduced ejection fraction**, indicating rapid ventricular filling into a dilated ventricle. - The patient's echocardiogram shows a **preserved ejection fraction**, and his symptoms are related to outflow obstruction, not volume overload. *Mitral regurgitation* - While **mitral regurgitation (MR)** can occur in HCM due to systolic anterior motion (SAM) of the mitral valve causing malcoaptation, the primary murmur heard due to the **LVOT obstruction** is a **systolic ejection murmur**. - The murmur of MR is typically a **holosystolic murmur** that radiates to the axilla and usually **softens with the Valsalva maneuver** as reduced preload can decrease the severity of regurgitation.

Question 374: A 75-year-old gentleman is brought to the ED with confusion that started earlier this morning. His family notes that he was complaining of feeling weak last night and also had a slight tremor at the time. He is afebrile and he has no known chronic medical conditions. Physical exam reveals a cooperative but confused gentleman. His mucous membranes are moist, he has no focal neurological deficits, and his skin turgor is within normal limits. His lab results are notable for: Serum Na+: 123 mEq/L Plasma osmolality: 268 mOsm/kg Urine osmolality: 349 mOsm/kg Urine Na+: 47 mEq/L Which of the following malignancies is most likely to be responsible for this patient's presentation?

A. Gastric adenocarcinoma
B. Small cell lung cancer (Correct Answer)
C. Esophageal squamous cell carcinoma
D. Non-seminomatous germ cell tumor
E. Rib osteosarcoma

Explanation: ***Small cell lung cancer*** - This patient's laboratory values (hyponatremia, low plasma osmolality, and inappropriately high urine osmolality with elevated urine sodium) are classic for the **Syndrome of Inappropriate Antidiuretic Hormone (SIADH)**. - **Small cell lung cancer** is the most common malignancy associated with paraneoplastic SIADH due to its ability to ectopically produce ADH. *Gastric adenocarcinoma* - While gastric adenocarcinomas can cause paraneoplastic syndromes, SIADH is an **uncommon** paraneoplastic manifestation of this type of cancer. - Other paraneoplastic syndromes, such as **Trousseau's syndrome** (migratory thrombophlebitis), are more classically associated with gastric adenocarcinoma. *Esophageal squamous cell carcinoma* - Esophageal cancer, including squamous cell carcinoma, is **rarely associated** with SIADH. - Its paraneoplastic manifestations are less defined and not prominent for ADH production. *Non-seminomatous germ cell tumor* - Germ cell tumors, particularly non-seminomatous types, are more commonly associated with paraneoplastic syndromes involving **human chorionic gonadotropin (hCG)** or **alpha-fetoprotein (AFP)** production. - While some germ cell tumors *can* release ADH, it is **not a primary cause** of SIADH compared to small cell lung cancer. *Rib osteosarcoma* - Osteosarcoma is a primary bone tumor and is **not typically associated** with paraneoplastic syndromes like SIADH. - Its primary clinical manifestations are related to local bone destruction and metastasis.

Question 375: A 36-year-old man comes to the clinic for "bumps under his nipples." He is anxious that this could be breast cancer as his sister was just recently diagnosed. Past medical history is unremarkable except for an appendectomy at age 13. He currently works as a personal trainer and reports a diet that consists mainly of lean meat. The patient reports drinking 1-2 beers over the weekends. Physical examination demonstrates a muscular physique with mobile smooth masses below the areola bilaterally with no discharge. What other physical exam finding is most likely to be seen in this individual?

A. Palmar erythema
B. Testicular atrophy (Correct Answer)
C. Bitemporal hemianopsia
D. Fluid wave
E. Spider angiomas

Explanation: ***Testicular atrophy*** - The bilateral subareolar masses suggest **gynecomastia**, which can be caused by an **imbalance of estrogens and androgens**. - **Androgen abuse** (e.g., anabolic steroids for muscle building as a personal trainer) can suppress endogenous testosterone production, leading to secondary hypogonadism and consequently, **testicular atrophy**. *Palmar erythema* - **Palmar erythema** is typically associated with **chronic liver disease**, which is not indicated by the patient's history or presenting symptoms. - While liver disease can cause gynecomastia due to impaired estrogen metabolism, there are no other signs pointing to liver dysfunction. *Bitemporal hemianopsia* - **Bitemporal hemianopsia** is a visual field defect caused by compression of the **optic chiasm**, commonly by a **pituitary adenoma**. - While some pituitary adenomas can secrete prolactin (leading to hypogonadism and sometimes gynecomastia), bitemporal hemianopsia is not the most likely finding associated with the probable cause of gynecomastia in this patient. *Fluid wave* - A **fluid wave** is a physical exam sign of **ascites**, which indicates significant fluid accumulation in the peritoneal cavity, usually due to **severe liver disease** or heart failure. - There are no clinical signs or symptoms in the patient's presentation to suggest ascites or these underlying conditions. *Spider angiomas* - **Spider angiomas** (or spider nevi) are small, arteriolar lesions commonly found on the trunk, neck, and face. They are classically associated with **chronic liver disease** or conditions with high estrogen levels (like pregnancy). - Similar to palmar erythema, there is no evidence of liver disease in this patient, making spider angiomas an unlikely finding.

Question 376: A 59-year-old man comes to the clinic for an annual well-exam. He was lost to follow-up for the past 3 years due to marital issues but reports that he feels fine. The patient reports, “I feel tired but it is probably because I am getting old. I do feel a little feverish today - I think I got a cold.” His past medical history is significant for hypertension that is controlled with hydrochlorothiazide. He reports fatigue, congestion, cough, and night sweats. He denies any sick contacts, recent travel, weight changes, chest pain, or dizziness. His temperature is 101°F (38.3°C), blood pressure is 151/98 mmHg, pulse is 97/min, and respirations are 15/min. His laboratory values are shown below: Hemoglobin: 13.5 g/dL Hematocrit: 41% Leukocyte count: 25,000/mm^3 Segmented neutrophils: 73% Bands: 8% Eosinophils: 1% Basophils: 2% Lymphocytes: 15% Monocytes: 2% Platelet count: 200,000/mm^3 What diagnostic test would be helpful in distinguishing this patient’s condition from pneumonia?

A. Erythrocyte sedimentation rate
B. Magnetic resonance imaging of the chest
C. Leukocyte alkaline phosphatase (Correct Answer)
D. Presence of smudge cells
E. C-reactive protein

Explanation: ***Leukocyte alkaline phosphatase*** - This patient's symptoms (fatigue, fever, night sweats, **elevated leukocyte count** with a left shift) suggest a **myeloproliferative disorder** like **Chronic Myeloid Leukemia (CML)**, which can mimic infection. - A **low Leukocyte Alkaline Phosphatase (LAP) score** is characteristic of CML, while an **elevated LAP score** is seen in bacterial infections (like pneumonia) and leukemoid reactions. *Erythrocyte sedimentation rate* - **ESR** is a general marker of **inflammation** and can be elevated in both pneumonia and various hematologic malignancies. - It does not specifically differentiate between inflammatory processes due to infection versus a myeloproliferative disorder. *Magnetic resonance imaging of the chest* - While MRI can detect pulmonary infiltrates suggestive of pneumonia, it is **not typically the first-line imaging** for pneumonia and would not specifically differentiate it from a hematologic malignancy. - **Chest X-ray or CT scan** would be more appropriate for initial pulmonary evaluation, but neither directly helps distinguish between infection and leukemia without other clinical data. *Presence of smudge cells* - **Smudge cells** (fragile lymphocytes) are characteristic of **Chronic Lymphocytic Leukemia (CLL)**. - This patient's **leukocyte differential** shows a predominance of neutrophils and bands, not lymphocytes, making CLL less likely. *C-reactive protein* - **CRP** is another **acute phase reactant** that is elevated in response to inflammation, including infections like pneumonia. - Similar to ESR, a high CRP level would not specifically distinguish between an infectious process and a myeloproliferative disorder.

Question 377: A 55-year-old woman presents to the clinic with joint pain and swelling of her hands. She reports that the pain lasts for about an hour in the morning and improves as her joints 'loosen up'. This condition has been bothering her for about 2 years but has recently been impacting her daily routine. She has not seen a doctor in years. Past medical history is significant for hypertension and she takes hydrochlorothiazide daily. Her grandmother and aunt both had rheumatoid arthritis. She is a current smoker and has smoked a half of a pack of cigarettes a day for the last 20 years. The temperature is 37°C (98.6°F), the blood pressure is 125/85 mm Hg, the respiratory rate is 17/min, and the heart rate is 98/min. Physical examination reveals tender swollen joints in her hands and wrists. Laboratory work is presented below: Hemoglobin 10.7 g/dL Hematocrit 37.5% Leukocyte count 14,000/mm3 Mean corpuscular volume 81.4 μm3 Platelet count 200,000/mm3 Erythrocyte sedimentation rate 45 mm/h Anti-citrullinated protein antibody 55 (normal reference values: < 20) CT findings reveal osteopenia and erosions in the metacarpophalangeal joints. The patient is started on methotrexate. Which of the following is likely to be found in the synovial fluid analysis?

A. Ragocytes (Correct Answer)
B. Calcium phosphate crystals
C. High lymphocyte count
D. Calcium pyrophosphate
E. Monosodium urate crystals

Explanation: ***Ragocytes*** - **Ragocytes** are polymorphonuclear leukocytes (neutrophils) that have phagocytosed immune complexes, appearing as cells with cytoplasmic inclusions. - Their presence in synovial fluid is highly suggestive of **rheumatoid arthritis**, especially in severe cases, indicating chronic inflammation and immune complex formation. *Calcium phosphate crystals* - **Calcium phosphate crystals** are rare causes of inflammatory arthritis and are typically associated with **calcific periarthritis** or destructive arthropathies. - They are not characteristic findings in **rheumatoid arthritis**, which involves immune-mediated inflammation rather than direct crystal deposition. *High lymphocyte count* - While lymphocytes are present in inflamed synovial fluid, a **predominantly high lymphocyte count** is more typical of viral arthritis or early-stage inflammatory conditions. - In established **rheumatoid arthritis**, the synovial fluid is primarily characterized by a high number of **neutrophils**, indicating active inflammation. *Calcium pyrophosphate* - **Calcium pyrophosphate dihydrate (CPPD) crystals** are responsible for **pseudogout**, leading to acute inflammatory arthritis. - These crystals are *rhomboid-shaped* and positively birefringent under polarized light, clinical features distinct from those presented in this case. *Monosodium urate crystals* - **Monosodium urate (MSU) crystals** are the hallmark of **gout**, causing sudden, severe attacks of joint pain, redness, and swelling. - These crystals are *needle-shaped* and negatively birefringent, making them easily distinguishable from other crystal types and not associated with rheumatoid arthritis.

Question 378: A 67-year-old man with a history of chronic alcoholism presents to the emergency department after a suicide attempt. The patient was found in his apartment by his grandson with wrist lacerations. He was rushed to the emergency department and was resuscitated en route. The patient has a past medical history of ischemic heart disease and depression. His pulse is barely palpable and he is not responding to questions coherently. His temperature is 98.2°F (36.8°C), blood pressure is 107/48 mmHg, pulse is 160/min, respirations are 14/min, and oxygen saturation is 99% on room air. After fluid resuscitation and wound care, his blood pressure improves to 127/55 mmHg. On physical exam, the patient complains of numbness surrounding his mouth and pain in the location of the lacerations of his wrists. Which of the following best describes the laboratory findings in this patient?

A. Hyperkalemia
B. Increased free iron
C. No lab abnormalities
D. Hypomagnesemia (Correct Answer)
E. Hypocalcemia

Explanation: ***Hypomagnesemia*** - **Chronic alcoholism** is a significant risk factor for hypomagnesemia due to decreased dietary intake, increased renal excretion, and gastrointestinal losses. - Clinical signs such as **numbness around the mouth** (circumoral paresthesia), **tachycardia**, and **agitation/confusion** can be manifestations of severe hypomagnesemia, which can also predispose to arrhythmias. *Hyperkalemia* - While electrolyte imbalances are common in alcoholism, **hyperkalemia** is less typical in this acute presentation unless associated with other complications like **renal failure** or certain medications. - The patient's symptoms (numbness, tachycardia) are not classic for hyperkalemia; hyperkalemia often presents with **muscle weakness** or **cardiac arrhythmias** (peaked T waves, widened QRS). *Increased free iron* - **Increased free iron** is typically associated with conditions like **hemochromatosis** or acute iron poisoning, neither of which is suggested by the patient's history or symptoms. - Chronic alcoholism can lead to iron overload in some cases, but this is usually chronic and does not manifest acutely with these neurological or cardiac symptoms. *No lab abnormalities* - Given the patient's history of **chronic alcoholism**, presentation with **tachycardia**, altered mental status, and circumoral paresthesia, it is highly unlikely that there would be no laboratory abnormalities. - Alcoholism frequently leads to significant **electrolyte disturbances** and nutritional deficiencies, making "no lab abnormalities" an improbable finding. *Hypocalcemia* - While **hypocalcemia** can cause circumoral paresthesia, it is often secondary to **hypomagnesemia** in alcoholic patients. - **Hypocalcemia** also typically presents with stronger signs of neuromuscular irritability like **tetany**, **Chvostek's sign**, or **Trousseau's sign**, which are not explicitly mentioned.

Question 379: A 33-year-old man comes to the physician because of right scrotal swelling for the past 2 weeks. He has had mild lower abdominal discomfort for the past 3 weeks. There is no personal or family history of serious illness. He appears healthy. Vital signs are within normal limits. Examination shows gynecomastia. There is no inguinal lymphadenopathy. There is a firm nontender nodule over the right testicle. When a light is held behind the scrotum, it does not shine through. When the patient is asked to cough, the nodule does not cause a bulge. The abdomen is soft and nontender. The liver is palpated 2 cm below the right costal margin. Digital rectal examination is unremarkable. Serum alpha-fetoprotein, LDH, and hCG levels are markedly elevated. An x-ray of the chest shows no abnormalities. Ultrasound of the testis shows a cystic 3-cm mass with variable echogenicity. A CT of the abdomen shows multiple hypoattenuating lesions on the liver and retroperitoneal lymph nodes. A radical inguinal orchiectomy with retroperitoneal lymph node dissection is performed. Which of the following is the most appropriate next step in management?

A. Radiation therapy
B. Cisplatin, etoposide, and bleomycin therapy (Correct Answer)
C. Active surveillance
D. Leucovorin, 5-fluorouracil and oxaliplatin therapy
E. Stem cell transplant

Explanation: ***Cisplatin, etoposide, and bleomycin therapy*** - The patient has **metastatic testicular cancer** (elevated tumor markers, liver lesions, retroperitoneal lymph nodes) diagnosed by orchiectomy, making **multi-agent chemotherapy** the most appropriate next step. - The **BEP regimen (Bleomycin, Etoposide, Cisplatin)** is the standard first-line treatment for metastatic germ cell tumors, offering high cure rates. *Radiation therapy* - While radiation therapy can be used in some testicular cancer cases, it's typically reserved for **localized disease** or specific **lymph node involvement** after initial chemotherapy. - It is not the primary treatment for widespread metastatic disease involving multiple organs like the liver and retroperitoneal lymph nodes. *Active surveillance* - **Active surveillance** is typically reserved for patients with **Stage I non-seminomatous germ cell tumors (NSGCT)** after orchiectomy, especially if they have favorable prognostic factors. - This patient has widespread metastatic disease, evidenced by elevated tumor markers, liver, and retroperitoneal lymph node involvement, making active surveillance an unsuitable and dangerous option. *Leucovorin, 5-fluorouracil and oxaliplatin therapy* - This regimen (FOLFOX) is a standard chemotherapy combination often used for **colorectal cancer** and some other gastrointestinal malignancies. - It is not the appropriate first-line treatment for metastatic testicular germ cell tumors. *Stem cell transplant* - **High-dose chemotherapy with stem cell rescue** is typically considered for **relapsed or refractory germ cell tumors** after initial standard chemotherapy has failed. - It is not the initial treatment for newly diagnosed metastatic testicular cancer.

Question 380: A 72-year-old female presents to the emergency department following a syncopal episode while walking down several flights of stairs. The patient has not seen a doctor in several years and does not take any medications. Your work-up demonstrates that she has symptoms of angina and congestive heart failure. Temperature is 36.8 degrees Celsius, blood pressure is 160/80 mmHg, heart rate is 81/min, and respiratory rate is 20/min. Physical examination is notable for a 3/6 crescendo-decrescendo systolic murmur present at the right upper sternal border with radiation to the carotid arteries. Random blood glucose is 205 mg/dL. Which of the following portends the worst prognosis in this patient?

A. Hypertension
B. Angina
C. Diabetes
D. Syncope
E. Congestive heart failure (CHF) (Correct Answer)

Explanation: ***Congestive heart failure (CHF)*** - Once **congestive heart failure** symptoms develop in severe aortic stenosis, the prognosis is very poor, with an average survival of 1.5-2 years if untreated. - This indicates significant myocardial dysfunction and increased risk of sudden cardiac death. *Syncope* - **Syncope** in aortic stenosis, while serious and indicating reduced cerebral perfusion, has a slightly better prognosis than CHF, with an average survival of 2-3 years untreated. - It often reflects a critical reduction in cardiac output, but the heart muscle itself may still have some compensatory capacity. *Angina* - **Angina** is a common symptom of aortic stenosis, reflecting increased myocardial oxygen demand or reduced coronary perfusion. - Untreated, patients with angina in aortic stenosis have an average survival of 3-5 years, which is better than syncope or CHF. *Hypertension* - While **hypertension** is a risk factor for aortic stenosis and can exacerbate symptoms, it is not a direct symptom of severe aortic stenosis itself but rather a co-morbidity. - Its presence doesn't inherently portend a worse prognosis for aortic stenosis than the severe symptomatic manifestations like syncope or CHF. *Diabetes* - **Diabetes** is a systemic disease that can accelerate atherosclerosis and increase cardiovascular risk, but it is a chronic condition rather than an acute symptom of severe aortic stenosis. - While it complicates management and overall prognosis, its impact is not as immediate or as severe as the development of CHF directly attributable to the aortic stenosis itself.

Question 381: A 77-year-old woman presents to her physician because of fatigue and progressive dyspnea despite receiving optimal treatment for heart failure. Her medical history is positive for heart failure, active tuberculosis, and chronic renal failure, for which she has been in long-term hemodialysis (13 years). The woman currently takes rifampin and isoniazid. Her physical exam shows the presence of hepatomegaly and jugular venous distention that fails to subside on inspiration (Kussmaul's sign) and an impalpable apical impulse. Her pulse is 122/min, respiratory rate 16/min, temperature 36.0°C (97.4°F), and blood pressure 120/60 mm Hg. Her cardiac monitor shows a prominent y descent in her jugular venous pulse. A cardiac ultrasound shows pericardial calcifications and small tubular-shaped ventricles. Which of the following is the most likely cause of this patient's current condition?

A. Constrictive pericarditis (Correct Answer)
B. Dilated cardiomyopathy
C. Atrial fibrillation
D. Restrictive cardiomyopathy
E. Hypertrophic cardiomyopathy

Explanation: ***Constrictive pericarditis*** - The patient presents with **fatigue, dyspnea, hepatomegaly, jugular venous distention with Kussmaul's sign**, and an **impalpable apical impulse**, all classic signs of **right-sided heart failure** due to impaired ventricular filling. - The history of **tuberculosis** and **chronic renal failure** (risk factors for pericardial disease), along with **pericardial calcifications** and **small, tubular-shaped ventricles** on ultrasound, strongly points to constrictive pericarditis. *Dilated cardiomyopathy* - This condition is characterized by **ventricular dilation** and **systolic dysfunction**, leading to signs of both left and right heart failure. - The ultrasound finding of **small, tubular-shaped ventricles** contradicts the definition of dilated cardiomyopathy. *Atrial fibrillation* - While atrial fibrillation can cause **palpitations, fatigue, and dyspnea**, it is an arrhythmia primarily affecting cardiac rhythm. - It does not directly explain the **pericardial calcifications, Kussmaul's sign**, or the specific ventricular morphology seen on ultrasound. *Restrictive cardiomyopathy* - This condition involves increased **ventricular stiffness**, leading to impaired diastolic filling and typically presents with signs of **diastolic heart failure**. - Although it can cause similar symptoms to constrictive pericarditis, it is primarily a **myocardial** disease and would not typically show **pericardial calcifications** on imaging. *Hypertrophic cardiomyopathy* - This involves **thickening of the ventricular walls**, often leading to **outflow tract obstruction** and **diastolic dysfunction**. - The imaging showing **small, tubular-shaped ventricles** and **pericardial calcifications** are inconsistent with hypertrophic cardiomyopathy, which would show thickened myocardium.

Question 382: A 75-year-old male presents to the emergency room complaining of severe lower abdominal pain and an inability to urinate. He reports that he last urinated approximately nine hours ago. When asked to urinate, only a few drops dribble from the tip of his penis. Further questioning reveals that the patient has experienced progressively worsening difficulty with urinating over the past two years. He has lived alone for five years since his wife passed away. He has not seen a doctor in that time. His temperature is 98.8°F (37.1°C), blood pressure is 145/90 mmHg, pulse is 115/min, and respirations are 22/min. He appears to be in severe pain. Physical examination reveals a distended bladder and significant tenderness to palpation over the inferior aspect of his abdomen. Which of the following sets of lab values would most likely be found in a urinalysis of this patient?

A. Urine osmolality 550 mOsmol/kg H2O, Urine Na+ 15 mEq/L, FENa 0.9%, red blood cell casts
B. Urine osmolality 400 mOsmol/kg H2O, Urine Na+ 25 mEq/L, FENa 1.5%, no casts
C. Urine osmolality 300 mOsmol/kg H2O, Urine Na+ 45 mEq/L, FENa 5%, no casts (Correct Answer)
D. Urine osmolality 200 mOsmol/kg H2O, Urine Na+ 35 mEq/L, FENa 3%, muddy brown casts
E. Urine osmolality 600 mOsmol/kg H2O, Urine Na+ 15 mEq/L, FENa 0.8%, hyaline casts

Explanation: ***Urine osmolality 300 mOsmol/kg H2O, Urine Na+ 45 mEq/L, FENa 5%, no casts*** - The patient's presentation with acute urinary retention due to **benign prostatic hyperplasia (BPH)** and subsequent obstructive uropathy leads to **postrenal acute kidney injury (AKI)**. If the obstruction is prolonged, it can lead to kidney damage and an inability to concentrate urine effectively, resulting in an **isosthenuric** urine (osmolality near plasma, ~300 mOsmol/kg H2O) and a higher fractional excretion of sodium (**FENa > 2-3%**). - **No casts** are typically seen in pure postrenal AKI unless superimposed intrinsic renal damage has occurred. The increased urine Na+ and FENa reflect tubular dysfunction due to prolonged obstruction. *Urine osmolality 550 mOsmol/kg H2O, Urine Na+ 15 mEq/L, FENa 0.9%, red blood cell casts* - This profile suggests **prerenal azotemia** with a low FENa and concentrated urine, indicating appropriate kidney response to hypoperfusion, which is not the primary issue here. **Red blood cell casts** indicate glomerulonephritis, typically seen in intrinsic renal disease, which is not supported by the patient's presentation of obstructive uropathy. *Urine osmolality 400 mOsmol/kg H2O, Urine Na+ 25 mEq/L, FENa 1.5%, no casts* - This urine profile suggests an intermediate state, possibly early or resolving prerenal injury, but not classic for established postrenal AKI. The **FENa is still relatively low**, indicating some preserved tubular function, which would be compromised in prolonged obstruction leading to AKI. *Urine osmolality 200 mOsmol/kg H2O, Urine Na+ 35 mEq/L, FENa 3%, muddy brown casts* - **Muddy brown casts** are characteristic of **acute tubular necrosis (ATN)**, and while ATN can be a complication of prolonged postrenal obstruction, it is not the initial or most direct finding for postrenal AKI. Also, an osmolality of 200 mOsmol/kg H2O would suggest significant inability to concentrate urine, common in ATN, but the presence of muddy brown casts is the key differentiating feature. *Urine osmolality 600 mOsmol/kg H2O, Urine Na+ 15 mEq/L, FENa 0.8%, hyaline casts* - This profile is highly suggestive of **prerenal azotemia**, characterized by a **highly concentrated urine** (high osmolality) and **low urinary sodium and FENa**, indicating robust renal sodium and water reabsorption in response to perceived hypovolemia. While hyaline casts can be seen in prerenal states, the overall picture does not fit the obstructive cause of AKI described.

Question 383: A 27-year-old male presents to the emergency department after being brought in from a house fire. The patient has extensive burns covering his body and is conscious but in severe pain. The patient has a past medical history notable for marijuana use. He is not currently on any medications. Physical exam is notable for extensive burns covering the patient's back, chest, thighs, and legs. The patient's oropharynx reveals no signs of damage or extensive smoke inhalation. The patient is breathing on his own and has normal breath sounds bilaterally. His temperature is 99.5°F (37.5°C), pulse is 145/min, blood pressure is 100/70 mmHg, respirations are 27/min, and oxygen saturation is 93% on room air. Which of the following interventions is most likely to reduce mortality in this patient?

A. Topical antibiotics
B. IV fluids (Correct Answer)
C. Oxygen administration
D. Oral antibiotics
E. Normal saline soaked dressings

Explanation: ***IV fluids*** - Due to **extensive burns**, patients experience significant fluid shifts and loss, leading to a risk of **hypovolemic shock**. IV fluid resuscitation is crucial to maintain **circulatory volume** and prevent organ hypoperfusion. - The patient's **tachycardia** (pulse 145/min) and **hypotension** (BP 100/70 mmHg) with extensive burns indicate significant fluid deficits, making immediate and aggressive IV fluid resuscitation the most critical intervention to reduce mortality. *Topical antibiotics* - While important for preventing **burn wound infection**, topical antibiotics are a secondary concern after initial resuscitation, especially in the context of acute hemodynamic instability. - They do not address the immediate systemic compromise from **fluid loss** and **shock**. *Oxygen administration* - The patient's oxygen saturation is 93% on room air, and there are **no signs of smoke inhalation** or airway damage, making immediate oxygen administration less critical than fluid resuscitation for mortality reduction. - While supportive, it does not address the primary threat of **hypovolemic shock** from massive fluid shifts. *Oral antibiotics* - Similar to topical antibiotics, oral antibiotics are used to prevent or treat **burn wound infections** but are not an immediate life-saving intervention for acute burn shock. - They are typically reserved for bacterial prophylaxis or treatment if an infection is suspected later. *Normal saline soaked dressings* - These dressings can help with initial burn care by cooling the burn and providing some pain relief, but they do **not address the systemic fluid loss** and hemodynamic instability. - They are part of local wound management but are not the primary intervention to prevent **mortality in severe burns**.

Question 384: A 69-year-old woman is brought to her primary care physician by her son who is worried about her weight loss. The son reports that over the past 2 months she has lost at least 12 pounds. The patient denies any change in appetite but complains of diarrhea and abdominal discomfort. Additionally, she reports that her stools “smell awful,” which is embarrassing for her. Her son mentions that he feels she is becoming forgetful. She forgets phone conversations and often acts surprised when he visits, even though he always confirms his visits the night before. Her medical history includes arthritis, which she admits has been getting worse, and gastroesophageal reflux disease. She takes omeprazole. She is widowed and recently retired from being a national park ranger. The patient’s temperature is 100.3°F (37.9°C), blood pressure is 107/68 mmHg, and pulse is 88/min. On physical exam, she has a new systolic ejection murmur at the left upper sternal border. Labs show normocytic anemia. A transesophageal echocardiogram reveals a small mobile mass on the aortic valve with moderate aortic insufficiency. A colonoscopy is obtained with a small bowel biopsy. A periodic acid-Schiff stain is positive for foamy macrophages. Which of the following is the best next step in management?

A. Doxycycline
B. Ibuprofen and hydroxychloroquine
C. Prednisone then sulfasalazine
D. Dietary changes
E. Ceftriaxone and trimethoprim-sulfamethoxazole (Correct Answer)

Explanation: ***Ceftriaxone and trimethoprim-sulfamethoxazole*** - This patient presents with symptoms (weight loss, diarrhea, neuropsychiatric changes, valvular vegetations, arthritis, fever) and biopsy findings (**foamy macrophages** with **PAS-positive** stain in the small bowel) consistent with **Whipple's disease**, caused by **Tropheryma whipplei**. - Initial treatment often involves **intravenous ceftriaxone** for 2-4 weeks, followed by **oral trimethoprim-sulfamethoxazole** for 1-2 years to eradicate the infection and prevent relapse, especially neurological complications. *Doxycycline* - While doxycycline is part of the **maintenance treatment** for Whipple's disease (used after initial IV therapy), it is generally not sufficient as the sole initial treatment, especially in cases with central nervous system involvement. - Its use alone may not adequately penetrate the CNS to treat potential neurological manifestations or prevent their progression. *Ibuprofen and hydroxychloroquine* - This regimen is used for certain rheumatological conditions, but it does not address the underlying **bacterial infection** in Whipple's disease. - Treating symptomatic arthritis without addressing the systemic infection would lead to disease progression and severe multiorgan dysfunction. *Prednisone then sulfasalazine* - This combination is typical for inflammatory bowel diseases or some forms of spondyloarthritis, which are inflammatory conditions, not infectious. - Steroids like prednisone would likely **worsen** an underlying bacterial infection by suppressing the immune response. *Dietary changes* - Although malabsorption in Whipple's disease can lead to nutritional deficiencies, dietary changes alone will not treat the underlying **Tropheryma whipplei infection**. - Nutritional support is important, but it is secondary to the crucial antibiotic treatment to resolve the disease.

Question 385: A 75-year-old man presents to his primary care physician for foot pain. The patient states that he has had chronic foot pain, which has finally caused him to come and see the doctor. The patient's past medical history is unknown and he has not seen a doctor in over 50 years. The patient states he has led a healthy lifestyle, consumes a plant-based diet, exercised regularly, and avoided smoking, thus his lack of checkups with a physician. The patient lives alone as his wife died recently. His temperature is 98.1°F (36.7°C), blood pressure is 128/64 mmHg, pulse is 80/min, respirations are 13/min, and oxygen saturation is 98% on room air. The patient's BMI is 19 kg/m^2 and he appears healthy. Physical exam demonstrates a right foot that is diffusely swollen, mildly tender, and deformed. The patient's gait is abnormal. Which of the following is associated with the underlying cause of this patient's presentation?

A. Methicillin-resistant bacterial agent
B. Unprotected sexual intercourse
C. Megaloblastic anemia
D. High-impact trauma to the foot
E. Hyperfiltration damage of the kidney (Correct Answer)

Explanation: ***Hyperfiltration damage of the kidney*** - The patient's presentation of a **deformed and diffusely swollen, mildly tender foot** in a 75-year-old, alongside his self-reported healthy lifestyle (plant-based diet, exercise), points toward **Charcot arthropathy (diabetic foot)**, which is typically a complication of **diabetes mellitus**. - **Hyperfiltration damage of the kidney** is a key early sign of **diabetic nephropathy**, occurring during stages 1 and 2, where the kidneys compensate for damage by increasing the glomerular filtration rate, eventually leading to proteinuria and chronic kidney disease. This is a common association with long-standing, undiagnosed diabetes. *Methicillin-resistant bacterial agent* - This typically causes **acute infections**, often with signs of severe inflammation, warmth, erythema, and possibly purulence. The patient's presentation is of **chronic foot pain** and **deformity**, less suggestive of an acute bacterial infection. - While foot ulcers related to diabetes can become infected with MRSA, the primary underlying cause of the foot deformity and pain is not MRSA itself, but rather the neuropathic and vascular complications of diabetes. *Unprotected sexual intercourse* - **Unprotected sexual intercourse** is a risk factor for sexually transmitted infections (STIs) and their sequelae, such as **reactive arthritis**. - Reactive arthritis typically presents with acute, asymmetric oligoarthritis, often affecting the lower extremities, and usually has associated urethritis or conjunctivitis, which are not mentioned in this chronic, deforming condition. *Megaloblastic anemia* - **Megaloblastic anemia** is primarily caused by **vitamin B12 or folate deficiency** and can lead to neurological symptoms like **peripheral neuropathy** (e.g., paresthesias, gait disturbance). - While peripheral neuropathy can contribute to foot problems, megaloblastic anemia itself does not directly cause the severe **bone and joint destruction** seen in Charcot arthropathy; it's a consequence of diabetic neuropathy. *High-impact trauma to the foot* - **High-impact trauma** can cause fractures, dislocations, or acute soft tissue injuries to the foot, leading to pain and swelling. - However, the patient's presentation is of **chronic pain and progressive deformity**, indicating a degenerative process rather than an acute traumatic injury. While trauma can exacerbate Charcot foot, it's not the underlying cause.

Question 386: A 65-year-old woman presents to her primary care physician for a wellness checkup. She states that she has felt well lately and has no concerns. The patient has a 12-pack-year smoking history and has 3 drinks per week. She is retired and lives at home with her husband. She had a normal colonoscopy 8 years ago and mammography 1 year ago. She can't recall when she last had a Pap smear and believes that it was when she was 62 years of age. Her temperature is 98.1°F (36.7°C), blood pressure is 137/78 mmHg, pulse is 80/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is within normal limits. Which of the following is the best next step in management?

A. Colonoscopy
B. Mammogram
C. No intervention needed
D. DEXA scan (Correct Answer)
E. Pap smear

Explanation: ***DEXA scan*** - A **DEXA scan** is recommended for all women aged 65 years and older to screen for **osteoporosis**, regardless of risk factors. - While she has several risk factors (female sex, age, smoking history), the age alone warrants screening. *Colonoscopy* - The patient had a normal colonoscopy 8 years ago, and routine screening for average-risk individuals typically occurs every 10 years, so it is **not yet due**. - There are **no new symptoms** to suggest the need for an earlier repeat colonoscopy. *Mammogram* - The patient had a mammogram 1 year ago, and screening is typically recommended every **1 to 2 years** for women in this age group, so it is not immediately due. - There are no new breast concerns to warrant an earlier mammogram. *No intervention needed* - This option is incorrect because the patient is a 65-year-old woman, placing her in a demographic for which a **DEXA scan** is routinely recommended as part of preventive care. - While she feels well, screening interventions are designed to detect conditions before symptoms appear. *Pap smear* - **Cervical cancer screening** with a Pap smear can be discontinued in women over age 65 who have a history of adequate negative screening tests and are not at high risk. - Since she had a Pap smear at 62 and has no known risk factors for cervical cancer, further screening is likely **not indicated**.

Question 387: A 23-year-old woman comes to the physician because of increasing pain and swelling of her hands and wrists for 3 days. She has been unable to continue her daily activities like writing or driving. She has had a nonpruritic generalized rash for 4 days. She had fever and a runny nose one week ago which resolved with over-the-counter medication. She is sexually active with a male partner and uses condoms inconsistently. She works as an attendant at an amusement park. Her temperature is 37.1°C (98.8°F), pulse is 90/min, and blood pressure is 118/72 mm Hg. Examination shows swelling and tenderness of the wrists as well as the metacarpophalangeal and proximal interphalangeal joints. Range of motion at the wrists is limited. A lacy macular rash is noted over the trunk and extremities. The remainder of the examination shows no abnormalities. Laboratory studies, including erythrocyte sedimentation rate and anti-nuclear antibody and anti-dsDNA serology, show no abnormalities. Which of the following is the most likely diagnosis?

A. Psoriatic arthritis
B. Parvovirus arthritis (Correct Answer)
C. Systemic lupus erythematosus
D. Rheumatoid arthritis
E. Disseminated gonococcal disease

Explanation: ***Parvovirus arthritis*** - The patient's presentation with acute, symmetric polyarthritis, a **lacy macular rash**, and a preceding flu-like illness is highly classic for **parvovirus B19 infection**. - In children, parvovirus B19 causes **erythema infectiosum** with a characteristic "slapped cheek" facial rash followed by a lacy reticular rash on the trunk and extremities. In adults, the **lacy/reticular rash pattern** is typical, while the facial erythema is less common. - The negative ANA and anti-dsDNA rule out lupus, and the absence of characteristic features for other conditions further supports this diagnosis, especially given the patient's exposure (amusement park attendant, likely increased contact with children). *Psoriatic arthritis* - This condition is characterized by arthritis often accompanied by **psoriatic skin lesions** (e.g., plaques, nail pitting, dactylitis), which are not described in this patient. - While it can cause joint pain, the rash described as "lacy macular" is not typical of psoriasis. *Systemic lupus erythematosus* - While lupus can cause polyarthritis and a rash, the rash is typically a **malar (butterfly) rash**, discoid rash, or photosensitive rash, not a lacy macular rash. - Crucially, the **negative anti-nuclear antibody (ANA)** and anti-dsDNA serology make lupus highly unlikely. *Rheumatoid arthritis* - **Rheumatoid arthritis** typically presents with chronic, symmetric polyarthritis affecting small joints, often with morning stiffness lasting over 30 minutes, and may involve specific serologies (e.g., rheumatoid factor, anti-CCP antibodies). - The acute onset over 3 days, the presence of a generalized rash, and the absence of typical lab abnormalities or chronic symptoms makes this less likely. *Disseminated gonococcal disease* - This typically presents with a triad of **tenosynovitis, dermatitis**, and **polyarthralgias** or frank arthritis. The skin lesions are usually **pustular or vesicular** on an erythematous base, not a lacy macular rash. - Although the patient is sexually active, the rash description and the lack of other specific symptoms (e.g., genital discharge, fever, systemic illness beyond the initial flu-like symptoms) make this less probable.

Question 388: A 70-year-old woman is evaluated for muscle pain and neck stiffness that has been progressing for the past 3 weeks. She reports that the neck stiffness is worse in the morning and gradually improves throughout the day. She feels fatigued, although there have not been any changes in her daily routine. Her past medical history includes coronary artery disease for which she takes a daily aspirin. Both of her parents died in their 80s from cardiovascular disease. Her blood pressure is 140/90 mm Hg, heart rate is 88/min, respiratory rate is 15/min, and temperature is 37.9°C (100.2°F). On further examination, the patient has difficulty standing up from a seated position, although muscle strength is intact. What is the best next step in management?

A. Electromyography
B. Erythrocyte sedimentation rate (Correct Answer)
C. Muscle biopsy
D. Antinuclear antibody
E. Lumbar puncture

Explanation: ***Erythrocyte sedimentation rate*** - The patient's symptoms of **muscle pain**, **neck stiffness**, **morning stiffness** that improves with activity, **fatigue**, elevated body temperature, and difficulty standing from a seated position are highly suggestive of **polymyalgia rheumatica**. - **Polymyalgia rheumatica** is an inflammatory condition characterized by elevated inflammatory markers like **erythrocyte sedimentation rate (ESR)** and **C-reactive protein (CRP)**. Assessing ESR is crucial for diagnosis and monitoring. *Electromyography* - **Electromyography (EMG)** measures muscle electrical activity and is primarily used to diagnose **neuropathic** or **myopathic** disorders, which are less likely given the clinical picture of polymyalgia rheumatica. - While it could show subtle changes in inflammatory myopathies, it is not the initial diagnostic test for this presentation. *Muscle biopsy* - A **muscle biopsy** is used to diagnose specific muscle diseases like polymyositis or dermatomyositis, where there is direct muscle weakness and inflammation. - In polymyalgia rheumatica, muscle strength is typically intact, and muscle biopsy findings are usually normal or non-specific. *Antinuclear antibody* - **Antinuclear antibody (ANA)** testing is used to screen for **autoimmune connective tissue diseases** like systemic lupus erythematosus, scleroderma, or Sjögren's syndrome. - While other autoimmune conditions can cause muscle pain, the constellation of symptoms (especially morning stiffness improving with activity and age of onset) points more specifically to polymyalgia rheumatica, where ANA is typically negative. *Lumbar puncture* - A **lumbar puncture** (spinal tap) is performed to analyze **cerebrospinal fluid (CSF)** and is used to diagnose conditions affecting the central nervous system, such as meningitis, encephalitis, or multiple sclerosis. - This procedure is not indicated for the evaluation of muscle pain and stiffness described by the patient.

Question 389: A 21-year-old man presents to his physician because he has been feeling increasingly tired and short of breath at work. He has previously had these symptoms but cannot recall the diagnosis he was given. Chart review reveals the following results: Oxygen tension in inspired air = 150 mmHg Alveolar carbon dioxide tension = 50 mmHg Arterial oxygen tension = 71 mmHg Respiratory exchange ratio = 0.80 Diffusion studies reveal normal diffusion distance. The patient is administered 100% oxygen but the patient's blood oxygen concentration does not improve. Which of the following conditions would best explain this patient's findings?

A. Septal defect since birth (Correct Answer)
B. Use of opioid medications
C. Pulmonary fibrosis
D. Pulmonary embolism
E. Vacation at the top of a mountain

Explanation: ***Septal defect since birth*** - A congenital heart disease like a **septal defect** causes a right-to-left **shunt**, meaning deoxygenated blood bypasses the lungs and mixes with oxygenated blood. - This type of shunt leads to **hypoxemia that is refractory to 100% oxygen** because the shunted blood will never pick up oxygen from the lungs. *Use of opioid medications* - Opioid use causes **respiratory depression**, leading to **hypoventilation** and increased arterial CO2 with decreased arterial O2. - However, the hypoxemia from hypoventilation would typically improve significantly with **100% oxygen administration**, unlike in this case. *Pulmonary fibrosis* - **Pulmonary fibrosis** causes thickening of the alveolar-capillary membrane, leading to impaired gas exchange and **diffusion limitation**. - While it causes hypoxemia, the diffusion studies are stated to be **normal**, and hypoxemia due to diffusion limitation often improves with supplemental oxygen. *Pulmonary embolism* - A **pulmonary embolism** leads to V/Q mismatch by blocking blood flow to a portion of the lung, causing ventilation with no perfusion. - Hypoxemia from V/Q mismatch generally **responds well to supplemental oxygen**, as the non-affected lung areas can compensate, unlike the scenario described. *Vacation at the top of a mountain* - Being at a high altitude causes **hypobaric hypoxia**, meaning there is a reduced partial pressure of oxygen in the inspired air. - This type of hypoxemia typically **improves with supplemental oxygen** as it increases the inspired oxygen tension, which is contrary to the patient's findings.

Question 390: A 57-year-old woman presents to her primary care physician for weakness. The patient states that she barely feels able to lift a bag of groceries from her car into her house anymore. The patient has a past medical history of a suicide attempt, constipation, anxiety, asthma, and atopic dermatitis. Her current medications include fluoxetine, lisinopril, albuterol, diphenhydramine, sodium docusate, and a multivitamin. She was recently started on atorvastatin for dyslipidemia. Her temperature is 97°F (36.1°C), blood pressure is 90/65 mmHg, pulse is 70/min, respirations are 11/min, and oxygen saturation is 98% on room air. On physical exam, you note a fatigued appearing woman with thinning hair. Cardiopulmonary exam is within normal limits. She demonstrates 3/5 strength in her upper and lower extremities with 1+ sluggish reflexes. Sensation is symmetrical and present in the upper and lower extremities. Pain/tenderness upon palpation of the patient's extremities is noted. Laboratory values are ordered as seen below: Hemoglobin: 12 g/dL Hematocrit: 36% Leukocyte count: 5,500/mm^3 with normal differential Platelet count: 190,000/mm^3 Serum: Na+: 139 mEq/L Cl-: 101 mEq/L K+: 4.4 mEq/L HCO3-: 24 mEq/L BUN: 20 mg/dL Glucose: 90 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.1 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following is the best next step in management?

A. Discontinue atorvastatin
B. TSH level (Correct Answer)
C. Coenzyme Q10
D. Muscle biopsy
E. Aldolase level

Explanation: ***TSH level*** - The patient's symptoms of **generalized weakness**, **constipation**, **fatigue**, **thinning hair**, and **sluggish reflexes** are highly suggestive of **hypothyroidism**. - A TSH level is the most appropriate initial screening test for evaluating thyroid function. *Discontinue atorvastatin* - While **statins can cause myopathy**, leading to muscle weakness and pain, the patient's presentation with **thinning hair** and **sluggish reflexes** points more strongly towards hypothyroidism. - Labs would likely show elevated **creatine kinase** in statin-induced myopathy, which is not provided as elevated here. *Coenzyme Q10* - **Coenzyme Q10** supplementation is sometimes suggested for statin-induced myopathy, but there is limited evidence for its efficacy, and it would not address the broader constellation of symptoms seen here. - This is an intervention, not a diagnostic step, and the underlying cause of weakness needs to be identified first. *Muscle biopsy* - A **muscle biopsy** is an invasive procedure and is typically reserved for cases where less invasive tests have failed to provide a diagnosis, especially in suspected **inflammatory myopathies** or **muscular dystrophies**. - It is not the initial diagnostic step for generalized weakness, particularly with symptoms suggestive of an endocrine disorder. *Aldolase level* - **Aldolase** is an enzyme found in muscle tissue and can be elevated in conditions causing **muscle breakdown**, similar to creatine kinase. - While it may be elevated in myopathies, the clinical picture with **thinning hair** and **sluggish reflexes** makes hypothyroidism a more likely initial diagnosis to investigate.

Question 391: A 38-year-old female presents to her primary care physician with complaints of several episodes of palpitations accompanied by panic attacks over the last month. She also is concerned about many instances over the past few weeks where food has been getting stuck in her throat and she has had trouble swallowing. She denies any prior medical problems and reports a family history of cancer in her mother and maternal grandfather but cannot recall any details regarding the type of cancer(s) or age of diagnosis. Her vital signs at today's visit are as follows: T 37.6 deg C, HR 106, BP 158/104, RR 16, SpO2 97%. Physical examination is significant for a nodule on the anterior portion of the neck that moves with swallowing, accompanied by mild lymphadenopathy. A preliminary work-up is initiated, which shows hypercalcemia, elevated baseline calcitonin, and an inappropriately elevated PTH level. Diagnostic imaging shows bilateral adrenal lesions on an MRI of the abdomen/pelvis. Which of the following is the most likely diagnosis in this patient?

A. Familial medullary thyroid cancer (FMTC)
B. Li-Fraumeni syndrome
C. Multiple endocrine neoplasia (MEN) IIa (Correct Answer)
D. Multiple endocrine neoplasia (MEN) I
E. Multiple endocrine neoplasia (MEN) IIb

Explanation: ***Multiple endocrine neoplasia (MEN) IIa*** - This patient presents with **medullary thyroid cancer** (due to the thyroid nodule, elevated calcitonin, and family history of cancer), **pheochromocytoma** (indicated by palpitations, panic attacks, hypertension, and adrenal lesions), and **primary hyperparathyroidism** (evidenced by hypercalcemia and inappropriately elevated PTH). These three conditions are the classic triad of MEN IIa. - The symptoms of food getting stuck in her throat are also consistent with the presence of a **thyroid nodule**. *Familial medullary thyroid cancer (FMTC)* - While the patient has **medullary thyroid cancer**, FMTC is typically characterized solely by medullary thyroid carcinoma without the associated pheochromocytoma or primary hyperparathyroidism seen in this case. - This patient's presentation includes **adrenal lesions** and **hyperparathyroidism**, which are not features of isolated FMTC. *Li-Fraumeni syndrome* - This syndrome is associated with a high risk of various cancers, including sarcomas, breast cancer, brain tumors, and adrenocortical carcinoma, but it is not typically associated with **medullary thyroid cancer, pheochromocytoma, or primary hyperparathyroidism** as a primary presentation. - The genetic basis is a mutation in the **TP53 gene**, and the clinical picture does not match the specific endocrine tumors observed here. *Multiple endocrine neoplasia (MEN) I* - MEN I is characterized by tumors of the **parathyroid, pituitary, and pancreas** (the 3 Ps). - This patient's presentation of medullary thyroid cancer, pheochromocytoma, and primary hyperparathyroidism does not include pituitary or pancreatic tumors, and medullary thyroid cancer and pheochromocytoma are not part of the MEN I spectrum. *Multiple endocrine neoplasia (MEN) IIb* - MEN IIb includes **medullary thyroid cancer** and **pheochromocytoma**, which are present in this patient. - However, MEN IIb also classically presents with characteristic **mucosal neuromas** and a **marfanoid habitus**, and *lacks* primary hyperparathyroidism, which this patient clearly exhibits.

Question 392: A 76-year-old man is brought to his geriatrician by his daughter, who reports that he has been "losing his memory." While the patient previously performed all household duties by himself, he has recently had several bills that were unpaid. He also called his daughter on several occasions after getting lost while driving and having "accidents" before getting to the toilet. On exam, the patient is conversant and alert to person, place, and time, though his gait is wide-based and slow. Which of the following diagnostic procedures would be most appropriate to confirm the suspected diagnosis in this patient?

A. Warfarin
B. Donepezil
C. Carbidopa/Levodopa
D. Memantine
E. Lumbar puncture (Correct Answer)

Explanation: ***Lumbar puncture*** - The patient's symptoms of **cognitive decline**, **gait disturbance**, and **urinary incontinence** (losing control before reaching the toilet) represent the classic triad of **Normal Pressure Hydrocephalus (NPH)**. - **Lumbar puncture** with removal of CSF (30-50 mL) serves as both a **diagnostic and therapeutic test** (tap test); transient improvement in symptoms, especially gait, strongly supports the diagnosis of NPH. - This is the only **diagnostic procedure** among the options; the others are medications/treatments. *Warfarin* - This is an **anticoagulant medication** (not a diagnostic procedure) used to prevent blood clots in atrial fibrillation or venous thromboembolism. - Has no role in diagnosing or treating NPH, which involves CSF dynamics, not coagulation. *Donepezil* - **Donepezil** is an **acetylcholinesterase inhibitor medication** (not a diagnostic procedure) used to treat Alzheimer's disease symptoms. - While the patient has cognitive decline, the classic NPH triad (cognitive, gait, incontinence) distinguishes this from typical Alzheimer's dementia. - This is a treatment option, not a diagnostic test. *Carbidopa/Levodopa* - This **medication combination** (not a diagnostic procedure) is the primary treatment for **Parkinson's disease**, replacing dopamine. - While Parkinson's causes gait issues, it doesn't typically present with this specific triad, and parkinsonian gait differs from NPH's magnetic/apraxic gait. - This is a treatment, not a diagnostic procedure. *Memantine* - **Memantine** is an **NMDA receptor antagonist medication** (not a diagnostic procedure) used in moderate to severe Alzheimer's disease. - Like donepezil, this treats dementia symptoms but is not a diagnostic test for NPH.

Question 393: A 43-year-old man is referred by his family physician because his urine dipstick reveals 3+ protein and urinalysis reveals 1-2 red cells/high power field, but is otherwise negative. He does not have any current complaints. His family history is irrelevant. He denies smoking and alcohol use. His temperature is 36.7°C (98.06°F), blood pressure is 130/82 mm Hg, and pulse is 78/min. Physical examination is unremarkable. Which of the following is the best next step in the management of this patient’s condition?

A. Reassurance
B. Repeat the urine dipstick test
C. 24-hour urine collection (Correct Answer)
D. Start captopril
E. Urine culture

Explanation: ***24-hour urine collection*** - The presence of **3+ proteinuria on dipstick** (approximately ≥300 mg/dL) is significant and requires **quantification** to assess the degree of proteinuria and guide further management. - A **24-hour urine collection** is the traditional gold standard method to quantify total protein excretion and determine if the patient has clinically significant proteinuria (>150 mg/day is abnormal; >3.5 g/day indicates nephrotic-range proteinuria). - Alternatively, a **spot urine protein-to-creatinine ratio (PCR)** or **albumin-to-creatinine ratio (ACR)** can be used, but among the given options, 24-hour collection is the appropriate next step. - The concurrent finding of **microscopic hematuria (1-2 RBCs/hpf)** further supports the need for evaluation of possible **glomerular disease** or other renal pathology. *Repeat the urine dipstick test* - Repeating a dipstick is appropriate for **trace or 1+ proteinuria** to rule out transient causes (exercise, fever, orthostatic proteinuria, concentrated urine). - However, **3+ proteinuria is too significant** to simply repeat the dipstick; it requires quantification to determine the severity and guide further diagnostic workup (e.g., renal biopsy if nephrotic-range). *Urine culture* - While infection can cause proteinuria and hematuria, the urinalysis is described as "otherwise negative," suggesting an absence of **leukocytes, nitrites, or bacteria** typical of a urinary tract infection. - The patient is **asymptomatic** without dysuria, frequency, or fever, making infection unlikely. - A urine culture would be appropriate if there were clinical signs of UTI. *Reassurance* - Giving reassurance would be **inappropriate and potentially harmful** given the finding of **3+ proteinuria**, which is a significant indicator of potential renal pathology. - Proteinuria of this magnitude can indicate **glomerulonephritis, diabetic nephropathy, hypertensive nephrosclerosis**, or other kidney diseases requiring further evaluation. - The presence of concurrent **microscopic hematuria** raises additional concern for glomerular disease. *Start captopril* - Captopril, an **ACE inhibitor**, is used to reduce proteinuria and provide renoprotection in patients with **confirmed chronic kidney disease**, particularly in the setting of **diabetes or hypertension**. - Initiating treatment is **premature** without first quantifying the proteinuria, establishing a diagnosis, and ruling out secondary causes. - The patient's blood pressure (130/82 mm Hg) is at the upper limit of normal but does not mandate immediate antihypertensive therapy before completing the diagnostic evaluation.

Question 394: A 69-year-old man presents to the emergency department with shortness of breath that has been worsening over the past month. The patient states that he has had worsening shortness of breath that has progressed to shortness of breath with simple activities and minor exertion. When he was unable to climb the stairs to his house today, he decided to come to the emergency department. The patient has a past medical history of poorly managed diabetes mellitus, hypertension, end stage renal disease, and obesity. His current medications include insulin, metformin, lisinopril, hydrochlorothiazide, and ibuprofen. The patient is notably non-compliant with his medications. An EKG and chest radiograph are normal. The patient had dialysis two days ago and attends most of his appointments. Laboratory values are ordered and are seen below: Serum: Na+: 135 mEq/L K+: 4.5 mEq/L Cl-: 100 mEq/L HCO3-: 19 mEq/L Urea nitrogen: 29 mg/dL Glucose: 75 mg/dL Creatinine: 2.5 mg/dL Ca2+: 9.2 mg/dL Mg2+: 1.7 mEq/L AST: 11 U/L ALT: 11 U/L Leukocyte count and differential: Leukocyte count: 4,500/mm^3 Platelet count: 150,000/mm^3 Neutrophil: 54% Lymphocyte: 25% Monocyte: 3% Eosinophil: 1% Basophil: 1% Hemoglobin: 8.2 g/dL Hematocrit: 22% Mean corpuscular volume: 82 µm^3 The patient appears comfortable at rest but demonstrates notable shortness of breath when exerting himself. His temperature is 99.5°F (37.5°C), pulse is 89/min, blood pressure is 144/85 mmHg, respirations are 10/min, and oxygen saturation is 97% on room air. Pulmonary and cardiac exam are within normal limits. Which of the following is a side-effect of the long-term therapy this patient should be started on right now?

A. Hyperkalemia
B. Pruritus
C. Hypertension (Correct Answer)
D. Hypokalemia
E. Visual halos

Explanation: ***Hypertension*** - This patient is experiencing symptomatic **anemia of chronic kidney disease** (Hgb 8.2 g/dL, Hct 22%) and should be started on **erythropoiesis-stimulating agents (ESA)** such as erythropoietin or darbepoetin. - **Hypertension is the most common side effect** of erythropoietin therapy, occurring in **20-30% of patients**. The mechanism involves increased blood viscosity from rising hematocrit, increased peripheral vascular resistance, and direct vasoconstrictive effects. - Patients on ESA therapy require **close blood pressure monitoring** and may need adjustment of antihypertensive medications. Blood pressure should be controlled before initiating ESA therapy. - Other important side effects include thrombotic events, headache, and flu-like symptoms. *Visual halos* - Visual halos are a classic symptom of **digoxin toxicity**, not a side effect of erythropoietin therapy. - While this patient has multiple cardiac risk factors, the primary issue is **anemia requiring ESA therapy**, not heart failure requiring digoxin. *Hyperkalemia* - Hyperkalemia is associated with **renal failure**, **ACE inhibitors** (lisinopril), or **potassium-sparing diuretics**, but the patient's current potassium is normal (4.5 mEq/L). - Hyperkalemia is **not a recognized side effect** of erythropoietin therapy. *Pruritus* - Pruritus can be a symptom of **chronic kidney disease** or **uremia** itself, but it is not a direct side effect of **erythropoietin therapy**. - While ESRD patients commonly experience pruritus, this is not related to ESA treatment. *Hypokalemia* - Hypokalemia is **not a recognized side effect** of erythropoietin therapy. - While ESA stimulates red blood cell production in bone marrow, this does not cause clinically significant potassium shifts or hypokalemia. - The patient's current potassium level is normal at 4.5 mEq/L.

Question 395: A 23-year-old woman presents to the emergency department complaining of nausea, vomiting, and abdominal pain. She has a 10-year history of type I diabetes mellitus treated with lispro and glargine. Upon questioning, she mentions that she stopped taking her insulin 3 days ago due to recent malaise and decreased appetite. She denies recent weight change, illicit drug use, or sexual activity. She does not take any other medications and she does not use tobacco products or alcohol. Upon physical examination she is afebrile. Her blood pressure is 105/70 mm Hg, pulse is 108/min and respiratory rate is 25/min. She appears lethargic, with clear breath sounds bilateral and a soft, nontender and nondistended abdomen. Laboratory results are as follows: Sodium 130 mEq/L Potassium 5.6 mEq/L Chloride 91 mEq/L Bicarbonate 12 mEq/L Glucose 450 mg/dL Which of the following is most likely to be found in this patient?

A. Suppression of antidiuretic hormone (ADH) secretion
B. Total body potassium depletion (Correct Answer)
C. Signs of hypocalcemia
D. Loss of sodium in urine is greater than free water loss
E. Normal-to-high phosphate levels

Explanation: ***Total body potassium depletion*** - Despite the **hyperkalemia** observed in the lab results (Potassium 5.6 mEq/L), patients with **diabetic ketoacidosis (DKA)** commonly experience significant **total body potassium depletion** due to osmotic diuresis and vomiting. - The apparent hyperkalemia is often due to an **extracellular shift of potassium** in acidosis, while intracellular stores are diminished. *Suppression of antidiuretic hormone (ADH) secretion* - Patients with DKA are typically **volume depleted** due to osmotic diuresis and vomiting, which would lead to **increased (not suppressed) ADH secretion** to conserve water. - **Elevated plasma osmolality** due to hyperglycemia also stimulates ADH release. *Signs of hypocalcemia* - While electrolyte imbalances are common in DKA, **hypocalcemia** is not a typical direct finding. **Hyperphosphatemia** can sometimes induce hypocalcemia, but phosphate levels are not yet known. - The patient's presentation does not suggest symptoms specifically related to hypocalcemia (e.g., tetany, arrhythmias). *Loss of sodium in urine is greater than free water loss* - In DKA, **osmotic diuresis** due to hyperglycemia leads to significant **loss of free water** in the urine, often exceeding sodium loss. - This results in **hypernatremia** or **pseudohyponatremia** after correction for glucose, but the primary loss is overall fluid. *Normal-to-high phosphate levels* - Patients with DKA typically experience **hypophosphatemia** due to increased renal phosphate wasting, despite an initial shift of phosphate out of cells with acidosis. - **Phosphate depletion** is a characteristic feature and often requires repletion during treatment.

Question 396: A 61-year-old man presents with back pain and hematuria. The patient says his back pain gradually onset 6 months ago and has progressively worsened. He describes the pain as moderate, dull and aching, and localized to the lower back and right flank. Also, he says that, for the past 2 weeks, he has been having intermittent episodes of hematuria. The patient denies any recent history of fever, chills, syncope, night sweats, dysuria or pain on urination. His past medical history is significant for a myocardial infarction (MI) 3 years ago status post percutaneous transluminal coronary angioplasty and peripheral vascular disease of the lower extremities, worst in the popliteal arteries, with an ankle:brachial index of 1.4. Also, he has had 2 episodes of obstructive nephrolithiasis in the past year caused by calcium oxalate stones, for which he takes potassium citrate. His family history is significant for his father who died of renovascular hypertension at age 55. The patient reports a 20-pack-year smoking history and moderates to heavy daily alcohol use. A review of systems is significant for an unintentional 6.8 kg (15 lb) weight loss over the last 2 months. The vital signs include: blood pressure 145/95 mm Hg, pulse 71/min, temperature 37.2℃ (98.9℉), and respiratory rate 18/min. On physical examination, the patient has moderate right costovertebral angle tenderness (CVAT). A contrast computed tomography (CT) scan of the abdomen and pelvis reveals an enhancing mass in the upper pole of the right kidney. A percutaneous renal biopsy of the mass confirms renal cell carcinoma. Which of the following was the most significant risk factor for the development of renal cell carcinoma (RCC) in this patient?

A. History of obstructive nephrolithiasis
B. Moderate to heavy daily alcohol use
C. 20-pack-year smoking history (Correct Answer)
D. Family history of renovascular hypertension
E. Peripheral vascular disease

Explanation: ***20-pack-year smoking history*** - **Smoking** is the single most important modifiable risk factor for **renal cell carcinoma (RCC)**, increasing the risk by 50-100% in a dose-dependent manner. - The duration and intensity of smoking, as indicated by a **20-pack-year history**, significantly contribute to the cumulative risk of developing RCC. *History of obstructive nephrolithiasis* - While **kidney stones** (nephrolithiasis) can cause symptoms similar to RCC (e.g., pain, hematuria), they are generally **not considered a direct risk factor** for RCC. - The presence of calcium oxalate stones does not predispose an individual to kidney cancer directly. *Moderate to heavy daily alcohol use* - The relationship between **alcohol consumption** and RCC risk is not as clear or as strong as with smoking. - Some studies suggest a potential link, but it is generally considered a **minor or inconsistent risk factor** compared to smoking. *Family history of renovascular hypertension* - **Renovascular hypertension** is hypertension caused by kidney artery stenosis, and while it might indicate underlying vascular issues, it is **not a direct risk factor for RCC**. - A family history of hypertension in general may be weakly associated with RCC, but specifically renovascular hypertension is not. *Peripheral vascular disease* - **Peripheral vascular disease (PVD)** is a manifestation of systemic atherosclerosis and shares common risk factors with RCC (e.g., smoking, hypertension), but it is **not an independent risk factor for RCC**. - PVD itself does not directly cause renal cell carcinoma.

Question 397: A 42-year-old woman presents to the clinic for a recurrent rash that has remitted and relapsed over the last 2 years. The patient states that she has tried multiple home remedies when she has flare-ups, to no avail. The patient is wary of medical care and has not seen a doctor in at least 15 years. On examination, she has multiple disc-shaped, erythematous lesions on her neck, progressing into her hairline. The patient notes no other symptoms. Lab work is performed and is positive for antinuclear antibodies. What is the most likely diagnosis?

A. Tinea capitis
B. Systemic lupus erythematosus (SLE)
C. Drug-induced lupus
D. Cutaneous lupus erythematosus (CLE) (Correct Answer)
E. Dermatomyositis

Explanation: **Cutaneous lupus erythematosus (CLE)** - The presentation of recurrent **disc-shaped, erythematous lesions** on the neck and hairline is characteristic of **discoid lupus**, a common form of CLE. - While **antinuclear antibodies (ANA)** are positive, the absence of systemic symptoms points towards a diagnosis limited to the skin rather than a systemic autoimmune disease. *Tinea capitis* - This is a **fungal infection** of the scalp, typically presenting with **scaly patches**, **hair loss**, and sometimes **pustules**. - It would not typically present with classic discoid lesions or a positive ANA. *Systemic lupus erythematosus (SLE)* - While ANA positive, **SLE** would involve additional systemic symptoms such as **arthritis**, **serositis**, **renal involvement**, or **hematologic abnormalities**, which are absent here. - Although cutaneous manifestations are common in SLE, the isolated skin lesions without systemic involvement make CLE a more likely diagnosis. *Drug-induced lupus* - This condition is caused by certain **medications** and typically resolves upon discontinuation of the causative drug. - The patient's history does not indicate recent medication use, and the long-standing, relapsing nature of the rash over two years makes a drug-induced cause less likely. *Dermatomyositis* - Characterized by **proximal muscle weakness** and distinct skin rashes such as **heliotrope rash** (periorbital violaceous discoloration) and **Gottron's papules** (violaceous papules over joints). - The patient presents with neither muscle weakness nor these specific skin findings.

Question 398: A 33-year-old man presents to the emergency department acutely confused. The patient was found down at a local construction site by his coworkers. The patient has a past medical history of a seizure disorder and schizophrenia and is currently taking haloperidol. He had recent surgery 2 months ago to remove an inflamed appendix. His temperature is 105°F (40.6°C), blood pressure is 120/84 mmHg, pulse is 150/min, respirations are 19/min, and oxygen saturation is 99% on room air. Physical exam is notable for a confused man who cannot answer questions. His clothes are drenched in sweat. He is not making purposeful movements with his extremities although no focal neurological deficits are clearly apparent. Which of the following is the most likely diagnosis?

A. Heat exhaustion
B. Nonexertional heat stroke
C. Neuroleptic malignant syndrome
D. Malignant hyperthermia
E. Exertional heat stroke (Correct Answer)

Explanation: ***Exertional heat stroke*** - This diagnosis is supported by the patient's presentation of **hyperthermia** (105°F), **tachycardia**, **confusion**, and a history of working at a **construction site** (suggesting physical exertion in a hot environment). - The patient's **drenched clothes from sweat** indicate the body's initial attempt to cool down, but the extremely high core temperature and confusion signify a failure of thermoregulation. *Heat exhaustion* - While heat exhaustion also involves **sweating** and can present with elevated body temperature, the core temperature is typically **below 104°F (40°C)**, and **marked altered mental status** (like severe confusion) is less common or less severe. - The patient's temperature of 105°F (40.6°C) and profound confusion are more indicative of heat stroke. *Nonexertional heat stroke* - Nonexertional (or classic) heat stroke usually affects populations with **compromised thermoregulation** (e.g., elderly, very young, chronically ill) who are exposed to high environmental temperatures **without significant physical exertion**. - The patient's age (33) and history of working at a construction site make exertional heat stroke more likely than nonexertional. *Neuroleptic malignant syndrome* - NMS is characterized by **fever, muscle rigidity** (often "lead pipe" rigidity), **altered mental status**, and **autonomic instability** (including tachycardia and diaphoresis), and is associated with **antipsychotic medications** like haloperidol. - However, NMS typically develops **gradually over days to weeks**, not acutely. The key differentiator here is the **clear environmental and exertional context** (construction site work), **acute onset** after being found down, and the **absence of characteristic muscle rigidity** that would be prominent in NMS. - Heat stroke is more probable given the immediate occupational exposure and clinical timeline. *Malignant hyperthermia* - Malignant hyperthermia is a rare, life-threatening condition associated with exposure to certain **anesthetic agents** (e.g., succinylcholine, volatile anesthetics) or, less commonly, severe exertion in susceptible individuals. - The patient's recent surgery was two months prior, and there is no mention of current exposure to triggers, making it unlikely to be the immediate cause of his acute presentation.

Question 399: A 65-year-old man comes to the emergency department 1 hour after a loss of consciousness. His wife said he suddenly fainted while she was adjusting his necktie. He regained consciousness within 30 seconds and was fully alert and oriented. He has had two similar episodes in the last year. He has anxiety and takes alprazolam as needed. He smokes half a pack of cigarettes daily and drinks two glasses of wine with dinner each night. His temperature is 37.2°C (98.9°F), pulse is 70/min and regular, respirations are 13/min, blood pressure is 130/82 mm Hg when supine and 122/80 mm Hg while standing. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. A complete blood count shows no abnormalities. Bedside cardiac monitoring shows infrequent premature ventricular contractions and QRS voltage below 5 mm in leads II and III. Which of the following is the most likely diagnosis?

A. Carotid sinus hypersensitivity (Correct Answer)
B. Cardiac arrhythmia
C. Panic attack
D. Structural cardiac abnormality
E. Orthostatic syncope

Explanation: ***Carotid sinus hypersensitivity*** - The sudden loss of consciousness after **adjusting a necktie** (pressure on the carotid sinus) is highly suggestive of carotid sinus hypersensitivity. - Repeated episodes of **syncope triggered by neck manipulation** in an otherwise healthy individual further support this diagnosis. *Cardiac arrhythmia* - While **infrequent PVCs** are noted, there are no findings to suggest a significant arrhythmia causing syncope (e.g., prolonged asystole, sustained ventricular tachycardia, or severe bradycardia). - The **normal vital signs** and prompt recovery with full alertness point away from a severe cardiac event. *Panic attack* - Although the patient has anxiety and takes alprazolam, a panic attack is less likely given the **clear physical trigger** (necktie adjustment) and the **absence of typical panic symptoms** like hyperventilation, chest pain, or fear of dying during the syncope episodes. - Syncope in panic attacks is usually psychogenic and not directly caused by external physical stimulation. *Structural cardiac abnormality* - The **cardiopulmonary examination is normal**, and the **low QRS voltage** alone is not specific enough to diagnose a structural abnormality causing syncope in this context. - The clear trigger of neck pressure makes a structural cardiac cause less probable as the primary etiology. *Orthostatic syncope* - The patient's **blood pressure shows only a slight drop** upon standing, which is not indicative of orthostatic hypotension significant enough to cause syncope. - The clear trigger of **neck pressure** rather than a change in position makes orthostatic syncope unlikely.

Question 400: A 45-year-old man with asthma comes to the physician because of a 1-month history of progressively worsening shortness of breath and cough. He also has a history of chronic sinusitis and foot drop. Current medications include an albuterol inhaler and inhaled corticosteroid. Physical examination shows diffuse wheezing over both lung fields and tender subcutaneous nodules on both elbows. Laboratory studies show a leukocyte count of 23,000/mm3 with 26% eosinophils and a serum creatinine of 1.7 mg/dL. Urine microscopy shows red blood cell casts. Which of the following is the most likely diagnosis in this patient?

A. Granulomatosis with polyangiitis
B. Polyarteritis nodosa
C. Eosinophilic granulomatosis with polyangiitis (Correct Answer)
D. Microscopic polyangiitis
E. Immunoglobulin A vasculitis

Explanation: ***Eosinophilic granulomatosis with polyangiitis (EGPA)*** - The patient presents with **asthma**, **chronic sinusitis**, **eosinophilia** (26%), and symptoms of vasculitis including **foot drop** (neuropathy), **renal impairment** (elevated creatinine, RBC casts), and **subcutaneous nodules**. This constellation is highly characteristic of EGPA (formerly Churg-Strauss syndrome). - EGPA is a **small-to-medium vessel vasculitis** defined by **asthma**, **eosinophilia**, and **granulomatous inflammation**. *Granulomatosis with polyangiitis (GPA)* - GPA typically involves the **upper and lower respiratory tracts** and **kidneys**, often presenting with chronic sinusitis, lung nodules, and glomerulonephritis. - While GPA can cause renal impairment and neuropathy, it is not primarily characterized by **asthma** and profound **eosinophilia**, which are key features in this patient. *Polyarteritis nodosa (PAN)* - PAN is a **necrotizing vasculitis of medium-sized arteries** that typically affects the kidneys, peripheral nerves, GI tract, and skin. - PAN is not associated with **asthma** or significant **eosinophilia**, and it typically **spares the lungs**. *Microscopic polyangiitis (MPA)* - MPA is a **small-vessel vasculitis** primarily affecting the kidneys and lungs, a common cause of **pulmonary-renal syndrome**. - While MPA can cause renal failure, and sometimes pulmonary symptoms, it does not typically present with **asthma** or marked **eosinophilia**. *Immunoglobulin A vasculitis (IgAV)* - IgAV, also known as Henoch-Schönlein purpura, is characterized by classic triad of **palpable purpura**, **arthralgia**, and **abdominal pain**, and frequently involves the kidneys. - IgAV primarily affects **small vessels** and is not associated with **asthma**, **eosinophilia**, or the specific neurological and skin manifestations seen in this patient.

Question 401: A 57-year-old man comes to the emergency department for the evaluation of worsening fatigue, urinary frequency, and constipation over the past 5 days. He was recently diagnosed with metastatic bladder cancer and is currently awaiting treatment. He has smoked 1 pack of cigarettes daily for 35 years. Physical examination shows dry mucous membranes and diffuse abdominal tenderness. An ECG shows a shortened QT interval. Which of the following sets of serum findings is most likely in this patient? $$$ Calcium %%% Phosphorus %%% Parathyroid hormone %%% 1,25-dihydroxyvitamin D $$$

A. ↑ ↓ ↓ ↓ (Correct Answer)
B. ↑ ↑ ↓ ↑
C. ↑ ↑ ↑ ↓
D. ↑ ↓ ↑ ↑
E. ↓ ↑ ↑ ↓

Explanation: ***↑ ↓ ↓ ↓*** - This pattern of **elevated calcium**, **low phosphorus**, **low parathyroid hormone (PTH)**, and **low 1,25-dihydroxyvitamin D** is characteristic of **humoral hypercalcemia of malignancy (HHM)**. Malignant cells, particularly those from bladder cancer, can secrete **parathyroid hormone-related peptide (PTHrP)**, mimicking PTH, leading to increased bone resorption and renal calcium reabsorption, while suppressing endogenous PTH and indirectly leading to low 1,25-dihydroxyvitamin D synthesis. - The patient's symptoms of fatigue, constipation, urinary frequency, and signs like dry mucous membranes and a shortened QT interval on ECG are all consistent with **hypercalcemia**. *↑ ↑ ↓ ↑* - This pattern suggests **hypercalcemia** with **elevated phosphorus** and **elevated 1,25-dihydroxyvitamin D**, which is inconsistent with HHM. Elevated phosphorus is more commonly seen in conditions like **renal failure** or **tumor lysis syndrome**, neither of which are indicated here. - Elevated 1,25-dihydroxyvitamin D is typically seen in **granulomatous diseases** (e.g., sarcoidosis) or **lymphomas** causing hypercalcemia, not bladder carcinoma. *↑ ↑ ↑ ↓* - This profile indicates **hypercalcemia**, **elevated phosphorus**, and **elevated PTH**, which is consistent with **primary hyperparathyroidism**. However, primary hyperparathyroidism typically presents with inappropriately elevated PTH for the level of hypercalcemia, and it's less likely to develop acute, severe hypercalcemia with malignancy unless concurrent. - The patient's presentation with advanced bladder cancer makes HHM a more likely cause of hypercalcemia than primary hyperparathyroidism. *↑ ↓ ↑ ↑* - This constellation, with **elevated calcium**, **low phosphorus**, and **elevated PTH**, is classic for **primary hyperparathyroidism**. In this condition, inappropriately high PTH levels cause increased bone resorption, renal calcium reabsorption, and renal phosphate excretion, leading to hypophosphatemia. - While primary hyperparathyroidism causes hypercalcemia, the clinical context of advanced metastatic bladder cancer makes HHM a much more probable diagnosis in this patient, and PTH would be suppressed in HHM due to PTHrP mimicking its effects. *↓ ↑ ↑ ↓* - This pattern describes **hypocalcemia** (low calcium) with **elevated phosphorus** and **elevated PTH**. This is the hallmark of **secondary hyperparathyroidism**, often seen in **chronic kidney disease**, where low calcium and high phosphorus stimulate PTH release. - The patient in the vignette presents with symptoms of hypercalcemia, not hypocalcemia, making this option inconsistent with the clinical picture.

Question 402: A 62-year-old man presents to the emergency department with hematuria and hemoptysis that started in the morning. He notes that he has had frequent lung infections throughout his adult life, the most recent being 2 weeks ago. He also mentions that he has had hematuria twice before but never as severe as he is having currently. His medical history is otherwise non-significant, and his only medication is acetaminophen as needed. His blood pressure is 136/92 mm Hg, heart rate is 86/min, respiratory rate is 16/min, and temperature is 37.0°C (98.6°F). Chest radiography shows a resolving right middle lobe airspace opacity. His initial laboratory tests are notable for elevated erythrocyte sedimentation rate and C-reactive protein level. While in the examination room, the patient develops a spontaneous nosebleed. What is the most likely diagnosis?

A. Goodpasture syndrome
B. IgA nephropathy
C. Minimal change disease
D. Post-streptococcal glomerulonephritis
E. Granulomatosis with polyangiitis (Correct Answer)

Explanation: ***Granulomatosis with polyangiitis*** - This patient presents with a **triad of upper airway (nosebleed), lower airway (hemoptysis, recurrent lung infections), and renal involvement (hematuria)**, which is classic for granulomatosis with polyangiitis (GPA), a form of ANCA-associated vasculitis. - The elevated **ESR and CRP** indicate systemic inflammation, which is common in vasculitic conditions. *Goodpasture syndrome* - Characterized by **glomerulonephritis and pulmonary hemorrhage (hemoptysis)**, but typically does not involve the upper airways (e.g., nosebleeds). - Diagnosis is confirmed by the presence of **anti-glomerular basement membrane antibodies**, which often presents more acutely. *IgA nephropathy* - Often presents with **recurrent episodes of gross hematuria**, frequently following an upper respiratory tract infection. - While it involves the kidneys, it **does not typically cause pulmonary or upper airway symptoms** such as hemoptysis or recurrent lung opacities. *Minimal change disease* - Characterized by **nephrotic syndrome (proteinuria, hypoalbuminemia, edema)** and rarely presents with hematuria. - **Does not cause pulmonary or upper airway manifestations** like hemoptysis or nosebleeds. *Post-streptococcal glomerulonephritis* - Typically occurs **1-3 weeks after a streptococcal infection** and presents with acute nephritic syndrome (hematuria, proteinuria, edema, hypertension). - **Does not involve recurrent lung infections or hemoptysis** and is less likely in an adult with recurrent hematuria episodes.

Question 403: A 75-year-old man is brought to the emergency department by his son. He is suffering from left-sided weakness. The symptoms started 2 hours ago with sudden left-sided weakness. The patient is a known hypertensive, who is inconsistently compliant with his 2 antihypertensive medications and a heavy smoker, with a 40 pack year history. Physical examination shows an elderly male in mild distress. The vital signs include: blood pressure 140/95 mm Hg, pulse 89/min and SpO2 98% on room air. Neurological examination shows left-sided hemiparesis, with no sensory, cognitive, or brain stem abnormalities. A CT scan of the head without IV contrast shows a right-sided ischemic infarct. What other finding is most likely to develop in this patient as his condition progresses?

A. Loss of deep tendon reflexes
B. Positive Babinski sign (Correct Answer)
C. Fasciculations
D. Flaccid paresis
E. Muscle atrophy

Explanation: ***Positive Babinski sign*** - The patient has an **acute ischemic stroke** affecting the **right cerebral hemisphere**, leading to left-sided hemiparesis. - As the initial **flaccid paralysis** and **spinal shock** phase resolves, **upper motor neuron (UMN) signs** such as spasticity, hyperreflexia, and a positive Babinski sign typically emerge due to damage to the corticospinal tract. *Loss of deep tendon reflexes* - This is characteristic of **lower motor neuron (LMN) lesions** or the initial acute phase of an upper motor neuron (UMN) lesion (spinal shock), which is usually transient. - In a progressive UMN lesion following stroke, **deep tendon reflexes** are expected to become **hyperactive**, not lost. *Fasciculations* - **Fasciculations** are spontaneous, visible twitchings of a bundle of muscle fibers and are a hallmark of **lower motor neuron (LMN) pathology**. - They are not typically seen in **upper motor neuron (UMN) lesions** like an ischemic stroke. *Flaccid paresis* - **Flaccid paresis** describes muscle weakness with reduced muscle tone, often seen in the acute phase of a stroke due to **spinal shock**. - However, as the condition progresses and spinal shock resolves, the **flaccid paresis** will typically evolve into **spastic paresis** due to upper motor neuron damage. *Muscle atrophy* - **Muscle atrophy** can occur due to disuse after a stroke, but it is a **late complication** and is not a primary neurological sign that *most likely develops* acutely as the condition progresses. - Significant **neurogenic atrophy** with severe fasciculations is characteristic of **lower motor neuron lesions**.

Question 404: A 38-year-old woman presents with generalized weakness and dizziness for the past 3 weeks. Past medical history is significant for systemic lupus erythematosus diagnosed 15 years ago, for which she takes hydroxychloroquine and methotrexate. No significant family history. Her vital signs include: temperature 37.1°C (98.7°F), blood pressure 122/65 mm Hg, pulse 100/min. Physical examination reveals generalized pallor; sclera are icteric. Her laboratory results are significant for the following: Hemoglobin 7.3 g/dL Mean corpuscular hemoglobin (MCH) 45 pg/cell Reticulocyte count 6% Direct antiglobulin test Positive Peripheral blood smear Spherocytes Which of the following best represents the most likely cause of this patient's condition?

A. Methotrexate side effect
B. Chronic inflammation
C. Red cell membrane defect
D. IgM-mediated hemolysis
E. IgG-mediated hemolysis (Correct Answer)

Explanation: ***IgG-mediated hemolysis*** - The combination of **anemia**, **reticulocytosis**, **spherocytes** on peripheral smear, **icteric sclera**, and a **positive direct antiglobulin test (DAT)** indicates **autoimmune hemolytic anemia (AIHA)**. - Given the patient's history of **systemic lupus erythematosus (SLE)**, AIHA is a common complication, and the presence of spherocytes and a positive DAT strongly points towards **IgG-mediated (warm) AIHA**. *Methotrexate side effect* - While methotrexate can cause **bone marrow suppression** leading to **anemia**, it typically presents as **macrocytic anemia** (high MCV) with **low reticulocyte count**, not the **hemolytic picture** (high reticulocyte count, spherocytes, icterus) seen here. - Methotrexate-induced anemia is usually not associated with a **positive DAT** or **spherocytosis**. *Chronic inflammation* - **Anemia of chronic disease (ACD)** due to chronic inflammation (e.g., SLE) typically causes **normocytic or microcytic anemia** with a **low reticulocyte count**. - It does not explain the **hemolytic features** such as **icterus**, **spherocytes**, or the **positive DAT**. *Red cell membrane defect* - **Red cell membrane defects** (e.g., **hereditary spherocytosis**) can cause hemolytic anemia with spherocytes, but the **positive DAT** points to an **immune-mediated cause** rather than an intrinsic red cell defect. - These conditions are typically **congenital** and would not present with an acute onset related to SLE. *IgM-mediated hemolysis* - **IgM-mediated hemolysis** (cold agglutinin disease) typically presents with **agglutination** on the peripheral smear, and often has characteristic involvement in **cold temperatures**. - While it can cause a **positive DAT**, the presence of **spherocytes** is more characteristic of **IgG-mediated warm AIHA**, which is common in SLE.

Question 405: A 50-year-old man presents to the urgent care clinic for 3 hours of worsening cough, shortness of breath, and dyspnea. He works as a long-haul truck driver, and he informs you that he recently returned to the west coast from a trip to Arkansas. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type 2, chronic obstructive pulmonary disease (COPD), and mild intellectual disability. He currently smokes 1 pack of cigarettes/day, drinks a 6-pack of beer/day, and he endorses a past history of injection drug use but currently denies any illicit drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 23/min. His physical examination shows mild, bilateral, coarse rhonchi, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, and a benign abdominal physical examination. He states that he ran out of his albuterol inhaler 6 days ago and has been meaning to follow-up with his primary care physician (PCP) for a refill. Complete blood count (CBC) and complete metabolic panel are within normal limits. He also has a D-dimer result within normal limits. Which of the following is the most appropriate next step in evaluation?

A. Chest computed tomography (CT) with contrast
B. Chest radiographs (Correct Answer)
C. Pulmonary function tests
D. Sputum gram stain and culture
E. Arterial blood gas

Explanation: ***Chest radiographs*** - A **chest X-ray** is the most appropriate initial imaging study for evaluating acute respiratory symptoms in a patient with a history of COPD and recent exacerbating factors (running out of albuterol). It can help identify common causes like **pneumonia**, **pneumothorax**, or **acute exacerbation of COPD**. - The patient's presentation with worsening cough, shortness of breath, and dyspnea, particularly in the context of running out of his albuterol inhaler, suggests a primary pulmonary issue that a chest X-ray can quickly assess. *Chest computed tomography (CT) with contrast* - A **chest CT with contrast** is more detailed but not the initial diagnostic study in this scenario, especially with a normal D-dimer ruling out pulmonary embolism as a high probability. - It exposes the patient to **higher radiation** and risks associated with contrast, making it less suitable as a first-line investigation unless the chest X-ray is inconclusive or more specific findings are suspected. *Pulmonary function tests* - **Pulmonary function tests (PFTs)** are used to diagnose and monitor chronic lung conditions like COPD, but they are generally not performed in an acute urgent care setting for patients presenting with acute respiratory distress. - PFTs require patient cooperation and are designed to assess baseline lung function, not to identify the **acute cause** of respiratory decompensation. *Sputum gram stain and culture* - A **sputum gram stain and culture** might be considered if there's strong suspicion of a bacterial infection (e.g., fever, purulent sputum), but the patient's current symptoms are more aligned with a COPD exacerbation or other acute pulmonary issue. - Without clear signs of bacterial infection, this test is **not the most immediate or appropriate first step** in evaluating acute dyspnea, as it requires time for results and may delay more crucial diagnostic steps. *Arterial blood gas* - An **arterial blood gas (ABG)** can provide information on oxygenation, ventilation, and acid-base status, which is useful in assessing the severity of respiratory failure. - However, it's typically ordered after an initial clinical and imaging assessment to quantify the physiological impact of the respiratory distress, rather than being the **very first diagnostic step** to identify the cause.

Question 406: A 38-year-old man presents to his physician for difficulty swallowing for 2 months. He describes food getting stuck down his windpipe and has been feeling very anxious around meal time because he is thinking that he may have esophageal cancer. He has had an influenza-like infection that lasted about 6 weeks in the past 3 months which exacerbated his asthma attacks. He used his puffers to relieve his symptoms and did not seek medical treatment. He is otherwise healthy. On examination, his blood pressure is 118/75 mm Hg, respirations are 17/min, pulse is 78/min, and temperature is 36.7°C (98.1°F). There is no evidence of enlarged lymph nodes or a sore throat. On palpation, the thyroid gland is enlarged and tender. He is a non-smoker with a BMI of 25 kg/m2. He has not used any medications recently. Which of the following is the most likely diagnosis?

A. Chronic lymphocytic thyroiditis
B. Lymphoma
C. Silent thyroiditis
D. Fibrous thyroiditis
E. Subacute granulomatous thyroiditis (Correct Answer)

Explanation: ***Subacute granulomatous thyroiditis*** - The presentation of an **enlarged and tender thyroid gland** following an **influenza-like infection** is highly characteristic of subacute granulomatous thyroiditis, also known as de Quervain's thyroiditis. - The patient's dysphagia can be explained by the **inflammation and swelling of the thyroid gland** putting pressure on the esophagus, as the dysphagia is not progressive and has been present for a couple of months, also this is not a progressive dysphagia. *Chronic lymphocytic thyroiditis* - This condition, also known as **Hashimoto's thyroiditis**, typically presents with a **non-tender goiter** and often leads to hypothyroidism, which is not suggested by the current symptoms. - While it is an autoimmune condition, it is not usually preceded by a viral infection leading to acute pain and tenderness. *Lymphoma* - Thyroid lymphoma usually presents as a **rapidly enlarging, firm, non-tender mass** in the neck, and may cause compressive symptoms. - It is not typically preceded by an influenza-like illness and would likely involve more marked constitutional symptoms unrelated to thyroid dysfunction itself. *Silent thyroiditis* - Silent thyroiditis is characterized by a **painless goiter** and transient hyperthyroidism followed by hypothyroidism. - The key differentiating factor here is the **absence of pain and tenderness** in silent thyroiditis, which are prominent features in this case. *Fibrous thyroiditis* - Also known as **Riedel's thyroiditis**, this is a rare condition characterized by a **hard, fixed, and painless thyroid gland** that can be mistaken for malignancy due to its invasive nature. - It does not typically follow a viral infection and the thyroid is usually stony hard rather than tender.

Question 407: A 62-year-old female is brought to the hospital by her daughter. Six hours ago, she was at a wedding giving a speech when she suddenly experienced difficulty finding words and a right facial droop. She denies any extremity weakness, paresthesias, or sensory deficits. She has a history of hypertension and type 2 diabetes. She takes hydrochlorothiazide and insulin. Her last HbA1c was 10.3% four months ago. Vital signs are within normal limits. There is right lower facial droop on exam, but she is able to raise her eyebrows symmetrically. Speech is slow and slightly dysarthric. She has difficulty naming some objects. Her exam is otherwise unremarkable. Brain MRI shows a 3.2-cm infarct in the left frontal region. The patient is admitted to the neurology service for further management. On hospital day three her laboratory results show the following: Serum Na+ 131 mEq/L Osmolality 265 mOsmol/kg H2O Urine Na+ 46 mEq/L Osmolality 332 mOsmol/kg H2O This patient is most likely to have which of the following additional findings?

A. Increased hydrostatic pressure
B. Decreased serum uric acid (Correct Answer)
C. Increased serum bicarbonate
D. Increased blood urea nitrogen
E. Increased urinary frequency

Explanation: ***Decreased serum uric acid*** - This patient's laboratory values are consistent with **syndrome of inappropriate antidiuretic hormone (SIADH)**, characterized by **hypotonic hyponatremia**, **low serum osmolality (<280 mOsmol/kg)**, and inappropriately **elevated urine osmolality (>100 mOsmol/kg)** with **urine sodium >40 mEq/L** in the setting of euvolemia. - **SIADH** is commonly associated with **decreased serum uric acid (hypouricemia)** due to **increased fractional excretion of uric acid**. The volume expansion (relative to total body water) leads to increased glomerular filtration and decreased proximal tubular reabsorption of uric acid. - CNS disorders, including stroke (as in this case), are a common cause of SIADH. *Increased hydrostatic pressure* - **Increased hydrostatic pressure** is associated with conditions causing edema such as **congestive heart failure**, cirrhosis, or venous obstruction. - SIADH patients are typically **euvolemic** without peripheral edema, as the excess water is distributed throughout total body water rather than causing increased intravascular hydrostatic pressure. *Increased serum bicarbonate* - **Increased serum bicarbonate** (metabolic alkalosis) is not a feature of SIADH. - Metabolic alkalosis typically results from acid loss (vomiting, NG suction), diuretic use, or mineralocorticoid excess, not from water retention. *Increased blood urea nitrogen* - In SIADH, patients are in a state of **euvolemia to mild volume expansion**, which typically leads to **decreased BUN** due to dilution and increased renal perfusion. - **Increased BUN** would suggest hypovolemia, decreased renal perfusion, or intrinsic renal dysfunction—none of which are consistent with SIADH. *Increased urinary frequency* - SIADH is characterized by **inappropriate retention of water** with continued ADH activity despite hypo-osmolality. - This leads to **concentrated urine** and typically **normal to decreased urine output**, not increased urinary frequency. - The inappropriately elevated urine osmolality (332 mOsmol/kg) in this patient confirms water retention rather than increased urinary losses.

Question 408: A 67-year-old man presents to the emergency department for a headache. The patient states his symptoms started thirty minutes ago. He states he experienced a sudden and severe headache while painting his house, causing him to fall off the ladder and hit his head. He has also experienced two episodes of vomiting and difficulty walking since the fall. The patient has a past medical history of hypertension, obesity, and atrial fibrillation. His current medications include lisinopril, rivaroxaban, atorvastatin, and metformin. His temperature is 99.5°F (37.5°C), blood pressure is 150/105 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. On physical exam, the patient localizes his headache to the back of his head. Cardiac exam reveals a normal rate and rhythm. Pulmonary exam reveals minor bibasilar crackles. Neurological exam is notable for minor weakness of the muscles of facial expression. Examination of cranial nerve three reveals a notable nystagmus. Heel to shin exam is abnormal bilaterally. The patient's gait is notably ataxic. A non-contrast CT scan of the head is currently pending. Which of the following is the most likely diagnosis?

A. Pontine hemorrhage
B. Cerebellar hemorrhage (Correct Answer)
C. Subarachnoid hemorrhage
D. Thalamic hemorrhage
E. Subdural hematoma

Explanation: ***Cerebellar hemorrhage*** - The sudden onset of a **severe headache**, localized to the back of the head, combined with **ataxia**, nystagmus, and minor facial weakness, in a patient on **anticoagulation** (rivaroxaban) for atrial fibrillation, strongly suggests a cerebellar hemorrhage. - **Vomiting** and **difficulty walking** are common symptoms due to the cerebellar involvement and increased intracranial pressure. *Pontine hemorrhage* - Pontine hemorrhages typically present with **quadriplegia**, profound **coma**, and **pinpoint pupils**, which are not observed in this patient. - While it can cause sudden headache and vomiting, the specific neurological deficits (ataxia, nystagmus, mild facial weakness) are less characteristic of a pontine lesion. *Subarachnoid hemorrhage* - Characterized by a **"thunderclap" headache** (sudden and severe), often described as the "worst headache of my life," and can cause focal neurological deficits depending on the location of rupture. - While the sudden onset and severity fit, the specific cerebellar signs (**nystagmus**, **ataxia**, posterior headache) point more directly to a cerebellar lesion, and the fall causing head trauma suggests a hemorrhage within the brain parenchyma. *Thalamic hemorrhage* - Thalamic hemorrhages commonly present with **contralateral hemisensory loss**, hemiparesis, and sometimes pupillary abnormalities. - The patient's presentation with prominent **ataxia**, nystagmus, and posterior headache is less typical for a thalamic hemorrhage. *Subdural hematoma* - Subdural hematomas usually result from **trauma** and can have a more **insidious onset** (especially chronic subdural hematomas in elderly or anticoagulated patients). - While the fall might suggest this, the acute onset of severe headache and the specific neurological signs like **ataxia** and nystagmus are more indicative of an intraparenchymal hemorrhage (like cerebellar) rather than a subdural collection compressing the brain surface.

Question 409: A 64-year-old woman with a history of rheumatic fever presents to her primary care clinician complaining of excessive fatigue with walking and difficulty lying flat. She had no prior physical limitations, but recently has been unable to walk more than 3 blocks without needing to stop and rest. Her cardiac exam is notable for a late diastolic murmur heard best at the apex in the left lateral decubitus position with no radiation. What is the most likely diagnosis?

A. Aortic Stenosis
B. Tricuspid Regurgitation
C. Mitral Regurgitation
D. Aortic Regurgitation
E. Mitral Stenosis (Correct Answer)

Explanation: ***Mitral Stenosis*** - A **late diastolic murmur heard best at the apex** in the left lateral decubitus position is a classic finding of **mitral stenosis**. - History of **rheumatic fever** is a strong risk factor for mitral stenosis due to scarring and thickening of the mitral valve leaflets. **Fatigue with exertion** and **dyspnea on lying flat (orthopnea)** are common symptoms of left atrial enlargement and pulmonary congestion. *Aortic Stenosis* - Characterized by a **systolic ejection murmur** best heard at the right upper sternal border, radiating to the carotids. - While it can cause exertional dyspnea and fatigue, the murmur timing and location do not match the patient's presentation. *Tricuspid Regurgitation* - Presents with a **holosystolic murmur** best heard at the left sternal border, often increasing with inspiration. - Unlike mitral stenosis, it is more commonly associated with right-sided heart failure symptoms like peripheral edema and ascites. *Mitral Regurgitation* - Characterized by a **holosystolic murmur** that radiates to the axilla, best heard at the apex. - Although also associated with rheumatic fever and causing fatigue, the timing of the murmur (systolic vs. diastolic) differentiates it from mitral stenosis. *Aortic Regurgitation* - Presents with an **early diastolic decrescendo murmur** best heard at the left sternal border. - While it can cause dyspnea on exertion, its murmur is distinctly different from the late diastolic murmur described.

Question 410: A 72-year-old man presents to his primary care physician for his annual exam. He has a very stoic personality and says that he is generally very healthy and has "the normal aches and pains of old age." On further probing, you learn that he does have pretty significant back and hip pain that worsens throughout the day. On physical exam you note bony enlargement of the distal interphalangeal joints bilaterally. Which of the following is the likely cause of his symptoms?

A. Rheumatoid arthritis
B. Osteoarthritis (Correct Answer)
C. Gout
D. Pseudogout
E. Osteopenia

Explanation: ***Osteoarthritis*** - The patient's age (72 years), back and hip pain that **worsens throughout the day** (classic for *wear-and-tear*), and **bony enlargement of the distal interphalangeal (DIP) joints** (Heberden's nodes) are highly characteristic of osteoarthritis. - This condition involves the progressive **degeneration of articular cartilage**, leading to bone-on-bone friction and osteophyte formation. *Osteopenia* - **Osteopenia** is a precursor to osteoporosis, characterized by **reduced bone mineral density**, making bones weaker. - It typically presents with **no symptoms** until it progresses to osteoporosis and causes fractures; it does not cause pain that worsens throughout the day or bony enlargements of joints. *Rheumatoid arthritis* - **Rheumatoid arthritis** typically affects the **small joints of the hands and feet symmetrically**, but it predominantly involves the **proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints**, sparing the distal interphalangeal (DIP) joints. - Pain and stiffness associated with rheumatoid arthritis are usually **worse in the morning** and *improve with activity*, in contrast to the patient's symptoms. *Gout* - **Gout** is an inflammatory arthritis caused by the deposition of **urate crystals**, typically presenting as *acute, severe attacks* of pain, swelling, and redness in a single joint, most commonly the **big toe**. - While it can affect other joints over time, it does not typically cause gradual onset, activity-related pain, or bony enlargement of DIP joints as described. *Pseudogout* - **Pseudogout**, or **calcium pyrophosphate deposition disease (CPPD)**, is caused by the deposition of **calcium pyrophosphate crystals** in joints. - Similar to gout, it causes *acute inflammatory arthritis*, often affecting larger joints like the knee or wrist, and is not characterized by the chronic, activity-related pain and DIP joint bony changes seen in this patient.

Question 411: A 77-year-old man with a history of hypertension and a 46 pack-year smoking history presents to the emergency department from an extended care facility with acute onset of headache, nausea, vomiting, and neck pain which started 6 hours ago and has persisted since. He is alert, but his baseline level of consciousness is slightly diminished per the nursing home staff. His temperature is 99.0°F (37.2°C), blood pressure is 164/94 mmHg, pulse is 90/min, respirations are 16/min, and oxygen saturation is 98% on room air. The patient's neurological exam is unremarkable with cranial nerves II-XII grossly intact and with stable gait with a walker. He is immediately sent for a head CT which is normal. What is the most appropriate next step in management?

A. Ultrasound
B. Lumbar puncture (Correct Answer)
C. Alteplase
D. Ibuprofen, acetaminophen, metoclopramide, and diphenhydramine
E. MRI

Explanation: ***Lumbar puncture*** - The patient's symptoms (acute severe headache, nausea, vomiting, neck pain) and risk factors (hypertension, smoking history) are highly suggestive of a **subarachnoid hemorrhage (SAH)**, even with a normal initial **non-contrast head CT**. - A **lumbar puncture (LP)** is the next critical diagnostic step to detect **xanthochromia** (due to bilirubin degradation from red blood cells) or elevated red blood cell count in the cerebrospinal fluid (CSF), which would confirm SAH. - CT has approximately **95% sensitivity in the first 6 hours**, but sensitivity decreases over time, making LP essential when clinical suspicion remains high. *Ultrasound* - **Ultrasound** is not a standard diagnostic tool for acute neurological symptoms like severe headache or suspected SAH. - It is primarily used for evaluating soft tissues, abdominal organs, and vascular structures like carotid arteries, but offers limited utility for intracranial bleeding. *Alteplase* - **Alteplase** (tissue plasminogen activator, tPA) is a thrombolytic agent used in acute ischemic stroke, characterized by focal neurological deficits due to arterial occlusion. - Administering alteplase in the setting of headache and neck pain without focal deficits, while SAH is suspected, could be fatal as it would worsen bleeding. *Ibuprofen, acetaminophen, metoclopramide, and diphenhydramine* - This combination of medications is used for **symptomatic relief** of headache and nausea but does not address the underlying potentially life-threatening cause. - Treating symptoms without a definitive diagnosis in suspected SAH could lead to delayed intervention and worse outcomes. *MRI* - While **MRI with specific sequences (FLAIR, GRE, SWI)** has high sensitivity for detecting SAH and is increasingly used in clinical practice, **lumbar puncture remains the traditional and most widely recommended next step** after a negative CT in suspected SAH. - LP directly detects **xanthochromia** (present 6-12 hours after bleeding) and RBCs in CSF, providing definitive evidence of SAH. - MRI may not always be readily available in the emergency setting, takes longer to perform, and requires patient stability and cooperation. - For standardized exams, **LP is the classic correct answer** when CT is negative but clinical suspicion for SAH remains high.

Question 412: A 42-year-old man with a history of tuberculosis presents to your office complaining of fatigue for two months. Serum laboratory studies reveal the following: WBC 7,000 cells/mm^3, Hb 9.0 g/dL, Hct 25%, MCV 88 fL, Platelet 450,000 cells/mm^3, Vitamin B12 500 pg/mL (200-800), and Folic acid 17 ng/mL (2.5-20). Which of the following is the most appropriate next step in the management of anemia in this patient?

A. Iron studies (Correct Answer)
B. Bone marrow biopsy
C. Observation
D. Colonoscopy
E. Erythropoietin administration

Explanation: ***Iron studies*** - The patient has **normocytic anemia** (MCV 88 fL) and a history of **tuberculosis**, which is a chronic inflammatory condition often associated with **anemia of chronic disease (ACD)**. - **Iron studies** are critical to differentiate between **ACD** (typically high ferritin, low transferrin saturation) and iron deficiency anemia, which can coexist. *Bone marrow biopsy* - A **bone marrow biopsy** is an invasive procedure and is typically reserved for cases of unexplained severe anemia, pancytopenia, or suspicion of primary bone marrow disorders that are not suggested by the current findings. - The current blood counts do not indicate an urgent need for bone marrow evaluation, as the **anemia is mild to moderate**, and other cell lines are normal (WBC) or elevated (platelets). *Erythropoietin administration* - **Erythropoietin administration** is used in specific anemias, such as **anemia of chronic kidney disease** or certain types of myelodysplastic syndromes. - It is not the initial step for diagnosing and managing anemia in a patient with a chronic inflammatory condition like tuberculosis without first assessing iron status or ruling out other treatable causes. *Observation* - **Observation** is inappropriate given the patient's symptomatic anemia (fatigue) and the identified abnormalities (Hb 9.0 g/dL). - Anemia warrants investigation to identify its cause and provide appropriate treatment, especially in the context of a chronic illness like tuberculosis. *Colonoscopy* - A **colonoscopy** is indicated if there is suspicion of **gastrointestinal blood loss**, which typically presents with **microcytic anemia** (low MCV) due to chronic iron deficiency. - This patient has **normocytic anemia**, and there are no symptoms suggestive of GI bleeding, making colonoscopy not the most appropriate first step.

Question 413: A 15-year-old girl comes to the physician with her father for evaluation of her tall stature. She is concerned because she is taller than all of her friends. Her birth weight and height were within normal limits. Her father is 174 cm (5 ft 7 in) tall; her mother is 162 cm (5 ft 3 in) tall. She is at the 98th percentile for height and 90th percentile for BMI. She has not had her menstrual period yet. Her mother has Graves disease. Vital signs are within normal limits. Examination shows a tall stature with broad hands and feet. There is frontal bossing and protrusion of the mandible. Finger perimetry is normal. The remainder of the examinations shows no abnormalities. Serum studies show a fasting serum glucose of 144 mg/dL. An x-ray of the left hand and wrist shows a bone age of 15 years. Which of the following is the most appropriate definitive treatment for this patient's condition?

A. Caloric restriction
B. Letrozole therapy
C. Methimazole therapy
D. Transsphenoidal adenomectomy (Correct Answer)
E. Leuprolide therapy

Explanation: ***Transsphenoidal adenomectomy*** - The patient's clinical presentation, including **tall stature with broad hands and feet**, frontal bossing, mandibular prognathism, primary amenorrhea, and elevated fasting glucose, is highly suggestive of **gigantism** (growth hormone excess before epiphyseal closure) due to a **GH-secreting pituitary adenoma**. - **Transsphenoidal adenomectomy** is the **definitive treatment** to surgically remove the GH-secreting tumor, thereby normalizing GH levels and preventing further progression of gigantism. - This is the most appropriate treatment to address the **underlying cause** and halt disease progression. *Caloric restriction* - While caloric restriction might impact overall growth, it is not a treatment for a hormonally driven condition like **gigantism** caused by a pituitary adenoma. - It would not address the underlying **excess growth hormone production** or prevent the associated physical changes and metabolic complications. *Letrozole therapy* - **Letrozole** is an **aromatase inhibitor** used primarily in the treatment of estrogen-dependent breast cancer and sometimes to induce ovulation or delay puberty in tall stature from other causes. - It does not directly target or reduce **growth hormone secretion** from a pituitary adenoma and is not appropriate for treating gigantism. *Methimazole therapy* - **Methimazole** is an **antithyroid medication** used to treat hyperthyroidism by reducing thyroid hormone production. - While the patient's mother has Graves' disease, this patient's symptoms are not indicative of thyroid dysfunction, and methimazole would not treat **GH excess** from a pituitary adenoma. *Leuprolide therapy* - **Leuprolide** is a **GnRH agonist** used to suppress puberty (e.g., in central precocious puberty) or for hormone-sensitive cancers. - It primarily affects the **hypothalamic-pituitary-gonadal axis** and has no direct role in treating **growth hormone excess** from a pituitary adenoma.

Question 414: A previously healthy 22-year-old man presents to the university clinic with increasing scrotal pain and swelling over the past 5 days. He also has dysuria and urinary frequency. He has never felt this type of pain before. The young man considers himself generally healthy and takes no medications. He is sexually active with one partner and uses condoms inconsistently. At the clinic, his temperature is 36.7℃ (98.1℉), the blood pressure is 115/70 mm Hg, the pulse is 84/min, and the respirations are 14/min. On examination, he has swelling and tenderness of the right scrotum, especially over the posterior aspect of the right testicle. The Prehn sign is positive. The remainder of the physical exam is unremarkable. Doppler sonography shows increased blood flow to the testis. Which of the following is the most appropriate next step in management?

A. Oral metronidazole for patient and sexual partner
B. IV ceftriaxone and oral doxycycline (Correct Answer)
C. Radical orchiectomy
D. Surgical exploration
E. Manual detorsion guided by Doppler sonography

Explanation: **IV ceftriaxone and oral doxycycline** - The patient's symptoms (scrotal pain, swelling, dysuria, urinary frequency), positive **Prehn's sign**, and **increased testicular blood flow** on Doppler sonography are highly suggestive of **epididymitis**, most likely caused by sexually transmitted infections (STIs) in a young, sexually active male. - **Empiric antibiotic treatment** for probable gonococcal and chlamydial infection (common causes of epididymitis in this age group) is the most appropriate next step, with **ceftriaxone** covering gonorrhea and **doxycycline** covering chlamydia. *Oral metronidazole for patient and sexual partner* - **Metronidazole** is primarily used to treat anaerobic bacterial infections and parasitic infections (e.g., *Trichomonas vaginalis*). - While *Trichomonas* can cause urethritis, it is not a common cause of epididymitis, and metronidazole would not cover the more likely bacterial etiologies of epididymitis such as *Neisseria gonorrhoeae* or *Chlamydia trachomatis*. *Radical orchiectomy* - **Radical orchiectomy** is the surgical removal of the testicle, typically reserved for confirmed cases of **testicular cancer**. - There are no indications of malignancy in this patient's presentation; the symptoms are inflammatory and infectious in nature. *Surgical exploration* - **Surgical exploration** is indicated if **testicular torsion** cannot be ruled out or if there are signs of **testicular abscess** or other surgical emergencies. - The positive **Prehn's sign** (relief of pain with scrotal elevation) and **increased blood flow** on Doppler argue against torsion and support epididymitis, making immediate surgical exploration unnecessary. *Manual detorsion guided by Doppler sonography* - **Manual detorsion** is a treatment for **testicular torsion**, a condition characterized by sudden, severe scrotal pain, an absent cremasteric reflex, a negative Prehn's sign, and **decreased or absent blood flow** on Doppler. - This patient's symptoms, especially the positive Prehn's sign and increased blood flow, are inconsistent with testicular torsion, making manual detorsion an inappropriate intervention.

Question 415: A 57-year-old man presents to the emergency department after a motor vehicle collision. The patient was the back seat restrained passenger in a vehicle that was rear ended at 25 miles/hour. The patient has a past medical history of diabetes, hypertension, and chronic obstructive pulmonary disease (COPD). His temperature is 97.5°F (36.4°C), blood pressure is 97/68 mmHg, pulse is 130/min, respirations are 22/min, and oxygen saturation is 99% on room air. The patient is subsequently worked up receiving a chest radiograph, ECG, FAST exam, and serum chemistries. A cardiac catheterization reveals equilibration in diastolic pressure across all cardiac chambers. Which of the following is the most likely diagnosis?

A. Tension pneumothorax
B. Hemorrhage
C. Tamponade (Correct Answer)
D. Congestive heart failure
E. Septic shock

Explanation: ***Tamponade*** - The finding of **equilibration of diastolic pressures across all cardiac chambers** is a classic hemodynamic sign of **cardiac tamponade**, indicating impaired ventricular filling due to extrinsic compression. - The patient's **hypotension** (97/68 mmHg), **tachycardia** (130/min), and history of trauma are consistent with **obstructive shock**, which cardiac tamponade can cause. *Tension pneumothorax* - While tension pneumothorax can cause **hypotension** and **tachycardia**, it would typically present with **markedly diminished or absent breath sounds** on one side and **tracheal deviation**, which are not mentioned. - The characteristic hemodynamic finding in tension pneumothorax is often **elevated central venous pressure** but not necessarily *equilibration of diastolic pressures* across all chambers. *Hemorrhage* - **Hemorrhage** would lead to **hypotension** and **tachycardia** due to hypovolemia, but it does not cause the specific finding of **equilibration of diastolic pressures** in the cardiac chambers. - Blood loss would typically manifest with other signs of **hypovolemic shock**, such as poor peripheral perfusion or a low hemoglobin, which are not indicated as the primary diagnostic finding here. *Congestive heart failure* - **Congestive heart failure** typically involves **elevated filling pressures** but not necessarily *equilibration* across all chambers, and the presentation would often include **dyspnea, pulmonary edema**, or peripheral edema, rather than acute post-traumatic shock with this specific hemodynamic profile. - The acute onset after trauma and the specific cardiac catheterization finding are inconsistent with acute exacerbation of chronic heart failure as the primary cause of shock. *Septic shock* - **Septic shock** is characterized by **vasodilation**, fever (or hypothermia), and signs of infection, leading to **distributive shock**. - While septic shock causes **hypotension** and **tachycardia**, it would not result in the specific finding of **equilibration of diastolic pressures** in the heart chambers, which points to an obstructive cause.

Question 416: A 72-year-old man comes to the physician for medical clearance for a molar extraction. He feels well. He reports he is able to climb 3 flights of stairs without experiencing any shortness of breath. He has hypertension, type 2 diabetes mellitus, and ischemic heart disease. He underwent an aortic valve replacement for severe aortic stenosis last year and had a prior episode of infective endocarditis 3 years ago. 12 years ago, he underwent a cardiac angioplasty and had 2 stents placed. Current medications include aspirin, warfarin, lisinopril, metformin, sitagliptin, and simvastatin. His temperature is 37.1°C (98.8°F), pulse is 92/min, and blood pressure is 136/82 mm Hg. A systolic ejection click is heard at the right second intercostal space. Which of the following is the most appropriate next step in management?

A. Administer oral amoxicillin 1 hour before the procedure (Correct Answer)
B. Discontinue aspirin and warfarin 72 hours prior to procedure
C. Administer oral clindamycin 1 hour before and 2 hours after the procedure
D. Obtain echocardiography prior to procedure
E. Avoid nitrous oxide during the procedure

Explanation: ***Administer oral amoxicillin 1 hour before the procedure*** - This patient has a **history of previous infective endocarditis**, which is an indication for **antibiotic prophylaxis** before dental procedures involving manipulation of gingival tissue or the periapical region of teeth per **2021 AHA guidelines**. - **Amoxicillin 2g orally** given 30-60 minutes before the procedure is the recommended first-line prophylaxis for patients not allergic to penicillins. - Note: Prosthetic valve replacement alone (without prior endocarditis) is **NOT an indication** for prophylaxis per current guidelines, but this patient's **prior endocarditis** makes prophylaxis necessary. *Discontinue aspirin and warfarin 72 hours prior to procedure* - For simple dental extractions, **aspirin should generally be continued** as the risk of thrombotic events (stent thrombosis, stroke in mechanical valve patients) outweighs bleeding risk. - **Warfarin** management should be individualized based on INR and thromboembolic risk; for mechanical valves, warfarin is typically continued if INR is therapeutic (<3.5), with local hemostatic measures used. - Blanket discontinuation 72 hours prior without bridging is **dangerous** in a patient with coronary stents and mechanical valve. *Administer oral clindamycin 1 hour before and 2 hours after the procedure* - **Clindamycin 600mg** is an alternative for patients with **penicillin allergy**; this patient has no documented allergy. - The correct regimen is a **single preoperative dose** 30-60 minutes before the procedure, **not post-procedure dosing**. *Obtain echocardiography prior to procedure* - This patient has **good functional capacity** (climbs 3 flights of stairs without symptoms) and recent valve replacement. - **Echocardiography is not required** for dental clearance in a stable patient with known cardiac history and preserved functional status. *Avoid nitrous oxide during the procedure* - There is **no specific contraindication** to nitrous oxide in patients with prosthetic valves, coronary disease, hypertension, or diabetes for dental procedures. - Nitrous oxide is generally safe with appropriate monitoring; this is not a primary management consideration.

Question 417: A 36-year-old man is brought in by ambulance after being found down on the sidewalk. It is uncertain how long he was down before being found, and he did not have any forms of identification when he was found. On presentation, the man is found to still be unconscious with a disheveled and unkempt appearance. He is also found to be taking slow, shallow breaths that smell of alcohol. His temperature is 98.8°F (37.1°C), blood pressure is 106/67 mmHg, pulse is 119/min, respirations are 5/min, and oxygen saturation is 87% on room air. His pupils are found to be fixed and contracted, and he has multiple bruises and scars on his body. Which of the following sets of findings would most likely be seen in this patient?

A. Decreased bicarbonate and decreased carbon dioxide
B. Normal bicarbonate and normal carbon dioxide
C. Increased bicarbonate and decreased carbon dioxide
D. Increased bicarbonate and increased carbon dioxide (Correct Answer)
E. Decreased bicarbonate and increased carbon dioxide

Explanation: ***Correct: Increased bicarbonate and increased carbon dioxide*** - This patient presents with **opioid overdose** causing severe **respiratory depression** (respirations 5/min, pinpoint pupils, altered mental status) - The profound **hypoventilation leads to CO2 retention** (respiratory acidosis) with **increased PaCO2** - While this appears to be an acute presentation, the **disheveled appearance, multiple scars, and chronic substance abuse history** suggest this may be **acute-on-chronic respiratory acidosis** - In patients with chronic respiratory acidosis (or repeated episodes), the kidneys compensate by **retaining bicarbonate**, leading to **elevated serum HCO3** - Even in primarily acute settings, some degree of renal compensation begins within hours, and chronic opioid users may have baseline compensated respiratory acidosis - **Expected findings:** Elevated PaCO2 (>45 mmHg) and elevated HCO3 (>26 mEq/L) *Incorrect: Decreased bicarbonate and increased carbon dioxide* - While the increased CO2 is correct for respiratory acidosis, this combination would suggest **concurrent metabolic acidosis** (e.g., lactic acidosis, ketoacidosis) - Although severe hypoxemia could cause lactic acidosis, the primary pathophysiology here is respiratory depression without clear evidence of severe metabolic derangement - This pattern would be seen in mixed respiratory acidosis with metabolic acidosis, which is less likely than compensated respiratory acidosis *Incorrect: Normal bicarbonate and normal carbon dioxide* - This would indicate **no acid-base disturbance**, which contradicts the severe hypoventilation (5/min) and hypoxemia (87% O2 sat) - The patient clearly has respiratory failure requiring immediate intervention *Incorrect: Increased bicarbonate and decreased carbon dioxide* - This combination indicates **compensated metabolic alkalosis** where respiratory compensation causes CO2 retention (though "decreased" is inconsistent) - The primary problem here is **respiratory depression causing CO2 retention**, not alkalosis - Decreased CO2 is the opposite of what occurs in hypoventilation *Incorrect: Decreased bicarbonate and decreased carbon dioxide* - This pattern suggests **compensated metabolic acidosis** where the lungs compensate by hyperventilating to blow off CO2 - This patient has **hypoventilation, not hyperventilation**, so CO2 would be increased, not decreased - This is incompatible with the clinical presentation of respiratory depression

Question 418: Four days after undergoing an elective total hip replacement, a 65-year-old woman develops a DVT that embolizes to the lung. Along with tachypnea, tachycardia, and cough, the patient would most likely present with a PaO2 of what?

A. 120 mmHg
B. 100 mmHg
C. 85 mmHg (Correct Answer)
D. 110 mmHg
E. 60 mmHg

Explanation: ***85 mmHg*** - A pulmonary embolism (PE) causes a **ventilation-perfusion (V/Q) mismatch**, leading to **hypoxemia** and a reduced PaO2. - While exact values vary, a PaO2 of 85 mmHg indicates **mild to moderate hypoxemia**, which is common in PE, especially with accompanying symptoms like tachypnea and tachycardia. *120 mmHg* - This value is significantly **higher than normal (75-100 mmHg)** and would indicate **hyperoxia**, which is inconsistent with acute pulmonary embolism causing respiratory distress. - A patient with PE would typically have **reduced oxygenation**, not supernormal levels, unless receiving high-flow supplemental oxygen. *100 mmHg* - A PaO2 of 100 mmHg is at the **upper end of the normal range** (75-100 mmHg) and would imply **no significant hypoxemia**. - Given the patient's symptoms of tachypnea, tachycardia, and cough following a DVT with embolization, a normal or high-normal PaO2 is unlikely without aggressive oxygen therapy (which is not stated). *110 mmHg* - This value is **above the normal range** and suggests **hyperoxia**, which is contrary to the pathophysiology of a pulmonary embolism. - A PE impairs gas exchange, leading to a decrease in PaO2, not an increase. *60 mmHg* - A PaO2 of 60 mmHg indicates **significant hypoxemia**, which might occur in a severe, large pulmonary embolism or in a patient with underlying lung disease. - While possible, 85 mmHg represents a more common, moderate hypoxemia seen in PE, especially given the prompt presentation of symptoms.

Question 419: A 33-year-old man comes to the physician because of gradually worsening bilateral foot pain for 2 months. The pain used to only occur after long walks and subside with rest. For the past week, the pain has been continuous and associated with burning sensations. He has also had transient painful nodules along the course of the leg veins for 4 months that resolve spontaneously. The patient is wearing an ankle brace for support because of a sprained left ankle that occurred three months ago. His mother was diagnosed with protein C deficiency as a teenager. He has smoked 2 packs of cigarettes daily for 15 years and does not drink alcohol. Vitals signs are within normal limits. Examination shows ulcers on the distal portion of his left great, second, and fifth toes. The feet are cool. Pedal pulses are barely palpable. Ankle-brachial pressure index is 0.3 in the left leg and 0.5 in the right leg. Which of the following interventions is most likely to reduce the risk of amputation in this patient?

A. Enoxaparin therapy
B. Bypass grafting
C. Simvastatin therapy
D. Smoking cessation (Correct Answer)
E. Removing the ankle brace

Explanation: ***Smoking cessation*** - This patient has **Buerger's disease (Thromboangiitis obliterans)**, indicated by: young age (<45 years), heavy smoking, **superficial thrombophlebitis** (transient painful nodules along leg veins), distal extremity involvement, and severe ischemia with markedly reduced **ankle-brachial pressure indices (ABPIs 0.3 and 0.5)**. - **Complete smoking cessation is the ONLY intervention that halts disease progression** in Buerger's disease and is absolutely essential to prevent amputation. Even minimal tobacco use (including secondhand smoke or nicotine replacement) can perpetuate disease activity. - This is the **most effective intervention** to prevent limb loss in this patient. *Enoxaparin therapy* - Enoxaparin is a **low-molecular-weight heparin** used for anticoagulation in conditions like deep vein thrombosis, pulmonary embolism, or acute coronary syndromes. - While this patient has thrombotic phenomena (superficial thrombophlebitis, family history of protein C deficiency), Buerger's disease is an **inflammatory arteritis** with thrombosis, not a primary thrombophilic condition. Anticoagulation does not address the underlying inflammatory process or prevent amputation. *Bypass grafting* - **Bypass grafting** or revascularization is challenging in Buerger's disease because the disease affects **small and medium-sized vessels distally**, often with inadequate target vessels for grafting. - While revascularization may be attempted in selected cases, it is **not the primary intervention** and has poor outcomes if smoking continues. Without smoking cessation, the disease will progress and grafts will fail. *Simvastatin therapy* - **Simvastatin** is a statin used to lower cholesterol and manage **atherosclerotic disease**. - Buerger's disease is **not atherosclerotic** in nature; it is an inflammatory vasculitis. While statins may have some anti-inflammatory effects, they do not address the primary pathophysiology and are not effective in preventing amputation in Buerger's disease without smoking cessation. *Removing the ankle brace* - The ankle brace is for a **previous sprained ankle** and provides musculoskeletal support. - While trauma and immobilization could theoretically affect local circulation, the brace is not the cause of his widespread, severe vascular disease. Removing it would not address the underlying **Buerger's disease** or prevent amputation.

Question 420: A 67-year-old woman is brought by ambulance from home to the emergency department after she developed weakness of her left arm and left face droop. According to her husband, she has a history of COPD, hypertension, and hyperlipidemia. She takes hydrochlorothiazide, albuterol, and atorvastatin. She is not on oxygen at home. She is an active smoker and has smoked a pack a day for 20 years. Her mother died of a heart attack at age 60 and her father died of prostate cancer at age 55. By the time the ambulance arrived, she was having difficulty speaking. Once in the emergency department, she is no longer responsive. Her blood pressure is 125/85 mm Hg, the temperature is 37.2°C (99°F), the heart rate is 77/min, and her breathing is irregular, and she is taking progressively deeper inspirations interrupted with periods of apnea. Of the following, what is the next best step?

A. Start tissue plasminogen activator (tPA)
B. Intubate the patient (Correct Answer)
C. Consult a cardiologist
D. Obtain an MRI of brain
E. Obtain non-contrast enhanced CT of brain

Explanation: ***Intubate the patient*** - The patient's **irregular breathing pattern with progressively deeper inspirations interrupted by periods of apnea** (known as **Cheyne-Stokes respiration**) combined with unresponsiveness due to probable acute stroke indicates imminent respiratory failure and the need for **airway protection**. - **Intubation** secures the airway, ensures adequate ventilation, and prevents aspiration during a neurological emergency. *Start tissue plasminogen activator (tPA)* - Although this patient likely has an **acute ischemic stroke**, the first priority is managing the **compromised airway and breathing**. - **tPA** administration is time-sensitive but requires stabilization of vital signs and exclusion of hemorrhage via neuroimaging, which hasn't occurred yet. *Consult a cardiologist* - While the patient has significant **cardiovascular risk factors** (**hypertension, hyperlipidemia, smoking, COPD, family history**), an acute cardiac event is not the immediate concern. - The pressing issue is **acute neurological deterioration with respiratory compromise**. *Obtain an MRI of brain* - An **MRI** offers detailed imaging for stroke but is **time-consuming** and **less accessible** in an emergency compared to CT. - The patient's critical respiratory status requires immediate intervention before non-urgent diagnostic imaging. *Obtain non-contrast enhanced CT of brain* - A **non-contrast CT scan of the brain** is crucial for differentiating between **ischemic** and **hemorrhagic stroke** and guiding treatment, specifically for tPA administration. - However, ensuring a **patent airway and stable ventilation** takes precedence over imaging in a patient with impending respiratory arrest.

Question 421: A 64-year-old woman is brought to the emergency department 1 hour after the onset of acute shortness of breath and chest pain. The chest pain is retrosternal in nature and does not radiate. She feels nauseated but has not vomited. She has type 2 diabetes mellitus, hypertension, and chronic kidney disease. Current medications include insulin, aspirin, metoprolol, and hydrochlorothiazide. She is pale and diaphoretic. Her temperature is 37°C (98°F), pulse is 136/min, and blood pressure is 80/60 mm Hg. Examination shows jugular venous distention and absence of a radial pulse during inspiration. Crackles are heard at the lung bases bilaterally. Cardiac examination shows distant heart sounds. Laboratory studies show: Hemoglobin 8.3 g/dL Serum Glucose 313 mg/dL Urea nitrogen 130 mg/dL Creatinine 6.0 mg/dL Which of the following is the most appropriate next step in management?

A. Furosemide therapy
B. Pericardiocentesis (Correct Answer)
C. Aspirin therapy
D. Hemodialysis
E. Norepinephrine infusion

Explanation: ***Pericardiocentesis*** * The patient presents with classic signs of **cardiac tamponade**, including **Beck's triad** (hypotension, jugular venous distension, distant heart sounds), **pulsus paradoxus** (absence of radial pulse during inspiration), and acute onset of shortness of breath and chest pain. * Given her history of **chronic kidney disease** and elevated urea/creatinine levels, uremic pericarditis is a likely cause, leading to significant pericardial effusion and tamponade. **Pericardiocentesis** is the definitive treatment to relieve pressure on the heart. *Furosemide therapy* * While **crackles** suggest pulmonary congestion, this patient is severely hypotensive with signs of cardiogenic shock due to tamponade. Administering a diuretic like **furosemide** would further reduce preload, worsening her already compromised cardiac output and hypotension. * The primary issue is extrinsic compression of the heart by pericardial fluid, not left ventricular failure responsive to diuresis. *Aspirin therapy* * The patient's chest pain and other symptoms could potentially point to an acute coronary syndrome, which would warrant **aspirin**. However, her profound hypotension and clear signs of cardiac tamponade (Beck's triad, pulsus paradoxus) make **cardiac tamponade** the more immediate and life-threatening concern. * Addressing the tamponade takes priority as its hemodynamic compromise is more acute and direct. *Hemodialysis* * The patient has severe **acute-on-chronic kidney disease** and likely **uremic pericarditis**. While **hemodialysis** is indicated for uremia, it is not the immediate life-saving intervention for **cardiac tamponade**. * **Pericardiocentesis** is required first to stabilize her hemodynamics; hemodialysis can be performed afterward to address the underlying uremia. *Norepinephrine infusion* * **Norepinephrine** is a powerful vasopressor that would increase systemic vascular resistance and blood pressure. While the patient is hypotensive, the underlying cause is **cardiac tamponade**, which mechanically obstructs cardiac filling and output. * **Vasopressors** alone will not resolve the mechanical obstruction and may even increase myocardial oxygen demand without increasing cardiac output, potentially worsening the situation. The tamponade must be relieved first.

Question 422: A 35-year-old female comes to the physician because of a 2-year history of progressive fatigue and joint pain. She has a 1-year history of skin problems and a 4-month history of episodic pallor of her fingers. She reports that the skin of her face, neck, and hands is always dry and itchy; there are also numerous “red spots” on her face. She has become more “clumsy” and often drops objects. She has gastroesophageal reflux disease treated with lansoprazole. She does not smoke. She occasionally drinks a beer or a glass of wine. Her temperature is 36.5°C (97.7°F), blood pressure is 154/98 mm Hg, and pulse is 75/min. Examination shows hardening and thickening of the skin of face, neck, and hands. There are small dilated blood vessels around her mouth and on her oral mucosa. Mouth opening is reduced. Active and passive range of motion of the proximal and distal interphalangeal joints is limited. Cardiopulmonary examination shows no abnormalities. Her creatinine is 1.4 mg/dL. The patient is at increased risk for which of the following complications?

A. Digital ulcers (Correct Answer)
B. Scleroderma renal crisis
C. Pulmonary arterial hypertension
D. Gastrointestinal dysmotility
E. Interstitial lung disease

Explanation: ***Digital ulcers*** - The patient exhibits several features of **systemic sclerosis (scleroderma)**, including **active Raynaud phenomenon** (**episodic pallor of fingers**), skin thickening, and telangiectasias (**red spots**). **Digital ulcers are the most immediate complication** given the active vascular symptoms. - Raynaud phenomenon causes repeated ischemia-reperfusion injury to the digits, and **up to 50% of patients with systemic sclerosis and Raynaud develop digital ulcers**, making this the highest near-term risk among the options. - The patient's **reduced mouth opening** and **limited range of motion in interphalangeal joints** are consistent with skin changes and joint involvement in scleroderma, further supporting the diagnosis and vascular complications. *Scleroderma renal crisis* - While **hypertension** is present (154/98 mm Hg) and **creatinine is elevated** (1.4 mg/dL), these findings are relatively mild and do not meet criteria for **scleroderma renal crisis**, which typically presents with **acute malignant hypertension** (>180/100 mmHg), rapidly progressive renal failure, microangiopathic hemolytic anemia, and thrombocytopenia. - Renal crisis tends to occur earlier in the disease course (within first 4-5 years) and is more common with diffuse cutaneous scleroderma and recent corticosteroid use. This patient's presentation suggests limited cutaneous involvement (face, neck, hands - consistent with CREST/limited variant). *Pulmonary arterial hypertension* - **Pulmonary arterial hypertension (PAH)** is a serious late complication of systemic sclerosis, particularly in limited cutaneous disease, but there are **no current signs or symptoms** on cardiopulmonary examination. - While this remains a long-term risk requiring screening, it is not the most immediate complication. PAH typically develops years after disease onset and would present with dyspnea, fatigue, and signs of right heart dysfunction. *Gastrointestinal dysmotility* - The patient **already has** **gastroesophageal reflux disease (GERD)**, which is a manifestation of gastrointestinal dysmotility in systemic sclerosis due to esophageal smooth muscle involvement. - Since the patient already has this complication (not "at risk for" a future complication), this is not the best answer. Further GI complications could occur, but digital ulcers represent a more immediate risk. *Interstitial lung disease* - **Interstitial lung disease (ILD)** is a common and severe complication of systemic sclerosis, particularly in the diffuse cutaneous form, and is a leading cause of mortality. - However, the patient's **cardiopulmonary examination is noted as normal**, which does not suggest active or clinically apparent ILD at this time. While this remains a long-term risk requiring monitoring (with pulmonary function tests and HRCT), it is not the most immediate complication given the active Raynaud phenomenon.

Question 423: A 16-year-old girl is brought to the physician because of a 6-month history of menstrual cramps, heavy menstrual flow, and fatigue; she has gained 5 kg (11 lb) during this period. Menses occur at regular 30-day intervals and last 8 to 10 days; during her period she uses 7 tampons a day and is unable to participate in any physical activities because of cramping. Previously, since menarche at the age of 11 years, menses had lasted 4 to 5 days with moderate flow. Her last menstrual period was 3 weeks ago. She has limited scleroderma with episodic pallor of the fingertips. She takes no medications. She is 160 cm (5 ft 3 in) tall and weighs 77 kg (170 lb); BMI is 30 kg/m2. Her temperature is 36.5°C (97.7°F), pulse is 56/min, respirations are 16/min, and blood pressure is 100/65 mm Hg. Physical examination shows a puffy face with telangiectasias and thinning of the eyebrows. Deep tendon reflexes are 1+ bilaterally with delayed relaxation. Pelvic examination shows a normal appearing vagina, cervix, uterus, and adnexa. Further evaluation of this patient is most likely to show which of the following findings?

A. Elevated TSH (Correct Answer)
B. Elevated androgens
C. Elevated LH:FSH ratio
D. Elevated midnight cortisol
E. Prolonged aPTT

Explanation: ***Elevated TSH*** - The patient's symptoms, including **heavy menstrual flow** (**menorrhagia**), **fatigue**, **weight gain**, **puffy face**, **thinning eyebrows**, **bradycardia**, and **delayed relaxation of deep tendon reflexes**, are highly suggestive of **hypothyroidism**. - **Elevated TSH** (thyroid-stimulating hormone) is the most sensitive and specific laboratory finding for **primary hypothyroidism**, indicating the thyroid gland is not producing enough thyroid hormones. *Elevated androgens* - Elevated androgens are associated with conditions like **polycystic ovary syndrome (PCOS)**, which typically presents with **oligomenorrhea** or **amenorrhea**, not menorrhagia. - While weight gain can occur in PCOS, other classic features like **hirsutism** or significant **acne** are not mentioned, and the other symptoms point away from this diagnosis. *Elevated LH:FSH ratio* - An **elevated LH:FSH ratio** is a characteristic finding in **polycystic ovary syndrome (PCOS)**. - As with elevated androgens, PCOS is unlikely given the patient's presentation of **heavy, regular periods** and other hypothyroid-consistent symptoms. *Elevated midnight cortisol* - Elevated midnight cortisol is indicative of **Cushing's syndrome**, which involves symptoms such as **central obesity**, **moon facies**, **buffalo hump**, **striae**, and **hypertension**. - While this patient has a puffy face and weight gain, her **hypotension** and other features like **bradycardia** are inconsistent with Cushing's. *Prolonged aPTT* - A prolonged aPTT (activated partial thromboplastin time) suggests a **coagulation disorder**, such as **hemophilia** or **von Willebrand disease (vWD)**, which could cause menorrhagia. - While vWD is a common cause of heavy menstrual bleeding, the array of other systemic symptoms (fatigue, weight gain, bradycardia, puffy face, delayed reflexes) strongly points towards an endocrine cause, specifically hypothyroidism, rather than solely a bleeding disorder.

Question 424: A 32-year-old man presents with hypertension that has been difficult to control with medications. His symptoms include fatigue, frequent waking at night for voiding, and pins and needles in the legs. His symptoms started 2 years ago. Family history is positive for hypertension in his mother. His blood pressure is 160/100 mm Hg in the right arm and 165/107 mm Hg in the left arm, pulse is 85/min, and temperature is 36.5°C (97.7°F). Physical examination reveals global hyporeflexia and muscular weakness. Lab studies are shown: Serum sodium 147 mEq/L Serum creatinine 0.7 mg/dL Serum potassium 2.3 mEq/L Serum bicarbonate 34 mEq/L Plasma renin activity low Which of the following is the most likely diagnosis?

A. Renal artery stenosis
B. Coarctation of aorta
C. Cushing syndrome
D. Primary aldosteronism (Correct Answer)
E. Essential hypertension

Explanation: ***Primary aldosteronism*** - The patient presents with **resistant hypertension**, **hypokalemia** (2.3 mEq/L), **metabolic alkalosis** (bicarbonate 34 mEq/L), and **low plasma renin activity**, which are classic features of primary aldosteronism. - Symptoms like **fatigue**, **nocturia**, and **paresthesias** (pins and needles) in the legs are consistent with severe hypokalemia, directly resulting from excessive aldosterone secretion. *Renal artery stenosis* - This condition typically causes **secondary hypertension** with **elevated renin levels** due to decreased renal perfusion, which contradicts the low plasma renin activity seen in this patient. - While it can cause hypokalemia because of increased renin-angiotensin-aldosterone system activation, the **primary driver** in this case, based on low renin, points away from renal artery stenosis. *Coarctation of aorta* - Characterized by **differential blood pressures** between the upper and lower extremities and sometimes between the arms, and a **systolic murmur** that is often present. - It does not typically present with severe **hypokalemia** or metabolic alkalosis or the low plasma renin activity observed in this patient. *Cushing syndrome* - This syndrome is caused by **excessive cortisol** and can lead to hypertension and hypokalemia, but it is also associated with distinct clinical features like **central obesity**, buffalo hump, moon facies, and proximal muscle weakness, which are not described. - While it can cause similar electrolyte imbalances, the lack of classic Cushingoid features makes it less likely, and the specific **low plasma renin** points more strongly to aldosterone excess. *Essential hypertension* - This is a diagnosis of exclusion, typically presenting without a clear secondary cause and with **normal electrolyte levels**. - The presence of severe **hypokalemia**, **metabolic alkalosis**, and **low plasma renin activity** indicates a secondary cause, ruling out essential hypertension.

Question 425: A 30-year-old man comes to the clinic with complaints of increased frequency of urination, especially at night, for about a month. He has to wake up at least 5-6 times every night to urinate and this is negatively affecting his sleep. He also complains of increased thirst and generalized weakness. Past medical history is significant for bipolar disorder. He is on lithium which he takes regularly. Blood pressure is 150/90 mm Hg, pulse rate is 80/min, respiratory rate is 16/min, and temperature is 36°C (96.8°F). Physical examination is normal. Laboratory studies show: Na+: 146 mEq/L K+: 3.8 mEq/L Serum calcium: 9.5 mg/dL Creatinine: 0.9 mg/dL Urine osmolality: 195 mOsm/kg Serum osmolality: 305 mOsm/kg Serum fasting glucose: 90 mg/dL Which of the following is the best initial test for the diagnosis of his condition?

A. Serum ADH level
B. MRI scan of brain
C. CT thorax
D. Chest X-ray
E. Water deprivation test (Correct Answer)

Explanation: ***Water deprivation test*** - The patient presents with **polyuria**, **polydipsia**, and **nocturia**, along with elevated **serum osmolality** and low **urine osmolality**, indicating a probable diagnosis of **diabetes insipidus**. The **water deprivation test** is the gold standard for differentiating between central and nephrogenic diabetes insipidus by assessing the kidney's response to fluid restriction and subsequently to desmopressin. - Given the history of **lithium use**, **nephrogenic diabetes insipidus** is a strong possibility, as lithium can impair the kidney's ability to respond to ADH. The water deprivation test will help clarify the type of diabetes insipidus. *Serum ADH level* - While **ADH levels** can be informative, they are often difficult to interpret in isolation and can vary based on hydration status; a single measurement might not be diagnostic. - The diagnosis of diabetes insipidus is primarily clinical and biochemical, with ADH levels used as an adjunct rather than a primary diagnostic test. *MRI scan of brain* - An **MRI of the brain** would be considered if **central diabetes insipidus** is highly suspected, as it could identify structural abnormalities of the hypothalamus or pituitary gland. - However, since the patient is on **lithium**, which commonly causes nephrogenic diabetes insipidus, evaluating renal response to dehydration and possibly ADH is the more immediate and appropriate next step before imaging. *CT thorax* - A **CT thorax** is not indicated in the initial workup for diabetes insipidus, as the patient's symptoms are not suggestive of a pulmonary or thoracic etiology. - This test would be used to investigate conditions like sarcoidosis or lung cancer, which can rarely cause central diabetes insipidus through ADH suppression or ectopic ADH production, but these are not the primary concerns here. *Chest X-ray* - A **chest X-ray** is generally not part of the initial diagnostic workup for diabetes insipidus. - It would only be considered if there were respiratory symptoms or a suspicion of conditions like **sarcoidosis** or **tuberculosis** that could involve the pituitary, but there are no such indications in this patient.

Question 426: A 29-year-old homeless man visits his local walk-in-clinic complaining of shortness of breath, fatigability, malaise, and fever for the past month. His personal history is significant for multiple inpatient psychiatric hospitalizations for a constellation of symptoms that included agitation, diarrhea, dilated pupils, and restless legs. On physical examination, his blood pressure is 126/72 mm Hg, heart rate is 117/min, body temperature is 38.5°C (101.3°F), and saturating 86% on room air. Auscultation reveals a holosystolic murmur that is best heard at the left sternal border and noticeably enhanced during inspiration. What is the underlying pathophysiological mechanism in this patient’s heart condition?

A. Failed delamination
B. Chemical endothelial damage (Correct Answer)
C. Verrucous lesions
D. Myxomatous degeneration
E. Fibrillin 1 (FBN1) mutations

Explanation: ***Chemical endothelial damage*** - The patient's history of recurrent psychiatric hospitalizations with symptoms of agitation, diarrhea, dilated pupils, and restless legs points to **substance abuse**, particularly consistent with IV drug use, a common issue in homeless individuals. This, in conjunction with the signs of infection (fever, malaise, elevated heart rate) and a heart murmur, strongly suggests **infective endocarditis** in an IV drug user. - **Intravenous drug use** introduces foreign substances and bacteria directly into the bloodstream, causing **chemical endothelial damage** to the heart valves. This damage, particularly to the **tricuspid valve** (indicated by the holosystolic murmur at the left sternal border enhanced by inspiration), provides a nidus for bacterial adherence and vegetation formation, leading to infective endocarditis. *Failed delamination* - **Failed delamination** is a developmental anomaly typically associated with **Ebstein's anomaly**, where the tricuspid valve leaflets are displaced into the right ventricle. - This condition is congenital and usually diagnosed earlier in life, contrasting with the patient's acquired symptoms of infection and drug use. *Verrucous lesions* - **Verrucous lesions** on heart valves are characteristic of **nonbacterial thrombotic endocarditis (NBTE)**, also known as marantic endocarditis. - While NBTE can occur in debilitated patients, it is typically associated with hypercoagulable states or advanced malignancy and does not usually present with the overt signs of infection (fever, malaise) seen in this patient. *Myxomatous degeneration* - **Myxomatous degeneration** is the primary pathophysiology behind **mitral valve prolapse**, a common cause of mitral regurgitation. - While it can cause a murmur, it does not typically lead to the inflammatory and infectious presentation described, nor is it usually associated with IV drug use. *Fibrillin 1 (FBN1) mutations* - **Fibrillin 1 (FBN1) mutations** are the genetic basis of **Marfan syndrome**, a connective tissue disorder. - Marfan syndrome can cause cardiovascular abnormalities, particularly **aortic root dilation** and **mitral valve prolapse**, but it does not directly explain the acute infectious presentation or the association with IV drug use.

Question 427: A 38-year-old woman comes to the physician because of a 1-month history of progressively worsening dyspnea, cough, and hoarseness of voice. Her pulse is 92/min and irregularly irregular, respirations are 20/min, and blood pressure is 110/75 mm Hg. Cardiac examination shows a rumbling mid-diastolic murmur that is best heard at the apex in the left lateral decubitus position. Which of the following is the most likely underlying cause of this patient's condition?

A. Antibody cross-reactivity (Correct Answer)
B. Sarcomeric gene mutation
C. Hematogenous spread of bacteria
D. Myxomatous degeneration
E. Congenital valvular defect

Explanation: ***Antibody cross-reactivity*** - The patient's symptoms (dyspnea, cough, hoarseness, irregular pulse, and a **rumbling mid-diastolic murmur** best heard at the apex) are classic for **rheumatic mitral stenosis**. - **Rheumatic fever** is caused by an immune response to *Streptococcus pyogenes* infection, where antibodies cross-react with cardiac tissue, leading to valvular damage. *Sarcomeric gene mutation* - This is the underlying cause of **hypertrophic cardiomyopathy**, which typically presents with exertional dyspnea, chest pain, and syncope, but not a mid-diastolic murmur consistent with mitral stenosis. - While it can cause heart failure symptoms, the specific murmur and valvular pathology do not align with hypertrophic cardiomyopathy. *Hematogenous spread of bacteria* - **Infective endocarditis** involves bacterial colonization of heart valves, which can cause valvular damage and murmurs, but usually presents with fever, new or changing murmur, and systemic emboli. - The patient's presentation of progressive dyspnea and chronic murmur is not typical for acute infective endocarditis. *Myxomatous degeneration* - This is the most common cause of **mitral valve prolapse (MVP)**, where the mitral leaflets become thickened and redundant. - MVP typically causes a **mid-systolic click** followed by a late systolic murmur, rather than a rumbling mid-diastolic murmur indicative of stenosis. *Congenital valvular defect* - While congenital defects can cause valvular dysfunction, a **bicuspid aortic valve** is the most common congenital defect and usually affects the aortic valve, leading to stenosis or regurgitation. - Mitral stenosis symptoms appearing in adulthood are rarely due to an isolated congenital mitral valve defect and the overall clinical picture points strongly to rheumatic heart disease.

Question 428: A 44-year-old woman comes to the physician because of progressively worsening shortness of breath with exertion and intermittent palpitations over the last 2 months. She has had neither chest pain nor a cough. Her pulse is 124/min and irregular. Physical examination shows a grade 4/6 high-pitched holosystolic murmur that is best heard at the apex and radiates to the back. The murmur increases in intensity when she clenches her hands into fists. The lungs are clear to auscultation. Further evaluation of this patient is most likely to show which of the following findings?

A. Obstruction of the right marginal artery on coronary angiogram
B. Diffuse ST elevations on electrocardiogram
C. Dilation of left atrium on echocardiogram (Correct Answer)
D. Reversible area of myocardial ischemia on nuclear stress test
E. Pulmonary artery thrombus on computed tomography scan

Explanation: ***Dilation of left atrium on echocardiogram*** - The patient's symptoms of **shortness of breath**, **palpitations**, and an **irregular pulse** suggest a cardiac etiology, specifically a **valvular problem**. The **holosystolic murmur** best heard at the **apex** and radiating to the **back**, which increases with handgrip (a maneuver that increases afterload), is highly characteristic of **mitral regurgitation**. - **Chronic mitral regurgitation** leads to **volume overload** in the left atrium, causing its **dilation** as it tries to accommodate the increased blood flow from both the pulmonary veins and the regurgitant jet from the left ventricle. This can also lead to **atrial fibrillation**, explaining the irregular pulse and palpitations. *Obstruction of the right marginal artery on coronary angiogram* - This finding would indicate **coronary artery disease** affecting the right coronary artery, typically presenting with **chest pain** or angina, which the patient explicitly denies. - While coronary artery disease can cause shortness of breath, the distinctive **holosystolic murmur** and its radiation are not primary features of isolated coronary artery obstruction. *Diffuse ST elevations on electrocardiogram* - **Diffuse ST elevations** are typically seen in conditions like **pericarditis**, which often presents with pleuritic chest pain and a pericardial friction rub, none of which are described. - It could also indicate an ST-elevation myocardial infarction (STEMI), but the 2-month history and the specific murmur point away from an acute coronary event. *Reversible area of myocardial ischemia on nuclear stress test* - This would suggest **ischemic heart disease**, again primarily indicated by **angina** or exertional chest discomfort, which is absent in this patient. - While ischemia can cause shortness of breath and palpitations, it does not explain the characteristic **holosystolic murmur** and its specific radiation. *Pulmonary artery thrombus on computed tomography scan* - A **pulmonary artery thrombus** (pulmonary embolism) would typically cause **acute dyspnea**, pleuritic chest pain, and sometimes hemoptysis, which are not mentioned. - While it can cause palpitations and an irregular pulse (due to right heart strain), it does not account for the **holosystolic murmur** heard at the apex and radiating to the back.

Question 429: A 57-year-old woman comes to the clinic complaining of decreased urine output. She reports that over the past 2 weeks she has been urinating less and less every day. She denies changes in her diet or fluid intake. The patient has a history of lupus nephritis, which has resulted in end stage renal disease. She underwent a renal transplant 2 months ago. Since then she has been on mycophenolate and cyclosporine, which she takes as prescribed. The patient’s temperature is 99°F (37.2°C), blood pressure is 172/102 mmHg, pulse is 88/min, and respirations are 17/min with an oxygen saturation of 97% on room air. Labs show an elevation in serum creatinine and blood urea nitrogen. On physical examination, she has 2+ pitting edema of the bilateral lower extremities. Lungs are clear to auscultation. Urinalysis shows elevated protein. A post-void bladder scan is normal. A renal biopsy is obtained, which shows lymphocyte infiltration and intimal swelling. Which of the following is the next best step in management?

A. Add diltiazem
B. Nephrectomy
C. Start intravenous steroids (Correct Answer)
D. Add ceftriaxone
E. Discontinue cyclosporine

Explanation: ***Start intravenous steroids*** - The patient presents with **decreased urine output**, elevated creatinine, and a recent kidney transplant with biopsy showing **lymphocyte infiltration** and **intimal swelling**, all highly suggestive of **acute cellular rejection**. - **High-dose intravenous steroids** (e.g., methylprednisolone) are the first-line treatment for acute cellular rejection to suppress the immune response and preserve graft function. *Add diltiazem* - **Diltiazem** is a calcium channel blocker used to treat hypertension and arrhythmias, and it can also interfere with cyclosporine metabolism, potentially increasing its levels. - While the patient has elevated blood pressure, adding diltiazem would not address the underlying **immune rejection** and would not be the primary intervention. *Nephrectomy* - **Nephrectomy** involves surgical removal of the transplanted kidney. This radical intervention is reserved for **irreversible graft failure** or severe complications like overwhelming infection or malignancy. - Given the acute presentation and possibility of reversing rejection with immunosuppression, nephrectomy is **premature** and not the next best step. *Add ceftriaxone* - **Ceftriaxone** is an antibiotic used to treat bacterial infections. - There is no clinical evidence in the stem (e.g., fever, signs of infection) to suggest a **bacterial infection** as the cause of her symptoms, making antibiotics inappropriate. *Discontinue cyclosporine* - **Cyclosporine** is an immunosuppressant essential for preventing transplant rejection. Discontinuing it would immediately increase the risk of more severe and potentially **irreversible rejection**. - While cyclosporine can cause nephrotoxicity, the biopsy findings of **cellular infiltration** point more towards rejection rather than primary drug toxicity, and the primary treatment for rejection involves increasing immunosuppression, not withdrawing it.

Question 430: A 68-year-old female presents to your office for her annual check-up. Her vitals are HR 85, T 98.8 F, RR 16, BP 125/70. She has a history of smoking 1 pack a day for 35 years, but states she quit five years ago. She had her last pap smear at age 64 and states all of her pap smears have been normal. She had her last colonoscopy at age 62, which was also normal. Which of the following is the next best test for this patient?

A. Pap smear
B. Chest radiograph
C. Abdominal ultrasound
D. Colonoscopy
E. Chest CT scan (Correct Answer)

Explanation: ***Chest CT scan*** - This patient is a 68-year-old female with a **35-pack-year smoking history** who quit 5 years ago, placing her in a high-risk group for lung cancer. - **Low-dose computed tomography (LDCT)** for lung cancer screening is recommended annually for individuals aged 50-80 with a 20-pack-year smoking history who currently smoke or have quit within the past 15 years. *Pap smear* - A Pap smear is not indicated as she had her last one at age 64 and all previous results were normal. - Guidelines recommend discontinuing Pap smears at age 65 if there is no history of moderate or severe dysplasia and three consecutive negative results within the last 10 years. *Chest radiograph* - A chest radiograph is a less sensitive and specific tool for detecting early lung cancer compared to LDCT. - It misses a significant proportion of early-stage lung cancers and is not recommended for lung cancer screening. *Abdominal ultrasound* - An abdominal ultrasound is generally used to screen for conditions like abdominal aortic aneurysm in specific high-risk populations (males 65-75 who have ever smoked). - There is no indication from the provided history for an abdominal ultrasound in this patient. *Colonoscopy* - This patient had a normal colonoscopy at age 62. - Current guidelines recommend repeating colonoscopy every 10 years if the previous one was normal, so she is not due for another one yet.

Question 431: A 72-year-old woman is brought to the emergency department because of lethargy and weakness for the past 5 days. During this period, she has had a headache that worsens when she leans forward or lies down. Her arms and face have appeared swollen over the past 2 weeks. She has a history of hypertension and invasive ductal carcinoma of the left breast. She underwent radical amputation of the left breast followed by radiation therapy 4 years ago. She has smoked two packs of cigarettes daily for 40 years. Current medications include aspirin, hydrochlorothiazide, and tamoxifen. Her temperature is 37.2°C (99°F), pulse is 103/min, and blood pressure is 98/56 mm Hg. Examination shows jugular venous distention, a mastectomy scar over the left thorax, and engorged veins on the anterior chest wall. There is no axillary or cervical lymphadenopathy. There is 1+ pitting edema in both arms. Which of the following is the most likely cause of this patient's symptoms?

A. Pulmonary embolism
B. Pulmonary tuberculosis
C. Lung cancer (Correct Answer)
D. Nephrotic syndrome
E. Constrictive pericarditis

Explanation: ***Lung cancer*** - The patient's history of **heavy smoking** and prior **breast cancer with radiation therapy** significantly increases her risk for developing **lung cancer**. - Symptoms like **headache worsened by bending/lying down**, **facial/arm swelling**, **jugular venous distention**, and **engorged chest wall veins** are classic signs of **superior vena cava (SVC syndrome)**, commonly caused by lung cancer compressing the SVC. *Pulmonary embolism* - This typically presents with **acute onset dyspnea**, **pleuritic chest pain**, and **tachycardia**, often without the progressive facial and arm swelling or engorged chest veins seen here. - While a possibility in a bedridden patient, the constellation of symptoms strongly points away from a primary pulmonary embolism. *Pulmonary tuberculosis* - Characterized by **chronic cough**, **fever**, **night sweats**, and **weight loss**, symptoms not predominantly featured in this patient's presentation. - While it can cause lymphadenopathy and venous obstruction in rare cases, the patient's risk factors and specific symptoms are more indicative of malignancy. *Nephrotic syndrome* - Primarily causes widespread **edema** (anasarca) due to **severe proteinuria** and **hypoalbuminemia**, which would present as generalized swelling rather than localized facial and arm swelling with prominent venous engorgement. - It would not typically explain the headache worsened by position or localized SVC syndrome signs. *Constrictive pericarditis* - Presents with signs of right-sided heart failure, including **jugular venous distention**, **ascites**, and peripheral edema, but without the specific facial/arm swelling or engorged superficial chest veins characteristic of SVC syndrome. - It usually results from chronic inflammation of the pericardium and is less likely to cause positional headaches or localized upper body venous obstruction.

Question 432: A 65-year-old male with a history of coronary artery disease and myocardial infarction status post coronary artery bypass graft (CABG) surgery presents to his cardiologist for a routine appointment. On physical exam, the cardiologist appreciates a holosystolic, high-pitched blowing murmur heard loudest at the apex and radiating towards the axilla. Which of the following is the best predictor of the severity of this patient's murmur?

A. Enhancement with expiration
B. Presence of audible S3 (Correct Answer)
C. Enhancement with hand grip maneuver
D. Presence of audible S4
E. Enhancement with inspiration

Explanation: ***Presence of audible S3*** - An **S3 gallop** indicates rapid ventricular filling into a stiff or volume-overloaded ventricle, suggesting significant ventricular dysfunction due to severe regurgitation and increased preload. - In the context of **mitral regurgitation (MR)**, an S3 is a strong predictor of **severe MR** and associated **left ventricular dysfunction**. *Enhancement with expiration* - This maneuver typically enhances **left-sided heart murmurs**, including mitral regurgitation, by increasing venous return to the left side of the heart. - While it confirms the murmur's origin, it does not directly predict the **severity** of the regurgitation. *Enhancement with hand grip maneuver* - The **handgrip maneuver** increases afterload, which can enhance the intensity of murmurs associated with regurgitant lesions like mitral regurgitation. - While helpful in identifying MR, it is not the best predictor of its **severity** compared to signs of ventricular dysfunction. *Presence of audible S4* - An **S4 heart sound** is associated with reduced ventricular compliance and atrial contraction against a stiff ventricle, often seen in conditions like **hypertension** or **aortic stenosis**. - It does not directly indicate the **severity of mitral regurgitation** or current ventricular volume overload. *Enhancement with inspiration* - This maneuver typically enhances **right-sided heart murmurs** by increasing venous return to the right side of the heart. - Since mitral regurgitation is a **left-sided murmur**, inspiration would likely have little to no effect or diminish its intensity.

Question 433: A 20-year-old man presents to the emergency department. The patient was brought in by his coach after he fainted during a competition. This is the second time this has happened since the patient joined the track team. The patient has a past medical history of multiple episodes of streptococcal pharyngitis which were not treated in his youth. He is not currently on any medications. He is agreeable and not currently in any distress. His temperature is 99.5°F (37.5°C), blood pressure is 132/68 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 98% on room air. On physical exam, you note a young man in no current distress. Neurological exam is within normal limits. Pulmonary exam reveals clear air movement bilaterally. Cardiac exam reveals a systolic murmur best heard at the lower left sternal border that radiates to the axilla. Abdominal exam reveals a soft abdomen that is non-tender in all 4 quadrants. The patient's cardiac exam is repeated while he squats. Which of the following is most likely true for this patient?

A. Decreased murmur intensity in mitral stenosis with squatting
B. Increased murmur intensity in mitral stenosis with squatting
C. Decreased murmur intensity in hypertrophic obstructive cardiomyopathy with squatting (Correct Answer)
D. Increased murmur intensity in aortic stenosis with squatting
E. Increased murmur intensity in hypertrophic obstructive cardiomyopathy with squatting

Explanation: ***Decreased murmur intensity in hypertrophic obstructive cardiomyopathy with squatting*** - This patient presents with **syncope during exercise** in a young athletic individual, which is highly suggestive of **hypertrophic obstructive cardiomyopathy (HOCM)**. - The **systolic murmur at the lower left sternal border radiating to the axilla** is characteristic of the **dynamic left ventricular outflow tract obstruction** seen in HOCM. - Squatting increases **venous return** (preload) and **systemic vascular resistance** (afterload), which **increases left ventricular volume** and **reduces the outflow tract obstruction**, leading to a **decreased murmur intensity**. - HOCM is the most common cause of **sudden cardiac death in young athletes** due to exercise-induced arrhythmias. *Decreased murmur intensity in mitral stenosis with squatting* - **Mitral stenosis** produces a **low-pitched diastolic rumble** best heard at the apex with the patient in the left lateral decubitus position, not a systolic murmur. - This patient has a **systolic murmur**, which rules out mitral stenosis as the diagnosis. - Additionally, mitral stenosis would not typically cause syncope during exercise in a young patient without significant symptoms at rest. *Increased murmur intensity in mitral stenosis with squatting* - While squatting does **increase flow across the mitral valve** and would increase a mitral stenosis murmur if present, this patient has a **systolic murmur**, not the diastolic murmur characteristic of mitral stenosis. - The clinical presentation of **exercise-induced syncope** is not typical for mitral stenosis, which more commonly presents with dyspnea, orthopnea, and hemoptysis. *Increased murmur intensity in aortic stenosis with squatting* - **Aortic stenosis** typically presents with a **crescendo-decrescendo systolic ejection murmur** best heard at the **right upper sternal border** with radiation to the carotids, not the left lower sternal border radiating to the axilla. - Squatting **increases afterload and preload**, which generally **increases the intensity** of aortic stenosis murmurs, but the murmur location and radiation pattern do not fit aortic stenosis. - While aortic stenosis can cause syncope, it typically occurs in older patients with calcific disease. *Increased murmur intensity in hypertrophic obstructive cardiomyopathy with squatting* - This is **physiologically incorrect** for HOCM. - Squatting **increases left ventricular volume** by increasing venous return and afterload, which **reduces the dynamic outflow tract obstruction** in HOCM. - **Decreased obstruction leads to decreased murmur intensity**, not increased intensity. - Maneuvers that **decrease LV volume** (standing, Valsalva, nitroglycerin) **increase** the HOCM murmur, while maneuvers that **increase LV volume** (squatting, passive leg raise, hand grip) **decrease** the murmur.

Question 434: A 56-year-old man presents to the physician for the evaluation of excess snoring over the past year. He has no history of a serious illness and takes no medications. He does not smoke. His blood pressure is 155/95 mm Hg. BMI is 49 kg/m2. Oropharyngeal examination shows an enlarged uvula. Examination of the nasal cavity shows no septal deviation or polyps. Examination of the lungs and heart shows no abnormalities. Polysomnography shows an apnea-hypopnea index of 2 episodes/h with a PCO2 of 51 mm Hg during REM sleep. Arterial blood gas analysis in room air shows: pH 7.33 PCO2 50 mm Hg PO2 92 mm Hg HCO3− 26 mEq/L Which of the following best explains these findings?

A. Obesity hypoventilation syndrome with obstructive sleep apnea
B. Central hypoventilation syndrome with obstructive sleep apnea
C. Central hypoventilation syndrome
D. Obesity hypoventilation syndrome (Correct Answer)
E. Obstructive sleep apnea-hypopnea syndrome

Explanation: ***Obesity hypoventilation syndrome*** - This is the correct diagnosis. The patient presents with **severe obesity (BMI 49 kg/m2)** and **chronic daytime hypercapnia (PCO2 50 mm Hg)** with compensated respiratory acidosis (pH 7.33, HCO3− 26 mEq/L). - The **apnea-hypopnea index (AHI) of 2 episodes/h is normal** and does not meet criteria for obstructive sleep apnea (OSA requires AHI ≥5). - Despite the absence of significant obstructive events, the patient has **chronic hypercapnia both awake and during REM sleep**, indicating impaired ventilatory drive due to obesity-related restrictive mechanics rather than upper airway obstruction. - **Obesity hypoventilation syndrome (OHS)** is diagnosed when BMI ≥30 kg/m2, daytime PCO2 ≥45 mm Hg, and sleep-disordered breathing is present without other causes of hypoventilation. *Obesity hypoventilation syndrome with obstructive sleep apnea* - While the patient is severely obese, the **AHI of 2 does not meet diagnostic criteria for OSA** (requires AHI ≥5). - OHS can coexist with OSA (called "overlap" when present), but in this case, the **absence of significant obstructive events** makes pure OHS without OSA the correct diagnosis. *Central hypoventilation syndrome with obstructive sleep apnea* - **Central hypoventilation syndrome** is rare and typically associated with neurological disorders (brainstem lesions, Ondine's curse) or congenital conditions. - This patient has **no neurological signs or symptoms** to suggest impaired central respiratory control. - The AHI of 2 does not support a diagnosis of OSA. *Central hypoventilation syndrome* - This diagnosis requires **failure of brainstem respiratory control centers** to regulate breathing properly. - There are **no clinical features** (neurological deficits, history of CNS pathology) to suggest a primary central cause of hypoventilation. - The patient's hypoventilation is best explained by **obesity-related mechanical restriction** and blunted chemoreceptor response, not central nervous system pathology. *Obstructive sleep apnea-hypopnea syndrome* - The **AHI of 2 episodes/h is normal** and does not meet diagnostic criteria for OSA (mild OSA: AHI 5-14, moderate: 15-29, severe: ≥30). - While obesity and enlarged uvula are risk factors for OSA, the **absence of significant obstructive events on polysomnography** excludes this diagnosis. - The **chronic daytime hypercapnia** in the setting of normal AHI points to OHS rather than OSA as the primary pathology.

Question 435: A 45-year-old man comes to the physician because of worsening shortness of breath and dry cough for 6 months. The patient's symptoms get worse when he walks more than about 150 yards. He also reports fatigue and difficulty swallowing solid foods. In cold weather, his fingers occasionally turn blue and become painful. He occasionally smokes cigarettes on weekends. His temperature is 37°C (98.6°F), and respirations are 22/min, pulse is 87/min, and blood pressure is 126/85 mm Hg. The skin over his trunk and arms is thickened and tightened. Fine inspiratory crackles are heard over bilateral lower lung fields on auscultation. Which of the following additional findings is most likely in this patient?

A. Decreased diffusing capacity (Correct Answer)
B. Decreased A-a gradient
C. Decreased right atrial pressure
D. Increased lung compliance
E. Increased airway resistance

Explanation: ***Decreased diffusing capacity*** - This patient's symptoms (shortness of breath, dry cough, fingertip cyanosis in cold weather, thickened/tightened skin, bilateral lower lung crackles, dysphagia) are highly suggestive of **systemic sclerosis** with **interstitial lung disease (ILD)** and potentially **pulmonary hypertension**. - **ILD** is a restrictive lung disease characterized by **fibrosis** of the alveolar-capillary membrane, which impairs gas exchange and leads to a **decreased diffusing capacity of the lung for carbon monoxide (DLCO)**. *Decreased A-a gradient* - A **decreased A-a gradient** (alveolar-arterial oxygen gradient) implies **efficient gas exchange**, which is contrary to the patient's symptoms of dyspnea and findings of ILD. - In conditions causing hypoxemia due to gas exchange impairment, such as ILD, the A-a gradient typically **increases** as oxygen transfer from alveoli to blood is compromised. *Decreased right atrial pressure* - This patient is at risk for **pulmonary hypertension** secondary to systemic sclerosis and ILD, which would lead to **increased pulmonary vascular resistance** and often **increased right heart pressures**, including right atrial pressure. - Therefore, a decreased right atrial pressure is unlikely in this clinical context and would not explain the patient's severe respiratory symptoms. *Increased lung compliance* - **Increased lung compliance** is characteristic of obstructive lung diseases like **emphysema**, where the elastic recoil of the lungs is reduced, making them easier to inflate. - In contrast, interstitial lung diseases, like that seen in systemic sclerosis, cause **pulmonary fibrosis**, leading to **decreased lung compliance** (stiffer lungs) and increased work of breathing. *Increased airway resistance* - **Increased airway resistance** is a hallmark of **obstructive lung diseases** such as asthma or COPD, where there is narrowing of the airways. - While some reactive airway components can occur, the primary pulmonary manifestation of systemic sclerosis is **interstitial lung disease (ILD)**, which is a **restrictive defect** rather than an obstructive one, and primarily impacts gas exchange rather than airflow resistance.

Question 436: A 72-year-old man with chronic lymphocytic leukemia (CLL) comes to the physician with a 2-day history of severe fatigue and dyspnea. He regularly visits his primary care physician and has not required any treatment for his underlying disease. His temperature is 36.7°C (98.1°F), pulse is 105/min, respiratory rate is 22/min, and blood pressure is 125/70 mm Hg. The conjunctivae are pale. Examination of the heart and lungs shows no abnormalities. The spleen is palpable 3 cm below the costal margin. No lymphadenopathy is palpated. Laboratory studies show: Hemoglobin 7 g/dL Mean corpuscular volume 105 μm3 Leukocyte count 80,000/mm3 Platelet count 350,000/mm3 Serum Bilirubin Total // Direct 6 mg/dL / 0.8 mg/dL Lactate dehydrogenase 650 U/L (Normal: 45–90 U/L) Based on these findings, this patient’s recent condition is most likely attributable to which of the following?

A. Bone marrow involvement
B. Splenomegaly
C. Evan’s syndrome
D. Autoimmune hemolytic anemia (Correct Answer)
E. Diffuse large B cell lymphoma

Explanation: ***Autoimmune hemolytic anemia*** - The patient's **anemia (Hb 7 g/dL)**, elevated **lactate dehydrogenase (LDH)**, relatively high **indirect bilirubin** (total bilirubin 6 mg/dL, direct 0.8 mg/dL, indicating mostly indirect), and **splenomegaly** are classic signs of **hemolysis**. - Given his underlying **CLL**, autoimmune hemolytic anemia (AIHA) is a common paraneoplastic complication, where increased lymphocyte production leads to **autoantibody formation** against red blood cells. *Bone marrow involvement* - While CLL can infiltrate the bone marrow, causing **marrow failure** and anemia, this typically presents with **pancytopenia** (low white blood cells, red blood cells, and platelets). - This patient has a **high leukocyte count** and **normal platelet count**, making marrow failure less likely to be the primary cause of his acute symptoms. *Splenomegaly* - **Splenomegaly** can contribute to anemia through **splenic sequestration** and **hypersplenism**, leading to shortened red blood cell survival. - However, the markedly elevated **LDH** and **indirect bilirubin** point specifically to an active hemolytic process, which is often *caused* by the autoimmune activity rather than being the sole mechanism of anemia. *Evan’s syndrome* - **Evan's syndrome** is a rare condition characterized by the coexistence of **autoimmune hemolytic anemia** and **immune thrombocytopenia**. - The patient's **platelet count is normal (350,000/mm3)**, ruling out Evan's syndrome as the specific diagnosis, although he does have one component (AIHA). *Diffuse large B cell lymphoma* - Transformation of CLL to **Diffuse Large B-cell Lymphoma (DLBCL)**, known as **Richter's transformation**, can cause rapidly worsening symptoms, including anemia. - However, the characteristic features of **hemolysis** (elevated LDH, indirect bilirubin) are not direct indicators of Richter's transformation; instead, Richter's would typically present with rapidly enlarging lymph nodes, worsening systemic symptoms, and a mass.

Question 437: An 84-year-old man presents to the emergency department for a loss of consciousness. The patient states that he was using the bathroom when he lost consciousness and fell, hitting his head on the counter. The patient has a past medical history of diabetes, hypertension, obesity, factor V leiden, constipation, myocardial infarction, and vascular claudication. His current medications include lisinopril, atorvastatin, valproic acid, propranolol, insulin, metformin, and sodium docusate. The patient denies use of illicit substances. His temperature is 99.5°F (37.5°C), blood pressure is 167/98 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam reveals an elderly man sitting comfortably in his stretcher. Cardiac exam reveals a systolic murmur heard at the right upper sternal border that radiates to the carotids. Pulmonary exam reveals mild bibasilar crackles. Neurological exam reveals 5/5 strength in his upper and lower extremities with normal sensation. The patient's gait is mildly unstable. The patient is unable to give a urine sample in the emergency department and states that he almost fainted again when he tried to. Which of the following is the most likely diagnosis?

A. Seizure
B. Cardiac arrhythmia
C. Postural hypotension
D. Situational syncope (Correct Answer)
E. Transient ischemic attack

Explanation: ***Situational syncope*** - The patient's loss of consciousness while **straining during defecation** (using the bathroom) is highly suggestive of **situational syncope**, which is a type of **reflex syncope** triggered by specific actions. - His complaint of almost fainting again when trying to provide a urine sample reinforces the diagnosis, as **micturition (urination) syncope** is another common form of situational syncope. *Seizure* - While a loss of consciousness occurred, the patient's presentation lacks typical features of a seizure such as a **postictal state**, tongue biting, or tonic-clonic movements. - The trigger (straining) and the near-syncopal episode with micturition are inconsistent with a primary seizure disorder. *Cardiac arrhythmia* - Although the patient has a history of myocardial infarction and is on **propranolol** (a beta-blocker), there are no specific findings on physical exam or in the history to strongly suggest an arrhythmia as the cause of syncope. - An arrhythmia-induced syncope typically doesn't have such a clear situational trigger like defecation or urination. *Postural hypotension* - Postural hypotension is characterized by a significant drop in blood pressure upon standing, leading to symptoms like dizziness or syncope. - While the patient is on several medications that could contribute to hypotension (e.g., lisinopril, propranolol), the syncope was specifically associated with straining, not just standing up. *Transient ischemic attack* - A TIA involves **transient neurological deficits** such as weakness, sensory changes, or speech disturbances, which typically last minutes to hours. - A transient loss of consciousness without focal neurological symptoms is not characteristic of a TIA.

Question 438: A 70-year-old woman is brought to the office after her nurse noticed her being apathetic, easily distracted, and starting to urinate in bed. Her medical history is relevant for hypertension, under control with medication. Physical examination reveals a blood pressure of 138/76 mm Hg, a heart rate of 70/min, and a respiratory rate 14/min and regular. On neurological examination, she has a broad-based shuffling gait, and increased muscle tone in her limbs that is reduced by distracting the patient. There is decreased coordination with exaggerated deep tendon reflexes, decreased attention and concentration, and postural tremor. Which of the following additional features would be expected to find in this patient?

A. Degeneration of the substantia nigra pars compacta
B. Caudate head atrophy
C. Accumulation of Lewy bodies in cortical cells
D. Dilation of the ventricular system (Correct Answer)
E. Accumulation of amyloid plaques and neurofibrillary tangles in the cerebral cortex

Explanation: ***Dilation of the ventricular system*** - The patient presents with a classic triad of **gait apraxia** (broad-based, shuffling gait), **dementia** (apathy, distractibility, decreased attention and concentration), and **urinary incontinence**, which are the hallmark symptoms of **Normal Pressure Hydrocephalus (NPH)**. NPH is characterized by **ventricular dilation without increased intracranial pressure**. - Other features like **increased muscle tone that reduces with distraction** (frontal release sign), **exaggerated deep tendon reflexes**, and **postural tremor** further support the diagnosis of NPH, as these are often seen due to involvement of frontal lobe pathways secondary to ventricular enlargement. *Degeneration of the substantia nigra pars compacta* - This is characteristic of **Parkinson's disease**, which typically presents with a rest tremor, bradykinesia, rigidity, and postural instability, but not typically with prominent early dementia and urinary incontinence in this combined clinical picture. - While Parkinson's can cause gait disturbance, the specific combination of symptoms (dementia, incontinence, and gait apraxia) points away from primary Parkinson's as the most likely diagnosis. *Caudate head atrophy* - **Caudate head atrophy** is a hallmark finding in **Huntington's disease**, which is characterized by chorea, psychiatric symptoms, and progressive cognitive decline. - The patient's symptoms, particularly the broad-based shuffling gait and urinary incontinence, are inconsistent with the typical presentation of Huntington's disease. *Accumulation of Lewy bodies in cortical cells* - This is a pathological feature of **Lewy body dementia (LBD)**. While LBD presents with dementia and Parkinsonian features, it also typically includes **recurrent visual hallucinations** and **fluctuations in attention and alertness**, which are not specified in this patient's presentation. - The patient's dominant features of gait apraxia and urinary incontinence along with dementia are more indicative of NPH. *Accumulation of amyloid plaques and neurofibrillary tangles in the cerebral cortex* - These are the pathological hallmarks of **Alzheimer's disease**, which primarily presents with progressive memory loss, executive dysfunction, and other cognitive deficits. - While dementia is a feature in this patient, the prominent gait disturbance and urinary incontinence are not typical early or dominant features of Alzheimer's disease.

Question 439: A 27-year-old Caucasian female presents complaining of recent weight loss and weakness. She reports that she feels dizzy and lightheaded every morning when she gets out of bed, and often at work whenever she must rise from her desk. Physical exam reveals several areas of her skin including her elbows and knees are more pigmented than other areas. Which of the following would be consistent with the patient's disease?

A. Pretibial myxedema
B. Hyperkalemia (Correct Answer)
C. Hypernatremia
D. Central obesity
E. Hyperglycemia

Explanation: ***Hyperkalemia*** - The patient's symptoms (weight loss, weakness, **orthostatic hypotension**, and **hyperpigmentation**) are classic for **primary adrenal insufficiency (Addison's disease)**. - In primary adrenal insufficiency, decreased **aldosterone** production leads to **impaired renal sodium reabsorption** and **potassium excretion**, resulting in **hyperkalemia**. *Pretibial myxedema* - This condition is characteristic of **Graves' disease**, which involves hyperthyroidism, not adrenal insufficiency. - It presents as localized thickening and induration of the skin, typically on the shins. *Hypernatremia* - **Hyponatremia** (low sodium) is a common finding in primary adrenal insufficiency due to impaired aldosterone action and increased ADH secretion. - **Hypernatremia** (high sodium) would be inconsistent with this diagnosis. *Central obesity* - **Central obesity** and **moon facies** are characteristic features of **Cushing's syndrome**, which is caused by *excess* glucocorticoids, the opposite of adrenal insufficiency. - Patients with Addison's disease often experience **weight loss** rather than weight gain. *Hyperglycemia* - **Hypoglycemia** is commonly seen in primary adrenal insufficiency due to the lack of **cortisol**, which plays a crucial role in maintaining blood glucose levels. - **Hyperglycemia** would suggest conditions like diabetes or Cushing's syndrome, not adrenal insufficiency.

Question 440: A 51-year-old woman with AIDS presents to her primary care physician with fatigue and weakness. She has a history of type 2 diabetes mellitus, hypertension, infectious mononucleosis, and hypercholesterolemia. She currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and denies any illicit drug use. Her temperature is 36.7°C (98.0°F), blood pressure is 126/74 mm Hg, pulse is 87/min, and respirations are 17/min. On physical examination, her pulses are bounding. The patient's complexion is pale. She has an enlarged cervical lymph node, and breath sounds remain clear. Further lab and tissue diagnostic evaluation reveal and confirms Burkitt's lymphoma with diffuse bulky disease. After receiving more information about her condition and treatment options, the patient agrees to start chemotherapy. Eight days after starting chemotherapy, she presents with decreased urinary output. Laboratory studies show: Creatinine 7.9 mg/dL BUN 41 mg/dL Serum uric acid 28 mg/dL Potassium 6.9 mEq/L Which therapy is most likely to reverse the patient's metabolic abnormalities?

A. Intravenous saline with mannitol with the goal of a daily urinary output above 2.5 L/day
B. Allopurinol 300 mg/day
C. Hemodialysis (Correct Answer)
D. Intravenous sodium bicarbonate with the goal of urinary pH > 7.0
E. Intravenous recombinant uricase enzyme rasburicase

Explanation: ***Hemodialysis*** - The patient presents with **severe acute kidney injury** (creatinine 7.9 mg/dL, BUN 41 mg/dL), **hyperkalemia** (potassium 6.9 mEq/L), and **hyperuricemia** (uric acid 28 mg/dL) following chemotherapy for Burkitt's lymphoma, indicative of **tumor lysis syndrome (TLS)**. - Given the severely elevated creatinine and potassium, **hemodialysis** is the most effective and rapid method to correct these life-threatening metabolic abnormalities and remove excess uric acid. *Intravenous saline with mannitol with the goal of a daily urinary output above 2.5 L/day* - While **intravenous fluid hydration** is crucial in preventing and managing TLS, and mannitol can promote diuresis, this approach is insufficient to reverse the **severe acute kidney injury** and **life-threatening hyperkalemia** already present. - The patient has **decreased urinary output**, indicating established renal dysfunction where aggressive fluid resuscitation alone may not be effective and could lead to fluid overload. *Allopurinol 300 mg/day* - **Allopurinol** inhibits **xanthine oxidase**, reducing the *production* of uric acid but does not facilitate the *removal* of pre-existing high levels of uric acid or other metabolic derangements. - It is primarily used for **prophylaxis** or less severe cases of hyperuricemia and would be too slow to address the acute, severe hyperuricemia and renal failure. *Intravenous sodium bicarbonate with the goal of urinary pH > 7.0* - **Alkalinization of urine** with sodium bicarbonate can help increase the solubility of uric acid and prevent its precipitation in renal tubules, but it is less effective than rasburicase for severe hyperuricemia and carries risks of **calcium phosphate precipitation** and metabolic alkalosis. - This approach does not address the hyperkalemia or the extent of renal failure, and its role as a primary intervention for established renal failure in TLS is limited. *Intravenous recombinant uricase enzyme rasburicase* - **Rasburicase** is highly effective in rapidly lowering uric acid levels by converting it to **allantoin**, a more soluble compound; however, it does not directly address the **hyperkalemia** or the underlying **acute kidney injury** that has already developed. - While important for hyperuricemia, it's not the definitive therapy for the entire spectrum of severe abnormalities presented, especially the life-threatening hyperkalemia and renal failure.

Question 441: A 58-year-old man presents to the emergency department following a fall while walking in a grocery store. He has a history of at least 6 previous collapses to the ground with no warning. When these episodes occur, he becomes pale, diaphoretic, and recovers quickly within a few seconds. These episodes always occur when he is standing. His past medical history is significant for type 2 diabetes mellitus, hypercholesterolemia, and one myocardial infarction. His medication list includes aspirin, clopidogrel, bisoprolol, metformin, rosuvastatin, and valsartan. Further history reveals that he has constipation, early satiety, and recently lost 2.2 kg (5 lb) of weight. While lying down, his blood pressure is 145/64 mm Hg and the heart rate is 112/min. After 2 minutes of standing, the blood pressure is 120/65 mm Hg and the heart rate is 112/min. A 12-lead ECG showed Q waves in leads II, III, and aVF. Laboratory results are given below: Hemoglobin 13.8 g/dL White blood cell count 8500/mm3 Platelets 250,000/mm3 Sodium 142 mEq/L Potassium 4.4 mEq/L Calcium 9.1 mg/dL Creatinine 1.0 mg/dL TSH 1.4 U/mL HbA1c 10.2% What additional clinical feature would most likely be present in this patient?

A. Heat intolerance
B. Diplopia
C. Erectile dysfunction (Correct Answer)
D. Lipodystrophy
E. Amyotrophy

Explanation: ***Erectile dysfunction*** - The patient exhibits features of **diabetic autonomic neuropathy**, including **orthostatic hypotension with absent compensatory tachycardia** (heart rate remains 112/min despite BP drop from 145/64 to 120/65 on standing - this failure of baroreceptor reflex is pathognomonic for autonomic dysfunction), **gastroparesis** (early satiety, weight loss, constipation), and poor glycemic control (HbA1c 10.2%). - **Erectile dysfunction** is a common manifestation of **diabetic autonomic neuropathy** due to impaired parasympathetic innervation affecting penile blood flow and nerve-mediated vasodilation. *Heat intolerance* - This is typically associated with **hyperthyroidism** or sometimes with impaired sweating from **sudomotor autonomic neuropathy**, but it's not the most direct or common manifestation given the other symptoms. - The patient's TSH is normal (1.4 U/mL), ruling out a thyroid cause. *Diplopia* - While possible in diabetes due to **cranial nerve palsies** (e.g., CN III, IV, VI neuropathy), it is not a direct or prominent symptom of *autonomic* neuropathy. - Diplopia would indicate a *somatic* neuropathy affecting ocular muscles, rather than an autonomic dysfunction. *Lipodystrophy* - This condition refers to abnormal fat distribution and is often seen with **insulin therapy** (at injection sites) or certain genetic syndromes, not directly related to diabetic autonomic neuropathy. - There is no information to suggest the patient is on insulin, and lipodystrophy does not explain the cluster of autonomic symptoms. *Amyotrophy* - **Diabetic amyotrophy** (proximal motor neuropathy) primarily causes **muscle weakness** and **wasting**, typically in the quadriceps, and severe pain in the affected areas. - This is a *somatic* neuropathy, affecting motor nerves, rather than the constellation of autonomic symptoms presented by the patient.

Question 442: A 63-year-old man presents with a 2-month history of increasing sensation of fullness involving his left flank. The patient reports recent episodes of constant pain. The patient is hypertensive (145/90 mm Hg) and is currently on medications including losartan and hydrochlorothiazide. His past medical history is otherwise unremarkable. He is a 30-pack-year smoker. His temperature is 37.7°C (99.9°F); pulse, 76/min; and respiratory rate, 14/min. Palpation of the left flank shows a 10 x 10-cm mass. The patient's laboratory parameters are as follows: Blood Hemoglobin 19.5 g/dL Leukocyte count 5,000/mm3 Platelet count 250,000/mm3 Urine Blood 2+ Protein negative RBC 45/hpf without dysmorphic features Abdominal CT scan confirms the presence of a large solid mass originating in the left kidney. These findings are most consistent with which of the following conditions?

A. Wilms tumor
B. Transitional cell carcinoma
C. Adenoma
D. Renal cell carcinoma (Correct Answer)
E. Angiomyolipoma

Explanation: ***Renal cell carcinoma*** - The constellation of **flank pain**, a palpable **flank mass**, and **hematuria** is the classic triad of renal cell carcinoma. - Additional findings like **hypertension**, **polycythemia** (high hemoglobin of 19.5 g/dL due to erythropoietin production by the tumor), and **smoker status** further support this diagnosis. *Wilms tumor* - This is primarily a **childhood tumor**, typically presenting before the age of 5, which is inconsistent with this 63-year-old patient. - While it can present with a palpable mass and hematuria, the patient's age makes this diagnosis highly unlikely. *Transitional cell carcinoma* - This cancer usually arises in the **renal pelvis** or ureter and is strongly associated with smoking and painless gross hematuria. - However, a large solid parenchymal mass as described by the CT scan points away from transitional cell carcinoma, which generally involves the collecting system. *Adenoma* - Renal adenomas are typically **small, benign tumors** that are often found incidentally and rarely cause symptoms like palpable masses or flank pain. - They are not associated with paraneoplastic syndromes such as polycythemia or significant hypertension secondary to tumor activity. *Angiomyolipoma* - These are **benign tumors** composed of fat, smooth muscle, and blood vessels, often associated with **tuberous sclerosis**. - While they can cause flank pain or hemorrhage, they typically appear as **fat-containing lesions** on imaging, and this patient's presentation with polycythemia and significant hypertension points to a malignant process.

Question 443: A 62-year-old woman referred to the cardiology clinic for the evaluation of fatigue and dyspnea for 4 months. She also has loose stools (2–4 per day), palpitations, and non-pitting edema up to her mid-calf. On examination, vital signs are unremarkable, but she appears to be flushed with mild bilateral wheezes can be heard on chest auscultation. Cardiovascular examination reveals a grade 2/6 holosystolic murmur at the left mid-sternal area, which is louder during inspiration. Basic laboratory investigations are unremarkable. Echocardiography reveals moderate to severe right ventricular dilatation with severe right ventricular systolic dysfunction. A CT of the chest and abdomen reveals a solid, non-obstructing 2 cm mass in the small intestine and a solid 1.5 cm mass in the liver. What is the most likely cause of her symptoms?

A. Carcinoid tumor (Correct Answer)
B. Bronchial asthma
C. Irritable bowel syndrome
D. Systemic mastocytosis
E. Whipple’s disease

Explanation: ***Carcinoid tumor*** - The patient's symptoms of **fatigue, dyspnea, flushing, loose stools, palpitations, non-pitting edema**, and **wheezing** are all classic manifestations of **carcinoid syndrome**. The finding of a solid mass in the **small intestine** with **liver metastasis** in conjunction with right-sided heart valve involvement (holosystolic murmur louder on inspiration, right ventricular dilatation and dysfunction) is highly suggestive of a neuroendocrine tumor producing vasoactive substances. - **Right-sided cardiac involvement** is a hallmark of **carcinoid syndrome**, as the vasoactive substances are typically metabolized by the lungs, protecting the left side of the heart. *Bronchial asthma* - While **wheezing** is present, it is usually the primary and often isolated respiratory symptom in asthma. Other systemic symptoms like **flushing, diarrhea, and right heart failure** are not characteristic of bronchial asthma. - Asthma is not associated with **gastrointestinal masses** or structural **cardiac abnormalities** like right ventricular dilation and dysfunction. *Irritable bowel syndrome* - While **loose stools** are seen in IBS, the presence of **flushing, wheezing, palpitations, and significant cardiac pathology** makes IBS an unlikely diagnosis. - IBS is a functional disorder and does not cause **solid masses** in the intestine or liver, nor does it lead to **right ventricular dysfunction**. *Systemic mastocytosis* - This condition can cause **flushing, diarrhea, and cardiac symptoms (tachycardia, hypotension)**, similar to carcinoid syndrome, due to the release of histamine and other mediators from mast cells. - However, characteristic features of systemic mastocytosis include **urticaria pigmentosa (cutaneous mastocytomas)**, bone pain, and elevated serum tryptase, which are not described in this patient. The presence of **solid intestinal and liver masses** is also more consistent with a tumor than mastocytosis. *Whipple’s disease* - This disease can cause **diarrhea, malabsorption, weight loss, and fatigue**, but it is also commonly associated with **arthralgias, lymphadenopathy, and neurological symptoms**. - **Whipple's disease** does not typically cause **flushing, wheezing, or discrete solid masses** in the intestine and liver, nor does it directly lead to **right-sided heart valve dysfunction** in this manner.

Question 444: A 33-year-old man comes to the emergency department because of repeated episodes of severe headache for the past 3 days. He is currently having his 2nd episode of the day. He usually has his first episode in the mornings. The pain is severe and localized to his right forehead and right eye. He had similar symptoms last summer. He works as an analyst for a large hedge fund management company and spends the majority of his time at the computer. He has been under a lot of stress because of overdue paperwork. He also has chronic shoulder pain. He has been using indomethacin every 6 hours for the pain but has had no relief. He has smoked one pack of cigarettes daily for 15 years. He appears restless. Vital signs are within normal limits. Physical examination shows drooping of the right eyelid, tearing of the right eye, and rhinorrhea. The right pupil is 2 mm and the left pupil is 4 mm. There is localized tenderness to his right supraspinatus muscle. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Medication overuse headache
B. Migraine headache
C. Giant cell arteritis
D. Subarachnoid hemorrhage
E. Cluster headache (Correct Answer)

Explanation: ***Cluster headache*** - This patient presents with episodic, **severe unilateral headache** (right forehead and eye) accompanied by **ipsilateral autonomic symptoms** (drooping eyelid, tearing, rhinorrhea, miosis, restlessness). These are classic features of cluster headache. - The **circadian pattern** (first episode in mornings), **seasonal recurrence** (similar symptoms last summer), and lack of response to indomethacin further support this diagnosis. *Medication overuse headache* - This type of headache typically results from the **chronic overuse of acute headache medications**, leading to a worsening or transformation of the baseline headache. - While the patient is using indomethacin, his headache is acute, episodic, and has specific autonomic features, which are not characteristic of medication overuse headache. *Migraine headache* - Migraines are often associated with **photophobia, phonophobia**, and **nausea/vomiting**, which are not reported here. - While they can be unilateral, the prominent ipsilateral autonomic symptoms and extreme restlessness are more indicative of cluster headache. *Giant cell arteritis* - Primarily affects **older individuals** (typically >50 years old) and is associated with symptoms like **jaw claudication, scalp tenderness**, and **visual disturbances**. - The patient's age (33) and specific symptom constellation do not align with giant cell arteritis. *Subarachnoid hemorrhage* - Presents as a **sudden-onset, "thunderclap" headache**, often described as the "worst headache of my life." - While severe, the patient's headaches are episodic over several days and have a clear pattern, unlike the acute onset of a subarachnoid hemorrhage, which also typically presents with meningeal signs.

Question 445: A 75-year-old man comes to the emergency department because of fatigue and black sticky stools during the past 3 days. He also complains of nausea and has had a 2-kg (4.4-lb) weight loss over the past month. He has a history of polycystic kidney disease, hypertension, and hyperlipidemia. He does not smoke or drink alcohol. Current medications include hydrochlorothiazide, furosemide, valsartan, and atorvastatin. He is thin and appears tired. His temperature is 37.0°C (98.6°F), pulse is 75/min, and blood pressure is 110/65 mm Hg. Examination shows conjunctival pallor and numerous excoriations on the extensor surfaces of his upper extremities. Abdominal examination shows no abnormalities. There is a flapping tremor when both wrists are flexed. Laboratory studies show: Hemoglobin 8.5 g/dL Platelets 109,000/mm3 Mean corpuscular volume 81 μm3 Prothrombin time 11 sec Partial thromboplastin time 34 sec Serum Creatinine 6.1 mg/dL Which of the following is the most likely underlying cause of this patient's current condition?

A. Acquired factor VII deficiency
B. Decreased levels of von Willebrand factor
C. Dysfunctional platelet aggregation (Correct Answer)
D. Inherited antithrombin deficiency
E. Impaired production of thrombopoietin

Explanation: ***Dysfunctional platelet aggregation*** - The patient presents with **pruritus (excoriations)**, **fatigue**, and **black, tarry stools (melena)**, indicating **gastrointestinal bleeding**. His lab findings show **anemia** (hemoglobin 8.5 mg/dL) and **thrombocytopenia** (platelets 109,000/mm³). - The significantly elevated **creatinine (6.1 mg/dL)** points to **severe kidney failure**, which commonly leads to uremia. In **uremia**, circulating toxins impair **platelet function**, specifically **platelet aggregation and adhesion**, even with a sufficient platelet count (though this patient also has thrombocytopenia). This **dysfunctional platelet aggregation** is the most likely cause of increased bleeding tendency in a patient with end-stage renal disease. *Acquired factor VII deficiency* - **Factor VII deficiency** would primarily manifest as a prolonged **prothrombin time (PT)**, as factor VII is part of the extrinsic coagulation pathway. - The patient's PT is 11 seconds, which is within the normal range, making **acquired factor VII deficiency** unlikely. *Decreased levels of von Willebrand factor* - **Decreased von Willebrand factor** (vWF) would lead to impaired primary hemostasis, prolonged bleeding time, and sometimes a slightly prolonged activated partial thromboplastin time (aPTT) if factor VIII levels are also affected (vWF protects factor VIII). - While bleeding is present, the primary issue in severe renal failure leading to bleeding is typically **platelet dysfunction**, not solely vWF deficiency. *Inherited antithrombin deficiency* - **Antithrombin deficiency** is a **thrombophilic disorder**, meaning it increases the risk of **thrombosis ( clot formation)**, not bleeding. - This condition would lead to symptoms like deep vein thrombosis or pulmonary embolism, which are not present in this clinical picture. *Impaired production of thrombopoietin* - **Thrombopoietin** is primarily produced by the **liver** and is the main regulator of **platelet production**. Impaired production would lead to **thrombocytopenia**. - While the patient has thrombocytopenia, the more pressing issue causing bleeding in renal failure is the **qualitative platelet defect (dysfunction)**, not merely a lack of platelet numbers, and the kidney itself is not the primary site of thrombopoietin production impacting overall levels significantly.

Question 446: An 8-year-old boy is brought to the physician by his father because of abnormal movements of his limbs. For the past four days, he has had uncontrolled jerking movements of his arms and legs and has been dropping cups and toys. His symptoms are worse when he is excited and improve while he is asleep. During the same time period, he has become increasingly irritable and tearful. He had a sore throat 6 weeks ago that resolved without treatment. His temperature is 37.3°C (99.2°F). Examination shows occasional grimacing with involuntary jerking movements of his limbs. Muscle strength and tone are decreased in all extremities. When he grips the physician's index and middle fingers with his hands, his grip increases and decreases continuously. This patient is at increased risk for which of the following complications?

A. Extraneural metastasis
B. Early-onset dementia
C. Diabetes mellitus
D. Attention deficit hyperactivity disorder
E. Mitral regurgitation (Correct Answer)

Explanation: ***Mitral regurgitation*** - This patient has **Sydenham chorea**, a major manifestation of **acute rheumatic fever (ARF)** following group A streptococcal pharyngitis 6 weeks ago - Classic features present: choreiform movements, emotional lability, milkmaid's grip (motor impersistence), hypotonia, and symptoms that worsen with stress and improve with sleep - **Rheumatic heart disease** develops in 50-60% of ARF patients, with the **mitral valve** being the most commonly affected (70-80% of cases) - Chronic valvular damage occurs due to molecular mimicry between streptococcal M protein and cardiac myosin, leading to autoimmune-mediated inflammation - **Mitral regurgitation** is the most common valvular lesion in acute ARF, and patients require long-term antibiotic prophylaxis to prevent recurrent episodes and progressive cardiac damage *Extraneural metastasis* - This refers to cancer spreading outside the nervous system and is completely unrelated to the clinical presentation - The patient has a post-infectious autoimmune condition (ARF), not a malignancy - Chorea in children with cancer would suggest paraneoplastic syndrome or CNS involvement, not metastasis *Early-onset dementia* - Sydenham chorea causes transient behavioral and cognitive changes but does not lead to progressive cognitive decline or dementia - Cognitive symptoms typically resolve within months, though some emotional/behavioral issues may persist - Dementia in children would suggest neurodegenerative disorders (e.g., leukodystrophies, storage diseases), not post-streptococcal sequelae *Diabetes mellitus* - There is no pathophysiologic link between acute rheumatic fever and diabetes mellitus - This metabolic disorder involves insulin deficiency or resistance and is unrelated to post-streptococcal autoimmune phenomena - Completely inappropriate complication for this clinical scenario *Attention deficit hyperactivity disorder* - While Sydenham chorea can cause transient hyperactivity, emotional lability, and attention difficulties, these are manifestations of the acute illness - True ADHD is a chronic neurodevelopmental disorder with different pathophysiology and diagnostic criteria - Behavioral symptoms in Sydenham chorea typically improve as the chorea resolves (usually within 3-6 months), unlike the persistent pattern required for ADHD diagnosis

Question 447: A patient presents to his primary care physician with complaints of regular headaches and upper abdominal pain. On physical examination, his spleen and liver seem enlarged, and his face is plethoric. Gastroendoscopy reveals several gastric ulcers ranging from 3–5 mm in greatest dimension. A bone marrow aspirate shows hypercellularity with fibrosis and serum erythropoietin is low. The patient is informed about a new treatment with ruxolitinib for the main cause of his symptoms. Which of the conditions below can develop due to the same mutation that is causing this patient's symptoms?

A. Acute monocytic leukemia
B. Essential thrombocythemia (Correct Answer)
C. Mantle cell lymphoma
D. Chronic myelogenous leukemia
E. Burkitt's lymphoma

Explanation: ***Essential thrombocythemia*** - The patient's symptoms (headaches, abdominal pain, splenomegaly, hepatomegaly, plethora, gastric ulcers, hypercellular bone marrow with fibrosis, low erythropoietin) are classic for **Polycythemia Vera (PV)**, which is almost always caused by a **JAK2 V617F mutation**. - **Essential thrombocythemia (ET)** is another **BCR-ABL1 negative myeloproliferative neoplasm** that shares the same **JAK2 V617F mutation** in about 50-60% of cases, making it a condition that can arise from the same genetic abnormality. *Acute monocytic leukemia* - This is a type of **acute myeloid leukemia**, characterized by a proliferation of **monoblasts** and **monocytes**. - It is not typically caused by the **JAK2 V617F mutation**; rather, it often involves mutations in genes like *NPM1*, *FLT3*, or *RUNX1*. *Mantle cell lymphoma* - This is a **B-cell non-Hodgkin lymphoma** characterized by the **t(11;14)(q13;q32) translocation**, leading to overexpression of **cyclin D1**. - It is completely unrelated to the **JAK2 V617F mutation** and does not present with features of a myeloproliferative neoplasm. *Chronic myelogenous leukemia* - This is a **myeloproliferative neoplasm** characterized by the **BCR-ABL1 fusion gene** (Philadelphia chromosome **t(9;22)**). - While it is a myeloproliferative neoplasm, it is distinct from Polycythemia Vera and is not caused by the JAK2 V617F mutation. *Burkitt's lymphoma* - This is an aggressive **B-cell non-Hodgkin lymphoma** strongly associated with translocations of the **MYC gene**, most commonly **t(8;14)**. - It has no connection to the **JAK2 V617F mutation** or myeloproliferative disorders.

Question 448: A 70-year-old male comes to the emergency department complaining of severe back pain. The pain started 20 minutes ago when he was sitting and watching TV. He describes the pain as intense, epigastric, and radiating to his back. His vitals on presentation to the emergency department are blood pressure is 150/75 mmHg, pulse is 110/min, and respirations are 24/min with an oxygen saturation of 98% on room air. His body mass index is 35 kg/m^2 and he appears pale and in visible pain. On abdominal exam, his abdomen is tender and a pulsatile mass is felt in the midline during deep palpation. His past medical history includes diabetes, hypertension well-controlled on medications, and a history of benign prostatic hyperplasia. His social history is notable for consuming 2-3 beers per night and a smoking history of ½ pack per day. Which of the following is considered the greatest risk factor for this patient's condition?

A. Smoking (Correct Answer)
B. Benign prostatic hyperplasia
C. Obesity
D. Diabetes
E. Alcohol consumption

Explanation: ***Smoking*** - **Smoking** is the single most significant modifiable risk factor for the development and expansion of **abdominal aortic aneurysms (AAAs)** due to its detrimental effects on arterial wall integrity. - Nicotine and other toxins in smoke contribute to **inflammation**, **oxidative stress**, and **elastin degradation** within the aortic wall. *Benign prostatic hyperplasia* - **Benign prostatic hyperplasia (BPH)** is not a risk factor for abdominal aortic aneurysm formation or rupture. - It is a condition of the prostate gland causing urinary symptoms and has no pathophysiological link to aortic disease. *Obesity* - While **obesity** is a risk factor for many cardiovascular diseases, its association with **abdominal aortic aneurysms (AAAs)** is less direct than other factors, often mediated through related conditions like hypertension. - Some studies suggest a **protective effect** or no significant association between obesity and AAA, although this remains an area of ongoing research. *Diabetes* - **Diabetes** is generally considered to have a **paradoxical or even protective effect** against the development of **abdominal aortic aneurysms (AAAs)**, although it significantly increases the risk of other vascular complications. - The exact mechanism is not fully understood but may involve changes in the aortic wall's structural properties or reduced inflammation in diabetic patients with AAAs. *Alcohol consumption* - **Moderate alcohol consumption** has not been consistently linked to an increased risk of **abdominal aortic aneurysms (AAAs)**. - **Excessive alcohol consumption** can contribute to overall cardiovascular disease risk, but it is not identified as a primary or strong independent risk factor for AAA formation or rupture.

Question 449: A 32-year-old woman presents with new left-arm pain. She was previously well but for 2 months has had episodes of low-grade fever, night sweats, and dizziness. She works as a stock assistant and has noticed left arm pain when she stocks shelves. She is taking a multivitamin but no other medications. On physical examination, her blood pressure is 126/72 in her right arm, but it cannot be measured in her left arm. The left radial pulse is not detectable. There is a bruit over the left subclavian area. Femoral and pedal pulses are normal and no abdominal bruits are heard. The left hand is cool but has no other evidence of ischemia. Which of the following is the most likely etiology of this patient’s condition?

A. Raynaud’s phenomenon
B. Fibromuscular dysplasia
C. Subclavian steal syndrome
D. Aortic coarctation
E. Takayasu arteritis (Correct Answer)

Explanation: ***Takayasu arteritis*** - This **large-vessel vasculitis** predominantly affects **young women** (typically <40 years old) and involves the aorta and its major branches, including the subclavian arteries. - The patient's **constitutional symptoms** (low-grade fever, night sweats) reflect the systemic inflammatory nature of the disease. - The **absent left radial pulse**, **unmeasurable left arm blood pressure**, and **subclavian bruit** indicate significant stenosis or occlusion of the left subclavian artery, a hallmark of Takayasu arteritis. - This arterial stenosis can lead to **subclavian steal syndrome** (a manifestation, not the etiology) and **arm claudication** with exertion (pain when stocking shelves). - The **normal femoral and pedal pulses** help localize the pathology to the upper extremity vessels. *Subclavian steal syndrome* - This is a **hemodynamic phenomenon** (manifestation), not an underlying etiology. - It occurs when subclavian artery stenosis causes retrograde flow from the vertebral artery to supply the affected arm, which can cause dizziness due to vertebrobasilar insufficiency. - The underlying **cause** in this young woman with systemic symptoms is most likely Takayasu arteritis. *Raynaud's phenomenon* - Characterized by **episodic vasospasm** of digital arteries in response to cold or stress, causing color changes (white-blue-red). - Does not cause **absent pulses**, **unequal blood pressures between arms**, **bruits**, or **constitutional symptoms**. *Aortic coarctation* - A **congenital narrowing of the aorta**, typically just distal to the left subclavian artery origin. - Would cause **hypertension in both upper extremities** with **diminished lower extremity pulses and blood pressures** (upper-lower discrepancy, not left-right arm discrepancy). - Does not explain the constitutional symptoms or isolated left arm findings. *Fibromuscular dysplasia* - A **noninflammatory arteriopathy** causing abnormal cellular proliferation in arterial walls, most commonly affecting **renal and carotid arteries**. - Typically occurs in **middle-aged women** without systemic symptoms. - While it can rarely affect subclavian arteries, the **constitutional symptoms** and pattern of large-vessel involvement strongly favor an inflammatory vasculitis like Takayasu arteritis.

Question 450: A 32-year-old woman comes to the clinic for a routine evaluation. This is her first time visiting this office. Her medical history is significant for cystic medial necrosis of the aorta. Her vital signs include: heart rate 85/min, respiratory rate 15/min, temperature 36.0°C (96.8°F), and blood pressure 110/80 mm Hg. Physical examination shows she is thin and tall with abnormally long extremities and spider-like fingers. Which of the following disorders does the patient most likely have?

A. Cystic fibrosis
B. Marfan syndrome (Correct Answer)
C. Tay-Sachs disease
D. Von Hippel-Lindau disease
E. Fabry disease

Explanation: ***Marfan syndrome*** - The patient's presentation with **cystic medial necrosis of the aorta**, a **tall, thin habitus** with **abnormally long extremities**, and **arachnodactyly (spider-like fingers)** are classic features of Marfan syndrome. - This is an **autosomal dominant disorder** caused by a defect in the **fibrillin-1 gene (FBN1)**, leading to abnormalities in connective tissue throughout the body, particularly affecting the cardiovascular, ocular, and skeletal systems. *Cystic fibrosis* - This is a genetic disorder primarily affecting the **lungs** and **digestive system**, leading to thick, sticky mucus. - It does not typically present with the skeletal or cardiovascular findings described in the patient, such as tall stature, arachnodactyly, or aortic pathologies. *Tay-Sachs disease* - This is a rare, fatal genetic disorder that progressively destroys **nerve cells** in the brain and spinal cord, predominantly affecting infants. - It is characterized by neurological regression and a **cherry-red spot** on the retina, and does not involve connective tissue abnormalities or aortic disease. *Von Hippel-Lindau disease* - This is a genetic disorder characterized by the growth of **tumors** and **cysts** in various parts of the body, including the brain, spinal cord, eyes, kidneys, and pancreas. - It does not present with the specific skeletal or cardiovascular features observed in the patient, such as arachnodactyly or aortic cystic medial necrosis. *Fabry disease* - This is an X-linked lysosomal storage disorder characterized by the accumulation of **globotriaosylceramide** in various tissues, leading to multi-systemic symptoms. - While it can affect the heart and kidneys, its key features include **acroparesthesias**, **angiokeratomas**, and **corneal opacities**, none of which are mentioned here.

Question 451: A 42-year-old man presents to his physician with dark urine and intermittent flank pain. He has no significant past medical history and generally is healthy. His temperature is 97.5°F (36.4°C), blood pressure is 182/112 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical examination is significant for bilateral palpable flank masses and discomfort to percussion of the costovertebral angle. Urinalysis is positive for red blood cells without any bacteria or nitrites. Which of the following diagnostic modalities should be used to screen members of this patient's family to assess if they are affected by the same condition?

A. Voiding cystourethrogram
B. Abdominal CT
C. Renal biopsy
D. Renal ultrasound (Correct Answer)
E. Genetic sequencing

Explanation: ***Renal ultrasound*** - **Renal ultrasound** is the preferred initial screening method for family members suspected of having **autosomal dominant polycystic kidney disease (ADPKD)** due to its non-invasiveness, accessibility, and high sensitivity for detecting cysts. - The combination of **bilateral palpable flank masses**, **hypertension**, **dark urine (hematuria)**, and the potential for a family history strongly points to ADPKD. *Voiding cystourethrogram* - This imaging study is primarily used to evaluate **vesicoureteral reflux (VUR)** and lower urinary tract anatomy, which is not indicated by the patient's symptoms. - It involves radiation exposure and catheterization, making it unsuitable for routine screening of asymptomatic family members for ADPKD. *Abdominal CT* - While an abdominal CT can visualize renal cysts effectively, it involves **ionizing radiation**, making it less suitable for routine screening of asymptomatic family members compared to ultrasound. - It would typically be reserved for cases where ultrasound findings are equivocal or for evaluating complications of ADPKD. *Renal biopsy* - **Renal biopsy** is an invasive procedure with risks, primarily used to diagnose kidney diseases based on histopathology, especially in cases of unexplained acute kidney injury or glomerular disease. - It is not a screening tool and would not be performed on asymptomatic family members. *Genetic sequencing* - **Genetic testing** can identify specific mutations in *PKD1* or *PKD2* genes, confirming ADPKD, but it is typically reserved for cases where imaging is inconclusive, for family planning, or in atypical presentations. - It is more expensive and complex than ultrasound, making it a second-line diagnostic tool rather than a primary screening method for a large population of family members.

Question 452: A 60-year-old man presents to the emergency department with pleuritic chest pain. He recently returned from a vacation in Germany and noticed he felt short of breath and had chest pain the following morning. The patient is generally healthy but did have surgery on his ankle 3 weeks ago and has been less ambulatory. His temperature is 99.0°F (37.2°C), blood pressure is 137/88 mm Hg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 96% on room air. Physical exam is notable for a warm and swollen lower extremity. The physician has high clinical suspicion for pulmonary embolism given the patient's risk factors and presentation. Which of the following findings would warrant further workup with a CT angiogram?

A. Bilateral wheezing
B. Green sputum
C. Decreased breath sounds over area of the lung
D. Increased breath sounds over area of the lung
E. Hemoptysis (Correct Answer)

Explanation: ***Hemoptysis*** - **Hemoptysis** (coughing up blood) in the presence of pleuritic chest pain, dyspnea, and risk factors for DVT (recent surgery, immobility, long travel) is a classic symptom of **pulmonary embolism (PE)**, often indicating pulmonary infarction due to arterial occlusion. - This symptom significantly increases the clinical probability of PE, warranting immediate and definitive diagnostic imaging like a **CT pulmonary angiogram (CTPA)**. *Bilateral wheezing* - **Bilateral wheezing** is typically associated with diffuse airway narrowing, as seen in conditions like **asthma** or **COPD**, and is not a specific indicator of pulmonary embolism. - While it can occur in PE due to bronchoconstriction, it is not a primary or highly specific sign that directly warrants a CT angiogram for PE when other more classic symptoms are present. *Green sputum* - **Green sputum** is a strong indicator of a **bacterial infection**, such as pneumonia or acute bronchitis, due to the presence of pus and bacterial products. - This symptom would lead to workup for infection rather than directly for pulmonary embolism, although pneumonia can sometimes present with similar symptoms. *Decreased breath sounds over area of the lung* - While localized **decreased breath sounds** can be seen with PE (e.g., due to atelectasis or pleural effusion), it is a **non-specific finding** that can also be caused by conditions like pneumonia, pleural effusion, or pneumothorax. - It does not, on its own, provide as strong an indication for PE as hemoptysis, given the other clinical context. *Increased breath sounds over area of the lung* - **Increased breath sounds** (e.g., bronchial breath sounds) typically indicate lung consolidation, characteristic of **pneumonia**, where solid tissue transmits sound more efficiently. - This finding is not associated with pulmonary embolism and would steer the diagnostic workup towards infectious processes rather than PE.

Question 453: A 54-year-old man comes to the emergency department because of severe pain in his right leg that began suddenly 3 hours ago. He has had repeated cramping in his right calf while walking for the past 4 months, but it has never been this severe. He has type 2 diabetes mellitus, hypercholesterolemia, and hypertension. Current medications include insulin, enalapril, aspirin, and simvastatin. He has smoked one pack of cigarettes daily for 33 years. He does not drink alcohol. His pulse is 103/min and blood pressure is 136/84 mm Hg. Femoral pulses are palpable bilaterally. The popliteal and pedal pulses are absent on the right. Laboratory studies show: Hemoglobin 16.1 g/dL Serum Urea nitrogen 14 mg/dL Glucose 166 mg/dL Creatinine 1.5 mg/dL A CT angiogram of the right lower extremity is ordered. Which of the following is the most appropriate next step in management?

A. Administer sodium bicarbonate
B. Administer mannitol
C. Administer normal saline (Correct Answer)
D. Remote ischemic preconditioning
E. Administer heparin anticoagulation

Explanation: ***Administer normal saline*** - The patient has an acute limb ischemia and needs a **CT angiogram** with contrast to locate the thrombus for intervention. Administering **normal saline** prior to contrast administration is crucial to prevent contrast-induced nephropathy, especially in a patient with **diabetes** and mildly elevated **creatinine**. - **Aggressive hydration** with intravenous fluids helps maintain renal perfusion and dilute the contrast agent, thereby reducing its nephrotoxic effects. *Administer sodium bicarbonate* - While sometimes used for renal protection, **sodium bicarbonate** is generally reserved for patients with more severe metabolic acidosis or for specific situations where its alkalizing properties are beneficial. - In this context, **normal saline** is the primary choice for generalized hydration and prevention of contrast-induced nephropathy before contrast administration. *Administer mannitol* - **Mannitol** is an osmotic diuretic used to induce diuresis and reduce intracranial pressure or treat cerebral edema. - It is **not the primary fluid** for preventing contrast-induced nephropathy and could potentially worsen dehydration if used inappropriately. *Remote ischemic preconditioning* - **Remote ischemic preconditioning** involves inducing brief, controlled periods of ischemia and reperfusion in one organ to protect another organ from a subsequent, more prolonged ischemic insult. - While an interesting concept, it is **not a standard or immediate treatment** for preventing contrast-induced nephropathy in this acute setting and has not shown consistent, strong evidence for this specific indication. *Administer heparin anticoagulation* - **Heparin anticoagulation** is critical for treating acute limb ischemia to prevent thrombus propagation. However, the question specifically asks for the most appropriate next step **in management regarding the CT angiogram**. - While heparin should be given, **renal protection** prior to contrast administration is a more immediate and specific concern related to the ordered diagnostic test. The question asks for the step **before** the CT angiogram.

Question 454: A previously healthy 19-year-old man is brought to the emergency department by his girlfriend after briefly losing consciousness. He passed out while moving furniture into her apartment. She said that he was unresponsive for a minute but regained consciousness and was not confused. The patient did not have any chest pain, palpitations, or difficulty breathing before or after the episode. He has had episodes of dizziness when exercising at the gym. His blood pressure is 125/75 mm Hg while supine and 120/70 mm Hg while standing. Pulse is 70/min while supine and 75/min while standing. On examination, there is a grade 3/6 systolic murmur at the left lower sternal border and a systolic murmur at the apex, both of which disappear with passive leg elevation. Which of the following is the most likely cause?

A. Prolonged QT interval
B. Hypertrophic cardiomyopathy (Correct Answer)
C. Mitral valve stenosis
D. Mitral valve prolapse
E. Bicuspid aortic valve

Explanation: ***Hypertrophic cardiomyopathy*** - This patient's **syncope associated with exertion** (moving furniture) and episodes of **dizziness during exercise** are highly suggestive of hypertrophic cardiomyopathy (HCM). - The presence of a **systolic murmur at the left sternal border and apex** that **decreases/disappears with passive leg elevation** indicates a dynamic left ventricular outflow tract (LVOT) obstruction that is sensitive to preload changes, a hallmark of HCM. - Passive leg elevation **increases preload** → **increases LV volume** → **decreases LVOT obstruction** → **decreases murmur intensity**. *Prolonged QT interval* - While it can cause syncope, especially exertional, a prolonged QT interval generally **does not present with dynamic murmurs** that change with preload. - ECG findings (not mentioned here) would be the primary diagnostic clue, not physical exam findings related to murmurs. *Mitral valve stenosis* - Mitral stenosis would typically present with a **diastolic murmur** (not systolic) and symptoms like dyspnea, fatigue, and possibly hemoptysis due to elevated left atrial pressure. - The murmur of mitral stenosis would not characteristically change with passive leg elevation in the manner described. *Mitral valve prolapse* - Mitral valve prolapse often presents with a **mid-systolic click** followed by a systolic murmur, which typically **intensifies with standing** or maneuvers that decrease left ventricular volume. - The murmur described here decreases with leg elevation (increased preload), which is the opposite behavior of a mitral prolapse murmur. *Bicuspid aortic valve* - A bicuspid aortic valve can cause an **aortic stenosis murmur** (a systolic ejection murmur heard best at the right upper sternal border) or regurgitation, but it generally **does not cause a dynamic murmur that changes with preload** in this characteristic fashion. - Symptoms related to bicuspid aortic valve disease (like syncope) would more commonly be associated with significant stenosis, not with a murmur that is acutely sensitive to preload changes.

Question 455: A 65-year-old woman was referred to a specialist for dysphagia and weight loss. She has a history of difficulty swallowing solid foods, which has become worse over the past year. She has unintentionally lost 2.3 kg (5 lb). A previous gastroscopy showed mild gastritis with a positive culture for Helicobacter pylori. A course of triple antibiotic therapy and omeprazole was prescribed. Follow-up endoscopy appeared normal with no H. pylori noted on biopsy. Her heartburn improved but the dysphagia persisted. She had a myocardial infarction four years ago, complicated by acute mitral regurgitation. Physical examination revealed a thin woman with normal vital signs. Auscultation of the heart reveals a 3/6 blowing systolic murmur at the apex radiating to the axilla. Breath sounds are reduced at the base of the right lung. The abdomen is mildly distended but not tender. The liver and spleen are not enlarged. Electrocardiogram shows sinus rhythm with a non-specific intraventricular block. Chest X-ray shows an enlarged cardiac silhouette with mild pleural effusion. What is the most probable cause of dysphagia?

A. Benign stricture
B. Thoracic aortic aneurysm
C. Left atrium enlargement (Correct Answer)
D. Achalasia
E. Diffuse esophageal spasm

Explanation: ***Left atrium enlargement*** - The patient's history of a **myocardial infarction** complicated by **acute mitral regurgitation** four years ago, combined with the current finding of a **3/6 blowing systolic murmur at the apex radiating to the axilla**, strongly suggests chronic severe mitral regurgitation leading to **left atrial enlargement**. - An enlarged left atrium can compress the **esophagus**, leading to **dysphagia**, particularly for solids, which is consistent with the patient's symptoms. The chest X-ray showing an **enlarged cardiac silhouette** and mild pleural effusion further supports a cardiac cause. *Benign stricture* - While benign strictures can cause **dysphagia for solids**, the patient's **normal follow-up endoscopy** makes this diagnosis less likely, as strictures would typically be visible. - Her improved heartburn after H. pylori eradication also suggests that **reflux esophagitis**, a common cause of benign strictures, is not the primary ongoing issue. *Thoracic aortic aneurysm* - A thoracic aortic aneurysm can cause **dysphagia due to esophageal compression**, but it is less likely to be the primary cause given the prominent cardiac findings specifically pointing to **mitral valve disease** and left atrial enlargement. - While the enlarged cardiac silhouette could be partially due to a dilated aorta, the specific murmur and history of mitral regurgitation make left atrial enlargement a more direct and probable cause of esophageal compression. *Achalasia* - **Achalasia** is characterized by the **failure of the lower esophageal sphincter to relax** and loss of esophageal peristalsis, typically causing dysphagia for both solids and liquids. The patient's primary complaint of difficulty swallowing solids and the absence of typical achalasia symptoms (e.g., regurgitation of undigested food, chest pain not resolving with nitrates) make this less likely. - The **normal endoscopy** also makes achalasia less probable, as it can sometimes show findings of esophageal dilation. *Diffuse esophageal spasm* - **Diffuse esophageal spasm** presents with intermittent **chest pain** and dysphagia for both solids and liquids, often triggered by stress or cold liquids. The patient's long-standing dysphagia predominantly for solids, without mention of significant chest pain or episodic nature, makes diffuse esophageal spasm less likely. - This condition is also typically diagnosed with **esophageal manometry**, which has not been performed, but the strong cardiac findings point away from a primary esophageal motility disorder.

Question 456: A 62-year-old man is brought to the physician by his wife for increased forgetfulness and unsteady gait over the past 3 months. He is a journalist and has had difficulty concentrating on his writing. He also complains of urinary urgency recently. His temperature is 36.8°C (98.2°F) and blood pressure is 139/83 mm Hg. He is oriented only to person and place. He is able to recall 2 out of 3 words immediately and 1 out of 3 after five minutes. He has a slow, broad-based gait and takes short steps. Neurological examination is otherwise normal. Urinalysis is normal. Which of the following is the most likely diagnosis?

A. Frontotemporal dementia
B. Normal pressure hydrocephalus (Correct Answer)
C. Vascular dementia
D. Lewy body dementia
E. Alzheimer disease

Explanation: ***Normal pressure hydrocephalus*** - This patient presents with the classic triad of **normal pressure hydrocephalus (NPH)**: **gait disturbance** (unsteady, broad-based, short-stepped), **urinary urgency** (often incontinence), and **cognitive impairment** (forgetfulness, difficulty concentrating). - The symptoms are progressive over three months and the neurological examination (apart from gait) is otherwise normal, fitting the profile of NPH. *Frontotemporal dementia* - This dementia subtype typically presents with prominent **behavioral changes** (disinhibition, apathy) or **language disturbance** (aphasia), which are not highlighted in this case. - While cognitive decline occurs, the classic triad of gait disturbance and urinary symptoms is not characteristic. *Vascular dementia* - Vascular dementia usually presents with a **step-wise decline** in cognitive function, often associated with a history of stroke or vascular risk factors like hypertension, hyperlipidemia, or diabetes. - The presented symptoms do not describe a step-wise decline, and the gait disturbance in NPH is distinct from focal neurological deficits seen in multi-infarct dementia. *Lewy body dementia* - Key features of Lewy body dementia include **fluctuating cognition**, **recurrent visual hallucinations**, and **spontaneous parkinsonism**, none of which are explicitly mentioned here. - While gait disturbance can occur, it's typically more **parkinsonian** (shuffling gait) rather than broad-based and unsteady, and urinary urgency is not a primary diagnostic criterion. *Alzheimer disease* - Alzheimer disease predominantly features prominent and progressive **memory impairment**, particularly for new information, along with other cognitive deficits. While forgetfulness is present, the pronounced gait disturbance and urinary urgency are not typical early or prominent features. - Gait disturbance in Alzheimer's is usually a later symptom, and urinary issues are often due to a later stage of cognitive decline or other causes.

Question 457: A 19-year-old woman presents with worsening pain in her neck for the past 5 days. She says she is not able to wear her tie for her evening job because it is too painful. She also reports associated anxiety, palpitations, and lethargy for the past 10 days. Past medical history is significant for a recent 3-day episode of flu-like symptoms about 20 days ago which resolved spontaneously. She is a non-smoker and occasionally drinks beer with friends on weekends. Her vital signs include: blood pressure 110/80 mm Hg, pulse 118/min. On physical examination, her distal extremities are warm and sweaty. There is severe bilateral tenderness to palpation of her thyroid gland, as well as mild symmetrical swelling noted. No nodules palpated. An ECG is normal. Laboratory findings are significant for low thyroid-stimulating hormone (TSH), elevated T4 and T3 levels, and an erythrocyte sedimentation rate (ESR) of 30 mm/hr. Which of the following is the most appropriate treatment for this patient's most likely diagnosis?

A. Atropine injection
B. Increase dietary intake of iodine
C. Aspirin (Correct Answer)
D. Reassurance
E. Levothyroxine administration

Explanation: ***Aspirin*** - This patient presents with symptoms and signs consistent with **subacute thyroiditis (de Quervain's thyroiditis)**, including recent flu-like illness, painful thyroid gland, symptoms of hyperthyroidism, and elevated ESR. - **Aspirin** or other **NSAIDs** are the primary treatment for managing the pain and inflammation associated with subacute thyroiditis. *Atropine injection* - **Atropine** is an anticholinergic medication primarily used to treat **bradycardia** and certain poisonings, which is not indicated here. - While the patient has tachycardia, it is secondary to hyperthyroidism and would not be directly managed with atropine. *Increase dietary intake of iodine* - Increasing **iodine intake** can worsen hyperthyroidism, especially in susceptible individuals like those with **iodine-induced hyperthyroidism**. - It is not relevant for the treatment of subacute thyroiditis, where the primary issue is inflammation and thyroid hormone release from damaged follicles. *Reassurance* - While patient reassurance is always part of good clinical care, it is **insufficient** as the sole treatment for a condition causing significant pain and hyperthyroid symptoms. - The patient requires specific intervention to manage her symptoms and inflammation. *Levothyroxine administration* - **Levothyroxine** is a synthetic thyroid hormone used to treat **hypothyroidism** or suppress TSH in certain thyroid conditions. - This patient is currently hyperthyroid, so administering levothyroxine would exacerbate her symptoms and is contraindicated.

Question 458: A 62-year-old man is brought to the emergency department because of headache, blurring of vision, and numbness of the right leg for the past 2 hours. He has hypertension and type 2 diabetes mellitus. Current medications include enalapril and metformin. He is oriented only to person. His temperature is 37.3°C (99.1°F), pulse is 99/min and blood pressure is 158/94 mm Hg. Examination shows equal pupils that are reactive to light. Muscle strength is normal in all extremities. Deep tendon reflexes are 2+ bilaterally. Sensation to fine touch and position is decreased over the right lower extremity. The confrontation test shows loss of the nasal field in the left eye and the temporal field in the right eye with macular sparing. He is unable to read phrases shown to him but can write them when they are dictated to him. He has short-term memory deficits. Which of the following is the most likely cause for this patient's symptoms?

A. Infarct of the right middle cerebral artery
B. Infarct of the right anterior cerebral artery
C. Infarct of the right posterior cerebral artery
D. Herpes simplex encephalitis
E. Infarct of the left posterior cerebral artery (Correct Answer)

Explanation: ***Infarct of the left posterior cerebral artery*** - The patient's inability to read but ability to write when dictated, known as **alexia without agraphia**, is a classic sign of an infarct in the **left posterior cerebral artery (PCA)** affecting the **splenium of the corpus callosum** and the **left visual cortex**. - The **right homonymous hemianopsia** with **macular sparing** (loss of the nasal field in the left eye and the temporal field in the right eye) is also characteristic of a left PCA infarct due to involvement of the optic radiations or primary visual cortex, with macular sparing often observed. *Infarct of the right middle cerebral artery* - A right MCA infarct would typically present with **left-sided motor and sensory deficits**, **left homonymous hemianopsia**, and **neglect** of the left side, which do not align with the patient's specific presentation of alexia without agraphia and right homonymous hemianopsia. *Infarct of the right anterior cerebral artery* - A right ACA infarct would primarily cause **left-sided lower extremity weakness** and **sensory loss**, often affecting the **frontal lobe** with behavioral changes. - It would not explain the visual field deficits or alexia without agraphia seen in this patient. *Infarct of the right posterior cerebral artery* - A right PCA infarct would cause **left homonymous hemianopsia** with or without macular sparing, but would not produce alexia without agraphia, which is a specific **language processing deficit** localized to the dominant (left) hemisphere. - It could lead to visual agnosia or prosopagnosia, but not the specific reading-writing dissociation observed. *Herpes simplex encephalitis* - Herpes simplex encephalitis typically presents with **fever**, **headache**, **seizures**, and **altered mental status**, often with **focal neurological deficits** affecting the **temporal** and **frontal lobes**. - While it can cause memory deficits and altered mental status, it would not typically present with the acute, specific combination of alexia without agraphia and distinct visual field deficits of vascular origin.

Question 459: A 61-year-old man comes to the physician for shortness of breath and chest discomfort that is becoming progressively worse. He has had increasing problems exerting himself for the past 5 years. He is now unable to walk more than 50 m on level terrain without stopping and mostly rests at home. He has smoked 1–2 packs of cigarettes daily for 40 years. He appears distressed. His pulse is 85/min, blood pressure is 140/80 mm Hg, and respirations are 25/min. Physical examination shows a plethoric face and distended jugular veins. Bilateral wheezing is heard on auscultation of the lungs. There is yellow discoloration of the fingers on the right hand and 2+ lower extremity edema. Which of the following is the most likely cause of this patient's symptoms?

A. Coronary plaque deposits
B. Chronic respiratory acidosis
C. Increased left atrial pressure
D. Elevated pulmonary artery pressure (Correct Answer)
E. Decreased intrathoracic gas volume

Explanation: ***Elevated pulmonary artery pressure*** * The patient's long history of **heavy smoking** and progressive exertional dyspnea, wheezing, plethoric face, distended jugular veins, and lower extremity edema are highly suggestive of **cor pulmonale** due to chronic obstructive pulmonary disease (COPD). * **COPD** leads to chronic hypoxia and vasoconstriction of pulmonary arteries, increasing **pulmonary artery pressure**, which eventually causes right ventricular failure (cor pulmonale) manifested by the systemic venous congestion symptoms. *Coronary plaque deposits* * While **coronary plaque deposits** can lead to chest discomfort, the prominent signs of **right-sided heart failure** (jugular venous distension, lower extremity edema) and chronic respiratory symptoms point away from isolated coronary artery disease as the primary cause. * The patient's wheezing and long smoking history are more indicative of a **respiratory rather than purely cardiac origin** for his dyspnea. *Chronic respiratory acidosis* * **Chronic respiratory acidosis** can occur in severe COPD, but it is a **consequence** of impaired gas exchange, not the primary cause of the patient's presenting symptoms of shortness of breath and chest discomfort with signs of overt heart failure. * While important, acidosis alone does not explain the **physical findings of right heart failure** such as jugular venous distention and peripheral edema. *Increased left atrial pressure* * **Increased left atrial pressure** is characteristic of **left-sided heart failure**, which typically presents with pulmonary edema (rales, pink frothy sputum) and symptoms like orthopnea and paroxysmal nocturnal dyspnea. * This patient's symptoms, particularly the **plethoric face, distended jugular veins, and lower extremity edema**, are classic signs of **right-sided heart failure**, not left-sided heart failure. *Decreased intrathoracic gas volume* * **Decreased intrathoracic gas volume** is usually seen in restrictive lung diseases (e.g., pulmonary fibrosis), not obstructive diseases like COPD, where gas trapping leads to **increased intrathoracic gas volume**. * The patient's wheezing and long smoking history are classic for **obstructive lung disease**, which is associated with air trapping and hyperinflation, rather than decreased lung volumes.

Question 460: A 64-year-old homeless man comes to the emergency department with right ear pain and difficulty hearing for 2 weeks. Over the last 5 days, he has also noticed discharge from his right ear. He does not recall the last time he saw a physician. His temperature is 39.0°C (102.2°F), blood pressure is 153/92 mm Hg, pulse is 113/minute, and respirations are 18/minute. He appears dirty and is malodorous. Physical examination shows mild facial asymmetry with the right corner of his mouth lagging behind the left when the patient smiles. He experiences severe ear pain when the right auricle is pulled superiorly. On otoscopic examination, there is granulation tissue at the transition between the cartilaginous and the osseous part of the ear canal. Which of the following is most likely associated with this patient's condition?

A. Opacified mastoid air cells
B. Elevated HBA1c (Correct Answer)
C. Condylar degeneration
D. Streptococcus pneumoniae
E. Malignant epithelial growth of the external auditory canal

Explanation: ***Elevated HBA1c*** - The patient's presentation with **severe ear pain**, **granulation tissue** in the external auditory canal, **facial nerve palsy**, and fever, particularly in an elderly, immunocompromised individual (homeless, poor hygiene), is highly suggestive of **necrotizing (malignant) otitis externa**. - **Diabetes mellitus**, indicated by an elevated HbA1c, is the most significant predisposing factor for necrotizing otitis externa, as it impairs the immune response and promotes the growth of **Pseudomonas aeruginosa**, the most common causative organism. *Opacified mastoid air cells* - While opacified mastoid air cells can be seen in mastoiditis, this condition typically presents with signs of inflammation **behind the ear** and often follows an acute otitis media. - The patient's symptoms, especially the granulation tissue and facial nerve involvement, are more characteristic of necrotizing otitis externa, which primarily affects the external auditory canal and skull base. *Condylar degeneration* - **Condylar degeneration** refers to issues with the temporomandibular joint (TMJ), which can cause ear pain, but typically presents with jaw clicking, limited mouth opening, and local pain in the TMJ area. - It does not explain the **granulation tissue**, fever, or **facial nerve palsy** observed in this patient. *Streptococcus pneumoniae* - **Streptococcus pneumoniae** is a common cause of **acute otitis media** and invasive bacterial infections. - However, in cases of **necrotizing otitis externa**, the primary causative agent is almost exclusively **Pseudomonas aeruginosa**. *Malignant epithelial growth of the external auditory canal* - While a malignant epithelial growth (e.g., squamous cell carcinoma) could cause ear pain, discharge, and potentially granulation tissue, it typically progresses more slowly and is less often associated with rapid onset of **fever** and **facial nerve palsy** to the extent seen here. - The clinical picture, especially in a diabetic patient, points more strongly towards an invasive infection rather than primary malignancy.

Question 461: A 63-year-old woman comes to the physician for a routine health maintenance examination. She reports feeling tired sometimes and having itchy skin. Over the past 2 years, the amount of urine she passes has been slowly decreasing. She has hypertension and type 2 diabetes mellitus complicated with diabetic nephropathy. Her current medications include insulin, furosemide, amlodipine, and a multivitamin. Her nephrologist recently added erythropoietin to her medication regimen. She follows a diet low in salt, protein, potassium, and phosphorus. Her temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 145/87 mm Hg. Physical examination shows 1+ edema around the ankles bilaterally. Laboratory studies show: Hemoglobin 9.8 g/dL Serum Glucose 98 mg/dL Albumin 4 g/dL Na+ 145 mEq/L Cl– 100 mEq/L K+ 5.1 mEq/L Urea nitrogen 46 mg/dL Creatinine 3.1 mg/dL Which of the following complications is the most common cause of death in patients receiving long-term treatment for this patient's renal condition?

A. Malignancy
B. Anemia
C. Cardiovascular disease (Correct Answer)
D. Discontinuation of treatment
E. Gastrointestinal bleeding

Explanation: ***Cardiovascular disease*** - Patients with **end-stage renal disease (ESRD)**, particularly those on dialysis, have a significantly increased risk of cardiovascular events, including **heart failure**, **myocardial infarction**, and stroke. This is due to accelerated **atherosclerosis**, hypertension, volume overload, and chronic inflammation prevalent in ESRD. - The patient's history of **hypertension** and **type 2 diabetes mellitus** with **diabetic nephropathy** further exacerbates the risk of cardiovascular complications, making it the leading cause of mortality. *Malignancy* - While patients with ESRD do have an increased risk of certain **malignancies** (e.g., kidney, bladder cancer), it is not the most common cause of death compared to cardiovascular disease. - The immune dysregulation in uremia contributes to this increased risk, but **cardiovascular disease** remains a more significant factor in mortality. *Anemia* - **Anemia** is a common complication of ESRD due to decreased **erythropoietin production**, as evidenced by the patient's low hemoglobin and erythropoietin prescription. - While anemia contributes to fatigue and can worsen cardiovascular outcomes, it is a modifiable risk factor and generally not the direct cause of death; rather, the underlying cardiovascular issues it exacerbates are. *Discontinuation of treatment* - While **non-compliance** or discontinuation of treatment can lead to poor outcomes and mortality, it is not considered the most common *medical* cause of death in patients receiving long-term treatment for ESRD. - The question asks for a medical complication, and cardiovascular disease is a direct physiological consequence of chronic kidney disease and its treatments. *Gastrointestinal bleeding* - **Gastrointestinal bleeding** can occur in ESRD patients due to uremic coagulopathy, angiodysplasia, and peptic ulcers, and it can be severe. - However, while a serious complication, it is **less common** as a cause of death compared to the overwhelming burden of cardiovascular disease in this patient population.

Question 462: A 55-year-old woman with type 1 diabetes mellitus comes to the physician because of a 3-month history of progressively worsening urinary incontinence. She has started to wear incontinence pads because of frequent involuntary dribbling of urine that occurs even when resting. She has the sensation of a full bladder even after voiding. Her only medication is insulin. Physical examination shows a palpable suprapubic mass. Urinalysis is unremarkable. Urodynamic studies show an increased post-void residual volume. Which of the following interventions is most likely to benefit this patient?

A. Prazosin therapy
B. Duloxetine therapy
C. Oxybutynin therapy
D. Intermittent catheterization (Correct Answer)
E. Amitriptyline therapy

Explanation: ***Intermittent catheterization*** - This patient presents with symptoms and findings consistent with **overflow incontinence** due to **diabetic autonomic neuropathy** affecting bladder function. - Intermittent catheterization is the most effective intervention for managing **high post-void residual volumes** and preventing complications like UTIs and kidney damage in such cases. *Prazosin therapy* - **Prazosin** is an alpha-1 adrenergic antagonist, typically used to treat **hypertension** and **benign prostatic hyperplasia**. - While it can relax the bladder neck, it is not the primary treatment for overflow incontinence due to impaired detrusor contractility and a high post-void residual. *Duloxetine therapy* - **Duloxetine** is a serotonin-norepinephrine reuptake inhibitor (SNRI) primarily used to treat **stress incontinence** by increasing urethral sphincter tone. - It would not address the underlying issue of poor bladder emptying and high post-void residual volume in this patient. *Oxybutynin therapy* - **Oxybutynin** is an anticholinergic medication used to treat **urge incontinence** by reducing involuntary detrusor contractions. - In this case of overflow incontinence, it could worsen bladder emptying by further inhibiting detrusor muscle contraction. *Amitriptyline therapy* - **Amitriptyline** is a tricyclic antidepressant that can have anticholinergic effects and is occasionally used for **nocturia** or **neuropathic pain**. - It is not indicated for the management of overflow incontinence due to poor bladder emptying and could potentially exacerbate urinary retention.

Question 463: A 55-year-old man with a past medical history of diabetes and hypertension presents to the emergency department with crushing substernal chest pain. He was given aspirin and nitroglycerin en route and states that his pain is currently a 2/10. The patient's initial electrocardiogram (ECG) is within normal limits, and his first set of cardiac troponins is 0.10 ng/mL (reference range < 0.10 ng/mL). The patient is sent to the observation unit. During a pharmacologic stress test, the patient is given dipyridamole, which causes his chest pain to recur. Which of the following is the most likely etiology of this patient's current symptoms?

A. Stress induced cardiomyopathy
B. Vasospastic vessel disease
C. Coronary steal (Correct Answer)
D. Dislodged occlusive thrombus
E. Cardiac sarcoidosis

Explanation: ***Coronary steal*** - The patient's chest pain recurring with dipyridamole strongly suggests **coronary steal**, as dipyridamole is a **vasodilator** that diverts blood flow away from stenotic areas. - This phenomenon is a hallmark of significant **coronary artery disease**, where non-ischemic areas dilate and 'steal' blood from areas distal to a fixed stenosis. *Stress induced cardiomyopathy* - This condition, also known as **Takotsubo cardiomyopathy**, usually follows extreme emotional or physical stress and presents with **ST-segment elevation** and apical ballooning on echocardiography, none of which are described. - While it mimics a myocardial infarction, the diagnostic clues (no stressor, normal ECG, and chest pain recurrence with dipyridamole) do not align. *Vasospastic vessel disease* - **Vasospastic angina** (Prinzmetal's angina) causes chest pain due to coronary artery spasms, often occurring at rest and responsive to vasodilators like nitroglycerin. - However, dipyridamole is more likely to exacerbate pain in fixed stenoses (coronary steal) rather than cause spasms, and the patient's presentation with initial crushing pain is less typical of vasospasm alone. *Dislodged occlusive thrombus* - A dislodged thrombus would typically cause an acute **myocardial infarction** with significant ECG changes (ST elevation or depression) and a substantial rise in cardiac troponins, neither of which are present. - The recurrence of pain with dipyridamole is not characteristic of symptom recurrence due to a dislodged thrombus. *Cardiac sarcoidosis* - **Cardiac sarcoidosis** involves granulomatous inflammation of the heart, leading to arrhythmias, heart failure, or heart block, but it does not typically present as recurrent chest pain exacerbated by dipyridamole. - The disease is usually diagnosed by biopsy or characteristic imaging findings, which are not mentioned and do not fit the acute presentation.

Question 464: A 15-year-old male presents to his pediatrician after school for follow-up after an appendectomy one week ago. The patient denies any abdominal pain, fevers, chills, nausea, vomiting, diarrhea, or constipation. He eats solids and drinks liquids without difficulty. He is back to playing basketball for his school team without any difficulty. He notes that his urine appears more amber than usual but suspects that it is due to dehydration. His physical exam is unremarkable; his laparoscopic incision sites are all clean without erythema. The pediatrician orders an urinalysis, which is notable for the following: Urine: Epithelial cells: Scant Glucose: Negative Protein: 3+ WBC: 3/hpf Bacteria: None Leukocyte esterase: Negative Nitrites: Negative The patient is told to return in 3 days for a follow up appointment; however, his urinalysis at that time is similar. What is the best next step in management?

A. Urine electrolytes and creatinine
B. Repeat urinalysis
C. Basic metabolic panel
D. Renal biopsy
E. Urine dipstick in the morning and in the afternoon (Correct Answer)

Explanation: ***Urine dipstick in the morning and in the afternoon*** - Persistent **proteinuria (3+)** without other signs of infection or inflammation, especially in an otherwise healthy and active adolescent, raises suspicion for **orthostatic (postural) proteinuria**. - Collecting urine samples at different times of the day (morning upon waking and in the afternoon after standing/activity) is crucial to differentiate orthostatic proteinuria from persistent proteinuria, as protein excretion in orthostatic proteinuria is typically higher when upright and absent or significantly reduced in the first morning void. *Urine electrolytes and creatinine* - While these can provide information about renal function and tubular handling, they are not the primary or initial step for evaluating isolated **proteinuria** in an asymptomatic patient. - They would be more useful if there were signs of **renal dysfunction** or electrolyte imbalances, which are not present here. *Repeat urinalysis* - The urinalysis has already been repeated with similar results, confirming the presence of isolated **proteinuria**. - Simply repeating it again without further investigation into the cause is unlikely to provide new diagnostic information. *Basic metabolic panel* - A BMP would provide information on **serum creatinine**, BUN, and electrolytes, which can assess overall kidney function. - However, in an asymptomatic patient with isolated proteinuria, it doesn't directly help in differentiating the cause of proteinuria, especially concerning orthostatic proteinuria. *Renal biopsy* - A **renal biopsy** is an invasive procedure and is generally reserved for cases of persistent, significant proteinuria of unclear etiology, especially if associated with **hematuria**, declining renal function, or other systemic features suggesting intrinsic kidney disease. - It would be premature to consider a biopsy without first attempting to characterize the nature of the proteinuria.

Question 465: A 45-year-old woman diagnosed with a meningioma localized to the tuberculum sellae undergoes endonasal endoscopic transsphenoidal surgery to resect her tumor. Although the surgery had no complications and the patient is recovering well with no neurological sequelae, she develops intense polydipsia and polyuria. Her past medical history is negative for diabetes mellitus, cardiovascular disease, or malignancies. Urine osmolality is 240 mOsm/L (300–900 mOsm/L), and her serum sodium level is 143 mEq/L (135–145 mEq/L). The attending decides to perform a water deprivation test. Which of the following results would you expect to see after the administration of desmopressin in this patient?

A. Reduction in urine osmolality to 80 mOsm/L
B. Reduction in urine osmolality to 125 mOsm/L
C. Increase in urine osmolality to greater than 264 mOsm/L (Correct Answer)
D. No changes in urine osmolality values
E. Increase in urine osmolality to 250 mOsm/L

Explanation: ***Increase in urine osmolality to greater than 264 mOsm/L*** - The patient's symptoms of **polydipsia and polyuria** following pituitary surgery, along with **low urine osmolality** (240 mOsm/L) and **normal serum sodium**, are highly suggestive of **central diabetes insipidus (CDI)**. - In central diabetes insipidus, the pituitary gland does not produce enough **antidiuretic hormone (ADH)**. Administration of **desmopressin (synthetic ADH)** will lead to a significant increase in urine osmolality as the kidneys are able to reabsorb water. *Reduction in urine osmolality to 80 mOsm/L* - A reduction in urine osmolality after desmopressin would indicate a worsening or no improvement in water reabsorption, which is inconsistent with the expected response in **central diabetes insipidus**. - This result would be more characteristic of **nephrogenic diabetes insipidus (NDI)** if the baseline urine osmolality was already very low and did not change significantly, or if there was an underlying renal issue. *Reduction in urine osmolality to 125 mOsm/L* - Similar to the previous option, a reduction in urine osmolality is contrary to the expected effect of desmopressin in **central diabetes insipidus**, where the goal is to concentrate the urine. - This value is still very dilute and would suggest that the kidneys are unable to respond to ADH, which is not the case in CDI where the problem is ADH deficiency. *No changes in urine osmolality values* - No change in urine osmolality after desmopressin would suggest that the kidneys are **unresponsive to ADH**, which is characteristic of **nephrogenic diabetes insipidus**. - In the described patient, the issue is an ADH deficiency due to pituitary surgery, not renal unresponsiveness. *Increase in urine osmolality to 250 mOsm/L* - While an increase in urine osmolality is expected, an increase only to 250 mOsm/L might be considered a **suboptimal response** or a less significant improvement than typically seen in true **central diabetes insipidus**. - In CDI, desmopressin usually leads to a substantial increase in urine osmolality, often exceeding 264 mOsm/L or even reaching normal concentrated levels (e.g., >750 mOsm/L), especially if the baseline is very low.

Question 466: A 46-year-old woman comes to the physician because of increasingly severe lower back pain for the past week. The pain is constant, and she describes it as 9 out of 10 in intensity. Six months ago, she underwent a lumpectomy for hormone receptor-negative lobular carcinoma of the right breast. She has undergone multiple cycles of radiotherapy. Vital signs are within normal limits. Examination shows a well-healed surgical incision over the right breast. There is severe tenderness to palpation over the 12th thoracic vertebra. The straight-leg raise test is negative. The remainder of the examination shows no abnormalities. Serum studies show: Glucose 76 mg/dL Creatinine 1 mg/dL Total bilirubin 0.8 mg/dL Alkaline phosphatase 234 U/L Aspartate aminotransferase (AST, GOT) 16 U/L Alanine aminotransferase (ALT, GPT) 12 U/L γ-Glutamyltransferase (GGT) 40 U/L (N=5–50) Which of the following is the most appropriate next step in management?

A. Bone biopsy
B. Positron emission tomography
C. MRI of the spine (Correct Answer)
D. Bone scintigraphy
E. X-ray of the spine

Explanation: ***MRI of the spine*** - The patient's history of **breast carcinoma**, severe localized back pain, and **elevated alkaline phosphatase** strongly suggest **vertebral metastasis**. MRI is the most sensitive and preferred imaging modality for detecting **spinal cord compression** or bone metastases in such cases. - **MRI** provides detailed soft tissue contrast, allowing for precise visualization of the spinal cord, nerve roots, and extent of tumor involvement, which is crucial for treatment planning. *Bone biopsy* - While a bone biopsy can confirm the diagnosis of metastasis, it is an **invasive procedure** and usually performed after less invasive imaging has identified a suspicious lesion. - It is not the most appropriate *initial* step, especially when rapid assessment for **spinal cord compression** (a neurosurgical emergency) is needed. *Positron emission tomography* - **PET scans** are useful for detecting distant metastases and assessing metabolic activity of tumors, but they provide less detailed anatomical information than MRI regarding **spinal cord compromise**. - Although it can detect bone metastases, its utility is more in systemic staging rather than immediate evaluation of severe localized spinal pain and potential compression. *Bone scintigraphy* - **Bone scintigraphy** (bone scan) is sensitive for detecting increased bone turnover associated with metastases, but it has **lower spatial resolution** than MRI and cannot directly visualize the spinal cord. - It may miss purely lytic lesions and is less specific for evaluating the extent of soft tissue involvement or risk of **spinal cord compression**. *X-ray of the spine* - **Plain radiographs** are often the *first* imaging study for back pain, but they have **low sensitivity** for detecting early bone metastases, especially before significant bone destruction has occurred. - X-rays would likely miss small lesions or those infiltrating the bone marrow and are inadequate for assessing **spinal cord compression**.

Question 467: A 37-year-old woman comes to the physician for a 6-month history of headaches, anorexia, and vomiting. She has had a 10-kg (22-lb) weight loss during this period. She has type 1 diabetes mellitus for which she takes insulin. The patient's mother and sister have hypothyroidism. Her blood pressure is 80/60 mm Hg. Physical examination shows hyperpigmentation of the lips and oral mucosa. Serum studies show a parathyroid hormone level of 450 pg/mL and antibodies directed against 21-hydroxylase. Which of the following is the most likely diagnosis?

A. Sheehan syndrome
B. Multiple endocrine neoplasia type 2A
C. Multiple endocrine neoplasia type 2B
D. Autoimmune polyendocrine syndrome type 1
E. Autoimmune polyendocrine syndrome type 2 (Correct Answer)

Explanation: ***Autoimmune polyendocrine syndrome type 2*** - This patient presents with **Addison's disease** (hyperpigmentation, hypotension, weight loss, anorexia, vomiting), **Type 1 diabetes mellitus**, and likely **autoimmune thyroid disease** (family history of hypothyroidism). This classic triad is characteristic of autoimmune polyendocrine syndrome type 2 (Schmidt syndrome). - The presence of **21-hydroxylase antibodies** confirms autoimmune adrenalitis, which is the primary cause of Addison's disease in APS Type 2. The elevated **parathyroid hormone** (PTH) level indicates **secondary hyperparathyroidism**, often a reactive response to vitamin D deficiency or chronic illness, not a primary component of this syndrome. *Sheehan syndrome* - This is a cause of **hypopituitarism** due to **postpartum hemorrhage** leading to ischemic necrosis of the pituitary gland. - The patient's symptoms (hyperpigmentation, diabetes mellitus, 21-hydroxylase antibodies) do not align with the typical presentation or etiology of Sheehan syndrome. Additionally, Sheehan syndrome would present with **hypopigmentation** (due to decreased ACTH), not hyperpigmentation. *Multiple endocrine neoplasia type 2A* - This syndrome is characterized by **medullary thyroid carcinoma**, **pheochromocytoma**, and **primary hyperparathyroidism**. - The patient's symptoms and laboratory findings (hyperpigmentation, T1DM, 21-hydroxylase antibodies) are not consistent with MEN 2A, which is a hereditary cancer syndrome, not an autoimmune disorder. *Multiple endocrine neoplasia type 2B* - This rare syndrome includes **medullary thyroid carcinoma**, **pheochromocytoma**, **mucosal neuromas**, and **marfanoid habitus**. - This patient does not exhibit any of the hallmark features of MEN 2B. *Autoimmune polyendocrine syndrome type 1* - APS type 1 is characterized by a triad of **chronic mucocutaneous candidiasis**, **hypoparathyroidism**, and **Addison's disease**. - While Addison's disease is present, the patient's other conditions (Type 1 diabetes, autoimmune thyroid disease) and the **elevated PTH** (rather than hypoparathyroidism) rule out APS type 1. APS-1 typically presents in childhood, while APS-2 presents in adulthood.

Question 468: A 53-year-old diabetic man with cellulitis of the right lower limb presents to the emergency department because of symptoms of fever and chills. His pulse is 122/min, the blood pressure is 76/50 mm Hg, the respirations are 26/min, and the temperature is 40.0°C (104.0°F). His urine output is < 0.5mL/kg/h. He has warm peripheral extremities. The hemodynamic status of the patient is not improving in spite of the initiation of adequate fluid resuscitation. He is admitted to the hospital. Which of the following is the most likely laboratory profile?

A. WBC count: 11,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 0.9 mmol/L
B. WBC count: 1234/mm3; high CVP; blood culture: gram-negative bacteremia; blood lactate level: 1.6 mmol/L
C. WBC count: 16,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 2.2 mmol/L (Correct Answer)
D. WBC count: 6670/mm3; low CVP; blood culture: gram-positive bacteremia; blood lactate level: 1.1 mmol/L
E. WBC count: 8880/mm3; high CVP; blood culture: gram-positive bacteremia; blood lactate level: 2.1 mmol/L

Explanation: ***WBC count: 16,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 2.2 mmol/L*** - This profile aligns with **septic shock** driven by gram-negative bacteria, presenting with **tachycardia**, **hypotension**, **fever**, and **poor urine output** despite fluid resuscitation. - A **high WBC count** (leukocytosis), **low CVP** (due to vasodilation and relative hypovolemia), **gram-negative bacteremia** (common in severe sepsis), and **elevated lactate** (indicating tissue hypoperfusion) are characteristic findings. *WBC count: 11,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 0.9 mmol/L* - While most components suggest sepsis (WBC count and low CVP), a **lactate level of 0.9 mmol/L** is within the normal range, contradicting the severe hypoperfusion and shock observed in the patient. - The patient's presentation with **hypotension** unresponsive to fluids and **oliguria** strongly indicates significant tissue hypoperfusion, which would typically result in a higher lactate. *WBC count: 1234/mm3; high CVP; blood culture: gram-negative bacteremia; blood lactate level: 1.6 mmol/L* - A **WBC count of 1234/mm3 (leukopenia)** is an atypical response for severe infection and sepsis; often, sepsis presents with leukocytosis. - A **high CVP** indicates fluid overload or cardiac dysfunction, which is not consistent with the initial low blood pressure and the need for fluid resuscitation seen in distributive shock. *WBC count: 6670/mm3; low central venous pressure (CVP); blood culture: gram-positive bacteremia; blood lactate level: 1.1 mmol/L* - A **WBC count of 6670/mm3** is within the normal range and does not reflect an adequate inflammatory response to severe infection and shock. - A **normal lactate level (1.1 mmol/L)** does not support the clinical picture of shock and tissue hypoperfusion despite the presence of gram-positive bacteremia. *WBC count: 8880/mm3; high CVP; blood culture: gram-positive bacteremia; blood lactate level: 2.1 mmol/L* - A **WBC count of 8880/mm3** is normal, which is unlikely in a severe sepsis presentation. - A **high CVP** is not consistent with the distributive shock state where there is often relative hypovolemia and vasodilation leading to low CVP.

Question 469: A 45-year-old African American woman presents to her primary care physician for not feeling well. She states she has had a cough for the past week. In addition, she also has abdominal pain and trouble focusing that has been worsening. She states that she has also lost 5 pounds recently and that her gastroesophageal reflux disease (GERD) has been very poorly controlled recently. The patient is a non-smoker and has a history of GERD for which she takes antacids. Laboratory studies are ordered and are below: Serum: Na+: 139 mEq/L K+: 4.1 mEq/L Cl-: 101 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 12 mg/dL Glucose: 70 mg/dL Creatinine: 0.9 mg/dL Ca2+: 12.5 mg/dL Alkaline phosphatase: 35 U/L Phosphorus: 2.0 mg/dL Urine: Color: amber Nitrites: negative Sodium: 5 mmol/24 hours Red blood cells: 0/hpf Which of the following is the most likely explanation of this patient's current presentation?

A. Malignancy
B. Antacid overuse
C. Increased 1,25-dihydroxyvitamin D
D. Viral illness
E. Increased parathyroid hormone (PTH) (Correct Answer)

Explanation: ***Increased parathyroid hormone (PTH)*** - The patient presents with **hypercalcemia** (12.5 mg/dL) and **hypophosphatemia** (2.0 mg/dL) along with symptoms like cough, abdominal pain, trouble focusing, weight loss, and worsening GERD, which are consistent with hypercalcemia. **Primary hyperparathyroidism** is a common cause of hypercalcemia and is characterized by inappropriately elevated PTH leading to increased calcium and decreased phosphate. - **Worsening GERD** can be a clinical manifestation of hypercalcemia, which can increase gastrin secretion. The combination of hypercalcemia and hypophosphatemia strongly points to issues with parathyroid hormone regulation. *Malignancy* - While malignancy can cause hypercalcemia (often through **parathyroid hormone-related peptide [PTHrP]** secretion or bone metastases), it typically presents with **low or suppressed PTH** levels, which contradicts the scenario implying elevated PTH. - **Hypercalcemia of malignancy** is often associated with more rapid onset and severe symptoms, and typically involves different patterns of phosphate and 1,25-dihydroxyvitamin D levels depending on the mechanism. *Antacid overuse* - Overuse of calcium-containing antacids can lead to **milk-alkali syndrome**, causing hypercalcemia. However, this syndrome is also characterized by **metabolic alkalosis** and **renal dysfunction**, neither of which are suggested by the provided lab values (normal HCO3-, normal creatinine). - Milk-alkali syndrome typically presents with **normal or elevated phosphate levels**, not the hypophosphatemia seen in this patient. *Increased 1,25-dihydroxyvitamin D* - Elevated **1,25-dihydroxyvitamin D** (active vitamin D) can cause hypercalcemia, often seen in conditions like **granulomatous diseases** (e.g., sarcoidosis) or **vitamin D intoxication**. However, this usually leads to increased phosphate absorption and thus **normal or elevated phosphate levels**, not hypophosphatemia. - While sarcoidosis (a granulomatous disease) could cause a cough and fatigue in an African American woman, the associated hypophosphatemia is not characteristic of vitamin D-mediated hypercalcemia without a primary PTH abnormality. *Viral illness* - A simple viral illness typically presents with **acute, self-limiting symptoms** like cough, fever, and malaise. It is highly unlikely to cause the chronic symptoms of abdominal pain, cognitive issues, weight loss, and especially the distinct electrolyte abnormalities of **hypercalcemia** and **hypophosphatemia**. - Viral illnesses do not directly lead to **calcium-phosphorus dysregulation** in the manner seen in this patient, and the duration and severity of her symptoms are not consistent with a typical viral infection.

Question 470: A 27-year-old woman is admitted to the emergency room with dyspnea which began after swimming and progressed gradually over the last 3 days. She denies cough, chest pain, or other respiratory symptoms. She reports that for the past 4 months, she has had several dyspneic episodes that occurred after the exercising and progressed at rest, but none of these were as long as the current one. Also, she notes that her tongue becomes ‘wadded’ when she speaks and she tires very quickly during the day. The patient’s vital signs are as follows: blood pressure 125/60 mm Hg, heart rate 92/min, respiratory rate 34/min, and body temperature 36.2℃ (97.2℉). Blood saturation on room air is initially 92% but falls to 90% as she speaks up. On physical examination, the patient is slightly lethargic. Her breathing is rapid and shallow. Lung auscultation, as well as cardiac, and abdominal examinations show no remarkable findings. Neurological examination reveals slight bilateral ptosis increased by repetitive blinking, and easy fatigability of muscles on repeated movement worse on the face and distal muscles of the upper and lower extremities. Which arterial blood gas parameters would you expect to see in this patient?

A. PaCO2 = 51 mm Hg, PaO2 = 58 mm Hg (Correct Answer)
B. PaCO2 = 37 mm Hg, PaO2 = 46 mm Hg
C. PaCO2 = 34 mm Hg, PaO2 = 61 mm Hg
D. PaCO2 = 31 mm Hg, PaO2 = 67 mm Hg
E. PaCO2 = 43 mm Hg, PaO2 = 55 mm Hg

Explanation: ***PaCO2 = 51 mm Hg, PaO2 = 58 mm Hg*** - The patient presents with symptoms highly suggestive of a **myasthenic crisis**, including progressive dyspnea, worsened by exertion (speaking), ptosis, and generalized muscle fatigability. These symptoms indicate **respiratory muscle weakness**, leading to hypoventilation. - **Hypoventilation** results in **hypercapnia (elevated PaCO2)** and **hypoxemia (decreased PaO2)**. An elevated PaCO2 of 51 mm Hg and decreased PaO2 of 58 mm Hg are consistent with this presentation, reflecting inadequate ventilation. *PaCO2 = 37 mm Hg, PaO2= 46 mm Hg* - A PaCO2 of 37 mm Hg is within the normal range or slightly low, suggesting that the patient is not significantly hypercapnic, which contradicts the clinical picture of **respiratory muscle weakness and hypoventilation**. - While PaO2 is significantly low at 46 mm Hg (indicating hypoxemia), the normal/low PaCO2 would point to a primary **oxygenation defect** (e.g., V/Q mismatch) rather than a ventilatory failure. *PaCO2 = 34 mm Hg, PaO2 = 61 mm Hg* - A PaCO2 of 34 mm Hg indicates **hypocapnia**, which is more consistent with hyperventilation rather than the hypoventilation expected from **respiratory muscle weakness** in myasthenic crisis. - While PaO2 of 61 mm Hg indicates hypoxemia, the accompanying hypocapnia suggests a primary **respiratory drive issue** or conditions causing hyperventilation, not ventilatory failure due to muscle weakness. *PaCO2 = 31 mm Hg, PaO2 = 67 mm Hg* - A PaCO2 of 31 mm Hg reflects significant **hypocapnia**, indicating that the patient is **hyperventilating**. This is contrary to what would be expected in a myasthenic crisis where respiratory muscle weakness leads to hypoventilation. - While PaO2 is decreased, suggesting some respiratory compromise, the ventilatory pattern (hypocapnia) does not match the clinical syndrome of **respiratory muscle fatigue**. *PaCO2 = 43 mm Hg, PaO2 = 55 mm Hg* - A PaCO2 of 43 mm Hg is within the **normal reference range**, which would mean there is no CO2 retention and thus no obvious **alveolar hypoventilation** from respiratory muscle weakness. - While PaO2 of 55 mm Hg indicates hypoxemia, the normal PaCO2 suggests that the hypoxemia is due to other causes like a **V/Q mismatch** rather than inadequate overall ventilation.

Question 471: A 47-year-old woman presents to her primary care physician because of pain on urination, urinary urgency, and urinary frequency for 4 days. This is the third time for her to have these symptoms over the past 7 months. She was recently treated for candidal intertrigo. Vital signs reveal a temperature of 36.7°C (98.0°F), blood pressure of 110/70 mm Hg and pulse of 75/min. Physical examination is unremarkable except for morbid obesity. Her father has type 2 diabetes complicated by end-stage chronic kidney disease. A1C is found to be 8.5%. The patient is given a prescription for her urinary symptoms. Which of the following is the best next step for this patient?

A. Sulphonylurea added to metformin
B. Bariatric surgery
C. Repeating the A1c test
D. Basal-bolus insulin
E. Metformin (Correct Answer)

Explanation: ***Metformin*** - The patient has symptoms suggestive of **uncontrolled type 2 diabetes**, including recurrent infections (urinary, intertrigo) and a familial history, despite an A1C of 8.5%. - **Metformin** is typically the first-line pharmacologic treatment for type 2 diabetes unless contraindicated, as it improves insulin sensitivity and reduces hepatic glucose production. *Sulphonylurea added to metformin* - While adding a sulfonylurea to metformin is an option for patients not reaching glycemic targets on metformin alone, **monotherapy with metformin** is the initial step for newly diagnosed or uncontrolled diabetes. - Sulfonylureas carry a higher risk of **hypoglycemia** compared to metformin and are generally added if metformin monotherapy is insufficient. *Bariatric surgery* - Bariatric surgery is a treatment option for **morbidly obese** individuals with type 2 diabetes, but it is typically considered after lifestyle modifications and pharmacotherapy have been attempted or when the BMI is very high (e.g., >40 or >35 with comorbidities). - It is not the immediate next step for managing newly diagnosed or uncontrolled diabetes, especially when first-line medications haven't been initiated. *Repeating the A1c test* - The elevated **A1C of 8.5%**, combined with classic symptoms of hyperglycemia (recurrent infections, polyuria from urinary symptoms), is sufficient for a diagnosis of diabetes. - Repeating the test immediately is unlikely to change the diagnosis and would delay necessary treatment initiation. *Basal-bolus insulin* - Basal-bolus insulin regimens are typically reserved for patients with very **high A1C levels** (e.g., >10%), significant symptoms of hyperglycemia, or those who have failed multiple oral hypoglycemic agents. - Given an A1C of 8.5%, initiating insulin is usually not the first pharmacologic step; metformin monotherapy is preferred.

Question 472: A 59-year-old man presents to his family practitioner with his wife. He has fallen several times over the past 3 months. Standing up from a seated position is especially difficult for him. He also complains of intermittent dizziness, excessive sweating, constipation, and difficulty performing activities of daily living. He denies fever, jerking of the limbs, memory disturbances, urinary incontinence, and abnormal limb movements. Past medical history includes a cholecystectomy 25 years ago and occasional erectile dysfunction. He takes a vitamin supplement with calcium and occasionally uses sildenafil. While supine, his blood pressure is 142/74 mm Hg and his heart rate is 64/min. After standing, his blood pressure is 118/60 mm Hg and his heart rate is 62/min. He is alert and oriented with a flat affect while answering questions. Extraocular movements are intact in all directions. No tremors are noticed. Muscle strength is normal in all limbs but with increased muscle tone. He is slow in performing intentional movements. His writing is small and he takes slow steps during walking with adducted arms and a slightly reduced arm swing. A trial of levodopa did not improve his symptoms. What is the most likely diagnosis?

A. Huntington disease
B. Shy-Drager syndrome (Correct Answer)
C. Parkinson’s disease
D. Progressive supranuclear palsy
E. Wilson disease

Explanation: ***Shy-Drager syndrome*** - The patient presents with **parkinsonism** (bradykinesia, rigidity, postural instability as evidenced by falls and difficulty standing) combined with severe **autonomic dysfunction** including orthostatic hypotension, intermittent dizziness, excessive sweating, constipation, and erectile dysfunction. - The **lack of improvement with levodopa**, the prominent **autonomic features**, and the absence of specific Parkinson's disease red flags (like resting tremor or initial unilateral symptoms) strongly point to Shy-Drager syndrome, which is now classified under **Multiple System Atrophy (MSA)** with predominant parkinsonian features (MSA-P). *Huntington disease* - This is characterized by **chorea** (involuntary jerking movements) and psychiatric disturbances, which are not described in the patient's presentation. - Typically presents with **cognitive decline** and **motor incoordination**, not the parkinsonian symptoms seen here. *Parkinson’s disease* - While this patient exhibits many features of **parkinsonism**, the prominent **autonomic dysfunction** and the **lack of response to levodopa** differentiate this case from typical Parkinson's disease. - **Resting tremor** is a hallmark of Parkinson's disease, but it is explicitly noted that no tremors were noticed in this patient. *Progressive supranuclear palsy* - Key features include **supranuclear ophthalmoplegia** (especially vertical gaze palsy), prominent early falls, and neck dystonia (retrocollis). - While early falls are present, the patient's **extraocular movements are intact in all directions**, making PSP less likely. *Wilson disease* - A rare genetic disorder characterized by **copper accumulation**, leading to hepatic, neurologic, and psychiatric symptoms. - Manifestations include **hepatic dysfunction**, **Kayser-Fleischer rings** in the cornea, and a variety of movement disorders (e.g., tremor, rigidity), but not typically the severe orthostatic hypotension or lack of levodopa response seen here.

Question 473: A 19-year-old man presents to the emergency department after 2 separate episodes of loss of consciousness. The first episode occurred 1 year ago while he was running in gym class. Witnesses reported clenching and shaking of both hands after he had fallen. On getting up quickly, he felt lightheaded, nauseated, and sweaty. He was given intravenous phenytoin because of concern that he may have had a seizure. His electroencephalogram was negative, and he was not started on long-term antiepileptics. One year later, a second episode of loss of consciousness occurred while playing dodgeball. He experienced a similar prodrome of lightheadedness and sweating. He has no history of seizures outside of these 2 episodes. Family history is non-contributory. He has a temperature of 37.0°C (98.6°F), a blood pressure of 110/72 mm Hg, and a pulse of 80/min. Physical examination is unremarkable. His 12-lead ECG shows normal sinus rhythm without any other abnormalities. Which of the following is the best next step in this patient?

A. Head-up tilt-table test
B. Dix-Hallpike maneuver
C. 24-hour Holter monitoring
D. Head computerized tomography (CT)
E. Echocardiography (Correct Answer)

Explanation: ***Echocardiography*** - This patient presents with **exertional syncope** (occurring during running and dodgeball), which is a **red flag** for cardiac causes and requires urgent evaluation for structural heart disease. - **Hypertrophic cardiomyopathy (HCM)** is the most common cause of sudden cardiac death in young athletes and classically presents with exertional syncope. - **Echocardiography** is the best initial test to evaluate for structural abnormalities including HCM, arrhythmogenic right ventricular cardiomyopathy (ARVC), valvular disease, and other cardiac causes. - While the patient has a prodrome suggestive of vasovagal syncope, **exertional triggers mandate ruling out life-threatening cardiac conditions first** before attributing symptoms to benign causes. *Head-up tilt-table test* - Tilt-table testing is the gold standard for diagnosing **vasovagal (neurocardiogenic) syncope**. - It is most appropriate for **non-exertional syncope** with typical prodrome after cardiac causes have been excluded. - In this case with **exertional syncope**, cardiac evaluation must take priority, making tilt-table testing premature at this stage. *Dix-Hallpike maneuver* - This maneuver diagnoses **benign paroxysmal positional vertigo (BPPV)**, which causes brief episodes of vertigo triggered by head position changes. - BPPV does not cause **loss of consciousness** or **tonic-clonic movements**, making this inappropriate for this presentation. *24-hour Holter monitoring* - Holter monitoring can detect cardiac arrhythmias that may cause syncope. - While potentially useful in the workup, **echocardiography should be performed first** to evaluate for structural heart disease in exertional syncope. - Holter monitoring has relatively low yield unless symptoms occur during the monitoring period; an exercise stress test or event monitor may be more appropriate if initial structural evaluation is normal. *Head computerized tomography (CT)* - Head CT evaluates for structural intracranial pathology such as hemorrhage, mass lesions, or stroke. - The patient's **normal EEG**, **clear exertional triggers**, and **typical vasovagal prodrome** make primary neurological causes unlikely. - Seizures rarely occur exclusively during exercise, and the clinical picture is more consistent with syncope (with convulsive movements due to cerebral hypoperfusion) rather than primary seizure disorder.

Question 474: A 35-year-old woman is brought to the emergency department for a severe, left-sided headache and neck pain that started 24 hours after she completed a half-marathon. Shortly after the headache started, she also had weakness of her right upper extremity and sudden loss of vision in her left eye, which both subsided on her way to the hospital. On arrival, she is alert and oriented to person, place, and time. Her temperature is 37.3°C (99.1°F), pulse is 77/min, respiratory rate is 20/min, and blood pressure is 160/90 mm Hg. Examination shows drooping of the left eyelid and a constricted left pupil. Visual acuity in both eyes is 20/20. There is no swelling of the optic discs. Muscle strength and deep tendon reflexes are normal bilaterally. A noncontrast CT scan of the head shows no abnormalities. Duplex ultrasonography of the neck shows absence of flow in the left internal carotid artery. Administration of which of the following is the most appropriate next step in management?

A. Alteplase
B. Sumatriptan
C. Mannitol
D. Heparin (Correct Answer)
E. Aspirin

Explanation: ***Heparin*** - The patient's presentation with headache, neck pain, Horner syndrome (left eyelid drooping and constricted pupil), transient right upper extremity weakness, and left eye vision loss following a half-marathon, along with imaging showing **absence of flow in the left internal carotid artery**, is highly suggestive of **carotid artery dissection**. - **Anticoagulation with heparin** is an appropriate initial management option to prevent thromboembolic complications such as stroke, especially given the acute symptoms and confirmed dissection without signs of intracranial hemorrhage on CT. - **Current guidelines** indicate that both anticoagulation (heparin/warfarin) and antiplatelet therapy (aspirin) are acceptable for carotid dissection, with **no definitive evidence showing superiority of one over the other**. Heparin may be preferred in acute settings with recent symptoms or when there are fluctuating/progressive neurological deficits. *Aspirin* - **Aspirin** is an **antiplatelet agent** that is also an acceptable treatment option for carotid artery dissection and is increasingly used as first-line therapy in many centers. - While aspirin would be appropriate, in this acute presentation with recent transient neurological deficits (within 24 hours), some clinicians prefer **initial anticoagulation with heparin** to more aggressively prevent thrombus propagation and recurrent embolic events during the hyperacute phase. - Either aspirin or heparin would be defensible choices; heparin is selected here given the very recent onset and transient focal deficits suggesting active thromboembolic risk. *Alteplase* - **Alteplase** is a **thrombolytic agent** used in acute ischemic stroke within a narrow time window (typically 3-4.5 hours from symptom onset). - It is **contraindicated in arterial dissection** due to high risk of hemorrhage and extension of the dissection. - The patient's symptoms are transient and have resolved, and there is no evidence of acute, disabling ischemic stroke that would warrant thrombolysis. *Sumatriptan* - **Sumatriptan** is a **triptan derivative** used for acute treatment of migraine headaches. - While the patient has severe headache, the associated neurological deficits (Horner syndrome, transient weakness and vision loss) and confirmed **carotid dissection on imaging** indicate a serious vascular pathology rather than primary migraine. - Sumatriptan is actually **contraindicated** in patients with cerebrovascular disease due to its vasoconstrictive effects. *Mannitol* - **Mannitol** is an **osmotic diuretic** used to reduce intracranial pressure in cases of cerebral edema or elevated intracranial pressure. - The patient's noncontrast CT scan showed no abnormalities, indicating no signs of mass effect, hemorrhage, or cerebral edema, making mannitol unnecessary.

Question 475: A 33-year-old Caucasian female presents to her primary care provider for pruritus and shortness of breath. Over the past year, she has experienced mild progressive diffuse pruritus. She also reports that her skin seems "hard" and that it has been harder to move her fingers freely. She initially attributed her symptoms to stress at work as a commercial pilot, but when her symptoms began impacting her ability to fly, she decided to seek treatment. She has a history of major depressive disorder and takes citalopram. She smokes 1 pack per day and drinks socially. Her temperature is 98.6°F (37°C), blood pressure is 148/88 mmHg, pulse is 83/min, and respirations are 21/min. On exam, she appears anxious with increased work of breathing. Dry rales are heard at her lung bases bilaterally. Her fingers appear shiny and do not have wrinkles on the skin folds. A normal S1 and S2 are heard on cardiac auscultation. This patient's condition is most strongly associated with which of the following antibodies?

A. Anti-DNA topoisomerase I (Correct Answer)
B. Anti-double-stranded DNA
C. Anti-U1-ribonucleoprotein
D. Anti-SS-A
E. Anti-cyclic citrullinated peptide

Explanation: ***Anti-DNA topoisomerase I*** - The patient's symptoms of **pruritus**, **"hard" skin**, difficulty moving fingers, and **dry rales at lung bases** are highly suggestive of **systemic sclerosis (scleroderma)**, particularly the **diffuse cutaneous systemic sclerosis** type. - **Anti-DNA topoisomerase I** (also known as **anti-Scl-70**) antibodies are strongly associated with **diffuse cutaneous systemic sclerosis** and are often linked to a higher risk of **interstitial lung disease**, correlating with the observed shortness of breath and dry rales. *Anti-double-stranded DNA* - **Anti-double-stranded DNA (anti-dsDNA)** antibodies are a hallmark of **systemic lupus erythematosus (SLE)**. - While SLE can cause skin changes and shortness of breath (e.g., pleuritis, interstitial lung disease), the specific presentation of **"hard" skin** and **lack of wrinkles in skin folds** is much more indicative of scleroderma than SLE. *Anti-U1-ribonucleoprotein* - **Anti-U1-ribonucleoprotein (anti-U1-RNP)** antibodies are primarily associated with **mixed connective tissue disease (MCTD)**. - MCTD can have overlapping features of systemic sclerosis, SLE, and polymyositis, but the predominant and severe **skin hardening** with **lung involvement** described points more directly to scleroderma. *Anti-SS-A* - **Anti-SS-A (Ro) antibodies** are primarily associated with **Sjögren's syndrome**, a chronic autoimmune disease affecting exocrine glands, leading to dry eyes and dry mouth. - They can also be present in SLE and neonatal lupus, but are **not typically associated with the extensive skin hardening and significant lung fibrosis** seen in this patient. *Anti-cyclic citrullinated peptide* - **Anti-cyclic citrullinated peptide (anti-CCP)** antibodies are highly specific for **rheumatoid arthritis (RA)**. - RA primarily causes **inflammatory arthritis** affecting synovial joints, and while it can have extra-articular manifestations, the patient's symptoms of diffuse skin hardening, pruritus, and specific lung findings do not fit the typical presentation of RA.

Question 476: A 22-year-old woman comes to the physician because of 1 week of progressive left anterior knee pain. The pain is worse after sitting for a prolonged period of time and while ascending stairs. She first noticed the pain the day after a basketball game. She has often taken painful blows to the side of the knees while playing basketball but does not recall this having happened in the last game. Four weeks ago, she was diagnosed with a chlamydial urinary tract infection and treated with azithromycin. She is sexually active with one male partner; they use condoms inconsistently. Her vital signs are within normal limits. She is 178 cm (5 ft 10 in) tall and weighs 62 kg (137 lb); BMI is 19.6 kg/m2. Physical examination shows tenderness over the left anterior knee that is exacerbated with anterior pressure to the patella when the knee is fully extended; there is no erythema or swelling. Which of the following is the most likely diagnosis?

A. Osgood-Schlatter disease
B. Patellofemoral pain syndrome (Correct Answer)
C. Patellar tendinitis
D. Medial collateral ligament injury
E. Anterior cruciate ligament injury

Explanation: **_Patellofemoral pain syndrome_** - The patient's symptoms of **anterior knee pain worse with prolonged sitting and ascending stairs**, along with **tenderness over the anterior knee exacerbated by patellar pressure**, are classic for **patellofemoral pain syndrome (PFPS)**. - PFPS is often triggered by changes in activity level, such as increased basketball playing, and is common in young, active individuals. *Osgood-Schlatter disease* - This condition typically presents with localized pain and swelling at the **tibial tubercle**, which is the insertion site of the patellar tendon. - It is more common in **adolescent males** undergoing growth spurts and is caused by repetitive stress on the immature apophysis, which does not fit this patient's age or presentation. *Patellar tendinitis* - **Patellar tendinitis** (jumper's knee) causes pain directly over the **patellar tendon**, usually just below the patella, especially with jumping and running. - While it can be related to athletic activity, the characteristic feature is **pain on palpation of the patellar tendon itself**, rather than just the anterior knee or patellar compression. *Medial collateral ligament injury* - An injury to the **medial collateral ligament (MCL)** typically presents with pain and tenderness along the **medial side of the knee**. - It is usually caused by a direct valgus stress to the knee, and physical examination would reveal **pain with valgus stress testing**, which is not described. *Anterior cruciate ligament injury* - An **anterior cruciate ligament (ACL) injury** usually results from a mechanism involving **sudden twisting or hyperextension** of the knee and is often associated with a **'popping' sensation** and significant knee instability. - The primary complaint is instability, and physical examination would show a **positive Lachman or anterior drawer test**, which is not consistent with the patient's symptoms.

Question 477: A 30-year-old woman comes to the physician because of increased urinary frequency over the past month. She also reports having dry mouth and feeling thirsty all the time despite drinking several liters of water per day. She has not had any weight changes and her appetite is normal. She has a history of obsessive compulsive disorder treated with citalopram. She drinks 1–2 cans of beer per day. Her vital signs are within normal limits. Physical examination shows no abnormalities. Laboratory studies show: Serum Na+ 130 mEq/L Glucose 110 mg/dL Osmolality 265 mOsmol/kg Urine Osmolality 230 mOsmol/kg The patient is asked to stop drinking water for 3 hours. Following water restriction, urine osmolality is measured every hour, whereas serum osmolality is measured every 2 hours. Repeated laboratory measurements show a serum osmolality of 280 mOsmol/kg and a urine osmolality of 650 mOsmol/kg. Which of the following is the most likely diagnosis?

A. Diabetes mellitus
B. Central diabetes insipidus
C. Primary polydipsia (Correct Answer)
D. Cerebral salt wasting
E. Nephrogenic diabetes insipidus

Explanation: ***Primary polydipsia*** - The patient's initial **hyponatremia** (Na+ 130 mEq/L) and low serum osmolality (265 mOsmol/kg) with **inappropriately dilute urine** (urine osmolality 230 mOsmol/kg) in the context of excessive water intake (several liters per day) is characteristic of primary polydipsia. - The ability to concentrate urine significantly after water restriction (urine osmolality increasing to 650 mOsmol/kg) indicates that the **kidneys can respond to ADH** and that ADH secretion is intact, ruling out diabetes insipidus. *Diabetes mellitus* - This condition is characterized by **elevated blood glucose levels**, which are absent in this patient (glucose 110 mg/dL is normal). - While diabetes mellitus causes polyuria and polydipsia, the specific laboratory findings (normal glucose and ability to concentrate urine after water restriction) are inconsistent with this diagnosis. *Central diabetes insipidus* - Patients with central DI would have **initially dilute urine** and would **not be able to concentrate urine** significantly in response to water restriction alone. - The patient's urine osmolality significantly increased (from 230 to 650 mOsmol/kg) after water restriction, indicating intact ADH secretion and kidney responsiveness. *Cerebral salt wasting* - This condition typically presents with **hyponatremia** and **dehydration**, often following brain injury or neurosurgery. - Patients usually have elevated urinary sodium excretion and clinical signs of volume depletion (hypotension, tachycardia), which are not present in this case. *Nephrogenic diabetes insipidus* - In nephrogenic DI, the **kidneys do not respond to ADH**, meaning urine osmolality would remain dilute even after water restriction and exogenous ADH administration. - The patient's ability to achieve concentrated urine (650 mOsmol/kg) after water restriction rules out this diagnosis.

Question 478: A 41-year-old woman comes to the physician because of a 3-month history of anxiety, difficulty falling asleep, heat intolerance, and a 6-kg (13.2-lb) weight loss. The patient's nephew, who is studying medicine, mentioned that her symptoms might be caused by a condition that is due to somatic activating mutations of the genes for the TSH receptor. Examination shows warm, moist skin and a 2-cm, nontender, subcutaneous mass on the anterior neck. Which of the following additional findings should most raise concern for a different underlying etiology of her symptoms?

A. Atrial fibrillation
B. Hyperreflexia
C. Nonpitting edema (Correct Answer)
D. Fine tremor
E. Lid lag

Explanation: ***Nonpitting edema*** - Nonpitting edema, often referred to as **myxedema**, is a classic sign of **hypothyroidism**, not hyperthyroidism. - The patient's symptoms (anxiety, insomnia, heat intolerance, weight loss) are indicative of **hyperthyroidism**, making myxedema an inconsistent finding that suggests a different underlying etiology. *Atrial fibrillation* - **Atrial fibrillation** is a common cardiovascular manifestation of **hyperthyroidism** due to the direct effects of thyroid hormones on the heart. - Its presence would support, rather than contradict, the suspected diagnosis of hyperthyroidism. *Hyperreflexia* - **Hyperreflexia** is a neurological finding often associated with the hypermetabolic state of **hyperthyroidism**. - Increased thyroid hormone levels can enhance neural excitability, making hyperreflexia an expected finding. *Fine tremor* - A **fine tremor** is a common and characteristic symptom of **hyperthyroidism**, resulting from increased adrenergic activity. - This finding would be consistent with the patient's other symptoms of thyroid overactivity. *Lid lag* - **Lid lag** is an ocular sign of **hyperthyroidism**, caused by sympathetic overstimulation of the Müller's muscle in the eyelid. - While not indicative of Graves' ophthalmopathy, it is a common finding in thyrotoxicosis and would be consistent with the patient's clinical picture.

Question 479: A 65-year-old man comes to the physician because of double vision that began this morning. He has hypertension and type 2 diabetes mellitus. He has smoked two packs of cigarettes daily for 40 years. His current medications include lisinopril, metformin, and insulin. Physical examination shows the right eye is abducted and depressed with slight intorsion. Visual acuity is 20/20 in both eyes. Extraocular movements of the left eye are normal. Serum studies show a hemoglobin A1c of 11.5%. Which of the following additional findings is most likely in this patient?

A. Absent direct light reaction on the right eye
B. Upper eyelid droop on the right eye (Correct Answer)
C. Absent consensual light reaction on the right eye
D. Loss of the right nasolabial fold
E. Loss of smell

Explanation: ***Upper eyelid droop on the right eye*** - The patient's presentation of a right eye that is **abducted and depressed** with risk factors of **poorly controlled diabetes** (HbA1c 11.5%) and **hypertension** strongly suggests an **ischemic oculomotor nerve (CN III) palsy**. - In **ischemic CN III palsy** (microvascular, as seen in diabetes), the **motor fibers** are affected, causing **ptosis (upper eyelid droop)** and abnormal eye position (down and out). - Crucially, the **parasympathetic fibers** (which control pupil constriction and run on the periphery of CN III) are typically **spared** in ischemic palsy because they have different blood supply and are located peripherally, making them more vulnerable to compressive lesions but resistant to ischemic injury. - Therefore, **ptosis is expected** while pupils remain reactive to light. *Absent direct light reaction on the right eye* - An absent direct light reaction would indicate **pupillary involvement** from parasympathetic fiber dysfunction. - This finding is characteristic of **compressive CN III palsy** (e.g., posterior communicating artery aneurysm), where external compression affects the peripheral parasympathetic fibers first. - In this patient with **ischemic CN III palsy** due to diabetes, the pupil is typically **spared** (remains reactive), making this finding unlikely. *Absent consensual light reaction on the right eye* - This would also indicate **parasympathetic fiber involvement** and pupillary dysfunction. - As with the direct light reaction, pupils are typically **spared in ischemic CN III palsy**, so this finding is unlikely in this diabetic patient. - The "pupil-sparing" nature of diabetic CN III palsy is a key distinguishing feature from compressive causes. *Loss of the right nasolabial fold* - Loss of the nasolabial fold indicates **facial nerve (CN VII) palsy**, causing weakness of facial expression muscles. - This is unrelated to the **oculomotor nerve dysfunction** described and would not explain the eye movement abnormalities. *Loss of smell* - Loss of smell (**anosmia**) indicates **olfactory nerve (CN I) dysfunction**. - This is completely unrelated to the ocular motor findings and is not associated with CN III palsy.

Question 480: Immediately after undergoing a right total knee replacement, a 69-year-old woman has severe abdominal pain, non-bloody emesis, and confusion. She has a history of Hashimoto thyroiditis that is well-controlled with levothyroxine and hyperlipidemia that is controlled by diet. She underwent bunion removal surgery from her right foot 10 years ago. Her temperature is 39°C (102.2°F), pulse is 120/min, and blood pressure is 60/30 mm Hg. Abdominal examination shows a diffusely tender abdomen with normal bowel sounds. She is confused and oriented to person but not place or time. Laboratory studies are pending. Which of the following is the most appropriate next step in the management of this patient?

A. High-dose hydrocortisone
B. Exploratory laparotomy
C. CT angiogram of the abdomen
D. Noncontrast CT of the head
E. Intravenous isotonic saline infusion (Correct Answer)

Explanation: ***Intravenous isotonic saline infusion*** - The patient presents with **shock** (BP 60/30 mm Hg, pulse 120/min, confusion), which is immediately life-threatening and requires urgent intervention. - **IV fluid resuscitation** is the **first priority** in any shock state to restore intravascular volume, improve tissue perfusion, and stabilize hemodynamics. - While this patient has features concerning for **acute adrenal crisis** (Hashimoto thyroiditis with possible polyglandular autoimmune syndrome, post-surgical stress, fever, hypotension, confusion), **fluid resuscitation must be initiated immediately** before or concurrent with other therapies. - In practice, **high-dose hydrocortisone should be given simultaneously** with fluids, but restoring circulating volume is the foundational first step. *High-dose hydrocortisone* - This patient has **Hashimoto thyroiditis** and presents with shock after major surgery (a known precipitant), raising strong suspicion for **acute adrenal crisis**. - Patients with autoimmune thyroid disease can have concurrent **autoimmune adrenal insufficiency** (Schmidt syndrome/APS-2). - **Hydrocortisone is critical** and should be given immediately (typically 100 mg IV), but **not before addressing the shock state** with fluid resuscitation. - This would be the appropriate **second step** or given concurrently with fluids. *Exploratory laparotomy* - While the patient has **severe abdominal pain** and **diffuse tenderness**, the overall presentation (fever, hypotension, post-op state) suggests **medical shock** rather than a surgical emergency. - **Normal bowel sounds** make mechanical obstruction or perforation less likely. - Surgery is inappropriate until the patient is hemodynamically stabilized and a surgical cause is confirmed. *CT angiogram of the abdomen* - This could evaluate for **mesenteric ischemia**, but the patient is **too unstable** for imaging. - The clinical picture better fits **adrenal crisis** or **septic shock** rather than vascular catastrophe. - **Delaying resuscitation** for imaging in a patient with severe hypotension would be harmful. *Noncontrast CT of the head* - The patient's **confusion** is most likely due to **hypoperfusion** and **shock** rather than a primary intracranial process. - **Altered mental status** is a common manifestation of shock and adrenal crisis. - Cerebral perfusion depends on adequate systemic blood pressure, making **circulatory stabilization the priority**.

Question 481: A 62-year-old man comes to the physician because of painless swelling in his left foot for 4 months. The swelling was initially accompanied by redness, which has since resolved. He has not had fever or chills. He has a history of coronary artery disease, hyperlipidemia, and type 2 diabetes mellitus. He has had 3 sexual partners over the past year and uses condoms inconsistently. His mother had rheumatoid arthritis. Current medications include clopidogrel, aspirin, metoprolol, losartan, atorvastatin, and insulin. He is 180 cm (5 ft 11 in) tall and weighs 95 kg (209 lb); BMI is 29 kg/m2. Vital signs are within normal limits. Cardiovascular examination shows no abnormalities. Examination of the feet shows swelling of the left ankle with collapse of the midfoot arch and prominent malleoli. There is no redness or warmth. There is a small, dry ulcer on the left plantar surface of the 2nd metatarsal. Monofilament testing shows decreased sensation along both feet up to the shins bilaterally. His gait is normal. Which of the following is the most likely diagnosis?

A. Diabetic arthropathy (Correct Answer)
B. Rheumatoid arthritis
C. Tertiary syphilis
D. Calcium pyrophosphate arthropathy
E. Reactive arthritis

Explanation: ***Diabetic arthropathy*** - This patient's long-standing **diabetes mellitus** and presence of **peripheral neuropathy** (decreased sensation on monofilament testing) strongly predispose him to **Charcot arthropathy**, a form of diabetic arthropathy. - The classic presentation includes painless swelling, **collapse of the midfoot arch** (rocker-bottom foot), prominent malleoli, and sometimes a **plantar ulcer**, all of which are present in this patient. *Rheumatoid arthritis* - Rheumatoid arthritis typically presents with **bilateral, symmetrical polyarthritis**, usually affecting smaller joints of the hands and feet, and often has morning stiffness. This patient has unilateral foot swelling. - While his mother had RA, his presentation with painless swelling, neuropathy, and specific foot deformities points away from typical RA. *Tertiary syphilis* - Tertiary syphilis can cause **Charcot joints (neuroarthropathy)**, similar to diabetes, but the patient's presentation is more consistent with diabetic complications given his medical history. - Although the patient has a history of inconsistent condom use, there are no other symptoms suggestive of syphilis such as **tabes dorsalis** or **gummas**. *Calcium pyrophosphate arthropathy* - This condition (pseudogout) is caused by the deposition of **calcium pyrophosphate crystals** in joints and typically presents with acute, painful inflammation. - The patient's swelling has been painless and chronic, and imaging would be needed to confirm crystal deposition, which is not suggested by the clinical picture. *Reactive arthritis* - Reactive arthritis typically presents as an **acute inflammatory oligoarthritis** often following a genitourinary or gastrointestinal infection, and is usually painful. - While the patient has a history of inconsistent condom use, there are no symptoms of a preceding infection (e.g., urethritis, conjunctivitis, diarrhea) and the chronic, painless nature of the swelling is inconsistent with reactive arthritis.

Question 482: A 9-year-old girl is brought to the physician by her mother because of a 3-day history of face and foot swelling, dark urine, and a rash on her hands and feet. The mother reports that her daughter has had a low-grade fever, shortness of breath, and a dry cough for the past 8 days. She has had generalized weakness and pain in her right knee and ankle. She has a ventricular septum defect that was diagnosed at birth. The patient appears lethargic. Her temperature is 38.4 (101.1°F), pulse is 130/min, respirations are 34/min, and blood pressure is 110/60 mm Hg. Examination shows small, non-blanching, purple lesions on her palms, soles, and under her fingernails. There is edema of the eyelids and feet. Funduscopic examination shows retinal hemorrhages. Holosystolic and early diastolic murmurs are heard. Laboratory studies show: Hemoglobin 11.3 g/dL Erythrocyte sedimentation rate 61 mm/h Leukocyte count 15,000/mm3 Platelet count 326,000/mm3 Urine Blood 4+ Glucose negative Protein 1+ Ketones negative Transthoracic echocardiography shows a small outlet ventricular septum defect and a mild right ventricular enlargement. There are no wall motion abnormalities, valvular heart disease, or deficits in the pump function of the heart. Blood cultures grow Streptococcus pyogenes. Which of the following is the most likely diagnosis?

A. Myocarditis
B. Acute lymphoblastic leukemia
C. Hand-Foot-and-Mouth Disease
D. Kawasaki disease
E. Infective endocarditis (Correct Answer)

Explanation: ***Infective endocarditis*** - The patient presents with **fever, new murmurs (holosystolic and early diastolic), Roth spots (retinal hemorrhages), Janeway lesions (non-blanching purple lesions on palms and soles), Osler's nodes (on fingertips/under fingernails), and splenomegaly (implied by elevated WBC and history of infection),** which are classic signs of infective endocarditis. The presence of a **ventricular septal defect (VSD)** is a predisposing cardiac lesion. - **Positive blood cultures for *Streptococcus pyogenes*** confirms the infection, and the **dark urine with blood and protein** suggests **glomerulonephritis**, a common complication of endocarditis. *Myocarditis* - While myocarditis can cause **fever, shortness of breath, and cardiac dysfunction**, it typically does not present with the characteristic peripheral stigmata of endocarditis such as **Janeway lesions, Osler's nodes, or Roth spots**. - The echocardiogram explicitly states **"no wall motion abnormalities, valvular heart disease, or deficits in the pump function"**, which would be expected in severe myocarditis. *Acute lymphoblastic leukemia* - Leukemia could explain **fatigue, fever, elevated WBC, and petechial rash**, but it would not typically cause **new cardiac murmurs, retinal hemorrhages (Roth spots), or positive blood cultures for *Streptococcus pyogenes***. - The specific signs of endocarditis, and the absence of profound anemia or thrombocytopenia, make leukemia less likely. *Hand-Foot-and-Mouth Disease* - This viral illness is characterized by **fever and vesicular rash on the hands, feet, and oral cavity**, primarily affecting young children. - It does not cause **cardiac murmurs, Roth spots, Osler's nodes, or Janeway lesions**, and would not typically lead to a *Streptococcus pyogenes* bacteremia. *Kawasaki disease* - Kawasaki disease presents with **fever, rash, conjunctivitis, oral mucosal changes, lymphadenopathy, and extremity changes (edema, peeling)**. - It **does not typically feature new cardiac murmurs, Janeway lesions, Osler's nodes, Roth spots, or positive bacterial blood cultures**, and primarily affects younger children.

Question 483: A 65-year-old woman comes to the physician because of increased difficulty hearing. She has also had dull and progressive pain in her hip and lower back for the past 2 months that is worse with exertion. Examination of the ears shows impaired hearing on the left with whispered voice test and lateralization to the right with Weber testing. There is localized tenderness over the right hip and groin area with decreased range of motion of the hip. The remainder of the examination shows no abnormalities. Serum studies show: Total protein 6.5 g/dL Alkaline phosphatase 950 U/L Calcium 9 mg/dL Phosphorus 4 mg/dL Which of the following is the most likely underlying mechanism of this patient's symptoms?

A. Defective bone matrix mineralization
B. Increased rate of bone remodeling (Correct Answer)
C. Metastatic destruction of the bone
D. Decreased bone mass with microarchitectural disruption
E. Proliferation of plasma cells in the bone marrow

Explanation: ***Increased rate of bone remodeling*** - The patient's symptoms (hip and back pain, conductive hearing loss, elevated **alkaline phosphatase** with normal calcium and phosphorus) are classic for **Paget's disease of bone**. - The Weber test lateralizing to the right (away from the affected left ear) confirms **conductive hearing loss** on the left, which occurs in Paget's disease due to involvement of the temporal bone and ossicular chain. - Paget's disease is characterized by anarchic, excessive **osteoclastic bone resorption** followed by compensatory, disorganized **osteoblastic bone formation**, leading to overall woven bone formation and an increased rate of bone turnover. *Defective bone matrix mineralization* - This mechanism is characteristic of **osteomalacia** or **rickets**, where there is inadequate mineralization of osteoid. - While it can cause bone pain and weakness, the hearing loss and markedly elevated alkaline phosphatase without corresponding severe hypocalcemia or hypophosphatemia make this less likely. *Metastatic destruction of the bone* - **Bone metastases** can cause localized pain and elevated alkaline phosphatase due to osteoblastic response (blastic lesions) or lytic lesions, but typically present with normal calcium and phosphorus only when the disease burden is high. - Hearing loss is not a common feature of bone metastases unless the skull base is specifically affected, and even then, the overall clinical picture with diffuse bone pain is more suggestive of a systemic bone disorder rather than localized metastasis. *Decreased bone mass with microarchitectural disruption* - This describes **osteoporosis**, which leads to increased fracture risk but typically does not cause the severe bone pain seen in this patient, significantly elevated alkaline phosphatase or hearing loss. - Bone mass reduction in osteoporosis is primarily due to a gradual imbalance between normal bone resorption and bone formation, not an anarchic increase in remodeling seen in Paget's. *Proliferation of plasma cells in the bone marrow* - This phenomenon is indicative of **multiple myeloma**, which causes bone pain, lytic lesions, **hypercalcemia**, and can lead to kidney failure due to light chain deposition. - While bone pain is present, the normal calcium, elevated alkaline phosphatase without significant hypercalcemia, and prominent hearing loss are inconsistent with a primary diagnosis of multiple myeloma.

Question 484: A 57-year-old man presents to his primary care provider because of chest pain for the past 3 weeks. The chest pain occurs after climbing more than 2 flight of stairs or walking for more than 10 minutes and resolves with rest. He is obese, has a history of type 2 diabetes mellitus, and has smoked 15-20 cigarettes a day for the past 25 years. His father died from a myocardial infarction at 52 years of age. Vital signs reveal a temperature of 36.7 °C (98.06°F), a blood pressure of 145/93 mm Hg, and a heart rate of 85/min. The physical examination is unremarkable. Which of the following best represents the most likely etiology of the patient’s condition?

A. Hypertrophy of the interventricular septum
B. Multivessel atherosclerotic disease with or without a nonocclusive thrombus
C. Intermittent coronary vasospasm with or without coronary atherosclerosis
D. Fixed, atherosclerotic coronary stenosis (> 70%) (Correct Answer)
E. Sudden disruption of an atheromatous plaque, with a resulting occlusive thrombus

Explanation: ***Fixed, atherosclerotic coronary stenosis (> 70%)*** - The patient's presentation with **exertional chest pain** that resolves with rest (stable angina), along with multiple **cardiovascular risk factors** (obesity, type 2 diabetes mellitus, smoking, family history of early MI, hypertension), strongly points towards **stable ischemic heart disease**. - This clinical picture is typically caused by a **fixed, hemodynamically significant stenosis** in one or more coronary arteries, usually greater than 70%, that limits blood flow during increased demand. *Multivessel atherosclerotic disease with or without a nonocclusive thrombus* - While the patient likely has **multivessel atherosclerosis**, the phrase "with or without a nonocclusive thrombus" leans towards **unstable angina** or NSTEMI, which typically involves a sudden change in symptoms or rest angina. - The patient's symptoms are **stable and reproducible** with exertion, resolving with rest, which is characteristic of stable angina rather than a thrombotic event. *Sudden disruption of an atheromatous plaque, with a resulting occlusive thrombus* - This mechanism describes an **acute coronary syndrome (ACS)**, such as an **ST-elevation myocardial infarction (STEMI)** or **non-ST-elevation myocardial infarction (NSTEMI)**. - ACS typically presents with new-onset, worsening, or rest angina, which is different from the stable, exertional pattern described in the patient. *Intermittent coronary vasospasm with or without coronary atherosclerosis* - **Coronary vasospasm** (e.g., Prinzmetal angina) typically causes chest pain that occurs **at rest**, often at night or in the early morning, and is not necessarily related to exertion. - While the patient could have underlying atherosclerosis, the **predictable exertional nature** of his symptoms makes vasospasm less likely as the primary etiology. *Hypertrophy of the interventricular septum* - **Interventricular septal hypertrophy** is characteristic of **hypertrophic cardiomyopathy (HCM)**, which can cause exertional chest pain due to outflow tract obstruction or myocardial ischemia. - However, HCM is less likely to be the primary etiology in a 57-year-old with multiple classic **atherosclerotic risk factors** and no mention of a heart murmur or family history of HCM.

Question 485: A 48-year-old man comes to the emergency department because of sudden right flank pain that began 3 hours ago. He also noticed blood in his urine. Over the past two weeks, he has developed progressive lower extremity swelling and a 4-kg (9-lb) weight gain. Examination shows bilateral 2+ pitting edema of the lower extremities. Urinalysis with dipstick shows 4+ protein, positive glucose, and multiple red cell and fatty casts. Abdominal CT shows a large right kidney with abundant collateral vessels and a filling defect in the right renal vein. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Factor V Leiden
B. Malignant erythropoietin production
C. Antiphospholipid antibodies
D. Increased lipoprotein synthesis
E. Loss of antithrombin III (Correct Answer)

Explanation: ***Loss of antithrombin III*** - The patient presents with **nephrotic syndrome** (lower extremity edema, weight gain, 4+ proteinuria, fatty casts), which causes massive urinary loss of proteins, including **antithrombin III**, a critical inhibitor of coagulation. - Loss of **antithrombin III** creates a **hypercoagulable state**, predisposing to **renal vein thrombosis** (RVT), which explains the acute flank pain, hematuria, enlarged kidney, and filling defect on CT. - This is the underlying mechanism linking the nephrotic syndrome to the thrombotic complication. *Factor V Leiden* - This is a **genetic mutation** causing Factor V resistance to activated protein C, leading to hypercoagulability. - While it can cause venous thrombosis, it does **not cause nephrotic syndrome** with massive proteinuria and fatty casts as seen in this patient. - This would be a predisposing factor, not the underlying cause of the nephrotic syndrome itself. *Antiphospholipid antibodies* - These antibodies cause a **hypercoagulable state** and can lead to both arterial and venous thromboses, including RVT. - However, they do **not directly cause nephrotic syndrome** with the massive proteinuria and fatty casts seen here. - Like Factor V Leiden, this would predispose to thrombosis but doesn't explain the primary renal pathology. *Increased lipoprotein synthesis* - This is a **consequence** of nephrotic syndrome, where hepatic compensation for albumin loss leads to increased synthesis of all proteins, including lipoproteins, causing hyperlipidemia. - It is a **secondary effect**, not the mechanism causing the hypercoagulable state and renal vein thrombosis. *Malignant erythropoietin production* - This would cause **polycythemia** (increased RBC count) and potentially thrombotic events due to hyperviscosity. - It does **not explain** the profound nephrotic syndrome with massive proteinuria, edema, and fatty casts. - There is no evidence of polycythemia in this clinical presentation.

Question 486: A 67-year-old male with a history of poorly controlled hypertension, COPD, and diabetes presents to his cardiologist for a routine appointment. He reports that he has no current complaints and has not noticed any significant changes in his health. On exam, the cardiologist hears an extra heart sound in late diastole that immediately precedes S1. This heart sound is most associated with which of the following?

A. Left ventricular hypertrophy (Correct Answer)
B. Increased filling pressures
C. Mitral regurgitation
D. Mitral stenosis
E. Ventricular dilation

Explanation: ***Left ventricular hypertrophy*** - An **S4 heart sound** in late diastole, immediately preceding S1, is typically heard with a **stiff, non-compliant left ventricle**, which is characteristic of **left ventricular hypertrophy**. - The patient's history of **poorly controlled hypertension and diabetes** are significant risk factors for developing left ventricular hypertrophy. *Increased filling pressures* - While increased filling pressures can occur in heart failure, an **S4** specifically indicates **diastolic dysfunction due to a hypertrophied ventricle**, not merely high filling pressures. - An **S3 heart sound** is more commonly associated with increased filling pressures and **ventricular dilation in systolic dysfunction**. *Mitral regurgitation* - **Mitral regurgitation** is typically characterized by a **holosystolic murmur**, which is a different auscultatory finding. - While chronic mitral regurgitation can lead to ventricular hypertrophy, the **S4 sound** itself reflects the underlying **stiffness of the ventricle**, not directly the valvular insufficiency. *Mitral stenosis* - **Mitral stenosis** is characterized by an **opening snap** followed by a **mid-diastolic rumble**, which is distinct from an S4 heart sound. - It involves a narrowed mitral valve orifice, causing impedance to blood flow from the left atrium to the left ventricle. *Ventricular dilation* - **Ventricular dilation** is typically associated with an **S3 heart sound**, which occurs in early diastole during rapid ventricular filling. - An **S4** signifies a **non-compliant, stiff ventricle** (often hypertrophied), rather than a dilated one.

Question 487: A 54-year-old man is brought to the emergency department 1 hour after an episode of loss of consciousness that lasted 3 minutes. Since awakening, he has had weakness of the left arm and leg, and his speech has been slurred. He has had a fever for 10 days. He has not had vomiting or headache. He was treated for bacterial sinusitis 3 weeks ago with amoxicillin-clavulanate. He has hypertension, hypothyroidism, hyperlipidemia, and type 2 diabetes mellitus. Current medications include amlodipine, hydrochlorothiazide, metformin, simvastatin, aspirin, and levothyroxine. His temperature is 38.6°C (101.4°F), pulse is 106/min, and blood pressure is 160/90 mm Hg. He is alert and oriented to person, place, and time. Examination shows multiple petechiae on his trunk and painless macules over both palms. A new grade 3/6 systolic murmur is heard best at the apex. He follows commands, but he slurs his words and has difficulty naming common objects. There is left facial droop. Muscle strength is 4/5 in the left upper and lower extremities. Deep tendon reflexes are 3+ on the left side and 2+ on the right side. The left big toe shows an extensor response. Fundoscopic examination shows retinal hemorrhages with white centers. Laboratory studies show: Hemoglobin 15.3 g/dL Leukocyte count 12,300/mm3 Serum Na+ 136 mEq/L Cl- 103 mEq/L K+ 4.3 mEq/L Glucose 108 mg/dL Creatinine 1.1 mg/dL Urine Protein 1+ Glucose negative Blood 1+ WBC 1–2/hpf RBC 7–10/hpf Which of the following is the most likely cause of these findings?

A. Temporal encephalitis
B. Contiguous spread of infection
C. Todd's paralysis
D. Ruptured saccular aneurysm
E. Septic emboli (Correct Answer)

Explanation: ***Septic emboli*** * The constellation of symptoms including **fever**, a **new cardiac murmur**, **petechiae**, **Janeway lesions** (painless macules on palms), **Roth spots** (retinal hemorrhages with white centers), and neurologic deficits (left-sided weakness, slurred speech, aphasia) strongly points towards **infective endocarditis** with subsequent **septic embolization**. * The neurologic deficits are consistent with an **embolic stroke** originating from vegetations on an infected heart valve, showering emboli to the brain. *Temporal encephalitis* * While **fever** and **neurologic deficits** can be seen, **temporal encephalitis** typically presents with **seizures**, **altered mental status**, and *specific abnormalities on MRI*, which are not the primary or most distinguishing features here. * The presence of **peripheral embolic phenomena** like petechiae, Janeway lesions, and Roth spots is not characteristic of primary encephalitis. *Contiguous spread of infection* * Although the patient had **bacterial sinusitis** 3 weeks prior, and intracranial complications can arise from contiguous spread, this mechanism would typically lead to conditions like **brain abscess** or **meningitis**, which usually present with different clinical findings such as headache, focal neurological signs progressing over time, or distinct CSF changes. * The sudden onset of neurological deficits following a transient loss of consciousness, combined with widespread embolic signs, makes a **septic embolic event** much more likely than direct extension from sinusitis. *Todd's paralysis* * **Todd's paralysis** refers to a **post-ictal focal weakness** following a **seizure**. While the patient had a 3-minute loss of consciousness, which could represent a seizure, the **systemic signs of infection** and **embolism** (fever, new murmur, petechiae, Janeway lesions, Roth spots) are not explained by Todd's paralysis alone. * Furthermore, the continued presence of neurological deficits along with the other findings suggests an underlying process other than a transient post-ictal state. *Ruptured saccular aneurysm* * A **ruptured saccular aneurysm** typically causes a **sudden, severe headache** (thunderclap headache), **nuchal rigidity**, and often **rapidly declining consciousness** due to **subarachnoid hemorrhage**. * Although focal neurological deficits can occur, the absence of severe headache, nuchal rigidity, and the presence of widespread signs of **infective endocarditis** make an aneurysm rupture an unlikely primary diagnosis.

Question 488: A 34-year-old woman, who had her first child 2 weeks ago, visits her family physician with concerns about constant fatigue and difficulty with breastfeeding. She was discharged from the intensive care unit after hospitalization for severe postpartum hemorrhage. Since then, she has tried multiple pumps and self-stimulation to encourage breast milk production; however, neither of these strategies has worked. Her blood pressure is 88/56 mm Hg and heart rate is 120/min. Which of the following best explains the underlying condition of this patient?

A. Pituitary infarction (Correct Answer)
B. Pituitary infection
C. Pituitary hemorrhage
D. Pituitary infiltration by histiocytes
E. Pituitary stalk epithelial tumor

Explanation: ***Pituitary infarction*** - The patient's history of **severe postpartum hemorrhage** causing hypovolemic shock, followed by **fatigue**, **difficulty breastfeeding**, **hypotension**, and **tachycardia**, are classic signs of **Sheehan syndrome**, which is caused by ischemic necrosis (infarction) of the pituitary gland. - The **lactotroph cells** in the anterior pituitary enlarge significantly during pregnancy, making them more vulnerable to ischemia when blood supply is compromised during hemorrhage. *Pituitary infection* - **Pituitary infections** (e.g., abscess) are rare and typically present with symptoms of inflammation such as fever, severe headaches, and meningeal signs, which are not described here. - While an infection could potentially affect pituitary function, it is not the classic presentation following postpartum hemorrhage. *Pituitary hemorrhage* - While postpartum hemorrhage is the cause of the pituitary injury, the **pituitary itself is not hemorrhaging** in Sheehan's syndrome; rather, it is undergoing infarction due to global hypoperfusion. - **Pituitary apoplexy** (hemorrhage into the pituitary) is an acute event with sudden onset of severe headache, visual disturbances, and rapid endocrine dysfunction, typically not related to postpartum hemorrhage directly in this manner. *Pituitary infiltration by histiocytes* - **Histiocytic infiltration** can occur in conditions like Langerhans cell histiocytosis or sarcoidosis, affecting pituitary function. - However, these conditions have distinct clinical features and are not directly linked to a recent history of postpartum hemorrhage as the precipitating event. *Pituitary stalk epithelial tumor* - A **pituitary stalk epithelial tumor** would typically cause symptoms due to mass effect or hormonal imbalances, which might include galactorrhea (if prolactin-secreting) or hypopituitarism over time. - This scenario does not fit the acute onset of symptoms following postpartum hemorrhage, which points to an ischemic event.

Question 489: A 58-year-old woman is brought to the emergency department because of a 2-day history of increasing chest pain and shortness of breath. She has had a productive cough with foul-smelling sputum for 1 week. Seven months ago, the patient had an ischemic stroke. She has gastritis and untreated hypertension. She currently lives in an assisted-living community. She has smoked one pack of cigarettes daily for 40 years. She has a 20-year history of alcohol abuse, but has not consumed any alcohol in the past 4 years. Her only medication is omeprazole. She appears to be in respiratory distress and speaks incoherently. Her temperature is 39.3°C (102.7°F), pulse is 123/min, respirations are 33/min, and blood pressure is 155/94 mm Hg. Auscultation of the lung shows rales and decreased breath sounds over the right upper lung field. Examination shows weakness and decreased sensation of the right upper and lower extremities. Babinski sign and facial drooping are present on the right. Arterial blood gas analysis on room air shows: pH 7.48 PCO2 31 mm Hg PO2 58 mm Hg O2 saturation 74% A chest x-ray shows infiltrates in the right posterior upper lobe. Which of the following is the strongest predisposing factor for this patient's respiratory symptoms?

A. Gastritis
B. Living in an assisted-living community
C. History of smoking
D. Past history of alcohol abuse
E. A history of ischemic stroke (Correct Answer)

Explanation: ***A history of ischemic stroke*** - The patient's prior **ischemic stroke** with residual neurological deficits (weakness, decreased sensation, facial drooping, Babinski sign) likely impairs her **swallowing reflexes** and **gag reflex**, greatly increasing the risk of **aspiration pneumonia**. - **Aspiration** of foul-smelling sputum, infiltrates in the **right posterior upper lobe** (a common location for aspiration), and her respiratory distress combined with neurological deficits strongly point to aspiration pneumonia, for which stroke is a major risk factor. *Gastritis* - While gastritis affects the gastrointestinal tract, there is no direct evidence suggesting it is a predisposing factor for this patient's **respiratory symptoms** or acute pneumonia. - No clear pathophysiological link between gastritis and increased risk of pneumonia. *Living in an assisted-living community* - Living in an **assisted-living community** can increase exposure to certain pathogens but does not directly predispose an individual to **aspiration pneumonia** in the same way neurological deficits do. - While institutionalization can be a risk for healthcare-associated infections, the specifics of this patient's presentation (foul-smelling sputum, specific lobe involvement) point more strongly to aspiration. *History of smoking* - A **long history of smoking** increases the risk for many respiratory conditions like COPD and general pneumonia by impairing mucociliary clearance and immune function, but is not the *strongest* predisposing factor for the *specific presentation* of aspiration pneumonia. - The symptoms, particularly the foul-smelling sputum and localization to the RUL, are more characteristic of **aspiration** rather than smoking-induced disease alone. *Past history of alcohol abuse* - A history of **chronic alcohol abuse** is a known risk factor for various types of pneumonia due to immunosuppression and a higher likelihood of aspiration; however, the patient has been abstinent for 4 years. - While a past history can have lasting effects, the more recent and direct impact of the **ischemic stroke** on swallowing function makes it a stronger and more immediate predisposing factor in this acute presentation.

Question 490: A 33-year-old woman presents to the physician because of abdominal discomfort, weakness, and fever. She has had a significant weight loss of 15 kg (33.1 lb) over the past 2 months. She has no history of medical illness and is not on any medications. Her pulse is 96/min, the blood pressure is 167/92 mm Hg, the respiratory rate is 20/min, and the temperature is 37.7°C (99.8°F). Her weight is 67 kg (147.71 lb), height is 160 cm (5 ft 3 in), and BMI is 26.17 kg/m2. Abdominal examination shows purple striae and a vaguely palpable mass in the left upper quadrant of the abdomen, which does not move with respirations. She has coarse facial hair and a buffalo hump along with central obesity. Her extremities have poor muscle bulk, and muscle weakness is noted on examination. An ultrasound of the abdomen demonstrates an adrenal mass with para-aortic lymphadenopathy. Which of the following is the most likely laboratory profile in this patient?

A. Impaired glucose tolerance, elevated serum cortisol, elevated 24-h urinary free cortisol, and high plasma ACTH
B. Normal glucose tolerance, elevated serum cortisol, normal 24-h urinary free cortisol, and normal plasma adrenocorticotropic hormone (ACTH)
C. Impaired glucose tolerance, elevated serum cortisol, elevated 24-h urinary free cortisol, and low plasma ACTH (Correct Answer)
D. Impaired glucose tolerance, reduced serum cortisol, normal 24-h urinary free cortisol, and low plasma ACTH
E. Impaired glucose tolerance, elevated serum cortisol, normal 24-h urinary free cortisol, and normal plasma ACTH

Explanation: ***Impaired glucose tolerance, elevated serum cortisol, elevated 24-h urinary free cortisol, and low plasma ACTH*** - The clinical picture of **Cushing's syndrome** is evident from purple striae, coarse facial hair, buffalo hump, central obesity, muscle weakness, hypertension, and abdominal mass. The adrenal mass with para-aortic lymphadenopathy points to an **adrenocortical carcinoma**, which independently produces cortisol. - In cases of **adrenal tumors** producing cortisol, the **exogenous cortisol suppresses ACTH production** from the pituitary, leading to low plasma ACTH levels. Elevated cortisol leads to **insulin resistance** and impaired glucose tolerance. *Impaired glucose tolerance, elevated serum cortisol, elevated 24-h urinary free cortisol, and high plasma ACTH* - While significant **hypercortisolism** would cause impaired glucose tolerance, elevated serum and urinary free cortisol, **high plasma ACTH** is characteristic of **Cushing's disease** (pituitary ACTH overproduction), not an adrenal tumor. - An adrenal tumor directly secretes cortisol, thereby **suppressing ACTH** via negative feedback. *Normal glucose tolerance, elevated serum cortisol, normal 24-h urinary free cortisol, and normal plasma adrenocorticotropic hormone (ACTH)* - With the strong clinical signs of Cushing's syndrome and an adrenal mass, **elevated serum cortisol** and **elevated 24-h urinary free cortisol** are highly expected, making "normal" results for these parameters incorrect. - **Impaired glucose tolerance** is a common consequence of chronic hypercortisolism, so normal glucose tolerance would be unlikely. *Impaired glucose tolerance, reduced serum cortisol, normal 24-h urinary free cortisol, and low plasma ACTH* - The clinical presentation clearly indicates **hypercortisolism** (Cushing's syndrome), making **reduced serum cortisol** and normal 24-h urinary free cortisol inconsistent with the diagnosis. - Low plasma ACTH would be appropriate for an adrenal tumor, but the cortisol levels contradict the clinical picture. *Impaired glucose tolerance, elevated serum cortisol, normal 24-h urinary free cortisol, and normal plasma ACTH* - While **impaired glucose tolerance** and **elevated serum cortisol** are consistent with Cushing's syndrome, a **normal 24-h urinary free cortisol** would be highly unlikely given the other clinical signs and the presence of an adrenal mass secreting cortisol. - **Normal plasma ACTH** is also incorrect; it should be suppressed in cases of primary adrenal hypercortisolism.

Question 491: A 27-year-old Caucasian female presents to her physician for episodes of urinary incontinence that began shortly after a breakup with her boyfriend. She claimed to be psychologically devastated when she found him sleeping with her brother and has had trouble caring for herself ever since. The patient states that the episodes came on suddenly and occur randomly. The patient denies any burning or pain upon urination. Upon obtaining further history, the patient also states that she has "stress spells" in which her vision becomes blurry or has blind spots. The patient also complains of frequent headaches. These symptoms have persisted for the past few years and she attributes them to arguments with her boyfriend. Embarrassed, the patient even admits to episodes of fecal incontinence which she also blames on her boyfriend's perpetual verbal and occasional physical abuse. The patient is teary and a physical exam is deferred until her mood improves. Which of the following is the most appropriate next step in management?

A. Magnetic resonance imaging (MRI) of the head
B. Psychological assessment for suicidal ideation
C. Cognitive behavioral therapy (CBT) for symptoms of regression
D. Urine dipstick and culture
E. Psychological assessment for conversion disorder (Correct Answer)

Explanation: ***Psychological assessment for conversion disorder*** - The patient presents with neurological symptoms (vision changes, headaches, fecal incontinence) that are inconsistent with known neurological conditions and are often associated with **psychological stress** or trauma. - The description of symptoms coming on suddenly and their variability, alongside the patient's emotional distress and history of trauma, are highly suggestive of **conversion disorder** (functional neurological symptom disorder). *Magnetic resonance imaging (MRI) of the head* - While vision changes and headaches can indicate neurological issues, the sudden onset, variability, and association with traumatic events make **conversion disorder** a more likely initial consideration. - An MRI would be considered if a neurological cause is suspected after ruling out psychological explanations or if there are **"hard" neurological signs** on examination. *Psychological assessment for suicidal ideation* - Although the patient is teary and distressed, there is no direct mention of hopelessness, helplessness, or thoughts of self-harm in the vignette to prioritize suicidal ideation specifically. - **Suicidal ideation assessment** is crucial in any severely distressed patient, but the presenting symptoms point more specifically towards a stress-related somatic disorder. *Cognitive behavioral therapy (CBT) for symptoms of regression* - CBT is a valid treatment for many psychological conditions, but initiating it before a clear diagnosis is made is premature. - The symptoms described are more consistent with a somatoform disorder rather than primarily **regression**, which involves retreating to an earlier developmental stage. *Urine dipstick and culture* - While urinary incontinence is reported, the patient denies burning or pain, and the incontinence is described as sudden and random, without typical signs of a **urinary tract infection (UTI)**. - Given the other prominent neurological and psychological symptoms, a UTI is less likely to be the primary diagnosis explaining the constellation of issues.

Question 492: A 24-year-old man presents with a complaint of breathlessness while jogging. He says that he recently started marathon training. He does not have any family history of asthma nor has any allergies. He currently takes no medication. The blood pressure is 120/80 mm Hg, and the heart rate is 67/min. With each heartbeat, he experiences pounding in his chest, and his head bobs. On physical examination, he has long fingers, funnel chest, and disproportionate body proportions with a decreased upper-to-lower segment ratio. On auscultation over the 2nd right intercostal space, an early diastolic murmur is heard, and 3rd and 4th heart sounds are heard. Echocardiography shows aortic root dilatation. The patient is scheduled for surgery. Which of the following is associated with this patient's condition?

A. Klinefelter syndrome
B. Intravenous drug abuse
C. Marfan's Syndrome (Correct Answer)
D. Kawasaki syndrome
E. Gonorrhea

Explanation: ***Marfan's Syndrome*** - The patient presents with **tall stature**, **long fingers (arachnodactyly)**, **funnel chest (pectus excavatum)**, and **aortic root dilation** with **aortic regurgitation** (early diastolic murmur, head bobbing, pounding in the chest), all classic features of Marfan syndrome. - This is a **connective tissue disorder** caused by a mutation in the **FBN1 gene**, leading to defective **fibrillin-1**, which is crucial for structural integrity in the heart, blood vessels, eyes, and skeleton. *Klinefelter syndrome* - Characterized by a **47, XXY karyotype** and typically presents with infertility, small testes, gynecomastia, and tall stature, but not the specific cardiovascular or skeletal features described. - While it can cause tall stature, it does not explain the **arachnodactyly**, **pectus excavatum**, or the severe **aortic root dilation** and regurgitation. *Intravenous drug abuse* - Primarily associated with **infective endocarditis**, particularly affecting the **tricuspid valve**, leading to heart murmurs related to infection, not the skeletal and aortic root abnormalities seen here. - This history would lead to a different clinical presentation, potentially involving fever, chills, and vegetations on valve leaflets, none of which are mentioned. *Kawasaki syndrome* - An **acute inflammatory vasculitis** primarily affecting young children, characterized by fever, rash, conjunctivitis, lymphadenopathy, and oral mucosal changes. - While it can cause **coronary artery aneurysms**, it does not explain the skeletal abnormalities or the specific presentation of aortic root dilation with regurgitation in an adult. *Gonorrhea* - A **sexually transmitted infection** that can lead to disseminated gonococcal infection, causing arthritis, tenosynovitis, and dermatitis. - It does not cause the specific skeletal abnormalities or the primary cardiac pathology of aortic root dilation and regurgitation described in this patient.

Question 493: A 38-year-old woman comes to the physician because of frequent headaches and blurring of vision. She also complains of weight gain, menstrual irregularities, and excessive growth of body hair. She says that, for the first time since she turned 18, her shoe and ring sizes have increased, and also complains that her voice has become hoarser. She does not smoke or drink alcohol. She takes no medications. Vital signs are within normal limits. Physical examination shows prominent frontal bossing, a protuberant mandible with spaces between the teeth, and large hands and feet. Serum studies show: Na+ 140 mEq/L Cl− 102 mEq/L K+ 4.1 mEq/L Ca2+ 10.6 mg/dL Phosphorus 4.7 mg/dL Glucose 180 mg/dL Which of the following is the most likely sequela of this patient's condition?

A. Deposition of mucopolysaccharides in the myocardium
B. Thickening of the coronary artery walls
C. Prolongation of the QT interval on ECG
D. Left ventricular hypertrophy (Correct Answer)
E. Reduced cardiac output

Explanation: ***Left ventricular hypertrophy*** - **Left ventricular hypertrophy (LVH)** is the **most common cardiac complication** of acromegaly, occurring in 60-90% of patients with chronic growth hormone (GH) excess. - The pathophysiology involves direct effects of **GH** and **insulin-like growth factor 1 (IGF-1)** on cardiac myocytes, leading to hypertrophy and interstitial fibrosis, along with increased afterload from hypertension. - LVH typically manifests early in the disease course and can progress to **diastolic dysfunction** and eventually systolic dysfunction if untreated. - This patient's clinical features (frontal bossing, prognathism, acral enlargement, hyperglycemia) are classic for **acromegaly**, making LVH the most likely cardiac sequela. *Reduced cardiac output* - While **acromegalic cardiomyopathy** can eventually progress to systolic dysfunction with reduced cardiac output and heart failure, this represents a **late-stage complication** occurring in <20% of cases. - This develops after years of untreated disease when the initial compensatory LVH progresses to dilated cardiomyopathy. - Since the question asks for the "most likely sequela," LVH is more appropriate as it occurs much more frequently and earlier in the disease course. *Deposition of mucopolysaccharides in the myocardium* - This finding is characteristic of **mucopolysaccharidoses** (e.g., Hurler syndrome, Hunter syndrome), which are lysosomal storage diseases. - While soft tissue hypertrophy occurs in acromegaly, it is due to **increased collagen deposition and glycosaminoglycan accumulation in soft tissues**, not the myocardium specifically. - This is not a recognized cardiac manifestation of acromegaly. *Thickening of the coronary artery walls* - While patients with acromegaly have increased cardiovascular risk due to **hypertension**, **diabetes mellitus**, and **dyslipidemia**, leading to accelerated atherosclerosis, this is not the primary or most characteristic cardiac sequela. - Coronary artery disease can develop but is less specific to acromegaly than the direct cardiac effects of GH/IGF-1 excess. *Prolongation of the QT interval on ECG* - **QT prolongation** is associated with electrolyte abnormalities (hypocalcemia, hypomagnesemia, hypokalemia), certain medications, and specific genetic syndromes. - This is not a recognized feature or sequela of acromegaly. - The patient's electrolytes in this case are within normal limits.

Question 494: A 47-year-old man comes to the physician for a routine health maintenance examination. He has no complaints and has no history of serious illness. He works as a forklift operator in a factory. His brother died of malignant melanoma. He smokes occasionally and drinks a glass of wine once a week. His pulse is 79/min and blood pressure is 129/84 mm Hg. Which of the following causes of death is this patient most at risk for over the next 15 years?

A. Industrial accident
B. Coronary artery disease (Correct Answer)
C. Prostate cancer
D. Malignant melanoma
E. Lung cancer

Explanation: ***Coronary artery disease*** - **Coronary artery disease (CAD)** is the **leading cause of death** in middle-aged men in the United States, making it the statistically most likely cause of death for this patient over the next 15 years. - This patient has multiple modifiable risk factors including male sex, smoking (even occasional), and blood pressure of 129/84 mm Hg (elevated blood pressure/stage 1 hypertension by current guidelines). - Even with relatively modest risk factors, the cumulative 15-year risk of cardiovascular mortality substantially exceeds other causes of death in this demographic group. *Industrial accident* - While working as a forklift operator carries some occupational risk, **industrial accidents** account for a very small proportion of deaths compared to chronic diseases in this age group. - There is no indication of high-risk working conditions or safety concerns that would elevate this above cardiovascular disease as a cause of death. *Prostate cancer* - At age 47, the patient is relatively young for **prostate cancer** mortality. Most prostate cancer deaths occur in men over 65. - While prostate cancer is common in older men, it typically has a long natural history, and mortality within 15 years would be less likely than cardiovascular disease in this age group. - No specific high-risk features (family history, African-American ethnicity) are mentioned. *Malignant melanoma* - Although his brother died of **malignant melanoma**, family history alone does not make this the most likely cause of death over cardiovascular disease. - The patient has no described personal risk factors (numerous nevi, history of severe sunburns, fair skin) or current lesions of concern. - Melanoma mortality rates are substantially lower than cardiovascular disease mortality in middle-aged men. *Lung cancer* - The patient smokes **occasionally**, which confers some increased risk, but this is not described as heavy or chronic smoking. - **Lung cancer** typically requires more substantial cumulative tobacco exposure (pack-years) to become a leading cause of mortality. - Even in smokers, cardiovascular disease often causes death before lung cancer in this age group, particularly with modest smoking history.

Question 495: A 62-year-old man comes to the physician because of fatigue and swelling of the lower legs for 3 weeks. One year ago, he had an 85% stenosis in the left anterior descending artery, for which he received 2 stents. He was diagnosed with hepatitis C 5 years ago. He has type 2 diabetes mellitus and arterial hypertension. Current medications include aspirin, metformin, and ramipril. He does not smoke or drink alcohol. His temperature is 37°C (98.6°F), pulse is 92/min, and blood pressure is 142/95 mm Hg. Examination shows 2+ pretibial edema bilaterally. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.2 g/dL Leukocyte count 6500/mm3 Platelet count 188,000/mm3 Serum Na+ 137 mEq/L Cl− 105 mEq/L K+ 5.2 mEq/L Urea nitrogen 60 mg/dL Glucose 110 mg/dL Creatinine 3.9 mg/dL Albumin 3.6 g/dL HbA1C 6.8% Urine Blood negative Glucose 1+ Protein 3+ WBC 0–1/hpf A renal biopsy shows sclerosis in the capillary tufts and arterial hyalinosis. Which of the following is the most likely underlying mechanism of this patient's findings?

A. Diabetes mellitus
B. Arterial hypertension (Correct Answer)
C. Amyloidosis
D. Membranoproliferative glomerulonephritis
E. Membranous nephropathy

Explanation: ***Arterial hypertension*** - The patient's **blood pressure of 142/95 mm Hg** and history of arterial hypertension, coupled with **arterial hyalinosis** and **glomerulosclerosis (sclerosis in the capillary tufts)** seen on biopsy, strongly indicate hypertensive nephrosclerosis as the primary cause of renal damage. **Arterial hyalinosis** is the pathognomonic finding of hypertensive nephropathy, resulting from chronic endothelial injury and plasma protein deposition in vessel walls. - The elevated **urea nitrogen (60 mg/dL)** and **creatinine (3.9 mg/dL)**, along with significant **proteinuria (3+)**, indicate substantial kidney damage, consistent with chronic hypertensive nephrosclerosis. - The inadequate blood pressure control despite ACE inhibitor therapy (ramipril) demonstrates ongoing hypertensive injury. *Diabetes mellitus* - While the patient has diabetes, the biopsy finding of **arterial hyalinosis** and **glomerulosclerosis** is more characteristic of hypertensive nephrosclerosis rather than diabetic nephropathy. - Diabetic nephropathy typically presents with **glomerular basement membrane thickening**, **mesangial expansion**, and **Kimmelstiel-Wilson nodules** (nodular glomerulosclerosis), which are not the primary biopsy findings described here. - Additionally, the patient's **good glycemic control (HbA1C 6.8%)** makes advanced diabetic nephropathy less likely. *Amyloidosis* - Amyloidosis would typically show characteristic **amyloid deposits** in the glomeruli and interstitium, which stain positive with **Congo red** and exhibit apple-green birefringence under polarized light, findings not reported. - Presentation usually includes significant proteinuria, often in the nephrotic range, and can affect multiple organs, but the specific biopsy findings of **arterial hyalinosis** point away from amyloidosis as the primary cause. *Membranoproliferative glomerulonephritis* - This condition is typically characterized by **mesangial and endothelial proliferation**, **glomerular basement membrane thickening** with a "tram-track" appearance (due to mesangial interposition), and often immune complex deposits. - While the patient has hepatitis C (a known risk factor for MPGN), the biopsy findings of **glomerulosclerosis** and **arterial hyalinosis** are not specific for MPGN, and the characteristic proliferative changes are not described. *Membranous nephropathy* - Membranous nephropathy is primarily characterized by **subepithelial immune complex deposits** and **diffuse thickening of the glomerular basement membrane** (spike and dome appearance on silver stain). - It is a common cause of nephrotic syndrome in adults, but the biopsy describes **glomerulosclerosis** and **arterial hyalinosis** which are not the hallmark features of membranous nephropathy.

Question 496: A tall, slender 32-year-old man comes to the emergency room because of sudden chest pain, cough, and shortness of breath. On physical examination, he has decreased breath sounds on the right. Chest radiography shows translucency on the right side of his chest. His pCO2 is elevated and pO2 is decreased. What is the most likely cause of his symptoms?

A. Spontaneous pneumothorax (Correct Answer)
B. Chronic obstructive pulmonary disease
C. Tension pneumothorax
D. Asthma
E. Pneumonia

Explanation: ***Spontaneous pneumothorax*** - The patient's presentation with **sudden chest pain**, **cough**, and **shortness of breath** in a **tall, slender young man** is classic for a primary spontaneous pneumothorax. - **Decreased breath sounds** on the affected side and **translucency on chest X-ray** (indicating air in the pleural space) further support this diagnosis. *Chronic obstructive pulmonary disease* - COPD typically affects older individuals with a history of smoking and presents with **chronic progressive dyspnea**, not sudden onset. - While COPD can lead to secondary spontaneous pneumothorax, the patient's age and lack of pre-existing lung disease make this less likely as the primary cause. *Tension pneumothorax* - A tension pneumothorax is a **life-threatening condition causing mediastinal shift** and severe hemodynamic compromise (e.g., hypotension, tracheal deviation) which are not described. - While it shares some features, the absence of these critical signs means a simple spontaneous pneumothorax is more likely first. *Asthma* - Asthma presents with **episodic wheezing**, cough, and shortness of breath, often triggered by allergens or exercise. - The sudden onset of symptoms with **decreased localized breath sounds** and radiological findings of transparencies do not align with typical asthma exacerbations. *Pneumonia* - Pneumonia usually involves **fever, productive cough, and localized crackles** or bronchial breath sounds on examination. - Chest X-rays in pneumonia show **infiltrates or consolidation**, which contrast with the translucency seen in this case.

Question 497: A 25-year-old woman presents to the emergency department with sudden onset of lower limb weakness for the past 2 days. She says she also hasn’t been able to urinate for that same period. There is no history of trauma, fever, weight loss, recent respiratory tract infection, or diarrhea. She has a past medical history of left arm weakness 18 months ago that resolved spontaneously. Her father had type 2 diabetes mellitus, ischemic heart disease, and left-sided residual weakness secondary to an ischemic stroke involving the right middle cerebral artery. Her vital signs include: blood pressure 120/89 mm Hg, temperature 36.7°C (98.0°F), pulse 78/min, and respiration rate 16/min. Muscle strength is 3/5 in both lower limbs with increased tone and exaggerated deep tendon reflexes. The sensation is decreased up to the level of the umbilicus. Muscle strength, tone, and deep tendon reflexes in the upper limbs are normal. On flexion of the neck, the patient experiences electric shock-like sensations that travel down to the spine. Funduscopic examination reveals mildly swollen optic discs bilaterally. Which of the following is the next best step in management for this patient?

A. Plasmapheresis
B. Riluzole
C. Intravenous methylprednisolone (Correct Answer)
D. Interferon beta
E. Intravenous immunoglobulin

Explanation: ***Intravenous methylprednisolone*** - The patient presents with classic signs of an **acute multiple sclerosis (MS) exacerbation**, including acute-onset motor weakness, bladder dysfunction, Lhermitte’s sign, and optic disc swelling. High-dose intravenous methylprednisolone is the **first-line treatment** for acute MS exacerbations, as it reduces inflammation and shortens the recovery period. - The history of a previous self-resolving neurological deficit 18 months prior (left arm weakness) suggests a demyelinating event, supporting a diagnosis of **relapsing-remitting MS**. *Plasmapheresis* - **Plasmapheresis** is considered an alternative treatment for severe MS relapses that are **refractory to corticosteroid therapy**. It is not typically the initial treatment of choice. - In this case, the patient has not yet received corticosteroids, so plasmapheresis would not be the next best step. *Riluzole* - **Riluzole** is a medication used to treat **amyotrophic lateral sclerosis (ALS)**, a progressive neurodegenerative disease. - This patient's symptoms are inconsistent with ALS; she has acute, multifocal neurological deficits and a history of a self-resolving episode, which are characteristic of MS. *Interferon beta* - **Interferon beta** is a **disease-modifying therapy** for MS used to reduce the frequency and severity of relapses and slow disease progression. - It is not used for the **acute treatment of an MS exacerbation** but rather for long-term management. *Intravenous immunoglobulin* - **Intravenous immunoglobulin (IVIG)** is sometimes used as an alternative treatment for MS exacerbations in patients who cannot tolerate or do not respond to corticosteroids, or in specific situations like **postpartum MS exacerbations**. - However, **corticosteroids** are generally preferred as the initial treatment for acute MS exacerbations due to their efficacy and established role.

Question 498: A 52 year-old woman comes to the physician because of intense retrosternal chest pain for the last three days. The pain is worse with breathing or coughing, and improves while sitting upright. She also reports a mild fever and shortness of breath. She was diagnosed with chronic kidney disease secondary to lupus nephritis 12 years ago and has been on hemodialysis since then, but she missed her last two appointments because of international travel. She also underwent a percutaneous coronary intervention eight months ago for a myocardial infarction. She takes azathioprine after hemodialysis. Her temperature is 37.8°C (100°F), pulse is 110/min, and blood pressure is 130/84 mm Hg. The lungs are clear to auscultation bilaterally with normal breath sounds. Cardiac examination reveals a high-pitched scratching that obscures both heart sounds. The remainder of the examination is otherwise unremarkable. Cardiac enzyme levels and anti-DNA antibodies are within normal limits. An x-ray of the chest shows no abnormalities. An ECG shows Q waves in the anterior leads. Which of the following is the most likely cause of these findings?

A. Adverse effect of medication
B. Serositis from an immunologic reaction
C. Infarction of myocardial segment
D. Low serum levels of thyroid hormone
E. Elevated serum levels of nitrogenous waste (Correct Answer)

Explanation: ***Elevated serum levels of nitrogenous waste*** - The patient's history of **chronic kidney disease** and missed hemodialysis sessions strongly suggest accumulation of **uremic toxins**, which can cause **uremic pericarditis**. - **Uremic pericarditis** presents with **pleuritic chest pain** that improves with sitting upright, a **pericardial friction rub** (high-pitched scratching sound), and is not typically associated with classic ECG changes of MI or elevated cardiac enzymes. *Adverse effect of medication* - While medications can cause chest pain, there is no specific medication the patient is taking (e.g., azathioprine) that typically causes this constellation of **pericardial symptoms** and **friction rub**. - The patient's missed dialysis sessions offer a much more direct and common explanation for her symptoms than an unspecified medication adverse effect. *Serositis from an immunologic reaction* - Although the patient has a history of **lupus nephritis**, current antibody levels (**anti-DNA antibodies within normal limits**) suggest that an acute lupus flare causing serositis is less likely than other causes. - Serositis due to lupus can cause pericarditis, but the **missed dialysis** makes uremia a more immediate and probable cause. *Infarction of myocardial segment* - The patient's **cardiac enzymes are within normal limits**, ruling out an **acute myocardial infarction (MI)**, which would be expected with ongoing myocardial ischemia. - While the ECG shows **Q waves**, indicating a *prior* MI (consistent with her history), it does not explain the *current* acute symptoms of pleuritic chest pain and friction rub. *Low serum levels of thyroid hormone* - **Hypothyroidism** can lead to **pericardial effusion**, but typically not acute, intense pleuritic chest pain and a friction rub as the primary presentation. - There are no other clinical signs or symptoms presented that would suggest **hypothyroidism** in this patient.

Question 499: A 72-year-old man is brought to the physician by his wife for forgetfulness, confusion, and mood changes for the past 4 months. His symptoms started with misplacing items such as his wallet and keys around the house. Two months ago, he became unable to manage their finances as it became too difficult for him. Last week, he became lost while returning home from the grocery store. His wife reports that he shows “no emotion” and that he is seemingly not concerned by his recent symptoms. He has hypertension, type 2 diabetes mellitus, and coronary artery disease. Current medications include aspirin, metoprolol, lisinopril, metformin, and rosuvastatin. His pulse is 56/min and blood pressure is 158/76 mm Hg. Neurologic examination shows loss of sensation on his right leg and an unsteady gait. When asked to stand with his eyes closed and palms facing upward, his right arm rotates inward. An MRI of the brain shows multiple deep white matter lesions. Which of the following is the most likely diagnosis?

A. Vitamin B12 deficiency
B. Frontotemporal dementia
C. Alzheimer disease
D. Lewy body dementia
E. Vascular dementia (Correct Answer)

Explanation: ***Vascular dementia*** - The patient's history of **hypertension, type 2 diabetes mellitus, and coronary artery disease** indicates significant vascular risk factors. The **multiple deep white matter lesions** on MRI are characteristic findings in vascular dementia, resulting from chronic **cerebral ischemia**. - The **insidious onset** with progressive **cognitive decline** (forgetfulness, confusion, financial difficulties, getting lost) combined with **focal neurological deficits** (loss of sensation, unsteady gait, pronator drift), and "no emotion" or lack of concern, strongly points towards vascular dementia. *Vitamin B12 deficiency* - While vitamin B12 deficiency can cause cognitive impairment and neurological symptoms, it typically manifests with **megaloblastic anemia** and **peripheral neuropathy**, which are not noted in this case. - The MRI findings of **multiple deep white matter lesions** are not characteristic of vitamin B12 deficiency, and the patient's extensive vascular risk factors are more indicative of a cerebrovascular etiology. *Frontotemporal dementia* - Characterized primarily by **early and prominent behavioral and personality changes** (e.g., disinhibition, apathy) or **language deficits**. While apathy is present ("no emotion"), the prominent **focal neurological deficits** and MRI findings of deep white matter lesions are less typical. - Unlike this case, memory impairment is usually not the initial or most prominent symptom in frontotemporal dementia until later stages, which contrasts with the patient's initial presentation of forgetfulness. *Alzheimer disease* - Alzheimer disease typically presents with **progressive memory impairment** as the hallmark symptom, often preceding other cognitive or neurological deficits. While memory loss is present here, the rapid progression (4 months), prominent focal neurological signs, and vascular risk factors are less typical. - MRI would typically show **cortical atrophy**, particularly in the hippocampus and medial temporal lobes, rather than multiple deep white matter lesions without significant atrophy. *Lewy body dementia* - Key features include **fluctuating cognition, recurrent visual hallucinations**, and spontaneous **parkinsonism**. None of these core features are explicitly described in the patient's presentation. - While mood changes and apathy can occur, the presence of **focal neurological deficits** and deep white matter lesions on MRI are not primary characteristics of Lewy body dementia.

Question 500: A 76-year-old woman presents to her primary care physician with an intense, throbbing, right-sided headache. She has a history of migraine headaches and tried her usual medications this afternoon with no alleviation of symptoms. She states that this headache feels different because she also has pain in her jaw that is worse with chewing. The pain came on gradually and is getting worse. In addition, over the past few months, she has had some difficulty getting up out of chairs and raising both her arms over her head to put on her clothes. She has had no recent falls or injuries. On exam, the patient's temperature is 98.3°F (36.8°C), blood pressure is 115/70 mmHg, pulse is 93/min, and respirations are 15/min. The patient has tenderness over her right temple. She has no focal neurological deficits, and no abnormalities on fundoscopic exam. Her physical exam is otherwise within normal limits. Given the patient's most likely diagnosis, which of the following methods of treatment should be used in order to prevent any further complications?

A. High dose steroids (Correct Answer)
B. Thrombolytics
C. Craniotomy
D. Lumbar puncture
E. Antibiotics

Explanation: **Correct: High dose steroids** - The patient's presentation with a new-onset, severe headache, **jaw claudication**, and proximal muscle weakness (difficulty getting out of chairs and raising arms) in an elderly woman is highly suggestive of **giant cell arteritis (GCA)**, also known as temporal arteritis, often co-occurring with **polymyalgia rheumatica**. - **High-dose steroids** (e.g., prednisone) are the primary treatment for GCA to rapidly reduce inflammation and prevent devastating complications such as **irreversible vision loss** due to ophthalmic artery occlusion. *Incorrect: Thrombolytics* - **Thrombolytics** are used to dissolve acute blood clots, typically in conditions like ischemic stroke or pulmonary embolism. - While GCA can lead to thrombotic events, the immediate treatment is to address the underlying inflammation with steroids, not to acutely break down clots that may have already formed or prevent them with a different mechanism. *Incorrect: Craniotomy* - A **craniotomy** is a surgical procedure involving the temporary removal of a bone flap from the skull to access the brain, usually indicated for conditions like brain tumors, aneurysms, or traumatic brain injury. - It is an invasive surgical intervention and has no role in the management of giant cell arteritis. *Incorrect: Lumbar puncture* - A **lumbar puncture** (spinal tap) is performed to collect cerebrospinal fluid (CSF) for diagnostic purposes, often to investigate infections, inflammatory conditions, or neurological disorders affecting the central nervous system. - While headaches can be a symptom of conditions requiring a lumbar puncture (e.g., meningitis), the constellation of symptoms (jaw claudication, proximal muscle weakness) strongly points away from general CNS infection or inflammation requiring CSF analysis. *Incorrect: Antibiotics* - **Antibiotics** are medications used to treat bacterial infections. - Giant cell arteritis is an autoimmune inflammatory condition, not an infection, and therefore antibiotics would be ineffective and inappropriate as a treatment.

Question 501: A 32-year-old woman presents with progressive shortness of breath and a dry cough. She says that her symptoms onset recently after a 12-hour flight. Past medical history is unremarkable. Current medications are oral estrogen/progesterone containing contraceptive pills. Her vital signs include: blood pressure 110/60 mm Hg, pulse 101/min, respiratory rate 22/min, oxygen saturation 88% on room air, and temperature 37.9℃ (100.2℉). Her weight is 94 kg (207.2 lb) and height is 170 cm (5 ft 7 in). On physical examination, she is acrocyanotic. There are significant swelling and warmth over the right calf. There are widespread bilateral rales present. Cardiac auscultation reveals accentuation of the pulmonic component of the second heart sound (P2) and an S3 gallop. Which of the following ventilation/perfusion (V/Q) ratios most likely corresponds to this patient’s condition?

A. 1.3 (Correct Answer)
B. 1
C. 0.8
D. 0.5
E. 0.3

Explanation: ***1.3*** - This value represents an increased V/Q ratio, or **dead space ventilation**, which is characteristic of a **pulmonary embolism (PE)**. In PE, a portion of the lung is ventilated but not perfused due to the embolism blocking blood flow, leading to wasted ventilation. - The patient's symptoms (sudden onset dyspnea after a long flight, use of oral contraceptives, calf swelling, hypoxia, and accentuated P2) are highly suggestive of a PE, which is the most likely cause of increased V/Q mismatch. *1* - A V/Q ratio of 1 indicates **perfect matching** of ventilation and perfusion, which is an ideal state not typically achieved throughout the entire lung, especially in disease. - This value would not explain the patient's severe **hypoxia** and overall clinical picture of respiratory distress. *0.8* - This is the **average normal V/Q ratio** for the lung as a whole, representing slightly more perfusion than ventilation. - While it's a normal physiological state, it does not account for the significant V/Q mismatch indicated by the patient's severe hypoxemia (SpO2 88%) and clinical symptoms. *0.5* - This value represents a **low V/Q ratio**, indicating relatively more perfusion than ventilation, often seen in conditions like **shunt physiology** (e.g., pneumonia, atelectasis, pulmonary edema). - While the patient has rales and an S3 gallop suggesting potential pulmonary edema or heart failure secondary to increased right heart strain, the primary pathophysiology in PE is increased V/Q due to unperfused but ventilated lung regions. *0.3* - This is a severely **low V/Q ratio**, approaching a **shunt**, where blood passes through the lungs without being adequately oxygenated. This is typical of conditions like **severe pneumonia, ARDS, or significant atelectasis**. - While PE can cause some degree of bronchoconstriction leading to areas of low V/Q, the predominant and most impactful V/Q mismatch in PE is the high V/Q ratio in areas of unperfused lung.

Question 502: A 43-year-old man with HIV comes to the physician because of fever and night sweats over the past 15 days. During this period, he has also had headaches and generalized weakness. He has no cough or shortness of breath. He has hypertension controlled with lisinopril and is currently receiving triple antiretroviral therapy. He has smoked one pack of cigarettes daily for the past 15 years and drinks one to two beers on weekends. He is a known user of intravenous illicit drugs. His temperature is 39°C (102°F), pulse is 115/min, respirations are 15/min, and blood pressure is 130/80 mm Hg. Examination shows several track marks on the forearms. The lungs are clear to auscultation. A holosystolic murmur that increases on inspiration is heard along the left sternal border. The remainder of the physical examination shows no abnormalities. Laboratory studies show a leukocyte count of 12,800/mm3 and an erythrocyte sedimentation rate of 52 mm/h. His CD4+ T-lymphocyte count is 450/mm3 (normal ≥ 500). Which of the following is the most likely sequela of the condition?

A. Retinal hemorrhages
B. Painful nodules on pads of the fingers
C. Hematuria
D. Hemorrhages underneath fingernails (Correct Answer)
E. Pulmonary embolism

Explanation: ***Hemorrhages underneath fingernails*** - This patient presents with **infective endocarditis** affecting the **tricuspid valve** (holosystolic murmur increasing with inspiration along left sternal border in an IV drug user). - **Splinter hemorrhages** (linear hemorrhages underneath fingernails) are a classic peripheral manifestation of infective endocarditis caused by **microemboli** and **vasculitis**. - While more common in left-sided endocarditis, peripheral stigmata can occur in right-sided endocarditis as well, and represent an important diagnostic clue. *Retinal hemorrhages* - **Roth spots** (retinal hemorrhages with pale centers) can occur in infective endocarditis but are less common than splinter hemorrhages. - They are also less specific, occurring in other conditions like acute leukemia and hypertensive retinopathy. *Painful nodules on pads of the fingers* - **Osler nodes** are painful, tender nodules on the pads of fingers/toes representing immunologic phenomena in endocarditis. - While characteristic of endocarditis, they are less commonly observed than splinter hemorrhages and occur in only 10-25% of cases. *Hematuria* - Can occur due to **immune complex glomerulonephritis** or **renal infarcts** from septic emboli. - While possible, it is not as specific or commonly recognized as a peripheral stigma of endocarditis compared to splinter hemorrhages. *Pulmonary embolism* - Right-sided endocarditis typically causes **septic pulmonary emboli** traveling through the pulmonary circulation. - However, this patient has **clear lungs on auscultation** and **no respiratory symptoms** (no cough, shortness of breath, or tachypnea), making active pulmonary involvement unlikely. - The question focuses on recognizable peripheral sequelae of the endocarditis itself.

Question 503: A 50-year-old man presents to the emergency department with a severe headache. The patient reports that it started approx. 2 hours ago and has steadily worsened. He describes it as a stabbing pain localized behind his left eye. The patient reports that he has been having similar headaches several times a day for the past week, most often at night. He denies any nausea, vomiting, and visual or auditory disturbances. He has no significant past medical history. Current medications are a multivitamin and caffeine pills. The patient reports regular daily alcohol use but does not smoke. His temperature is 37.0°C (98.6°F), the blood pressure is 120/70 mm Hg, the pulse is 85/min, the respiratory rate is 18/min, and the oxygen saturation is 99% on room air. The patient is in moderate distress from the pain. The physical exam is significant for unilateral diaphoresis on the left forehead, left-sided rhinorrhea, and pronounced lacrimation of the left eye. The remainder of the physical exam is normal. Laboratory tests are normal. Non-contrast CT of the head shows no evidence of intracranial masses or hemorrhage. High flow oxygen and fluid resuscitation are initiated. Ibuprofen 200 mg orally is administered. Despite these interventions, the patient continues to be in significant pain. What is the next best step in management?

A. RF ablation of the left trigeminal nerve
B. CT angiography
C. Deep brain stimulation of the posterior inferior hypothalamus
D. Verapamil
E. Administer subcutaneous sumatriptan (Correct Answer)

Explanation: ***Administer subcutaneous sumatriptan*** - This patient's presentation with severe, unilateral, retro-orbital pain, accompanied by **ipsilateral autonomic symptoms** (lacrimation, rhinorrhea, unilateral diaphoresis) and episodic occurrence, is highly characteristic of a **cluster headache**. - **Subcutaneous sumatriptan** is a highly effective acute abortive treatment for cluster headaches due to its rapid onset of action, making it the most appropriate next step given the patient's ongoing severe pain despite initial symptomatic management. *RF ablation of the left trigeminal nerve* - **RF ablation of the trigeminal nerve** is a treatment for refractory trigeminal neuralgia, a different headache disorder characterized by lancinating facial pain. - It is an **invasive procedure** and not an acute management strategy for cluster headache. *CT angiography* - A **CT angiography** would be indicated if there was suspicion of a vascular abnormality such as an aneurysm or dissection, which would typically present with a "thunderclap" headache, but may also have focal neurological deficits. - While always considered in severe headache, the patient's symptoms are classic for cluster headache and the initial non-contrast CT was unremarkable; thus, it is not the most immediate next step for acute symptom relief. *Deep brain stimulation of the posterior inferior hypothalamus* - **Deep brain stimulation (DBS)** of the posterior inferior hypothalamus is a neurosurgical treatment reserved for **highly refractory chronic cluster headaches** that have failed all other medical therapies. - It is not an acute management strategy and is considered only in severe, debilitating, and treatment-resistant cases. *Verapamil* - **Verapamil** is a calcium channel blocker used as a **prophylactic treatment** for cluster headaches to reduce the frequency and severity of attacks. - It is not an acute abortive treatment for an ongoing cluster headache attack, which requires rapid symptom relief.

Question 504: A 77-year-old woman is brought by ambulance to the emergency department after she developed weakness of her right arm along with a right-sided facial droop. By the time the ambulance arrived, she was having difficulty speaking. Past medical history is significant for hypertension, diabetes mellitus type II, and hyperlipidemia. She takes lisinopril, hydrochlorothiazide, metformin, and atorvastatin. On arrival to the emergency department, her vital signs are within normal limits. On physical examination, she is awake and alert but the right side of her mouth is dropping, making it difficult for her to speak clearly. Her heart has a regular rate and rhythm and her lungs are clear to auscultation bilaterally. Fingerstick glucose is 85 mg/dL. Her right upper extremity strength is 2/5 and her left upper extremity strength is 5/5. Which of the following is the best next step in management?

A. Obtain transcranial doppler
B. Start tissue plasminogen activator (tPA)
C. Consult cardiology
D. Intubate the patient
E. Obtain noncontrast CT of the brain (Correct Answer)

Explanation: ***Obtain noncontrast CT of the brain*** - An **urgent noncontrast CT of the brain** is the **most crucial initial step** in managing acute neurological deficits suggestive of stroke. - This imaging is essential to **rule out hemorrhagic stroke** before considering thrombolytic therapy like tPA. *Obtain transcranial doppler* - **Transcranial Doppler (TCD)** can be used to assess cerebral blood flow and identify vascular stenosis but is not the immediate first-line diagnostic imaging for an acute stroke presentation. - TCD is typically performed **after initial imaging** to determine the presence of large vessel occlusion or monitor for vasospasm, not to differentiate between ischemic and hemorrhagic stroke. *Start tissue plasminogen activator (tPA)* - While **tPA** is a treatment for acute ischemic stroke, it is **contraindicated in hemorrhagic stroke**. - Without a **noncontrast CT scan to rule out hemorrhage**, administering tPA can be life-threatening. *Consult cardiology* - Consulting cardiology is important for evaluating potential cardiac sources of emboli (e.g., atrial fibrillation) as a cause of stroke but it is **not the immediate next step** in managing acute stroke symptoms. - The **immediate priority is diagnosing the type of stroke** and determining eligibility for acute interventions. *Intubate the patient* - **Intubation** is reserved for patients with compromise of their **airway, breathing, or circulation (ABCs)**, or a significantly decreased level of consciousness (e.g., GCS < 8). - This patient is described as **awake and alert**, making intubation unnecessary at this stage.

Question 505: A 44-year-old man is brought to the emergency department after sustaining high-voltage electrical burns over his left upper limb. On examination, the tip of his left middle finger is charred, and there are 2nd-degree burns involving the whole of the left upper limb. Radial and ulnar pulses are strong, and there are no signs of compartment syndrome. An exit wound is present over the sole of his right foot. His temperature is 37.7°C (99.8°F), the blood pressure is 110/70 mm Hg, the pulse is 105/min, and the respiratory rate is 26/min. His urine is reddish-brown, and urine output is 0.3 mL/kg/h. Laboratory studies show: Hemoglobin 13.9 g/dL Hematocrit 33% Leukocyte count 11,111/mm3 Serum Creatinine 4.6 mg/dL Creatine phosphokinase 15,230 U/L K+ 7.7 mEq/L Na+ 143 mEq/L What is the most likely mechanism for this patient's renal failure?

A. Septicemia leading to acute pyelonephritis
B. Rhabdomyolysis, myoglobinuria, and renal injury (Correct Answer)
C. Direct visceral electrical injury to the kidneys
D. Fluid and electrolyte loss and hypovolemia
E. Volume overload because of excessive intravenous fluid resuscitation

Explanation: ***Rhabdomyolysis, myoglobinuria, and renal injury*** - The high **creatine phosphokinase (CPK)** level of 15,230 U/L indicates significant **muscle damage** (**rhabdomyolysis**) from the high-voltage electrical burn. - **Myoglobin** released from damaged muscle is **nephrotoxic** and precipitates in the renal tubules, leading to **acute kidney injury**, evidenced by **reddish-brown urine** and elevated **creatinine (4.6 mg/dL)**. *Septicemia leading to acute pyelonephritis* - While burns can lead to infection, there are no specific signs of **septicemia** or **pyelonephritis** (e.g., fever, flank pain) in the provided information. - The patient's **hyperkalemia** and elevated **CPK** are not typical findings for pyelonephritis. *Direct visceral electrical injury to the kidneys* - **Direct electrical injury** to internal organs such as the kidneys is **rare** unless the electrical current traverses the abdomen. - The entry and exit wounds (left upper limb and right foot) suggest a current path that is **less likely** to directly involve the kidneys. *Fluid and electrolyte loss and hypovolemia* - Although **burn injuries** can cause significant fluid loss, this patient's **blood pressure (110/70 mm Hg)** and **heart rate (105/min)** do not strongly suggest severe **hypovolemic shock**. - The **hemoglobin (19.9 g/dL)** and **hematocrit (33%)** also do not directly point to severe acute fluid loss as the primary cause of renal failure in the context of other findings. *Volume overload because of excessive intravenous fluid resuscitation* - The patient's **low urine output (0.3 mL/kg/h)** suggests **renal failure**, not fluid overload. - There is no mention of **fluid resuscitation** being administered, making this an unlikely cause of the current presentation.

Question 506: A 34-year-old primigravida presents with progressive shortness of breath on exertion and while sleeping. The patient says that she uses 2 pillows to breathe comfortably while sleeping at night. These symptoms started in the 3rd week of the 2nd trimester of pregnancy. She does not have any chronic health problems. She denies smoking and alcohol intake. Vital signs include: blood pressure 110/50 mm Hg, temperature 36.9°C (98.4°F), and regular pulse 90/min. Previous physical examination in the 1st trimester had disclosed no cardiac abnormalities, but on current physical examination, she has a loud S1 and a 2/6 diastolic rumble over the cardiac apex. A transthoracic echocardiogram shows evidence of mitral valve stenosis. Which of the following is the best initial treatment for this patient?

A. Loop diuretics
B. Percutaneous mitral balloon valvotomy (PMBV) (Correct Answer)
C. Valve replacement
D. Open valve commissurotomy
E. No therapy is required

Explanation: **Percutaneous mitral balloon valvotomy (PMBV)** - This patient presents with **symptomatic mitral stenosis** during the second trimester of pregnancy, evidenced by progressive **shortness of breath, orthopnea**, and characteristic findings of a **loud S1 and diastolic rumble**. Due to the high risk of **maternal and fetal complications** with continued severe symptoms, an intervention is necessary. - **PMBV** is the **preferred initial treatment for symptomatic severe mitral stenosis** in pregnant patients with suitable valve morphology who are not responding to medical therapy because it is less invasive than surgery and generally well-tolerated. *Loop diuretics* - While **loop diuretics** can help manage **pulmonary congestion** and **dyspnea** by reducing preload, they are a **symptomatic treatment** and do not address the underlying mechanical obstruction of mitral stenosis. - In a patient with severe, progressive symptoms of mitral stenosis during pregnancy, medical therapy alone is often insufficient, and definitive intervention is required. *Valve replacement* - **Surgical valve replacement** is a **major invasive procedure** with significant risks to both the mother and fetus, including higher rates of miscarriage, prematurity, and maternal mortality. - It is typically reserved for cases where PMBV is not feasible or has failed, or if there are other concomitant cardiac lesions requiring surgical correction. *Open valve commissurotomy* - **Open valve commissurotomy** is a surgical procedure that is more invasive than PMBV and carries similar risks as valve replacement for a pregnant patient. - It is generally considered when **PMBV is contraindicated** due to unsuitable valve anatomy or has been unsuccessful, and surgical intervention is deemed necessary. *No therapy is required* - This patient's symptoms are **progressive and significantly impacting her quality of life**, indicating that medical intervention is necessary to prevent further decompensation and improve maternal and fetal outcomes. - Untreated symptomatic mitral stenosis in pregnancy can lead to severe complications such as **pulmonary edema, heart failure, and maternal/fetal mortality**.

Question 507: A 65-year-old man presents to the diabetes clinic for a check-up. He has been successfully managing his diabetes through diet alone, and has not experienced any complications related to retinopathy, neuropathy, or nephropathy. He recently started a new exercise regimen and is eager to see whether his weight has declined since his last visit. The nurse measures his height to be 170 cm and his weight to be 165 lb (75 kg). What range does this patient’s body mass index currently fall into?

A. < 18.5
B. > 30.0
C. 25.0 - 29.9 (Correct Answer)
D. 18.5 - 24.9
E. > 40.0

Explanation: ***25.0 - 29.9*** - To calculate BMI, divide weight in kilograms by the square of height in meters: Weight = 75 kg, Height = 1.70 m. - BMI = 75 / (1.70 * 1.70) = 75 / 2.89 ≈ **25.95 kg/m²**, which falls within the **overweight** range of 25.0 to 29.9. *< 18.5* - A BMI less than 18.5 indicates **underweight**. - The calculated BMI of approximately 25.95 is significantly higher than this range. *> 30.0* - A BMI greater than 30.0 indicates **obesity**. - The calculated BMI of approximately 25.95 is below this threshold, indicating the patient is not obese. *18.5 - 24.9* - A BMI between 18.5 and 24.9 is considered the **normal or healthy weight** range. - The patient's BMI of approximately 25.95 is slightly above this range, placing him in the overweight category. *> 40.0* - A BMI greater than 40.0 indicates **morbid obesity** or **Class III obesity**. - The patient's calculated BMI of 25.95 is substantially lower than this severe obesity classification.

Question 508: A 55-year-old caucasian man presents to his primary care physician with a complaint of double vision, which started suddenly with no precipitating trauma. Twelve years ago, he presented to his physician with painful vision loss, which has since resolved. Since that initial episode, he had numerous episodes early-on in his disease course: two additional episodes of painful vision loss, as well as three episodes of right arm weakness and three episodes of urinary retention requiring catheterization. All of his prior episodes responded to supportive therapy and steroids. Which of the following features of this patient's disease is linked to a more benign disease course?

A. Gender
B. Age at onset
C. Number of episodes early in the disease
D. Initial presenting symptoms (Correct Answer)
E. Race

Explanation: ***Initial presenting symptoms*** - **Optic neuritis** (painful vision loss) or **sensory symptoms** as initial presentations are associated with a **more benign disease course** in multiple sclerosis. - This patient presented with optic neuritis 12 years ago, which is a favorable prognostic indicator. - Motor symptoms, cerebellar symptoms, or polysymptomatic onset at presentation typically indicate a **more aggressive prognosis** with faster disability accumulation. *Age at onset* - This patient had onset at approximately **43 years old** (late onset). - **Later age of onset** (after 40 years) is associated with a **more aggressive disease course** and poorer prognosis in MS. - Earlier age of onset (20s-30s) is typically linked to a more benign relapsing-remitting course with slower progression. *Number of episodes early in the disease* - A **higher number of relapses** early in the disease course (this patient had 8 episodes) is associated with **worse prognosis** and faster disability accumulation. - Frequent early attacks indicate higher disease activity and greater neurological damage. *Gender* - **Female gender** is associated with higher MS incidence and often a slightly more benign course compared to males. - This patient is **male**, which is not a favorable prognostic factor. *Race* - **Caucasian ethnicity** has the highest MS prevalence but does not predict a more benign course. - African Americans tend to have more aggressive disease with faster disability progression, making Caucasian race relatively neutral prognostically.

Question 509: A 26-year-old man presents to the emergency department complaining of hemoptysis for the past day. He has also experienced fatigue, weight loss (10 kg (22 lb) over the last 2 months), and occasional dry cough. He is a college student and works part-time as a cashier in a bookstore. He is sexually active with his girlfriend and uses condoms occasionally. He smokes 2–3 cigarettes on weekends and denies alcohol use. Today, his pulse is 97/min, the blood pressure is 128/76 mm Hg, the temperature is 36.7°C (98.0°F). On physical exam, the patient is well developed with mild gynecomastia. His heart has a regular rate and rhythm. Lung examination reveals vesicular sounds with occasional crepitations bilaterally. The abdominal exam is non-contributory. His right testicle is tender and larger than the left. The swelling does not transilluminate and does not change in size after performing a Valsalva maneuver. His laboratory work is positive for elevated levels of beta-HCG. What is the most likely diagnosis in this patient?

A. Testicular malignancy (Correct Answer)
B. Orchitis
C. Spermatocele
D. Hydrocele
E. Inguinal hernia

Explanation: ***Testicular malignancy*** - The triad of **hemoptysis (pulmonary metastases)**, **testicular mass that does not transilluminate**, and **elevated beta-HCG** is highly suggestive of testicular germ cell tumor. - **Gynecomastia** is often associated with elevated beta-HCG, which can stimulate estrogen production. *Orchitis* - Orchitis typically presents with **acute, painful testicular swelling** often accompanied by fever and systemic symptoms, which is not fully consistent with the chronic weight loss and hemoptysis. - While it can cause tenderness, it is usually associated with **inflammation or infection** and not typically with elevated beta-HCG or systemic metastatic symptoms. *Spermatocele* - A spermatocele is a **benign cyst** that contains sperm, typically located in the epididymis, and usually **transilluminates**. - It is not associated with elevated beta-HCG, gynecomastia, or systemic symptoms like hemoptysis and weight loss. *Hydrocele* - A hydrocele is a collection of fluid around the testicle that usually **transilluminates** and is typically painless or causes a dull ache. - It is not associated with an elevated beta-HCG, gynecomastia, or signs of metastatic disease like hemoptysis. *Inguinal hernia* - An inguinal hernia is the protrusion of abdominal contents through the inguinal canal, - It would typically **change in size with a Valsalva maneuver** and is not associated with specific laboratory findings like elevated beta-HCG or symptoms of distant metastasis.

Question 510: A 46-year-old woman comes to the physician with a 4-month history of lethargy. She has had joint pain for the past 15 years and does not have a primary care physician. Her temperature is 37.4°C (99.3°F), pulse is 97/min, and blood pressure is 132/86 mm Hg. Physical examination shows pallor of the oral mucosa and nontender subcutaneous nodules on both elbows. The distal interphalangeal joints of both hands are flexed and the proximal interphalangeal joints appear hyperextended. Range of motion in the fingers is restricted. The liver span is 6 cm and the spleen tip is palpated 4 cm below the left costal margin. Laboratory studies show: Hematocrit 33% Leukocyte count 1,800/mm3 Segmented neutrophils 35% Lymphocytes 60% Platelet count 130,000/mm3 Increased serum titers of which of the following is most specific for this patient's condition?

A. Anti-U1-RNP antibody
B. Rheumatoid factor
C. Antinuclear antibody
D. Anti-CCP antibody (Correct Answer)
E. Anti-Sm antibody

Explanation: ***Anti-CCP antibody*** - The patient's presentation with **long-standing joint pain**, **nodules**, specific finger deformities (**swan neck deformity** - PIP hyperextension with DIP flexion), **splenomegaly**, and **pancytopenia** (WBC 1,800/mm³, platelets 130,000/mm³, hematocrit 33%) is highly suggestive of **Felty's syndrome**, a severe complication of **rheumatoid arthritis (RA)**. - **Anti-CCP antibodies** are highly specific for RA (over 95% specificity) and can be present years before symptoms develop, making them the most specific marker for this condition. *Anti-U1-RNP antibody* - This antibody is characteristic of **mixed connective tissue disease (MCTD)**, which presents with overlapping features of SLE, systemic sclerosis, and polymyositis. - While joint pain can occur in MCTD, the classic deformities, nodule presence, and specific hematologic findings (leukopenia, thrombocytopenia, anemia) better align with Felty's syndrome due to rheumatoid arthritis. *Rheumatoid factor* - **Rheumatoid factor (RF)** is positive in about 80% of RA patients, but it is less specific than anti-CCP antibodies as it can be elevated in other autoimmune diseases, chronic infections, and even in healthy individuals. - While likely positive in this patient, its lower specificity means it's not the *most* specific marker compared to anti-CCP antibodies. *Antinuclear antibody* - **Antinuclear antibody (ANA)** is a screening test for various autoimmune diseases, particularly **systemic lupus erythematosus (SLE)**, and is positive in many systemic autoimmune conditions. - Its high sensitivity but low specificity (positive in other conditions and even in 5-10% of the healthy population) means it is not the most specific marker for this patient's condition. *Anti-Sm antibody* - **Anti-Smith (Sm) antibody** is highly specific for **systemic lupus erythematosus (SLE)**. - The patient's clinical picture, particularly the long history of joint pain with specific deformities and subcutaneous nodules, is not typical for SLE, making anti-Sm antibody an unlikely specific finding.

Question 511: An 85-year-old man presents to his primary care provider after feeling "lightheaded." He said he helped his wife in the garden for the first time, but that while moving some bags of soil he felt like he was going to faint. He had a big breakfast of oatmeal and eggs prior to working in the garden. He has no significant past medical history and takes a baby aspirin daily. Physical exam reveals an elderly, well-nourished, well-built man with no evidence of cyanosis or tachypnea. Vital signs show normal temperature, BP 150/70, HR 80, RR 18. Cardiac exam reveals crescendo-decrescendo systolic murmur. What is the most likely cause of this patient's diagnosis?

A. Infection
B. Atherosclerosis
C. Calcification (Correct Answer)
D. Congenital defect
E. Malnutrition

Explanation: ***Calcification*** - The patient's age (85 years old) and the presence of a **crescendo-decrescendo systolic murmur** strongly suggest **aortic stenosis**. The most common cause of aortic stenosis in the elderly is **degenerative calcification** of the aortic valve. - His **lightheadedness** upon exertion (moving bags of soil) is consistent with symptoms of aortic stenosis, as the narrowed valve restricts blood flow to the brain during increased demand. *Infection* - While infective endocarditis can cause new murmurs and systemic symptoms, it typically presents with **fever**, **fatigue**, and signs of infection, which are not described in this patient. - The type of murmur in endocarditis is often **regurgitant** or can have a rapidly changing character, rather than the classic crescendo-decrescendo systolic murmur of aortic stenosis. *Atherosclerosis* - Although atherosclerosis is a common process in the elderly and can affect large vessels, it does **not** directly cause aortic stenosis. The valve pathology is primarily a **degenerative calcific process** rather than atherosclerotic plaque formation. - While atherosclerosis and calcific aortic stenosis share some risk factors (age, hypertension, hyperlipidemia), the mechanism of valve narrowing is through progressive **calcification and fibrosis** of the valve leaflets, not atheroma formation. *Congenital defect* - While a **bicuspid aortic valve** is a common congenital defect that can lead to aortic stenosis, symptoms typically present much earlier in life (40s-60s) due to accelerated calcification. - An 85-year-old presenting with new symptoms is more likely to have age-related **degenerative calcific aortic stenosis** rather than a late manifestation of an undiagnosed congenital defect. *Malnutrition* - Malnutrition is not directly associated with the development of a crescendo-decrescendo systolic murmur or **aortic stenosis**. - While severe malnutrition can cause various systemic issues, it does not explain the specific cardiac findings and exertional symptoms described in this well-nourished patient.

Question 512: A 33-year-old man is brought into the emergency department with fever, lethargy, and confusion. He is a cachectic man in acute distress, unable to respond to questions or follow commands. His friend confides that the patient has been sexually active with multiple male partners and was diagnosed with HIV several months ago, but was lost to follow up. Based on prior records, his most recent CD4 count was 65 cells/uL. Which of the following is the most appropriate next step in management?

A. CT head without contrast (Correct Answer)
B. Lumbar puncture
C. Recheck CD4 and HIV viral load serologies
D. MRI brain with contrast
E. Neurological exam with fundoscopy

Explanation: ***CT head without contrast*** - With signs of **increased intracranial pressure** (lethargy, confusion, inability to follow commands), performing a non-contrast CT head is crucial to rule out a **mass lesion** or **herniation risk** before any invasive procedures like a lumbar puncture. - This patient's severely low **CD4 count** (65 cells/uL) puts him at very high risk for opportunistic central nervous system infections such as **toxoplasmosis** or **PML**, or even CNS lymphoma, which can cause mass lesions. *Lumbar puncture* - A **lumbar puncture** is contraindicated in the presence of signs suggestive of increased intracranial pressure until a **mass lesion** has been excluded by imaging. - Performing a lumbar puncture in such a situation could precipitate **brain herniation**, which can be fatal. *Recheck CD4 and HIV viral load serologies* - While important for long-term management, rechecking these labs is not the most **immediate next step** for an acutely ill patient with severe neurological symptoms. - The patient requires urgent diagnosis and treatment for his acute condition, which could be life-threatening, before focusing on **baseline serologies**. *MRI brain with contrast* - An **MRI brain with contrast** provides more detailed imaging than a CT, but a non-contrast CT is faster and sufficient for initial screening for mass lesions or herniation risk. - In an emergency setting with an unstable patient, the **rapid accessibility** of CT makes it the preferred initial imaging modality. *Neurological exam with fundoscopy* - A neurological exam and fundoscopy are important components of the work-up but are **diagnostic steps**, not a management step. - These exams will help localize the lesion and assess for **papilledema**, but imaging is required to confirm the presence of a mass or rule out herniation risk.

Question 513: A 40-year-old woman visits her physician’s office with her husband. Her husband says that she has been complaining of recurring headaches over the past few months. A year ago she was diagnosed with diabetes and is currently on treatment for it. About 6 months ago, she was diagnosed with high blood pressure and is also taking medication for it. Her husband is concerned about the short span during which she has been getting all these symptoms. He also says that she occasionally complains of changes and blurring in her vision. In addition to all these complaints, he has observed changes in her appearance, more prominently her face. Her forehead and chin seem to be protruding more than usual. Suspecting a hormonal imbalance, which of the following initial tests would the physician order to indicate a possible diagnosis?

A. Chest X-ray
B. Pituitary magnetic resonance image (MRI)
C. Serum growth hormone
D. Glucose suppression test
E. Serum insulin-like growth factor-1 (IGF-1) (Correct Answer)

Explanation: ***Serum insulin-like growth factor-1 (IGF-1)*** - Elevated **serum IGF-1 levels** are the most sensitive and reliable initial screening test for **acromegaly**, reflecting sustained growth hormone excess. - The clinical presentation with **new-onset diabetes**, **hypertension**, **headaches**, **visual changes**, and **facial prognathism** strongly suggests acromegaly, a condition caused by excessive growth hormone (GH) secretion. *Chest X-ray* - A chest X-ray is primarily used to evaluate **pulmonary or cardiac conditions** and would not directly screen for hormonal imbalances like acromegaly. - While acromegaly can lead to **cardiomegaly** or **sleep apnea**, a chest X-ray is not the initial diagnostic test for growth hormone excess itself. *Pituitary magnetic resonance image (MRI)* - A **pituitary MRI** is the imaging study of choice to confirm the presence of a **pituitary adenoma** after biochemical confirmation of acromegaly, not an initial screening test. - It visualizes the pituitary gland and helps locate the tumor but is ordered *after* biochemical tests indicate GH excess. *Serum growth hormone* - A single random **serum growth hormone (GH) level** can be misleading because GH secretion is pulsatile, making a single measurement unreliable for diagnosing acromegaly. - While acromegaly involves elevated GH, a random sample is not the optimal initial diagnostic test due to its **fluctuating levels**. *Glucose suppression test* - The **oral glucose tolerance test (OGTT)** with GH measurement is the confirmatory test for acromegaly, used to demonstrate **failure of GH suppression** after glucose load. - This is a diagnostic procedure performed *after* an elevated IGF-1 level suggests acromegaly, not an initial screening test.

Question 514: A 62-year-old woman with hypertension and type 2 diabetes mellitus comes to the physician because of increasing shortness of breath and a dry cough over the past 6 months. She has smoked 1 pack of cigarettes daily for the past 40 years. Chest auscultation shows scattered expiratory wheezes in both lung fields. Spirometry shows an FEV1:FVC ratio of 65% and an FEV1 of 70% of predicted. Her diffusing capacity for carbon monoxide (DLCO) is 42% of predicted. Which of the following is the most likely diagnosis?

A. Pulmonary fibrosis
B. Bronchial asthma
C. Emphysema (Correct Answer)
D. Bronchiectasis
E. Chronic bronchitis

Explanation: ***Emphysema*** - The patient's history of **40 pack-years of smoking**, combined with **obstructive lung disease (FEV1:FVC ratio of 65%)** and a **markedly reduced DLCO (42% of predicted)**, strongly indicates emphysema. - **DLCO reduction** is characteristic of emphysema due to the destruction of alveolar-capillary membranes, which impairs gas exchange. *Pulmonary fibrosis* - Pulmonary fibrosis presents with shortness of breath and dry cough, but it is a **restrictive lung disease**, meaning both FEV1 and FVC would be reduced proportionally, leading to a **normal or increased FEV1:FVC ratio**. - While DLCO is reduced in pulmonary fibrosis, the **obstructive pattern on spirometry** rules out this diagnosis. *Bronchial asthma* - Asthma is characterized by **reversible airway obstruction** and often presents with wheezing and shortness of breath. - However, asthma typically has a **normal DLCO**, as the diffusion capacity of the lung is usually preserved. *Bronchiectasis* - Bronchiectasis involves **permanent dilation of the bronchi** and can cause chronic cough, sputum production, and obstructive lung physiology. - While it can cause some airflow obstruction and reduced DLCO in severe cases, the **primary features often include chronic productive cough** and recurrent infections, and the DLCO reduction is typically less severe than seen in emphysema, unless it's very advanced. *Chronic bronchitis* - Chronic bronchitis is defined by a **chronic productive cough** for at least 3 months in each of 2 consecutive years, in a patient for whom other causes have been excluded. - It causes **obstructive lung disease** and can present with wheezing but typically has a **normal or only slightly reduced DLCO**, as the primary issue is inflammation and mucus production in the airways, not destruction of the alveolar-capillary membrane.

Question 515: A 55-year-old male smoker presents to your office with hemoptysis, central obesity, and a round face with a "moon-like" appearance. He is found to have a neoplasm near the hilum of his left lung. A biopsy of the tumor reveals small basophilic cells with finely granular nuclear chromatin (a "salt and pepper" pattern). Which of the following is the most appropriate treatment for this patient?

A. Tamoxifen
B. Cisplatin and radiotherapy (Correct Answer)
C. Watchful waiting
D. Surgical resection
E. Prednisone

Explanation: ***Cisplatin and radiotherapy*** - The patient presents with symptoms highly suggestive of **small cell lung carcinoma (SCLC)** due to his smoking history, central hilar mass, and paraneoplastic syndrome (Cushing's syndrome from **ACTH production**, causing central obesity and moon facies). - SCLC is characterized by its **aggressive nature** and poor prognosis, and it is **highly responsive to chemotherapy** (e.g., cisplatin/etoposide) and **radiotherapy**, which are the mainstays of treatment. *Tamoxifen* - **Tamoxifen** is an **estrogen receptor modulator** used primarily in the treatment of **hormone-sensitive breast cancer**. - It has no role in the treatment of small cell lung carcinoma, which is not typically hormone-sensitive. *Watchful waiting* - **Watchful waiting** is an inappropriate approach for SCLC, as it is a **rapidly growing** and highly metastatic cancer. - Delaying treatment would lead to rapid disease progression and significantly worsen the patient's already poor prognosis. *Surgical resection* - **Surgical resection** is generally **not indicated for SCLC** because it tends to be widely metastatic at presentation, even if not clinically evident. - It is typically considered only for very early-stage SCLC, which is rare, and often followed by adjuvant chemotherapy. *Prednisone* - **Prednisone** is a corticosteroid that might be used to manage some symptoms of Cushing's syndrome, but it **does not treat the underlying SCLC**. - While it may offer symptomatic relief for certain paraneoplastic effects, it is not a primary cancer treatment and would not impact tumor growth or progression.

Question 516: A 40-year-old man with persistent moderate asthma presents for a pulmonary function test. His ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) is 0.69, and his FEV1 is 65% of his predicted values. What other findings can be expected in the remainder of his pulmonary function test?

A. Decreased diffusion capacity of carbon monoxide (DLCO)
B. Decrease in FEV1 with albuterol
C. Increase in fractional exhalation of nitric oxide (Correct Answer)
D. Decrease in total lung capacity
E. Increase in FEV1 with methacholine

Explanation: ***Increase in fractional exhalation of nitric oxide*** - An increase in **fractional exhalation of nitric oxide (FeNO)** is a marker of **airway inflammation**, which is characteristic of asthma. - This finding would further support the diagnosis of asthma in a patient with **obstructive lung disease** as indicated by the FEV1/FVC ratio and reduced FEV1. *Decreased diffusion capacity of carbon monoxide (DLCO)* - A decreased **DLCO** is typically seen in conditions affecting the **alveolar-capillary membrane**, such as emphysema or interstitial lung disease. - In uncomplicated asthma, the **DLCO** is usually normal or even slightly increased due to increased pulmonary blood volume. *Decrease in FEV1 with albuterol* - **Albuterol** is a **short-acting beta-agonist (SABA)**, a bronchodilator that should *increase* FEV1 in a patient with reversible airway obstruction like asthma. - A **decrease** in FEV1 after albuterol administration would be an unexpected and abnormal response, not consistent with asthma. *Decrease in total lung capacity* - A **decrease in total lung capacity (TLC)** is characteristic of **restrictive lung diseases**, where lung expansion is limited. - Asthma is an **obstructive lung disease**, and patients often exhibit **air trapping** and **hyperinflation**, leading to a *normal or increased* TLC, not a decrease. *Increase in FEV1 with methacholine* - **Methacholine** is a **bronchoconstrictor** used in bronchial challenge tests to *induce* bronchospasm and a *decrease* in FEV1 in asthmatic patients. - An **increase** in FEV1 with methacholine would be contrary to its pharmacological effect and the expected response in asthma.

Question 517: A 56-year-old man presents to his general practitioner with frequent episodes of facial flushing for the past 2 weeks. He says the episodes are associated with mild headaches and a sensation of fullness in his head and neck. Additionally, he has developed recurrent, often severe, itching after taking a hot shower. The patient denies any smoking history but says he drinks alcohol socially. His blood pressure is 160/90 mm Hg, and his temperature is 37.0°C (98.6°F). On physical examination, his face and neck appear red. Cardiac examination reveals a regular rate and rhythm. Lungs are clear to auscultation bilaterally. The spleen is noted to be palpable just below the costal margin. A complete blood count shows a hemoglobin level of 19.5 g/dL, a total leukocyte count of 12,000/mm3, and a platelet count of 450,000/mm3. Which of the following sets of abnormalities is most likely present in this patient?

A. ↑ Blood viscosity, ↓ blood flow with an M-spike of immunoglobulin G
B. ↑ Blood viscosity, ↓ blood flow, ↓ erythropoietin (Correct Answer)
C. ↑ Blood viscosity, ↓ blood flow with blast cells
D. ↑ Blood viscosity, ↓ blood flow with an M-spike of immunoglobulin M
E. ↓ Blood viscosity, ↑ blood flow, ↓ erythropoietin, ↑ ferritin

Explanation: ***↑ Blood viscosity, ↓ blood flow, ↓ erythropoietin*** - The patient's symptoms (facial flushing, headaches, fullness in head/neck, **post-shower pruritus**) and lab findings (hemoglobin **19.5 g/dL**, elevated WBC and platelets) are classic for **polycythemia vera (PV)**. - In polycythemia vera, the increased red blood cell mass leads to **increased blood viscosity** and thus **decreased blood flow**, causing hyperviscosity symptoms. - The excess RBC production is driven by autonomous proliferation (typically due to **JAK2 V617F mutation**), which occurs independently of erythropoietin. The elevated RBC mass suppresses **erythropoietin** levels through negative feedback from the kidneys. - Post-shower pruritus (aquagenic pruritus) is pathognomonic for PV and results from basophil and mast cell degranulation triggered by temperature changes. *↑ Blood viscosity, ↓ blood flow with an M-spike of immunoglobulin G* - While increased blood viscosity and decreased blood flow occur in polycythemia vera, an **M-spike of immunoglobulin G** is characteristic of **multiple myeloma**, not polycythemia vera. - Multiple myeloma presents with anemia (not erythrocytosis), bone pain, hypercalcemia, and renal dysfunction. *↑ Blood viscosity, ↓ blood flow with blast cells* - The presence of **blast cells** in peripheral blood would suggest **acute leukemia**, which is not supported by this clinical picture. - Polycythemia vera is a chronic myeloproliferative neoplasm; blast cells are generally absent in the peripheral blood unless there is transformation to acute leukemia (rare complication). *↑ Blood viscosity, ↓ blood flow with an M-spike of immunoglobulin M* - An **M-spike of immunoglobulin M** is a hallmark of **Waldenström macroglobulinemia**, a lymphoplasmacytic lymphoma. - While Waldenström can cause hyperviscosity syndrome, it presents with anemia, not erythrocytosis, along with lymphadenopathy and hepatosplenomegaly from lymphoid infiltration. *↓ Blood viscosity, ↑ blood flow, ↓ erythropoietin, ↑ ferritin* - **Decreased blood viscosity** and **increased blood flow** would occur in anemia, which is the opposite of this patient's presentation with significantly elevated hemoglobin. - While erythropoietin is indeed decreased in polycythemia vera, **↑ ferritin** is not a primary feature and would be more suggestive of iron overload (hemochromatosis) or an acute phase response to inflammation.

Question 518: A 52-year-old postmenopausal woman seeks evaluation at a medical clinic with complaints of back pain and increased fatigue for 6 months. For the past week, the back pain has radiated to her legs and is stabbing in nature (7/10 in intensity). There are no associated paresthesias. She unintentionally lost 4.5 kg (10.0 lb) in the past 6 months. There is no history of trauma to the back. The past medical history is insignificant and she does not take any medications. The physical examination is normal. The laboratory results are as follows: Hemoglobin 10 g/dL Hematocrit 30% Mean corpuscular volume 80 fL Serum creatinine 1.5 mg/dL Serum total protein 9 g/dL Serum albumin 4.2 g/dL Serum calcium 11.2 mg/dL A peripheral blood smear shows normocytic normochromic cells. An X-ray reveals multiple osteolytic lesions in the vertebrae and long bones. Serum protein electrophoresis shows a monoclonal spike. A bone marrow biopsy shows increased plasma cells making up greater than 50% of the total cell population. Which of the following is the most likely diagnosis in this patient?

A. POEMS syndrome
B. Monoclonal gammopathy of unknown significance
C. Waldenstrom macroglobulinemia
D. Metastatic bone disease
E. Multiple myeloma (Correct Answer)

Explanation: ***Multiple myeloma*** - The patient's presentation with **back pain**, **fatigue**, **anemia**, **elevated creatinine**, **hypercalcemia**, **osteolytic lesions**, and a **monoclonal spike** on serum protein electrophoresis, along with **>50% plasma cells** in bone marrow, is classic for **multiple myeloma**. - These findings fulfill the criteria for active multiple myeloma, characterized by end-organ damage (e.g., **CRAB criteria**: **C**alcium elevation, **R**enal failure, **A**nemia, **B**one lesions) and significant plasma cell infiltration. *POEMS syndrome* - While POEMS syndrome involves **monoclonal plasma cell proliferation**, it presents with features like **Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, and Skin changes**, which are not described in this patient. - The dominant symptoms of **bone pain**, **anemia**, **hypercalcemia**, and **renal failure** are not typical primary manifestations of POEMS syndrome. *Monoclonal gammopathy of unknown significance* - **MGUS** is characterized by the presence of a **monoclonal protein** without evidence of end-organ damage (**CRAB criteria**) or significant bone marrow plasma cell infiltration (typically <10%). - This patient exhibits **hypercalcemia**, **renal dysfunction**, **anemia**, **bone lesions**, and **>50% plasma cells**, all of which rule out MGUS. *Waldenstrom macroglobulinemia* - This is a **lymphoplasmacytic lymphoma** often associated with **hyperviscosity syndrome**, **lymphadenopathy**, and a **monoclonal IgM spike**, none of which are highlighted in this patient's presentation. - While it involves elevated protein and sometimes anemia, the **osteolytic lesions** and **hypercalcemia** are not characteristic of Waldenstrom macroglobulinemia; it rarely causes destructive bone lesions. *Metastatic bone disease* - Although metastatic bone disease can cause **osteolytic lesions** and **back pain**, it typically does not present with a **monoclonal protein spike** or **elevated plasma cells** in the bone marrow. - The detailed laboratory findings, including **monoclonal gammopathy** and **high plasma cell percentage**, are highly specific to plasma cell dyscrasias rather than solid tumor metastases.

Question 519: A 72-year-old male with history of hypertension, diabetes mellitus, cluster headaches, and basal cell carcinoma presents with complaints of progressive dyspnea. He has had increasing shortness of breath, especially when going on walks or mowing the lawn. In addition, he had two episodes of extreme lightheadedness while moving some of his furniture. His temperature is 98.2°F (36.8°C), blood pressure is 135/92 mmHg, pulse is 70/min, respirations are 14/min, and oxygen saturation is 94% on room air. Physical exam is notable for clear lung fields and a 3/6 systolic ejection murmur best heard at the right 2nd intercostal space. In addition, the carotid pulses are delayed and diminished in intensity bilaterally. Which of the following would most likely be seen in association with this patient’s condition?

A. Colonic angiodysplasia (Correct Answer)
B. Erectile dysfunction
C. Cerebral artery aneurysm
D. Deep vein thrombosis
E. Carotid atherosclerosis

Explanation: ***Colonic angiodysplasia*** - This patient's presentation of exertional dyspnea, lightheadedness, a 3/6 systolic ejection murmur best heard at the right 2nd intercostal space, and diminished/delayed carotid pulses is highly suggestive of **aortic stenosis**. - **Heyde’s syndrome** is the classic association of severe aortic stenosis with acquired **Gastrointestinal (GI) bleeding** from colonic angiodysplasia. *Erectile dysfunction* - While erectile dysfunction is common in older males with **vascular disease** and comorbidities like hypertension and diabetes, it is not a direct or specific association with aortic stenosis in the same way Heyde's syndrome is. - It reflects generalized vascular health but doesn't have a unique pathophysiological link to aortic valve pathology. *Cerebral artery aneurysm* - **Cerebral artery aneurysms** are associated with conditions like polycystic kidney disease or connective tissue disorders (e.g., Ehlers-Danlos, Marfan syndrome), but not typically with aortic stenosis. - There is no direct causal or strong correlational link between aortic stenosis and cerebral aneurysms. *Deep vein thrombosis* - **Deep vein thrombosis (DVT)** is a risk in patients with immobility, certain malignancies, hypercoagulable states, and heart failure, but it is not specifically or exclusively associated with aortic stenosis as a unique complication. - While chronic illness can increase DVT risk, it lacks the specific association seen with angiodysplasia. *Carotid atherosclerosis* - Carotid atherosclerosis is common in a 72-year-old male with risk factors like hypertension and diabetes. However, the prominent "diminished and delayed" carotid pulses described ("**pulsus parvus et tardus**") are a direct physical finding of **severe aortic stenosis** due to reduced stroke volume and delayed ejection, rather than simply being a concurrent atherosclerotic disease. - While carotid atherosclerosis can coexist, the specific pulse characteristic is a direct consequence of the valvular pathology.

Question 520: A 65-year-old woman comes to the physician for a 18-month history of gradual enlargement of her fingertips and a 2-month history of a hoarse voice. She has had decreased appetite after a respiratory tract infection 3 months ago and a 8-kg (17.6-lb) weight loss during this period. The patient has never smoked. She was diagnosed with obstructive sleep apnea 10 years ago and uses a CPAP mask at night. She retired from her job as an administrative assistant at a local college 5 years ago. She appears tired. Her vital signs are within normal limits. Physical examination shows increased convexity of the nail fold and painful swelling of the soft tissue of her fingers and ankles. There is no discoloration of her lips and oral mucosa. There is faint wheezing in the right upper lung field. This patient's condition is most likely associated with which of the following findings?

A. Increased serum ACE
B. Increased serum ADH
C. Reticular opacities on chest x-ray (Correct Answer)
D. Peripheral cyanosis
E. Pleural effusion on chest x-ray

Explanation: ***Reticular opacities on chest x-ray*** - The patient presents with **digital clubbing** and **hypertrophic osteoarthropathy (HPO)** - evidenced by painful soft tissue swelling of fingers and ankles. - While **lung cancer** is a major concern given the **hoarseness** (recurrent laryngeal nerve involvement), **unilateral wheezing** (bronchial obstruction), and **weight loss**, clubbing with HPO can also be associated with **idiopathic pulmonary fibrosis (IPF)**. - **Reticular opacities** are the characteristic radiographic finding of **interstitial lung disease**, including IPF, which commonly presents with digital clubbing. - IPF patients may develop secondary infections and constitutional symptoms including weight loss. *Increased serum ACE* - **Elevated serum ACE** is primarily associated with **sarcoidosis**, a granulomatous disease. - While sarcoidosis can cause clubbing and pulmonary symptoms, the **painful periostitis** (hypertrophic osteoarthropathy) and **unilateral wheezing** are not typical features. *Increased serum ADH* - **Increased serum ADH** indicates **syndrome of inappropriate antidiuretic hormone secretion (SIADH)**, a paraneoplastic syndrome most commonly associated with **small cell lung cancer**. - SIADH presents with **hyponatremia** and symptoms such as confusion, nausea, or seizures, which are not described in this patient. *Peripheral cyanosis* - **Peripheral cyanosis** indicates reduced oxygen saturation in peripheral tissues, typically from poor circulation or severe hypoxemia. - While advanced interstitial lung disease can cause hypoxemia, the question specifically notes **no discoloration of lips and oral mucosa**, indicating absence of cyanosis. *Pleural effusion on chest x-ray* - **Pleural effusions** are commonly associated with **lung malignancy**, particularly adenocarcinoma. - While lung cancer is in the differential given the hoarseness and unilateral findings, the **bilateral clubbing and symmetric HPO** are more characteristic of diffuse pulmonary processes like ILD rather than localized malignancy with effusion.

Question 521: A previously healthy 24-year-old man is brought to the emergency department 30 minutes after an episode of loss of consciousness. He was standing in line at a bus stop when he suddenly became tense, fell down, and lost consciousness; this was followed by 4 minutes of violent jerky movements of his arms and legs. He was confused after the episode. He has no recollection of the event or its immediate aftermath. On arrival, he is alert and oriented to time, place, and person. His temperature is 37.7°C (99.4°F), pulse is 98/min, and blood pressure is 130/70 mm Hg. Physical examination shows blood in the mouth. Neurologic examination shows no focal findings. A CT scan of the head shows no abnormalities. Further evaluation of this patient is most likely to show which of the following laboratory findings?

A. Increased serum sodium
B. Reduced serum creatine kinase
C. Reduced serum bicarbonate (Correct Answer)
D. Increased serum magnesium
E. Increased serum calcium

Explanation: ***Reduced serum bicarbonate*** - The patient's presentation with sudden loss of consciousness, tonic-clonic movements, postictal confusion, and tongue biting is classic for a **generalized tonic-clonic seizure** - Prolonged intense muscle activity during the seizure leads to **anaerobic metabolism** and **lactic acidosis** - The accumulated lactic acid consumes bicarbonate as a buffer, resulting in **reduced serum bicarbonate** and metabolic acidosis - This is typically transient and resolves within hours as lactate is cleared *Increased serum sodium* - Seizures do not typically cause **hypernatremia** as a direct consequence - While severe hyponatremia can precipitate seizures, the seizure itself does not increase sodium levels - Serum sodium is generally unchanged immediately post-seizure *Reduced serum creatine kinase* - The violent muscle contractions during a **tonic-clonic seizure** cause **rhabdomyolysis** (muscle breakdown) - This results in a significant **increase in serum creatine kinase (CK)**, not a reduction - Elevated CK is a common and expected finding after generalized tonic-clonic seizures and may peak 24-48 hours post-seizure *Increased serum magnesium* - There is no physiological mechanism by which a seizure would cause **hypermagnesemia** - Magnesium levels are typically unaffected by seizure activity - Note: Low magnesium can be a cause of seizures, but the seizure itself doesn't increase magnesium *Increased serum calcium* - **Serum calcium** levels are not directly affected by the acute seizure event - While severe **hypocalcemia** can precipitate seizures, a seizure does not cause hypercalcemia - Calcium homeostasis remains stable during and after typical seizures

Question 522: A 69-year-old woman is brought to the physician by her husband because of multiple falls and difficulty maintaining balance while standing or walking over the past year. During this period, she has had blurred vision and diplopia. Her husband has had difficulty understanding her speech for the past 3 months. She has become withdrawn and now refuses to go to social gatherings. Examination shows a broad-based gait and dysarthria. The visual acuity is 20/20 in each eye. There is conjugate limitation of both eyes while looking down. Muscle tone is increased in bilateral upper extremities. Bradykinesia is present. Mental status examination shows apathy. She responds to questions with 1–2 words after a delay of several seconds. Grasp reflex is present. An MRI of the brain is most likely to show which of the following?

A. Enlarged ventricles with mild cortical atrophy
B. Frontal atrophy with intact hippocampi
C. Atrophy of cerebellum and brainstem
D. Midbrain atrophy with intact pons (Correct Answer)
E. Asymmetric focal cortical atrophy

Explanation: ***Midbrain atrophy with intact pons*** - The constellation of **supranuclear ophthalmoplegia** (especially impaired vertical gaze), **postural instability with falls**, **dysarthria**, **bradykinesia**, and **cognitive changes** (apathy, delayed responses) in an older adult is highly characteristic of **Progressive Supranuclear Palsy (PSP)**. - **PSP** classically manifests with **atrophy of the midbrain**, particularly the **tegmentum**, while the pons remains relatively spared, giving the characteristic "hummingbird sign" or "penguin sign" on MRI in sagittal view. *Enlarged ventricles with mild cortical atrophy* - This finding is common in **normal pressure hydrocephalus (NPH)**, which presents with a triad of **gait ataxia**, **urinary incontinence**, and **dementia**. - While gait disturbance and cognitive decline are present here, the prominent **supranuclear ophthalmoplegia** and **increased muscle tone** are not typical of NPH. *Frontal atrophy with intact hippocampi* - This pattern is characteristic of **frontotemporal dementia (FTD)**, which often presents with **behavioral changes**, **personality alterations**, or **language deficits**. - While apathy is present, the pronounced oculomotor dysfunction, bradykinesia, and falls point away from a primary FTD diagnosis. *Atrophy of cerebellum and brainstem* - **Cerebellar atrophy** would typically cause more prominent **appendicular ataxia**, **dysmetria**, and nystagmus, which are not the primary features described. - Diffuse **brainstem atrophy** can be seen in various neurodegenerative conditions but does not specifically pinpoint the selective midbrain involvement characteristic of PSP. *Asymmetric focal cortical atrophy* - This finding is more typical of **cortical degenerative conditions** like **corticobasal degeneration (CBD)** or some forms of **frontotemporal dementia**. - CBD might present with asymmetric parkinsonism and apraxia, but the prominent supranuclear ophthalmoplegia and the specific midbrain atrophy pattern are more indicative of PSP.

Question 523: A 66-year old man with a 45-pack-year smoking history presents with abdominal pain and constipation. He reports that he has had a worsening cough for several months and has lost 20 pounds over this time period. You order a complete metabolic profile, which demonstrates hypercalcemia. A chest radiograph shows a centrally located mass suspicious for malignancy. Which of the following is the most likely explanation?

A. Metastatic abdominal cancer
B. Carcinoid tumor causing carcinoid syndrome
C. Squamous cell carcinoma producing a peptide with hormonal activity (Correct Answer)
D. Small cell carcinoma producing a peptide with hormonal activity
E. Squamous cell carcinoma producing parathyroid hormone

Explanation: ***Squamous cell carcinoma producing a peptide with hormonal activity*** - The combination of **hypercalcemia**, a **central lung mass** in a patient with a heavy **smoking history**, and symptoms like abdominal pain and constipation (due to hypercalcemia) strongly suggests **paraneoplastic syndrome** due to squamous cell carcinoma. - **Squamous cell carcinoma (SCC)** of the lung is well-known to produce **parathyroid hormone-related peptide (PTHrP)**, leading to **humoral hypercalcemia of malignancy (HHM)**, which mimics the effects of PTH. *Metastatic abdominal cancer* - While metastatic cancer can cause weight loss and abdominal symptoms, it doesn't typically present with a **central lung mass** as the primary suspicious finding for malignancy and **hypercalcemia** without bone metastases. - This option does not explain the presence of a **central lung mass** and associated hypercalcemia. *Carcinoid tumor causing carcinoid syndrome* - **Carcinoid tumors** can cause weight loss and abdominal pain, but they are typically associated with **carcinoid syndrome** (flushing, diarrhea, bronchospasm), not hypercalcemia. - **Carcinoid tumors** rarely cause hypercalcemia and are not typically associated with large central lung masses and a heavy smoking history in this manner. *Small cell carcinoma producing a peptide with hormonal activity* - **Small cell lung carcinoma (SCLC)** is associated with **paraneoplastic syndromes**, most notably **SIADH (syndrome of inappropriate antidiuretic hormone secretion)** leading to hyponatremia, and **Cushing's syndrome** due to ectopic ACTH production. - While SCLC is a central lung mass and associated with smoking, it is **less commonly linked to PTHrP-mediated hypercalcemia** than squamous cell carcinoma. *Squamous cell carcinoma producing parathyroid hormone* - **Squamous cell carcinoma** produces **parathyroid hormone-related peptide (PTHrP)**, not true **parathyroid hormone (PTH)**. - **PTHrP** mimics PTH in its effects but is structurally different; ectopic production of actual PTH by a non-parathyroid tumor is extremely rare.

Question 524: A 42-year-old woman presents to the urgent care clinic with recurrent chest pain and pressure radiating to her jaw. ECG is obtained and shows ST-segment elevation, but her cardiac enzymes are repeatedly found to be within normal ranges. She has a heart rate of 82/min and a blood pressure of 128/76 mm Hg. Physical examination reveals regular heart sounds with no friction rub. Which of the following options is an acceptable treatment regimen for this patient’s suspected condition?

A. Calcium channel blockers and nitrates (Correct Answer)
B. Nitrates only
C. Beta-blockers, nitrates and aspirin
D. Aspirin and clopidogrel
E. Aspirin, clopidogrel, beta-blockers, and nitrates

Explanation: **Calcium channel blockers and nitrates** - This patient likely has **Prinzmetal's angina** (vasospastic angina), characterized by recurrent chest pain, ST-segment elevation on ECG, and normal cardiac enzymes, consistent with **coronary artery spasm**. - **Calcium channel blockers** (e.g., diltiazem, amlodipine) and **nitrates** are the cornerstone of treatment, as they directly relax coronary arteries and prevent spasms. *Nitrates only* - While **nitrates** can alleviate acute symptoms of Prinzmetal's angina by vasodilation, they are generally **insufficient for long-term prevention** of recurrent spasms. - **Calcium channel blockers** are crucial for sustained prophylaxis against vasospasm. *Beta-blockers, nitrates and aspirin* - **Beta-blockers** are generally **contraindicated** in Prinzmetal's angina as they can worsen **coronary artery spasm** by blocking beta-2 mediated vasodilation, leading to unopposed alpha-adrenergic vasoconstriction. - **Aspirin** is not the primary treatment for vasospastic angina, as the pain is due to spasm rather than thrombotic occlusion. *Aspirin and clopidogrel* - **Aspirin** and **clopidogrel** are **antiplatelet agents** primarily used to prevent thrombus formation in atherosclerotic coronary artery disease. - They are not indicated as a first-line treatment for Prinzmetal's angina, where chest pain is due to **coronary vasospasm**, not platelet aggregation. *Aspirin, clopidogrel, beta-blockers, and nitrates* - This combination includes several treatments that are either **ineffective** or **harmful** for Prinzmetal's angina. - **Beta-blockers** are contraindicated, and **antiplatelet agents** (aspirin, clopidogrel) are not primary treatments for vasospasm.

Question 525: A 62-year-old man is brought to the emergency department by his wife because she thinks he has had a stroke. He has hypertension and type 2 diabetes mellitus. Current medications include enalapril and metformin. He has smoked 1 pack of cigarettes per day for the past 35 years. His blood pressure is 162/95 mm Hg. A CT scan of the brain shows a lacunar stroke involving the left subthalamic nucleus. The patient most likely presented with which of the following findings on physical examination?

A. Cogwheel rigidity
B. Dystonia
C. Hemispatial agnosia
D. Vertical gaze palsy
E. Hemiballismus (Correct Answer)

Explanation: ***Hemiballismus*** - A lacunar stroke in the **subthalamic nucleus (STN)** typically causes **hemiballismus**, which is characterized by wild, involuntary, large-amplitude flinging movements on one side of the body. - The STN is part of the **basal ganglia circuit** and its damage leads to disinhibition of the thalamus, resulting in hyperkinetic movements. *Cogwheel rigidity* - This is a feature of **Parkinson's disease**, resulting from damage to the **substantia nigra** affecting dopamine production, not typically a direct result of a lacunar stroke in the subthalamic nucleus. - It is characterized by a jerky resistance to passive movement in a limb. *Dystonia* - Characterized by sustained or repetitive muscle contractions resulting in **twisting and repetitive movements** or abnormal fixed postures. - While basal ganglia dysfunction can cause dystonia, it's a broader term, and **hemiballismus** is a more specific and classic presentation of STN lesions. *Hemispatial agnosia* - Refers to a deficit in attention to one side of space, most commonly associated with lesions in the **non-dominant (right) parietal lobe**. - This is distinct from the motor symptoms expected from a subthalamic nucleus lesion. *Vertical gaze palsy* - Commonly associated with lesions in the **midbrain**, particularly the **dorsal midbrain syndrome (Parinaud syndrome)**. - This is not a typical presentation of a lacunar stroke specifically involving the subthalamic nucleus.

Question 526: A 47-year-old man presents to the physician’s office with an inability to maintain an erection. He can achieve an erection, but it is brief and decreases soon after the penetration. His erectile dysfunction developed gradually over the past 2 years. He denies decreased libido, depressed mood, or anhedonia. He does not report any chronic conditions. He has a 20-pack-year history of smoking and drinks alcohol occasionally. He weighs 120 kg (264.5 lb), his height is 181 cm (5 ft 11 in), and his waist circumference is 110 cm (43 in). The blood pressure is 145/90 mm Hg and the heart rate is 86/min. Physical examination is performed including a genitourinary and rectal examination. It reveals no abnormalities besides central obesity. Which of the following laboratory tests is indicated to investigate for the cause of the patient’s condition?

A. Total serum bilirubin
B. 24-hour urine cortisol
C. Plasma calcium
D. Fasting serum glucose (Correct Answer)
E. Follicle-stimulating hormone

Explanation: ***Fasting serum glucose*** - The patient has **risk factors for insulin resistance and type 2 diabetes**, including obesity, central obesity (waist circumference 110 cm), hypertension, and a sedentary lifestyle. - **Type 2 diabetes mellitus is a common cause of erectile dysfunction** due to vascular and neurological complications, making fasting serum glucose an essential diagnostic step. *Total serum bilirubin* - **Elevated bilirubin** is typically associated with **liver or hemolytic disorders**, neither of which are suggested by the patient's presentation. - While chronic illness can impact sexual function, bilirubin is not a primary screening tool for erectile dysfunction. *24-hour urine cortisol* - A 24-hour urine cortisol test is used to diagnose **Cushing's syndrome**, which can cause obesity and hypertension, but the patient's symptoms are more consistent with metabolic syndrome. - There are no other features suggestive of Cushing's, such as **proximal muscle weakness, striae, or buffalo hump**, making this test less relevant initially. *Plasma calcium* - **Abnormal calcium levels** can indicate conditions like hyperparathyroidism or certain malignancies, which are not typically linked as direct causes of erectile dysfunction. - There are no symptoms such as **nephrolithiasis, bone pain, or neuropsychiatric changes** to suggest calcium dysregulation. *Follicle-stimulating hormone* - While **gonadotropin levels** (FSH and LH) are relevant in evaluating **hypogonadism**, this patient denies decreased libido or symptoms suggestive of primary hypogonadism. - A **total testosterone level is a more appropriate initial screening test for hypogonadism** if indicated, as FSH primarily reflects testicular function.

Question 527: A 39-year-old woman with type 1 diabetes mellitus comes to the physician because of a 2-month history of fatigue and hair loss. She has smoked one pack of cigarettes daily for the past 15 years. Her only medication is insulin. Her pulse is 59/min and blood pressure is 102/76 mm Hg. Physical examination shows dry skin, coarse hair, and a nontender, diffuse neck swelling in the anterior midline. Further evaluation of this patient is most likely to show which of the following findings?

A. DR5 subtype on HLA haplotype analysis
B. Biphasic spindle cells on biopsy of the swelling
C. Diffusely increased uptake on a radioactive iodine scan
D. B8 subtype on HLA haplotype analysis
E. Antimicrosomal antibodies in serum (Correct Answer)

Explanation: ***Antimicrosomal antibodies in serum*** - The patient's symptoms (fatigue, hair loss, dry skin, coarse hair, bradycardia, diffuse neck swelling) and history (type 1 diabetes) are highly suggestive of **Hashimoto's thyroiditis**, an autoimmune thyroid disease. - **Antimicrosomal antibodies (anti-TPO antibodies)** are characteristic markers for Hashimoto's thyroiditis, indicating autoimmune destruction of thyroid tissue. *DR5 subtype on HLA haplotype analysis* - While type 1 diabetes is associated with certain HLA subtypes (e.g., DR3, DR4), **DR5** is not typically linked to Hashimoto's thyroiditis. - This option is less specific and less directly indicative of the present thyroid pathology compared to antimicrosomal antibodies. *Biphasic spindle cells on biopsy of the swelling* - **Biphasic spindle cells** are characteristic of **solitary fibrous tumors** or **synovial sarcomas**, neither of which fits the clinical picture of a diffuse, nontender neck swelling associated with hypothyroidism. - A biopsy of a typical Hashimoto's goiter would show **lymphocytic infiltration** and **Hürthle cells**. *Diffusely increased uptake on a radioactive iodine scan* - **Diffusely increased uptake** on a radioactive iodine scan is characteristic of **Graves' disease** (hyperthyroidism), where the thyroid gland is overactive. - In Hashimoto's thyroiditis, especially in the hypothyroid phase, uptake is typically **reduced** or normal, as the gland's function is impaired. *B8 subtype on HLA haplotype analysis* - **HLA-B8** is associated with certain autoimmune conditions like **Graves' disease** and **myasthenia gravis**, but it is not a primary or direct indicator for Hashimoto's thyroiditis. - As with other HLA subtypes, serological markers are more directly diagnostic for thyroid diseases.

Question 528: A 10-year-old boy presents to the emergency department accompanied by his parents with a swollen and painful right knee after he fell from his bicycle a few hours ago. The patient’s mother says he fell off the bike and struck the ground with his whole weight on his right knee. Immediately, his right knee swelled significantly, and he experienced severe pain. The patient’s past medical history is significant for previous episodes of easy bruising that manifest as small bluish spots, but not nearly as severe. The family history is significant for an uncle who had similar symptoms, and who was diagnosed at the age of 13 years old. The patient is afebrile, and the vital signs are within normal limits. On physical examination, a large bruise is present over the right knee that is extending several inches down the leg. The right tibiofemoral joint is warm to the touch and severely tender to palpation. Which of the following is the most likely diagnosis in this patient?

A. Factor V Leiden
B. Hemophilia A (Correct Answer)
C. Homocystinuria
D. Protein C deficiency
E. von Willebrand disease

Explanation: ***Hemophilia A*** - The combination of a **hemarthrosis** (swollen, painful knee after trauma), a history of **easy bruising**, and a **family history** of similar bleeding issues in a male relative points strongly to an X-linked bleeding disorder like hemophilia A. - Hemophilia A is caused by a deficiency in **Factor VIII**, leading to impaired fibrin clot formation and prolonged bleeding, especially into joints and muscles. *Factor V Leiden* - **Factor V Leiden** is a **thrombophilia**, a condition that increases the risk of **blood clotting** (thrombosis), not bleeding. - It would manifest as deep vein thrombosis, pulmonary embolism, or other thrombotic events, which are contrary to the presented symptoms. *Homocystinuria* - **Homocystinuria** is an inherited disorder of **amino acid metabolism** that primarily affects connective tissue, the brain, and the cardiovascular system. - While it can lead to **thromboembolic events**, it does not typically cause bleeding episodes or hemarthrosis. *Protein C deficiency* - **Protein C deficiency** is another **thrombophilia**, increasing the risk of **venous and arterial thrombosis**. - Like Factor V Leiden, it is associated with excessive clotting, not the bleeding symptoms described in the patient. *von Willebrand disease* - **von Willebrand disease** is a common bleeding disorder, but it typically causes **mucocutaneous bleeding** (e.g., nosebleeds, heavy menstrual periods, prolonged bleeding from cuts). - While severe forms can lead to joint bleeds, hemophilia A is a more classic presentation for severe spontaneous or post-traumatic **hemarthrosis** in a young boy with a significant family history.

Question 529: A 32-year-old man comes to the physician because of a 2-week history of a cough and shortness of breath. He also noted several episodes of blood-tinged sputum over the last 4 days. He has a 3-month history of progressive fatigue. His temperature is 37.5°C (98.6°F), pulse is 86/min, respirations are 17/min, and blood pressure is 150/93 mm Hg. Examination shows pale conjunctivae. Crackles are heard on auscultation of the chest. Laboratory studies show: Hemoglobin 10.2 g/dL Leukocyte count 9200/mm3 Platelet count 305,000/mm3 Serum Na+ 136 mEq/L Cl- 101 mEq/L K+ 4.5 mEq/L HCO3- 25 mEq/L Urea nitrogen 28 mg/dL Creatinine 2.3 mg/dL Anti-GBM antibodies positive Antinuclear antibodies negative Urine Blood 2+ Protein 2+ RBC 11–13/hbf RBC casts rare He is started on prednisone and cyclophosphamide. Which of the following is the most appropriate next step in management?

A. Perform hemodialysis
B. Administer inhalative fluticasone
C. Perform plasmapheresis (Correct Answer)
D. Administer enalapril
E. Administer immune globulins

Explanation: ***Perform plasmapheresis*** - The patient presents with **Goodpasture syndrome**, characterized by **pulmonary hemorrhage** (cough, shortness of breath, hemoptysis) and **glomerulonephritis** (elevated creatinine, proteinuria, hematuria, RBC casts). - Given the **positive anti-GBM antibodies** and rapidly progressive disease, **plasmapheresis** is crucial to remove circulating anti-GBM antibodies, along with immunosuppression (prednisone and cyclophosphamide), to halt tissue damage. *Perform hemodialysis* - While the patient has elevated creatinine and early signs of renal impairment, his **blood pressure is 150/93 mm Hg** and **creatinine is 2.3 mg/dL**, indicating that he is not in immediate renal failure requiring hemodialysis yet. - Hemodialysis is used for **end-stage renal disease** or severe acute kidney injury with complications like severe uremia, hyperkalemia, or fluid overload, which are not explicitly present or severe enough for urgent dialysis in this case. *Administer inhalative fluticasone* - Inhalative fluticasone is a **corticosteroid primarily used for asthma or COPD** to reduce airway inflammation. - While the patient has pulmonary symptoms, his condition is due to **systemic autoimmune disease (Goodpasture syndrome)**, not asthma, and requires systemic immunosuppression and antibody removal. *Administer enalapril* - Enalapril is an **ACE inhibitor** used to treat **hypertension** and **renal disease** by reducing proteinuria and blood pressure. - While the patient has hypertension, his primary issue is an **aggressive autoimmune disease**, which requires immediate immunosuppression and plasmapheresis. Enalapril could be considered later for blood pressure control and renoprotection, but it is not the most urgent next step. *Administer immune globulins* - **Intravenous immune globulin (IVIG)** may be used in certain autoimmune conditions as an immunomodulatory agent, but it is **not the first-line treatment for Goodpasture syndrome**. - **Plasmapheresis** is the preferred method for rapidly removing pathogenic anti-GBM antibodies from circulation in Goodpasture syndrome, in conjunction with potent immunosuppressants.

Question 530: A 40-year-old man presents to the physician for a pre-employment medical check-up. He has no symptoms and his past medical history is insignificant. He is a non-smoker. His temperature is 36.9°C (98.4°F), the heart rate is 76/min, the blood pressure is 124/82 mm Hg, and the respiratory rate is 16/min. His general and systemic examination does not reveal any abnormality. Laboratory evaluation is completely normal; however, his chest radiogram shows a single irregularly shaped nodule in the upper lobe of his right lung. The nodule has circumscribed margins and appears to be surrounded by normally aerated lung parenchyma. The nodule is approx. 7 mm (0.28 in) in diameter. The pattern of calcification is nonspecific and there are no signs of atelectasis or pneumonitis. The physician compares the radiogram with another radiogram which was obtained 5 years back. However, there was no pulmonary nodule in the previous radiogram. No other radiograms are available for comparison. Which of the following is the next best step in the diagnostic evaluation of this patient?

A. CT-guided transthoracic needle aspiration (TTNA)
B. Transbronchial needle aspiration (TBNA)
C. Positron emission tomography (PET) scan
D. Thin-section computed tomography (CT) through the nodule (Correct Answer)
E. Single-photon emission CT (SPECT) scan

Explanation: ***Thin-section computed tomography (CT) through the nodule*** - A **solitary pulmonary nodule (SPN)** discovered on a chest X-ray requires further characterization, even if asymptomatic. A **thin-section CT scan** is the next appropriate step to better define the nodule's characteristics, such as size, growth, borders, and presence of calcification patterns, which are crucial for assessing malignancy risk. - The absence of a nodule on a chest radiogram 5 years prior and the non-specific calcification in an asymptomatic, non-smoking 40-year-old indicates a need for more detailed imaging to guide management, which a thin-section CT provides. *CT-guided transthoracic needle aspiration (TTNA)* - **TTNA** is an invasive procedure generally reserved for nodules with a **high suspicion of malignancy** based on initial imaging (like CT) and patient risk factors, or when less invasive methods have failed to yield a diagnosis. - Performing TTNA directly after a chest X-ray without further CT characterization is premature as it carries risks such as **pneumothorax** and hemorrhage. *Transbronchial needle aspiration (TBNA)* - **TBNA** is typically used for sampling hilar, mediastinal, or peribronchial lesions, as well as peripheral nodules that are accessible via bronchoscope. - Given the nodule's position in the **upper lobe of the right lung** and its relatively small size (7mm), initial assessment with CT is preferred before considering an invasive procedure like TBNA. *Positron emission tomography (PET) scan* - A **PET scan** is useful for assessing the **metabolic activity** of a nodule, which helps differentiate between benign and malignant lesions. However, it is typically performed after a thin-section CT scan has provided detailed anatomical information and the nodule is of sufficient size (usually >8-10 mm) to avoid false negatives. - For a 7 mm nodule, the sensitivity of a PET scan can be lower, and it may not be the initial imaging modality chosen without more detailed CT information. *Single-photon emission CT (SPECT) scan* - **SPECT scans** are primarily used for evaluating specific organ functions, such as myocardial perfusion or bone metabolism, and are not indicated for the initial characterization or diagnostic evaluation of a solitary pulmonary nodule. - This imaging modality would not provide the necessary anatomical detail or metabolic information relevant to determine the nature of a lung nodule.

Question 531: A 70-year-old male is brought to the emergency department from a nursing home due to worsening mental status. His nurse reports that the patient has been very lethargic and sleeping more than usual for the past week. She found him confused and difficult to arouse this morning and decided to bring him to the ER. His past medical history is significant for small cell carcinoma of the lung for which he is receiving chemotherapy. He is also on lithium and bupropion for bipolar disorder. Other medications include metoprolol, valsartan, metformin, and insulin. On admission, blood pressure is 130/70 mm Hg, pulse rate is 100/min, respiratory rate is 17/min, and temperature is 36.5°C (97.7°F). He is drowsy and disoriented. Physical examination is normal. Finger-stick glucose level is 110 mg/dL. Other laboratory studies show: Na+ 120 mEq/L (136—145 mEq/L) K+ 3.5 mEq/L (3.5—5.0 mEq/L) Cl- 107 mEq/L (95—105 mEq/L) Creatinine 0.8 mg/dL (0.6—1.2 mg/dL) Serum osmolality 250 mOsm/kg (275—295 mOsm/kg) Urine Na+ 70 mEq/L Urine osmolality 340 mOsm/kg He is admitted to the hospital for further management. Which of the following is the most likely cause of this patient's condition?

A. Psychogenic polydipsia
B. Lithium
C. Infection
D. Carcinoma (Correct Answer)
E. Bupropion

Explanation: ***Carcinoma*** - This patient's **small cell lung carcinoma** is the most likely cause of his presentation, as it is one of the **most common causes of paraneoplastic SIADH**. - The laboratory findings are **classic for SIADH**: euvolemic hyponatremia (Na+ 120 mEq/L), low serum osmolality (250 mOsm/kg), inappropriately concentrated urine (urine osmolality 340 mOsm/kg), and elevated urine sodium (70 mEq/L). - The **altered mental status** (lethargy, confusion) is consistent with severe hyponatremia. - Small cell lung cancer accounts for approximately **15% of all SIADH cases** and should always be considered in this clinical context. *Psychogenic polydipsia* - While excessive water intake can cause hyponatremia, it typically presents with **very dilute urine** (low urine osmolality <100 mOsm/kg) and **low urine sodium** (<20 mEq/L). - This patient has **concentrated urine** (340 mOsm/kg) and **elevated urine sodium** (70 mEq/L), which are inconsistent with psychogenic polydipsia. *Lithium* - Lithium toxicity can cause neurological symptoms but typically causes **nephrogenic diabetes insipidus**, leading to **hypernatremia** or normal sodium levels, not hyponatremia. - Lithium-induced SIADH is exceedingly rare and would not be the most likely diagnosis in a patient with known small cell lung cancer. - The patient's creatinine is normal (0.8 mg/dL), making significant lithium toxicity less likely. *Infection* - Infections (particularly pneumonia, meningitis, or CNS infections) can cause SIADH and altered mental status. - However, this patient has **no fever** (temperature 36.5°C), and there are no other signs suggesting active infection. - The **direct paraneoplastic association** between small cell lung cancer and SIADH makes carcinoma the more likely primary cause. *Bupropion* - Bupropion has been rarely associated with SIADH in case reports, but this is an **uncommon adverse effect**. - Given the patient's **well-established risk factor** (small cell lung carcinoma) for SIADH, the malignancy is a far more likely cause than medication effect.

Question 532: A 32-year-old Caucasian woman presents with a three-month history of weight loss, anxiety, and tremors. She recalls frequent heart palpitations and new discomfort while being outside in the heat. Her labs include a TSH level of 0.1 mIU/L. Additionally, the patient’s serum is positive for antibodies that stimulate the TSH receptor. What process is unique to this patient’s diagnosis?

A. Stimulation of retroorbital fibroblasts (Correct Answer)
B. Elevated levels of cholesterol and low density lipoprotein (LDL)
C. Binding of thyroid hormones to cardiac myocytes
D. Hyperplasia of thyroid follicular cells
E. Lymphocyte-mediated destruction of the thyroid gland

Explanation: ***Stimulation of retroorbital fibroblasts*** - This patient's symptoms (weight loss, anxiety, tremors, heat intolerance, palpitations, low TSH, positive TSH receptor antibodies) are highly classic for **Graves' disease**. - Unique to Graves' disease among thyroid disorders is the **TSH receptor antibody** stimulation of retroorbital fibroblasts and adipocytes, leading to the characteristic symptom of **Graves' ophthalmopathy** (exophthalmos), which is a key distinguishing feature. *Elevated levels of cholesterol and low density lipoprotein (LDL)* - **Elevated cholesterol** and **LDL** are typically associated with **hypothyroidism**, where the metabolic rate is slowed down, leading to decreased clearance of lipids. - In **hyperthyroidism** (Graves' disease), the metabolic rate is increased, often leading to **decreased cholesterol** and LDL levels. *Binding of thyroid hormones to cardiac myocytes* - While **thyroid hormones** do bind to receptors on **cardiac myocytes** in hyperthyroid states, leading to increased heart rate and contractility, this process is not unique to Graves' disease. - This **binding** and its effects on the heart are a general feature of **hyperthyroidism**, regardless of its underlying cause (e.g., toxic multinodular goiter, thyroiditis). *Hyperplasia of thyroid follicular cells* - **Hyperplasia of thyroid follicular cells** occurs in various conditions, including other forms of **hyperthyroidism** and even in some forms of **goiter** without hyperthyroidism. - While it is present in Graves' disease due to constant stimulation by TSH receptor antibodies, it is not a **unique pathological process** specific only to Graves' disease. *Lymphocyte-mediated destruction of the thyroid gland* - **Lymphocyte-mediated destruction** of the thyroid gland is characteristic of **Hashimoto's thyroiditis**, which typically leads to **hypothyroidism**. - In contrast, Graves' disease involves **autoantibody stimulation** of the thyroid leading to hyperthyroidism, not destruction of the gland.

Question 533: A 41-year-old woman comes to the physician because of a 1-year history of fatigue, irregular menstrual cycles, and recurrent sinus infections. Examination shows hirsutism and hypopigmented linear striations on the abdomen. Serum studies show hypernatremia, hypokalemia, and metabolic alkalosis. A 24-hour urinary cortisol level is elevated. Serum ACTH is also elevated. High-dose dexamethasone does not suppress serum cortisol levels. Which of the following is the most likely underlying cause of this patient's condition?

A. Pheochromocytoma
B. Adrenal adenoma
C. Pituitary adenoma
D. Adrenal carcinoma
E. Small cell lung cancer (Correct Answer)

Explanation: ***Small cell lung cancer*** - The combination of **elevated ACTH** and **failure to suppress cortisol** with high-dose dexamethasone suggests an **ectopic ACTH-producing tumor**. - **Small cell lung cancer** is the most common cause of **ectopic ACTH syndrome**, leading to severe Cushing's syndrome with rapid onset and significant metabolic derangements like **hypernatremia**, **hypokalemia**, and **metabolic alkalosis**. *Pheochromocytoma* - This condition causes episodic or sustained **hypertension** and symptoms related to catecholamine excess (e.g., palpitations, sweating, headaches). - It does not primarily lead to the cortisol excess and distinct metabolic disturbances observed in this patient. *Adrenal adenoma* - An **adrenal adenoma** producing cortisol would lead to **Cushing's syndrome** with **low ACTH** due to negative feedback. - The patient's **elevated ACTH** rules out a primary adrenal cause of cortisol excess. *Pituitary adenoma* - A **pituitary adenoma** (Cushing's disease) often shows **partial suppression** of cortisol with high-dose dexamethasone (though not always complete suppression). - While it causes elevated ACTH, the prominent **metabolic derangements** and strong resistance to suppression are more typical of ectopic ACTH production. *Adrenal carcinoma* - An **adrenal carcinoma** producing cortisol would also lead to **Cushing's syndrome** with **low ACTH** due to negative feedback. - The patient's **elevated ACTH** is inconsistent with a primary adrenal tumor.

Question 534: A 35-year-old Caucasian female with a history of rheumatoid arthritis presents to your clinic with pleuritic chest pain that improves while leaning forward. Which of the following additional findings would you expect to observe in this patient?

A. Exaggerated amplitude of pulse on inspiration (Correct Answer)
B. Pulsatile abdominal mass
C. Increase in jugular venous pressure on inspiration
D. S3 heart sound
E. Continuous machine-like murmur

Explanation: ***Exaggerated amplitude of pulse on inspiration*** - The clinical presentation of **pleuritic chest pain that improves while leaning forward** is highly suggestive of **acute pericarditis**. - **Pulsus paradoxus** (an exaggerated drop in systolic blood pressure >10 mmHg during inspiration, manifesting as decreased pulse amplitude) can occur when pericarditis is complicated by **pericardial effusion**. - While not present in all cases of acute pericarditis, pulsus paradoxus is the most relevant finding among the options listed and suggests developing **cardiac tamponade physiology**. - Rheumatoid arthritis can cause serositis including pericarditis with effusion. *Pulsatile abdominal mass* - A **pulsatile abdominal mass** is characteristic of an **abdominal aortic aneurysm (AAA)**, which is unrelated to pericarditis. - AAA typically presents with abdominal or back pain, not pleuritic chest pain. *Increase in jugular venous pressure on inspiration* - An **increase in JVP on inspiration** is known as **Kussmaul's sign**, which is characteristic of **constrictive pericarditis** or **right ventricular failure**. - In acute pericarditis, this sign is not typically present unless chronic constriction has developed. *S3 heart sound* - An **S3 heart sound** is heard during early diastole and indicates **rapid ventricular filling**, typically associated with **heart failure** or **volume overload**. - S3 is not a feature of acute pericarditis, which primarily involves pericardial inflammation. *Continuous machine-like murmur* - A **continuous machine-like murmur** is the classic finding for **patent ductus arteriosus (PDA)**, a congenital heart defect. - This has no association with pericarditis or rheumatoid arthritis.

Question 535: A 32-year-old man comes to the physician because of a 3-month history of progressively worsening shortness of breath on exertion. He is concerned that he has asthma and would like to be started on albuterol. Which of the following findings is most likely to indicate a different diagnosis in this patient?

A. Decrease in systolic blood pressure by 16 mm Hg during inspiration
B. Decrease in FEV1 by 6% after administration of high-dose methacholine (Correct Answer)
C. 129% of the predicted diffusion capacity of the lung for carbon monoxide
D. Visibility of 11 posterior ribs in the midclavicular line above the diaphragm on chest x-ray
E. Bipyramidal crystals measuring 50 μm on sputum analysis

Explanation: ***Decrease in FEV1 by 6% after administration of high-dose methacholine*** - A **positive methacholine challenge test** is defined by a decrease in **FEV1 of ≥20%**, which indicates bronchial hyperreactivity characteristic of asthma. - A **6% decrease is negative** and essentially **rules out bronchial hyperreactivity**, the hallmark pathophysiologic feature of asthma. - This finding most strongly indicates a **different diagnosis** should be pursued (such as cardiac causes, deconditioning, or other pulmonary pathology). *Decrease in systolic blood pressure by 16 mm Hg during inspiration* - This represents **pulsus paradoxus** (>10 mmHg drop during inspiration). - While this can indicate **cardiac tamponade** or **constrictive pericarditis**, it is also a **classic finding in severe asthma exacerbations** due to large intrathoracic pressure swings. - Therefore, this does not reliably indicate a different diagnosis from asthma. *129% of the predicted diffusion capacity of the lung for carbon monoxide* - **Elevated DLCO** is unusual and may suggest **pulmonary hemorrhage**, **polycythemia**, or **obesity**. - Asthma typically has **normal or slightly reduced DLCO**, so this finding is somewhat atypical but not as definitive as a negative methacholine challenge. *Visibility of 11 posterior ribs in the midclavicular line above the diaphragm on chest x-ray* - **Hyperinflation** (>10 posterior ribs visible) is a hallmark of obstructive airway diseases including **asthma** and **COPD**. - This finding **supports** rather than refutes an asthma diagnosis. *Bipyramidal crystals measuring 50 μm on sputum analysis* - These are **Charcot-Leyden crystals** formed from eosinophil breakdown. - They are **characteristic of asthma** and other eosinophilic conditions. - This finding **supports** an asthma diagnosis.

Question 536: A 34-year-old woman presents to her primary care provider after intermittently passing bright pink urine over several days. She is concerned this discoloration is due to blood. Her medical history is unremarkable, she denies being sick in the past weeks and has only taken a couple of diclofenac capsules for pelvic pain associated to her menstrual period. She does not drink alcohol or smoke cigarettes. At the doctor’s office, her blood pressure is 150/90 mm Hg, pulse is 80/min, respiratory rate is 18/min, and temperature is 36.5°C (97.7°F). On physical exam, she has 2+ pitting edema up to her knees. A urinalysis is taken which shows red blood cells, red blood cell casts, and acanthocytes. No proteinuria was detected. Her serum creatinine is 2.4 mg/dL, blood urea nitrogen 42 mg/dL, serum potassium 4.8 mEq/L, serum sodium 140 mEq/L, serum chloride 102 mEq/L. Which of the following is the most appropriate next step in the management of this case?

A. Discontinuation of NSAID
B. Fomepizole
C. Intravenous fluid therapy and electrolyte correction
D. Noncontrast computed tomography
E. Renal biopsy (Correct Answer)

Explanation: ***Renal biopsy*** - The patient presents with **acute nephritic syndrome**, characterized by **hypertension**, **edema**, and **active urine sediment** (RBCs, RBC casts, acanthocytes) indicating glomerular inflammation, despite no overt proteinuria. - Given the features of rapid progression (elevated creatinine) and the classic findings of nephritic urine, a **renal biopsy** is crucial for establishing the specific diagnosis (e.g., IgA nephropathy, post-infectious glomerulonephritis, rapidly progressive glomerulonephritis) and guiding appropriate immunosuppressive therapy. *Discontinuation of NSAID* - While **NSAIDs** can cause acute kidney injury, the presence of **RBC casts** and **acanthocytes** in the urine strongly points towards a **glomerular pathology**, which is not typically caused solely by NSAID use. - Although NSAIDs should generally be avoided in kidney injury, simply discontinuing them would not address the underlying glomerular disease. *Fomepizole* - **Fomepizole** is an antidote used for **ethylene glycol** or **methanol poisoning**, which cause a severe **metabolic acidosis** and often acute kidney injury with oxalate crystals. - The patient's presentation does not suggest toxic alcohol ingestion; she has no severe acidosis, and the urine sediment points to intrinsic glomerular disease. *Intravenous fluid therapy and electrolyte correction* - While the patient has **elevated creatinine** and potential fluid overload (pitting edema), her electrolytes are currently within normal limits, and the initial management should focus on diagnosing the underlying cause of her nephritic syndrome. - Aggressive fluid administration might worsen her **hypertension** and **edema** in the setting of acute kidney injury with fluid retention. *Noncontrast computed tomography* - A **noncontrast CT** is useful for identifying kidney stones, hydronephrosis, or large renal masses as causes of hematuria but would not provide the specific diagnosis for a **glomerular disease** manifesting with RBC casts and acanthocytes. - It would not show the microscopic changes crucial for diagnosing glomerulonephritis, making it a less appropriate initial step compared to a renal biopsy in this context.

Question 537: A 28-year-old man comes to the physician for a follow-up examination after a previous visit showed an elevated serum calcium level. He has a history of bipolar disorder. His mother had a parathyroidectomy in her 30s. The patient does not drink alcohol or smoke. Current medications include lithium and a daily multivitamin. His vital signs are within normal limits. Physical examination shows no abnormalities. Laboratory studies show: Serum Sodium 146 mEq/L Potassium 3.7 mEq/L Calcium 11.2 mg/dL Magnesium 2.3 mEq/L PTH 610 pg/mL Albumin 4.2 g/dL 24-hour urine Calcium 23 mg Which of the following is the most likely cause of this patient’s findings?

A. Lithium toxicity
B. Parathyroid adenoma
C. Excess calcium intake
D. Excess vitamin D intake
E. Abnormal calcium sensing receptors (Correct Answer)

Explanation: ***Abnormal calcium sensing receptors*** - The patient's **hypocalciuric hypercalcemia** (high serum calcium, low urine calcium) in the presence of an **elevated PTH** suggests a defect in calcium sensing. - The family history of parathyroidectomy in the mother is consistent with an inherited condition affecting **calcium-sensing receptors (CaSRs)**, such as **familial hypocalciuric hypercalcemia (FHH)**. *Lithium toxicity* - **Lithium** can cause hypercalcemia by increasing the set point for calcium at the parathyroid gland, leading to increased PTH secretion. - However, lithium typically does not lead to **hypocalciuria** to the extent seen in FHH, as it does not directly affect the kidney's CaSR in the same manner. *Parathyroid adenoma* - A **parathyroid adenoma** would cause **primary hyperparathyroidism**, characterized by hypercalcemia and elevated PTH. - However, primary hyperparathyroidism typically presents with **hypercalciuria** due to the PTH-mediated increase in renal calcium reabsorption being overwhelmed by the increased filtered calcium load, unlike the hypocalciuria seen here. *Excess calcium intake* - **Excess calcium intake** could lead to hypercalcemia, but this would typically suppress PTH (unless it's a milk-alkali syndrome variant). - It would also lead to **hypercalciuria** as the kidneys attempt to excrete the excess calcium, which is not observed here with a suppressed 24-hour urine calcium. *Excess vitamin D intake* - **Excess vitamin D intake** causes hypercalcemia by increasing intestinal calcium absorption and bone resorption, and would typically lead to **suppressed PTH** levels. - It would also typically result in **hypercalciuria** due to the increased filtered calcium load, contrasting with the low urine calcium in this patient.

Question 538: A 53-year-old woman presents to her primary care physician with complaints of pain and swelling in her hands and fingers. She states that she has had these symptoms since she was in her 20s, but they have recently become more severe. She states that her wedding ring no longer fits, due to increased swelling of her fingers. She is a 30-pack-year smoker with a body mass index (BMI) of 31 kg/m2. The vital signs include: blood pressure 122/78 mm Hg, heart rate 72/min, and respiratory rate 15/min. On physical exam, a mild systolic murmur is heard over the apex, and her lungs are clear bilaterally. There is swelling of all the digits bilaterally, and a yellow-white plaque is noted beneath 3 of her nail beds. When asked about the plaques, she states that she was given itraconazole for them about 3 weeks ago; however, the plaques did not resolve. When asked further about joint pain, she notes that she has had shoulder and knee pain for the last several years, although she has not sought medical care for this. Which of the following is the best initial step in this patient’s therapeutic management?

A. Administer methotrexate
B. Administer indomethacin
C. Administer indomethacin and methotrexate (Correct Answer)
D. Administer sulfasalazine
E. Administer indomethacin and sulfasalazine

Explanation: ***Administer indomethacin and methotrexate*** - This patient presents with symptoms highly suggestive of **psoriatic arthritis**, including typical joint pain distribution (hands, fingers, shoulders, knees), **dactylitis** (swelling of all digits causing the wedding ring to no longer fit), and **nail lesions** (yellow-white plaques unresponsive to antifungals). - Given the patient's severe and chronic symptoms, a **combination of a non-steroidal anti-inflammatory drug (NSAID) like indomethacin for symptomatic relief and a disease-modifying anti-rheumatic drug (DMARD) like methotrexate** is the most appropriate initial therapy to control inflammation and prevent joint damage. *Administer methotrexate* - While **methotrexate** is a cornerstone DMARD for psoriatic arthritis, it takes several weeks to exert its full therapeutic effects. - Administering methotrexate alone would not provide immediate relief for the patient's significant pain and swelling. *Administer indomethacin* - **Indomethacin**, an NSAID, would provide symptomatic relief from pain and inflammation. - However, NSAIDs alone do not modify the disease course or prevent joint damage in psoriatic arthritis; therefore, it is an insufficient long-term monotherapy. *Administer sulfasalazine* - **Sulfasalazine** is an alternative DMARD used in psoriatic arthritis, often considered for patients who cannot tolerate methotrexate or for milder forms, especially with peripheral arthritis. - However, for a patient with severe, chronic, and potentially erosive disease suggested by long-standing symptoms and diffuse dactylitis, **methotrexate is generally preferred due to its stronger efficacy profile** as an initial DMARD for psoriatic arthritis if no contraindications exist. *Administer indomethacin and sulfasalazine* - This combination provides short-term symptomatic relief (indomethacin) and long-term disease modification (sulfasalazine). - While a valid option, **methotrexate is generally considered the first-line DMARD for psoriatic arthritis**, especially in severe cases, due to its greater efficacy in controlling both skin and joint manifestations compared to sulfasalazine.

Question 539: A 19-year-old male arrives to student health for an annual check up. He is up to date on his infant and childhood vaccinations up to age 10. At age 12, he received a single dose of the tetanus, diphtheria, and acellular pertussis vaccine, and a quadrivalent meningococcal conjugate vaccine. A month ago, he received the influenza vaccine. The patient has no significant medical history. He takes over the counter ibuprofen for occasional headaches. He has a father with hypertension and hyperlipidemia, and his brother has asthma. He is sexually active with his current girlfriend. He denies tobacco use, illicit drug use, and recent or future travel. The patient’s temperature is 98°F (36.7°C), blood pressure is 118/78 mmHg, pulse is 70/min, and respirations are 14/min with an oxygen saturation of 99% O2 on room air. A physical examination is normal. What of the following is the best recommendation for vaccination?

A. Human papillomavirus vaccine (Correct Answer)
B. Hepatitis A vaccine
C. Herpes zoster vaccine
D. Pneumococcal vaccine
E. Tetanus and reduced diphtheria toxoid booster

Explanation: ***Human papilloma virus*** - This patient, being 19 years old and **sexually active**, is a prime candidate for the **HPV vaccine** to prevent infections that can lead to various cancers. - The CDC recommends routine HPV vaccination at age 11-12, but catch-up vaccination is recommended for individuals up to age 26 if not adequately vaccinated previously. *Hepatitis A vaccine* - The Hepatitis A vaccine is generally recommended for individuals at **increased risk** of infection, such as travelers to endemic areas, men who have sex with men, or those with chronic liver disease, none of which apply to this patient. - There is no indication for routine vaccination without specific risk factors in this otherwise healthy young male. *Herpes zoster vaccine* - The herpes zoster (shingles) vaccine is recommended for adults **age 50 years and older** to prevent shingles. - This patient is only 19 years old, making him too young for this vaccine recommendation. *Pneumococcal vaccine* - Pneumococcal vaccines (PCV13 and PPSV23) are typically recommended for **young children**, adults **65 years and older**, or individuals with **certain underlying medical conditions** (e.g., chronic heart, lung, or kidney disease, or immunocompromised states). - This 19-year-old patient has no such risk factors for pneumococcal disease. *Tetanus and reduced diphtheria toxoid booster* - The patient received a Tdap vaccine at age 12. A Td booster is recommended **every 10 years** for adults. - Since it has been only 7 years since his last Tdap vaccine, he is not due for a Td booster at this time.

Question 540: A 57-year-old man with a history of coronary artery disease has been brought to the emergency department due to the sudden onset of chest pain. He was diagnosed with hypertension 12 years ago and takes enalapril regularly. The patient is hypotensive to 70/42 mm Hg, and on further examination his skin is cold and clammy. He is diagnosed with a life-threatening condition that resulted from inadequate circulation of blood, with decreased cardiac output and high pulmonary capillary wedge pressure. Which of the conditions below can cause the same disorder? I. Acute myocardial infarction II. Atrial fibrillation III. Hemorrhage IV. Valvular stenosis V. Pulmonary embolism VI. Sepsis

A. I, II, IV (Correct Answer)
B. I, II, IV, V
C. I, IV, VI
D. I, II, III
E. I, IV, V

Explanation: ***I, II, IV (Acute myocardial infarction, Atrial fibrillation, Valvular stenosis)*** - The patient's presentation with **hypotension**, **cold and clammy skin**, **decreased cardiac output**, and **high pulmonary capillary wedge pressure** is characteristic of **cardiogenic shock**. - **Acute myocardial infarction** causes cardiogenic shock through direct myocardial damage and pump failure, leading to elevated left ventricular filling pressures and high PCWP. - **Atrial fibrillation** can cause cardiogenic shock through loss of atrial kick (reducing CO by 20-30%), rapid ventricular rates impairing diastolic filling, and tachycardia-induced cardiomyopathy—all resulting in pump failure with elevated PCWP. - Severe **valvular stenosis** (aortic or mitral) causes cardiogenic shock by obstructing cardiac output and causing backward transmission of pressure, resulting in elevated PCWP. *I, II, IV, V* - This option incorrectly includes **pulmonary embolism** as a cause of cardiogenic shock with **high pulmonary capillary wedge pressure**. - While pulmonary embolism causes profound hypotension and shock, it produces **obstructive shock** with **low or normal PCWP** due to right ventricular outflow obstruction and right heart failure, not left heart pump failure. *I, IV, VI* - This option incorrectly includes **sepsis** and excludes **atrial fibrillation**. - **Sepsis** causes **distributive shock** characterized by **low systemic vascular resistance** and typically **low or normal PCWP** initially, though late septic cardiomyopathy can occur, it does not present with the classic high PCWP pattern described. *I, II, III* - This option incorrectly includes **hemorrhage** as a cause of cardiogenic shock. - **Hemorrhage** causes **hypovolemic shock** with **low cardiac output** due to reduced preload and **low PCWP**, not the high PCWP characteristic of cardiogenic shock. *I, IV, V* - This option incorrectly includes **pulmonary embolism** and excludes **atrial fibrillation**. - **Pulmonary embolism** causes **obstructive shock** with right ventricular dysfunction and **low or normal PCWP**, not the elevated PCWP seen in cardiogenic shock from left heart pump failure.

Question 541: A 55-year-old man presents to the physician for the evaluation of excessive daytime sleepiness over the past six months. Despite sleeping 8–9 hours a night and taking a nap during the day, he feels drowsy and is afraid to drive. His wife complains of loud snoring and gasping during the night. His blood pressure is 155/95 mm Hg. BMI is 37 kg/m2. Oropharyngeal examination shows a small orifice and an enlarged tongue and uvula. The soft palate is low-lying. The examination of the nasal cavity shows no septal deviation or polyps. Examination of the lungs and heart shows no abnormalities. Polysomnography shows an apnea-hypopnea index of 20 episodes/h. The patient is educated about weight loss, exercise, and regular sleep hours and duration. Which of the following is the most appropriate next step in management?

A. Continuous positive airway pressure (Correct Answer)
B. Upper airway neurostimulation
C. Supplemental oxygen
D. Oral appliances
E. Upper airway surgery

Explanation: ***Continuous positive airway pressure*** - This patient presents with symptoms and polysomnography findings consistent with **moderate to severe obstructive sleep apnea (OSA)** (apnea-hypopnea index of 20 episodes/h). **CPAP is the first-line treatment** for such cases. - CPAP works by **delivering pressurized air** via a mask, creating a pneumatic splint that prevents the collapse of the upper airway during sleep, thereby reducing apneas and hypopneas. *Upper airway neurostimulation* - This therapy involves stimulating the **hypoglossal nerve** to activate upper airway muscles, improving airway patency. - However, it is generally considered a **second-line treatment** for patients with moderate to severe OSA who **cannot tolerate or fail CPAP therapy**. *Supplemental oxygen* - While oxygen therapy can reduce nocturnal desaturation, it **does not address the underlying airway obstruction** that causes apneas and hypopneas. - It might even **worsen apnea by blunting the ventilatory drive**, making it an inappropriate primary treatment for OSA. *Oral appliances* - **Mandibular advancement devices (MADs)** can be effective for **mild to moderate OSA**, or for patients with severe OSA who cannot tolerate CPAP. - They work by repositioning the jaw and tongue forward to enlarge the pharyngeal space, but CPAP is generally more effective for the severity described. *Upper airway surgery* - Various surgical procedures, such as **uvulopalatopharyngoplasty (UPPP)**, aim to remove excess tissue in the pharynx to enlarge the airway. - Surgery is typically reserved for patients who **fail or cannot tolerate CPAP and oral appliances** and are carefully selected based on anatomical considerations.

Question 542: A 60-year-old man comes to the emergency department because of a 3-day history of fever and shortness of breath. He has a history of COPD treated with inhaled albuterol. His temperature is 39.0°C (102.2°F), pulse is 95/min, respirations are 20/min, and blood pressure is 130/80 mm Hg. Cardiopulmonary examination shows decreased breath sounds and poor air movement over the left lung. A lateral decubitus x-ray of the chest shows a pleural effusion height of 2 cm. Thoracentesis is performed and pleural fluid analysis shows a protein concentration of 4.0 g/dL and LDH of 280 U/L. Which of the following is the most likely underlying cause of this patient's effusion?

A. Decreased intrapleural pressure
B. Increased pulmonary capillary permeability (Correct Answer)
C. Decreased plasma oncotic pressure
D. Increased pulmonary capillary pressure
E. Impaired lymphatic flow

Explanation: ***Increased pulmonary capillary permeability*** - This patient presents with **fever**, **shortness of breath**, and a **pleural effusion** in the setting of COPD. The pleural fluid analysis shows a **protein concentration of 4.0 g/dL** and **LDH of 280 U/L**, which are **high absolute values** strongly suggestive of an **exudative effusion**. - An exudative effusion indicates inflammation and increased permeability of the pleural capillaries, allowing proteins and other large molecules to leak into the pleural space. Given the acute presentation with fever and respiratory symptoms in a patient with COPD, **pneumonia with associated para-pneumonic effusion** is the most likely diagnosis. The inflammatory process in pneumonia increases local capillary permeability, resulting in protein-rich fluid accumulation in the pleural space. - This mechanism distinguishes exudates from transudates, which result from alterations in hydrostatic or oncotic pressures without primary inflammation. *Decreased intrapleural pressure* - This mechanism is associated with conditions like **atelectasis**, where a collapsed lung creates negative pressure in the pleural space, drawing fluid toward it. - Effusions from decreased intrapleural pressure are typically **transudative** with low protein and LDH levels, which is inconsistent with this patient's findings. The acute febrile presentation also does not fit with atelectasis as the primary process. *Decreased plasma oncotic pressure* - This occurs in conditions like **nephrotic syndrome**, **cirrhosis**, or **severe malnutrition**, where low serum albumin reduces the oncotic pressure gradient. - Decreased plasma oncotic pressure results in **transudative effusions** with low protein (typically < 3.0 g/dL) and low LDH, which contradicts this patient's high protein and LDH values. Additionally, there are no clinical features suggesting hypoalbuminemia. *Increased pulmonary capillary pressure* - This mechanism is characteristic of **congestive heart failure**, where elevated hydrostatic pressure in the pulmonary capillaries forces fluid into the pleural space. - Heart failure typically produces **transudative effusions** with low protein and LDH. This patient's high protein (4.0 g/dL) and elevated LDH (280 U/L) are inconsistent with a hydrostatic mechanism. Furthermore, the acute fever and normal blood pressure argue against heart failure as the primary cause. *Impaired lymphatic flow* - Impaired lymphatic drainage can cause pleural effusions, as seen in **malignancy** (lymphatic obstruction), **chylothorax** (thoracic duct injury), or lymphatic abnormalities. - While lymphatic obstruction can produce exudative effusions (especially in malignancy), the **acute onset with fever** points more strongly toward an infectious/inflammatory process rather than a chronic lymphatic disorder. Chylothorax would show milky fluid with high triglycerides, not seen here.

Question 543: A 59-year-old man is brought to the emergency department by a coworker for right arm weakness and numbness. The symptoms started suddenly 2 hours ago. His coworker also noticed his face appears to droop on the right side and his speech is slurred. He has a history of hypertension, hyperlipidemia, type 2 diabetes, and peripheral arterial disease. He works as a partner at a law firm and has been under more stress than usual lately. His father died of a stroke at age 70. The patient has smoked a pack of cigarettes daily for the last 40 years. He drinks two pints (750 mL) of whiskey each week. He takes aspirin, atorvastatin, lisinopril, and metformin daily. He is 167.6 cm (5 ft 6 in) tall and weighs 104.3 kg (230 lb); BMI is 37 kg/m2. His temperature is 37.1°C (98.8°F), pulse is 92/min, respirations are 15/min, and blood pressure is 143/92 mm Hg. He is fully alert and oriented. Neurological examination shows asymmetry of the face with droop of the lips on the right. There is 3/5 strength in right wrist flexion and extension, and right finger abduction. Sensation to light touch and pinprick is reduced throughout the right arm. Which of the following is the strongest predisposing factor for this patient's condition?

A. Excessive alcohol intake
B. Obesity
C. Hypertension (Correct Answer)
D. Increased stress
E. Hyperlipidemia

Explanation: ***Hypertension*** - **Hypertension is the single most important modifiable risk factor for stroke**, accounting for approximately 50% of stroke risk in population studies - This patient's blood pressure of **143/92 mm Hg despite being on lisinopril** indicates poorly controlled hypertension, which significantly increases stroke risk - Hypertension directly damages blood vessels through chronic endothelial injury and accelerates **atherosclerosis**, leading to both ischemic and hemorrhagic stroke *Excessive alcohol intake* - Heavy alcohol consumption (>2 drinks/day) increases stroke risk, particularly hemorrhagic stroke - This patient's intake of two pints weekly (~5 drinks) is moderate-to-heavy but not the strongest risk factor compared to poorly controlled hypertension - The association between alcohol and stroke is less consistent than that of hypertension *Obesity* - **Obesity (BMI 37 kg/m²)** increases stroke risk indirectly by promoting hypertension, diabetes, and dyslipidemia - It is an important risk factor but acts primarily through these intermediate mechanisms rather than as a direct cause - Hypertension remains the more potent and direct predisposing factor *Increased stress* - Chronic stress may contribute to stroke risk through effects on blood pressure, inflammation, and health behaviors - However, stress is a **weak and indirect risk factor** with inconsistent epidemiological evidence - It does not compare to the well-established, quantifiable impact of hypertension *Hyperlipidemia* - **Hyperlipidemia** promotes atherosclerosis and is an established risk factor for ischemic stroke - The patient is on atorvastatin, which likely provides some protection - While significant, hypertension has consistently been shown to have the **greatest population-attributable risk for stroke** among all modifiable factors

Question 544: A previously healthy 61-year-old man comes to the physician because of a 6-month history of morning headaches. He also has fatigue and trouble concentrating on his daily tasks at work. He sleeps for 8 hours every night; his wife reports that he sometimes stops breathing for a few seconds while sleeping. His pulse is 71/min and blood pressure is 158/96 mm Hg. He is 178 cm (5 ft 10 in) tall and weighs 100 kg (220 lb); BMI is 31.6 kg/m2 . Which of the following is the most likely cause of this patient's hypertension?

A. Proliferation of adrenal chromaffin cells
B. Overproduction of cortisol
C. Hypophyseal neoplasm
D. Nocturnal upper airway obstruction (Correct Answer)
E. Hypersecretion of aldosterone

Explanation: ***Nocturnal upper airway obstruction*** - The patient's **obesity (BMI 31.6)**, **morning headaches**, fatigue, difficulty concentrating, and spousal report of **witnessed apneic episodes during sleep** are classic signs of **obstructive sleep apnea (OSA)**. - OSA causes **intermittent hypoxia and hypercapnia** during sleep, leading to **sympathetic nervous system activation**, increased catecholamine release, and **sustained hypertension** even during waking hours. - OSA is one of the most common **secondary causes of hypertension**, especially in obese patients. *Proliferation of adrenal chromaffin cells* - This describes a **pheochromocytoma**, which typically presents with **paroxysmal hypertension**, severe episodic headaches, palpitations, and diaphoresis (the classic "triad"). - While headaches are present, the **sleep-related breathing disturbances** and obesity are not consistent with pheochromocytoma. *Overproduction of cortisol* - This suggests **Cushing's syndrome**, which includes symptoms like central obesity, **moon facies, buffalo hump, purple striae**, muscle weakness, and easy bruising, along with hypertension. - The patient lacks the classic cushingoid features, and the symptoms are more consistent with sleep-disordered breathing. *Hypophyseal neoplasm* - A pituitary tumor could cause hypertension if it leads to conditions like **Cushing's disease** (ACTH-secreting) or **acromegaly** (growth hormone excess). - However, there are no specific symptoms pointing towards a pituitary tumor (no visual field defects, acromegalic features, or cushingoid appearance), and the prominent **witnessed apneas** fit OSA much better. *Hypersecretion of aldosterone* - This is characteristic of **primary hyperaldosteronism (Conn's syndrome)**, which commonly presents with hypertension, often accompanied by **hypokalemia**, muscle weakness, and polyuria. - The patient's symptoms do not suggest electrolyte abnormalities or other classic signs of mineralocorticoid excess.

Question 545: A 58-year-old woman presents to her primary care physician with complaints of an aching pain and stiffness in her neck, shoulders, and hips for the past several months. She reports difficulty in rising from a seated position as well as in raising her arms above her head. The patient also states that she has had fatigue and chronic fevers for the past month. Close and careful physical examination reveals normal muscle strength (despite some pain with testing and palpation), but limited range of motion of the neck, shoulders, and hips. There is no evidence in the history or physical examination of giant cell (temporal) arteritis. An initial work-up reveals a hemoglobin of 9 g/dL on a complete blood count. Further laboratory results are still pending. Which of the following results would be expected in the work-up of this patient's presenting condition?

A. Normal erythrocyte sedimentation rate and normal serum creatinine kinase
B. Elevated serum C-reactive protein and normal erythrocyte sedimentation rate
C. Normal erythrocyte sedimentation rate and elevated serum creatine kinase
D. Elevated erythrocyte sedimentation rate and normal serum creatine kinase (Correct Answer)
E. Elevated erythrocyte sedimentation rate and elevated serum creatine kinase

Explanation: ***Elevated erythrocyte sedimentation rate and normal serum creatine kinase*** - **Polymyalgia Rheumatica (PMR)** is characterized by an **elevated erythrocyte sedimentation rate (ESR)** and/or **C-reactive protein (CRP)**, reflecting the underlying inflammatory process. - **Creatine kinase (CK)** levels are typically **normal** in PMR, as the condition primarily involves inflammation of the synovium, bursae, and joint capsules, rather than direct muscle fiber damage. *Elevated erythrocyte sedimentation rate and elevated serum creatine kinase* - While an **elevated ESR** is characteristic of PMR, an **elevated CK** would suggest a primary muscle disorder like **polymyositis** or **dermatomyositis**, which is not supported by the clinical picture of *normal muscle strength* despite pain. - The patient's inability to raise arms and difficulty rising point to **tendon/bursal inflammation** not myonecrosis. *Normal erythrocyte sedimentation rate and normal serum creatine kinase* - A **normal ESR** would make the diagnosis of PMR highly unlikely, as it is a key diagnostic criterion and indicator of inflammation. - While **normal CK** is consistent with PMR, the absence of an elevated ESR would lead away from an inflammatory condition. *Elevated serum C-reactive protein and normal erythrocyte sedimentation rate* - Although **elevated CRP** is common in PMR, a **normal ESR** would be unusual, as both markers of inflammation are typically elevated concurrently in this condition. - The combination of *elevated CRP and normal ESR* could occur if the CRP response is very acute and the ESR is lagging, but in chronic PMR, both are usually high. *Normal erythrocyte sedimentation rate and elevated serum creatine kinase* - A **normal ESR** contradicts the inflammatory nature of PMR, which consistently shows elevated inflammatory markers. - An **elevated CK** suggests muscle damage, which is not characteristic of PMR, where muscle strength is typically preserved despite pain and stiffness.

Question 546: A 23-year-old man is admitted to the intensive care unit with acute respiratory distress syndrome (ARDS) due to influenza A. He has no history of serious illness and does not smoke. An x-ray of the chest shows diffuse bilateral infiltrates. Two weeks later, his symptoms have improved. Pulmonary examination on discharge shows inspiratory crackles at both lung bases. This patient is most likely to develop which of the following long-term complications?

A. Panacinar emphysema
B. Asthma
C. Pulmonary embolism
D. Interstitial lung disease (Correct Answer)
E. Spontaneous pneumothorax

Explanation: ***Interstitial lung disease*** - Patients who recover from **acute respiratory distress syndrome (ARDS)**, especially severe cases like that induced by influenza A, often develop **pulmonary fibrosis** leading to interstitial lung disease. - The presence of **inspiratory crackles at both lung bases** after recovery from ARDS strongly suggests residual fibrotic changes. *Panacinar emphysema* - This condition is typically associated with **alpha-1 antitrypsin deficiency** or long-term smoking history, neither of which is indicated in this patient. - Emphysema involves destruction of alveoli, not typically a direct long-term consequence of ARDS. *Asthma* - Asthma is a chronic inflammatory airway disease characterized by **reversible airflow obstruction**, usually with a history of recurrent episodes, not necessarily a direct sequela of ARDS. - This patient's previous lack of serious illness and the nature of ARDS recovery make new-onset asthma unlikely as a long-term complication. *Pulmonary embolism* - While ARDS patients are at increased risk of **venous thromboembolism** during the acute phase due to immobility and inflammation, it is an acute complication, not a typical long-term sequela. - Long-term complications are more related to lung parenchymal damage rather than persistent embolic risk. *Spontaneous pneumothorax* - Although ARDS can be complicated by **barotrauma** and pneumothorax during mechanical ventilation, a spontaneous pneumothorax as a long-term complication after recovery is less common. - It does not explain the persistent bilateral basal crackles.

Question 547: A 28-year-old woman presents with a 12-month history of headache, tinnitus, retrobulbar pain, and photopsias. She says the headaches are mild to moderate, intermittent, diffusely localized, and refractory to nonsteroidal anti-inflammatory drugs (NSAIDs). In addition, this past week, she began to have associated dizziness and photopsia with the headaches. Physical examination reveals a body temperature of 36.5°C (97.7°F), blood pressure of 140/80 mm Hg, and a respiratory rate of 13/min and regular. BMI is 29 kg/m2. Neurological examination is significant for peripheral visual field loss in the inferior nasal quadrant, diplopia, bilateral abducens nerve palsy, and papilledema. A T1/T2 MRI of the brain did not identify extra-axial or intra-axial masses or interstitial edema, and a lumbar puncture showed an opening pressure of 27 cm H2O, with a cerebrospinal fluid analysis within the normal range. Which of the following best describes the pathogenic mechanism underlying these findings?

A. Systemic hypertension
B. Increased cerebrospinal fluid production
C. Aqueductal stenosis
D. Arachnoid granulation adhesions
E. Elevated intracranial venous pressure (Correct Answer)

Explanation: ***Elevated intracranial venous pressure*** - The combination of **papilledema**, **abducens nerve palsy**, normal brain MRI, and normal CSF analysis with **elevated opening pressure** (27 cm H2O; normal <20-25 cm H2O) is classic for **idiopathic intracranial hypertension (IIH)**, also known as pseudotumor cerebri. - The primary pathogenic mechanism in IIH is often thought to be impaired **CSF absorption** due to elevated **intracranial venous pressure**, particularly within the dural venous sinuses, which can be exacerbated by obesity. *Systemic hypertension* - While the patient has slightly elevated blood pressure (140/80 mmHg), **systemic hypertension** rarely directly causes **papilledema** or **abducens nerve palsy** without other signs of hypertensive encephalopathy or end-organ damage, which are not described. - The elevated intracranial pressure is not directly explained by simply high systemic blood pressure, especially with normal brain imaging. *Increased cerebrospinal production* - **Increased CSF production** is a very rare cause of intracranial hypertension, typically associated with choroid plexus tumors. - The normal CSF analysis and absence of a mass on MRI make this an unlikely primary mechanism. *Aqueductal stenosis* - **Aqueductal stenosis** would lead to **obstructive hydrocephalus**, characterized by ventricular enlargement on MRI, which was not observed in this patient. - While it causes elevated ICP, the normal ventricular size rules out this specific structural obstruction. *Arachnoid granulation adhesions* - **Arachnoid granulation adhesions** could theoretically impair CSF absorption, leading to elevated intracranial pressure. - However, direct evidence of such adhesions is not typically observed on routine MRI, and the underlying cause often relates to a more systemic issue affecting CSF outflow, such as the venous drainage problem described in the correct option.

Question 548: A 79-year-old woman with type 2 diabetes mellitus and hypertension undergoes 99mTc cardiac scintigraphy for the evaluation of a 3-month history of retrosternal chest tightness on exertion. The patient's symptoms are reproduced following the administration of dipyridamole. A repeat ECG shows new ST depression and T wave inversion in leads V5 and V6. Which of the following is the most likely underlying mechanism of this patient's signs and symptoms during the procedure?

A. Dilation of coronary vasculature
B. Ruptured cholesterol plaque within a coronary vessel
C. Increased myocardial oxygen demand
D. Reduced left ventricular preload
E. Coronary steal phenomenon (Correct Answer)

Explanation: ***Correct: Coronary steal phenomenon*** - **Dipyridamole** is a **coronary vasodilator** that preferentially dilates **healthy coronary arteries** with intact endothelium and normal vasodilatory capacity. - In patients with **coronary artery stenosis**, the vessels distal to the stenosis are already maximally dilated at baseline due to autoregulation. - When dipyridamole causes further vasodilation of healthy vessels, blood flow is redistributed **away from** the ischemic areas supplied by stenotic vessels toward the healthy myocardium—this is the **"steal" phenomenon**. - The patient's **ST depression and T wave inversion** in V5-V6 indicate lateral wall ischemia due to this maldistribution of coronary blood flow, not from increased oxygen demand. - This mechanism makes dipyridamole useful for **pharmacologic stress testing** in patients who cannot exercise, as it reveals flow-limiting coronary stenoses without increasing heart rate or contractility. *Incorrect: Increased myocardial oxygen demand* - This is the mechanism of **exercise stress testing** or **dobutamine stress testing**, which increase heart rate, contractility, and blood pressure. - **Dipyridamole does NOT increase myocardial oxygen demand**—it is a pure vasodilator that does not have positive inotropic or chronotropic effects. - The ischemia induced by dipyridamole is due to **supply maldistribution** (steal), not increased demand. - This distinction is clinically important: dipyridamole is chosen for patients who cannot exercise precisely because it avoids increasing cardiac workload. *Incorrect: Ruptured cholesterol plaque within a coronary vessel* - This describes the pathophysiology of **acute coronary syndrome (ACS)**, including unstable angina, NSTEMI, or STEMI. - ACS typically presents with **sudden-onset chest pain at rest**, prolonged symptoms, and more dramatic ECG changes (ST elevation or deep T wave inversions). - This patient has **chronic stable angina** with reproducible exertional symptoms over 3 months, and the ECG changes occurred during a controlled stress test—not consistent with acute plaque rupture. *Incorrect: Dilation of coronary vasculature* - While dipyridamole does cause **coronary vasodilation**, this is not itself the mechanism of ischemia—it's the **differential** vasodilation that causes the problem. - The phrase "dilation of coronary vasculature" describes the drug's action but not the pathophysiologic consequence. - The specific mechanism by which this vasodilation causes ischemia is the **coronary steal phenomenon**, making that the more precise and complete answer. *Incorrect: Reduced left ventricular preload* - Dipyridamole can cause mild systemic vasodilation and slight reduction in preload, but this is **not the mechanism of myocardial ischemia** in this case. - Reduced preload typically causes symptoms of **hypotension** (lightheadedness, dizziness) rather than ischemic chest pain and ST-T wave changes. - The **lateral wall ischemia** pattern (V5-V6) indicates regional myocardial oxygen supply-demand mismatch due to coronary artery disease, not a global reduction in preload.

Question 549: A 42-year-old woman with hypertension comes to the physician because of a 2-month history of persistent reddening of her face, daytime fatigue, and difficulty concentrating. She has fallen asleep multiple times during important meetings. Her only medication is lisinopril. She is 170 cm (5 ft 7 in) tall and weighs 88 kg (194 lb); BMI is 30 kg/m2. Her blood pressure is 145/85 mm Hg. Physical examination shows erythema of the face that is especially pronounced around the cheeks, nose, and ears. Serum glucose concentration is 120 mg/dL. Which of the following is the most likely cause of this patient's facial discoloration?

A. Antibody-mediated vasculopathy
B. Increased bradykinin production
C. Increased cortisol levels (Correct Answer)
D. Increased serotonin levels
E. Increased erythropoietin production

Explanation: ***Increased cortisol levels*** - The patient's **facial plethora (reddening)**, **obesity** (BMI 30 kg/m2), **hypertension**, and **elevated fasting glucose** (120 mg/dL) are classic features of **Cushing's syndrome**, caused by sustained high cortisol levels. - Her symptoms of **fatigue** and **difficulty concentrating**, coupled with **daytime sleepiness**, are also common non-specific manifestations associated with chronic hypercortisolism. *Antibody-mediated vasculopathy* - This typically presents with **purpura**, **livedo reticularis**, or **ulcers**, not generalized facial reddening or plethora. - Conditions like **vasculitis** often involve systemic symptoms such as fever, arthralgias, and myalgias, which are not described. *Increased bradykinin production* - **Bradykinin** can cause **angioedema**, a rapid swelling of the deep dermis and subcutaneous tissue, often involving the face, lips, or tongue. - This is distinct from generalized facial reddening and would also present with episodes of sudden swelling rather than persistent reddening. *Increased serotonin levels* - Elevated **serotonin levels**, usually due to a **carcinoid tumor**, can cause **flushing episodes** that are typically paroxysmal and associated with diarrhea, bronchospasm, and valvular heart disease. - The patient's facial reddening is described as persistent rather than paroxysmal, and other classic symptoms of carcinoid syndrome are absent. *Increased erythropoietin production* - High levels of **erythropoietin** lead to **polycythemia**, which can cause a **ruddy complexion** (plethora) due to an increase in red blood cell mass. - While plethora may be present, polycythemia would also typically present with other symptoms like headache, dizziness, and pruritus after bathing, and would commonly be associated with erythrocytosis on lab tests, which is not mentioned.

Question 550: A 57-year-old woman presents to her physician’s office because she is coughing up blood. She says that she first observed a somewhat reddish sputum a few months ago. However, over the past couple of weeks, the amount of blood she coughs has significantly increased. She has been smoking for the past 30 years. She says that she smokes about 2 packs of cigarettes daily. She does not have fever, night sweats, weight loss, or chills. She reports progressive difficulty in breathing. On examination, her vital signs are stable. On auscultation of her chest, she has an expiratory wheeze. Oxygen saturation is 98%. Which of the following would be the next best step in the management of this patient?

A. Bronchoscopy
B. CT scan
C. Oxygen supplementation
D. Endoscopy
E. Chest radiograph (Correct Answer)

Explanation: **Chest radiograph** - A **chest radiograph** is the most appropriate initial diagnostic step in a patient with hemoptysis and a significant smoking history. It helps identify potential causes like lung cancer, pneumonia, or tuberculosis. - Given the patient's long smoking history and progressive symptoms, a chest X-ray can quickly reveal suspicious lesions or infiltrates guiding further investigation. *Bronchoscopy* - While eventually likely needed, **bronchoscopy** is generally performed after initial imaging (like a chest X-ray) has identified a potential area of concern or if the X-ray is normal but suspicion for a bronchial lesion remains high. - It allows for direct visualization of the airways and biopsies, but it's not the very first step in evaluating **stable hemoptysis**. *CT scan* - A **CT scan** of the chest provides more detailed imaging than a chest X-ray and is often the next step if the X-ray is abnormal or inconclusive. - However, for initial assessment in a stable patient, a chest X-ray is typically performed first due to its lower cost, radiation exposure, and quick availability. *Oxygen supplementation* - The patient's **oxygen saturation is 98%**, indicating she is not in acute respiratory distress requiring immediate oxygen supplementation. - Oxygen is a supportive measure, not a diagnostic step to determine the cause of **hemoptysis**. *Endoscopy* - **Endoscopy** (referring to upper gastrointestinal endoscopy) is used to investigate bleeding from the gastrointestinal tract, not the respiratory system. - **Hemoptysis** is blood coughed up from the lungs, while **hematemesis** is vomiting blood from the GI tract.

Question 551: A 46-year-old woman presents to her primary care physician for her annual examination. At her prior exam one year earlier, she had a Pap smear which was within normal limits. Which of the following health screenings is recommended for this patient?

A. Colorectal screening (Correct Answer)
B. Blood glucose and/or HbA1c screening
C. Blood pressure at least once every 3 years
D. Yearly Pap smear
E. Bone mineral density screening

Explanation: ***Colorectal screening*** - **Colorectal cancer screening** is generally recommended to start at age **45 years** for individuals at average risk. - This patient is 46 years old, making immediate colorectal screening appropriate based on current guidelines. *Blood glucose and/or HbA1c screening* - **Blood glucose or HbA1c screening** for diabetes is recommended starting at age **35 for all adults** or earlier if there are risk factors such as obesity or a family history of diabetes. - While this patient is 46, this screening should have already been initiated, and it is not the *most* uniquely recommended screening for this specific age that might have been overlooked. *Blood pressure at least once every 3 years* - **Blood pressure screening** should be performed **at least annually** for adults aged 40 and older, or more frequently if there are risk factors. - Screening only every 3 years is insufficient for a 46-year-old patient. *Yearly Pap smear* - **Pap smear frequency** has changed; for women aged 30-65 with normal results, screening is recommended every **3 years** with cytology alone, or every 5 years with high-risk HPV testing alone or co-testing. - A yearly Pap smear is no longer typical practice for a woman with normal prior results and no specific risk factors. *Bone mineral density screening* - **Bone mineral density (BMD) screening** for osteoporosis is typically recommended for women starting at age **65 years** or earlier if they have significant risk factors. - This patient is 46 years old and has no mentioned risk factors, so BMD screening is not routinely indicated at this age.

Question 552: A 72-year-old man presents to the emergency department after a fall. The patient was found lying down on the floor in his room in his retirement community. The patient has a past medical history of Alzheimer dementia and a prosthetic valve. His current medications include donepezil and warfarin. His temperature is 97.7°F (36.5°C), blood pressure is 85/50 mmHg, pulse is 160/min, respirations are 13/min, and oxygen saturation is 97% on room air. The patient is started on IV fluids and a type and screen is performed. Laboratory values are ordered as seen below. Hemoglobin: 13 g/dL Hematocrit: 39% Leukocyte count: 5,500 cells/mm^3 with normal differential Platelet count: 225,000/mm^3 INR: 2.5 AST: 10 U/L ALT: 12 U/L A chest radiograph and EKG are performed and are within normal limits. A full physical exam is within normal limits. The patient's vitals are repeated. His temperature is 99.5°F (37.5°C), blood pressure is 110/70 mmHg, pulse is 90/min, respirations are 10/min, and oxygen saturation is 98% on room air. Which of the following is the best next step in management?

A. CT scan (Correct Answer)
B. Urgent blood transfusion
C. Fresh frozen plasma
D. Exploratory laparoscopy
E. Exploratory laparotomy

Explanation: ***CT scan*** - A patient with a **prosthetic valve** on **warfarin** and a fall is at high risk for **intracranial hemorrhage**, even without focal neurological deficits. - While initial vitals improved after IV fluids, the mechanism of injury (fall) and medication profile warrant a **CT scan** of the head to rule out serious internal injury, especially given the history of dementia which might mask symptoms. *Urgent blood transfusion* - The patient's **hemoglobin (13 g/dL)** and **hematocrit (39%)** are within normal limits, indicating no acute need for blood transfusion due to hemorrhage. - Transfusions are typically reserved for patients with significant blood loss or severe symptomatic anemia. *Fresh frozen plasma* - The patient's **INR of 2.5** is within the therapeutic range for a patient with a prosthetic valve on warfarin. - There is no evidence of active bleeding or supratherapeutic anticoagulation that would necessitate the administration of **fresh frozen plasma (FFP)** to reverse anticoagulation. *Exploratory laparoscopy* - There are no clinical signs or symptoms, such as abdominal pain, distension, or evidence of intra-abdominal bleeding (e.g., declining hemoglobin, peritoneal signs), to suggest an indication for an **exploratory laparoscopy**. - The patient's physical exam was described as normal. *Exploratory laparotomy* - Similar to laparoscopy, there is no clinical evidence of acute abdominal injury or hemorrhage, which would necessitate an **exploratory laparotomy**. - This invasive procedure is reserved for cases with strong suspicion of significant intra-abdominal pathology or trauma.

Question 553: A 59-year-old man with angina pectoris comes to the physician because of a 6-month history of shortness of breath on exertion that improves with rest. He has hypertension and hyperlipidemia. Current medications include aspirin, metoprolol, and nitroglycerine. Echocardiography shows left ventricular septal and apical hypokinesis. Cardiac catheterization shows 96% occlusion of the left anterior descending artery. The patient undergoes angioplasty and placement of a stent. The patient's shortness of breath subsequently resolves and follow-up echocardiography one week later shows normal regional contractile function. Which of the following is the most accurate explanation for the changes in echocardiography?

A. Myocardial scarring
B. Unstable angina pectoris
C. Stress cardiomyopathy
D. Hibernating myocardium (Correct Answer)
E. Cardiac remodeling

Explanation: ***Hibernating myocardium*** - This refers to chronically **ischemic but viable myocardium** that shows reduced contractility at rest due to persistent hypoperfusion, which improves or normalizes after revascularization. - The resolution of symptoms and normalization of regional contractile function after stent placement in this patient with chronic angina and a highly occluded LAD artery is highly consistent with this phenomenon. *Myocardial scarring* - **Myocardial scarring** represents irreversible damage and fibrosis, typically resulting from a myocardial infarction (heart attack). - Scarred tissue does not regain contractile function even after revascularization; the observed improvement in contractility rules out this explanation. *Unstable angina pectoris* - **Unstable angina** is characterized by new-onset angina, crescendo angina, or angina at rest, indicating an acute coronary syndrome. - While the patient had angina, the prompt and complete resolution of contractile dysfunction post-revascularization points to a chronic ischemic state rather than an acute, potentially irreversible event or a transient episode of unstable angina that would not cause such persistent functional changes. *Stress cardiomyopathy* - Also known as **Takotsubo cardiomyopathy**, this condition involves transient left ventricular dysfunction, often triggered by severe emotional or physical stress, mimicking a myocardial infarction. - It typically resolves spontaneously over weeks or months and is not caused by fixed coronary artery occlusion that improves with revascularization via stenting. *Cardiac remodeling* - **Cardiac remodeling** refers to changes in the size, shape, and function of the heart in response to chronic stress, such as hypertension or chronic ischemia. - While the patient's long-standing hypertension and hyperlipidemia could lead to some remodeling, the rapid and complete improvement in regional contractility specifically after LAD revascularization best explains the phenomenon as hibernating myocardium, a specific type of physiological adaptation, rather than general remodeling.

Question 554: A 78-year-old man presents with fatigue and exertional dyspnea. The patient says that symptoms onset gradually 4 weeks ago and have not improved. He denies any history of anemia or nutritional deficiency. Past medical history is significant for ST-elevation myocardial infarction 6 months ago, status post coronary artery bypass graft, complicated by recurrent hemodynamically unstable ventricular tachycardia. Current medications are rosuvastatin, aspirin, and amiodarone. His blood pressure is 100/70 mm Hg, the pulse is 71/min, the temperature is 36.5°C (97.7°F), and the respiratory rate is 16/min. On physical examination, patient appears lethargic and tired. Skin is dry and coarse, and there is generalized pitting edema present. A complete blood count (CBC) and a peripheral blood smear show evidence of normochromic, normocytic anemia. Additional laboratory tests reveal decreased serum level of iron, decreased TIBC (total iron-binding capacity) and increased serum level of ferritin. Which of the following is the most likely etiology of the anemia in this patient?

A. Iron deficiency anemia
B. Thalassemia
C. Pernicious anemia
D. Anemia of chronic disease (Correct Answer)
E. Hemolytic anemia

Explanation: ***Anemia of chronic disease*** - The patient's history of **ST-elevation myocardial infarction** and **ventricular tachycardia**, combined with his current medications and symptoms, points to an underlying chronic inflammatory state. - Lab findings of **normochromic, normocytic anemia**, **decreased serum iron**, **decreased total iron-binding capacity (TIBC)**, and **increased ferritin** are classic for anemia of chronic disease. *Iron deficiency anemia* - This condition is characterized by **decreased serum iron**, **increased TIBC**, and **decreased ferritin**, which is inconsistent with this patient's labs. - The patient denies any history of anemia or nutritional deficiency, and no sources of blood loss are mentioned despite the use of **aspirin**. *Thalassemia* - Thalassemia typically presents with **microcytic, hypochromic anemia**, which contradicts the patient's **normocytic, normochromic anemia**. - It is a genetic disorder usually identified earlier in life, unlike this patient's gradual onset of symptoms in old age. *Pernicious anemia* - Pernicious anemia is a type of **macrocytic anemia** (due to B12 deficiency), which is inconsistent with the patient's **normocytic anemia**. - It would typically involve **neurological symptoms** and **megaloblastic changes** on a peripheral smear, none of which are reported. *Hemolytic anemia* - Hemolytic anemia is characterized by evidence of **red blood cell destruction**, such as elevated reticulocyte count, increased LDH, decreased haptoglobin, and increased indirect bilirubin, none of which are mentioned. - The patient's history and lab findings are not typical for a primary hemolytic process.

Question 555: A 37-year-old woman presents to her primary care physician for bilateral nipple discharge. The patient states that she has observed a milky discharge coming from her nipples for the past month. On review of systems, the patient states that she has felt fatigued lately and has experienced decreased libido. She also endorses headaches that typically resolve by the middle of the day and a 5 pound weight gain this past month. The patient has a past medical history of obesity, schizophrenia, and constipation. Her temperature is 99.5°F (37.5°C), blood pressure is 145/95 mmHg, pulse is 60/min, respirations are 15/min, and oxygen saturation is 98% on room air. On physical exam, you note an obese, fatigued-appearing woman. Dermatologic exam reveals fine, thin hair over her body. Cardiopulmonary exam is within normal limits. Neurological exam reveals cranial nerves II-XII as grossly intact. The patient exhibits 1+ sluggish reflexes. Which of the following is the most likely diagnosis?

A. Dopamine blockade in the tuberoinfundibular pathway
B. Protein-secreting CNS mass
C. Normal pregnancy
D. Viral infection of the thyroid gland
E. Autoimmune destruction of the thyroid gland (Correct Answer)

Explanation: ***Autoimmune destruction of the thyroid gland*** - The patient's symptoms of **fatigue**, **weight gain**, **constipation**, **bradycardia** (pulse 60/min), and **sluggish reflexes** are classic signs of **hypothyroidism**. - **Nipple discharge** can occur due to secondary **hyperprolactinemia** caused by increased TRH (thyrotropin-releasing hormone) from the hypothalamus in an attempt to stimulate the underactive thyroid. **Autoimmune destruction** (e.g., Hashimoto's thyroiditis) is the most common cause of hypothyroidism. *Dopamine blockade in the tuberoinfundibular pathway* - This could lead to **hyperprolactinemia** and nipple discharge, especially if she is on **antipsychotic medications** for schizophrenia. - However, it does not explain the other prominent symptoms of **hypothyroidism** such as fatigue, weight gain, constipation, and bradycardia. *Protein-secreting CNS mass* - A **prolactinoma** (a type of protein-secreting CNS mass) can cause **galactorrhea**, headaches, and decreased libido. - However, it would not typically cause the systemic symptoms of **hypothyroidism** like constipation, weight gain, fatigue, and bradycardia. *Normal pregnancy* - **Pregnancy** can cause nipple discharge and fatigue, but vital signs indicate **bradycardia** (pulse of 60/min) rather than the typical tachycardia of pregnancy. - There is no mention of missed periods or other classic signs of pregnancy; therefore, it is less likely given the full symptom constellation. *Viral infection of the thyroid gland* - A viral infection of the thyroid gland (e.g., **subacute thyroiditis**) can initially present with **hyperthyroidism** followed by a hypothyroid phase. - However, the patient's symptoms are primarily hypothyroid from the onset, and the presentation does not suggest an acute inflammatory process typical of viral thyroiditis.

Question 556: A 41-year-old woman presents to the emergency room with chest pain. She has had progressive substernal chest pain accompanied by weakness and mild shortness of breath for the past 2 hours. Her past medical history is notable for poorly controlled systemic lupus erythematosus (SLE), Sjogren syndrome, and interstitial lung disease. She was hospitalized last year with pericarditis presumed to be from SLE. Her temperature is 98.6°F (37°C), blood pressure is 106/56 mmHg, pulse is 132/min, and respirations are 26/min. On exam, the skin overlying the internal jugular vein fills at 9 cm above the sternal angle and distant heart sounds are appreciated. There is no friction rub. She is given 1000cc of intravenous fluids with no appreciable change in her blood pressure. An electrocardiogram in this patient would most likely reveal which of the following findings?

A. Polymorphic P waves
B. ST elevations in leads II, III, and aVF
C. Peaked T waves
D. Wide QRS complexes with no P waves
E. Electrical alternans (Correct Answer)

Explanation: ***Electrical alternans*** - The patient's symptoms (chest pain, shortness of breath, **hypotension**, **tachycardia**, **elevated JVP**, and **distant heart sounds**) in the context of a history of **pericarditis** and **SLE** are highly suggestive of **cardiac tamponade.** - **Electrical alternans**, characterized by alternating QRS complex heights due to the swinging motion of the heart in a large pericardial effusion, is a classic EKG finding for cardiac tamponade. - This finding reflects the mechanical swinging of the heart within the pericardial fluid, causing beat-to-beat variation in QRS amplitude. *Polymorphic P waves* - **Polymorphic P waves** (multifocal atrial tachycardia) occur when there are at least three different P wave morphologies on the EKG, indicating multiple ectopic atrial foci. - This is typically seen in patients with severe lung disease or other conditions causing increased atrial stretch, but it is not a direct consequence or typical finding of cardiac tamponade. *ST elevations in leads II, III, and aVF* - **ST elevations in leads II, III, and aVF** indicate an **inferior myocardial infarction**, which is caused by coronary artery occlusion. - While chest pain is present, the patient's other signs (elevated JVP, distant heart sounds, hypotension not responding to fluids, history of pericarditis/SLE) point away from an acute MI and strongly towards cardiac tamponade. *Peaked T waves* - **Peaked T waves** are characteristic of **hyperkalemia**, a condition of excessively high potassium levels in the blood. - While hyperkalemia can cause cardiac symptoms, it does not typically present with the specific hemodynamic compromise and physical exam findings (elevated JVP, distant heart sounds) described, which are classic for cardiac tamponade. *Wide QRS complexes with no P waves* - **Wide QRS complexes with no P waves** are characteristic of a **ventricular arrhythmia**, such as ventricular tachycardia or idioventricular rhythm. - While the patient is hypotensive and tachycardic, the presenting symptoms and physical exam findings are not directly indicative of a primary ventricular arrhythmia, but rather suggest an extracardiac compression of the heart due to tamponade.

Question 557: A 57-year-old immigrant from Nigeria presents to the emergency department for sudden, severe pain and swelling in her lower extremity. She was at a rehabilitation hospital when her symptoms became apparent. The patient has a past medical history of obesity, diabetes, bipolar disorder, and tonic-clonic seizures. Her current medications include metformin, insulin, lisinopril, and valproic acid. The patient is a prominent IV drug and alcohol user who has presented to the ED many times for intoxication. On physical exam you note anasarca and asymmetric lower extremity swelling. Based on the results of a doppler ultrasound of her swollen lower extremity, heparin is started. The patient is then transferred to the general medicine floor for continued management. Laboratory studies are shown below. Serum: Na+: 137 mEq/L K+: 5.5 mEq/L Cl-: 100 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 22 mg/dL Ca2+: 5.7 mg/dL Creatinine: 1.7 mg/dL Glucose: 70 mg/dL The patient's presentation includes generalized edema (anasarca) along with laboratory abnormalities. What is the most likely underlying diagnosis that explains her overall clinical presentation?

A. Liver failure
B. Nephrotic syndrome (Correct Answer)
C. Antithrombin III deficiency
D. Prothrombin gene mutation
E. Factor V Leiden

Explanation: ***Nephrotic syndrome*** - The patient presents with **anasarca** (generalized edema), **asymmetric lower extremity swelling**, and laboratory findings consistent with **nephrotic syndrome**. - Classic features present: **anasarca** (from hypoalbuminemia and fluid retention), **hypercoagulable state** leading to DVT (loss of antithrombin III in urine), and **renal dysfunction** (elevated creatinine 1.7 mg/dL). - The **hypocalcemia (5.7 mg/dL)** is explained by low albumin—total calcium appears low because ~40% of serum calcium is albumin-bound; ionized calcium is likely normal. - Nephrotic syndrome is characterized by: heavy proteinuria (>3.5 g/day), hypoalbuminemia, hyperlipidemia, and edema—this patient's presentation fits this diagnosis. - Risk factors include diabetes (diabetic nephropathy is a common cause of nephrotic syndrome in adults). *Liver failure* - Although **anasarca** and **edema** can occur in liver failure due to decreased albumin synthesis and portal hypertension, the laboratory values do not show typical signs of severe hepatic dysfunction (e.g., elevated transaminases, bilirubin, or prolonged INR). - The **elevated creatinine** and **hypercoagulable state with DVT** point more towards a primary renal issue rather than liver failure. - Liver failure typically causes **hypocoagulability**, not the hypercoagulability seen here. *Antithrombin III deficiency* - This is a **hereditary thrombophilia** that increases the risk of **venous thromboembolism**, which could explain the DVT. - However, it does **not explain** the patient's **anasarca**, **hypocalcemia**, **elevated creatinine**, or generalized fluid retention. - This would be a complication of nephrotic syndrome (acquired AT-III deficiency from urinary loss), not the primary diagnosis. *Prothrombin gene mutation* - This is another **genetic thrombophilia** (G20210A mutation) that increases the risk of **blood clots**. - Similar to Antithrombin III deficiency, it accounts for DVT risk but **fails to explain** the widespread edema, electrolyte abnormalities, and renal dysfunction. *Factor V Leiden* - The **Factor V Leiden mutation** is the most common inherited cause of **thrombophilia**, predisposing individuals to venous thromboembolism. - While relevant to explaining DVT in isolation, it does **not explain** the patient's severe generalized edema, hypocalcemia, or renal impairment—all of which are key to this clinical presentation.

Question 558: A 62-year-old man comes to the physician because of increasing pain in his right leg for 2 months. The pain persists throughout the day and is not relieved by rest. He tried taking acetaminophen, but it provided no relief from his symptoms. There is no family history of serious illness. He does not smoke. He occasionally drinks a beer. Vital signs are within normal limits. On examination, the right tibia is bowing anteriorly; range of motion is limited by pain. An x-ray of the right leg shows a deformed tibia with multiple lesions of increased and decreased density and a thickened cortical bone. Laboratory studies show markedly elevated serum alkaline phosphatase and normal calcium and phosphate levels. This patient is most likely to develop which of the following complications?

A. Osteosarcoma
B. Renal insufficiency
C. Impaired hearing
D. Pancytopenia
E. High-output cardiac failure (Correct Answer)

Explanation: ***High-output cardiac failure*** - The patient's presentation with **bone pain**, **tibia bowing**, mixed **lytic and blastic lesions** on X-ray, and markedly **elevated alkaline phosphatase** with normal calcium and phosphate is classic for **Paget's disease of bone**. - **Paget's disease** involves increased bone turnover, leading to highly vascularized bone. This increased vascularity can create **arteriovenous shunts**, expanding the vascular bed and increasing cardiac output, eventually leading to **high-output cardiac failure**. - While this complication is **rare** (<3% of cases) and typically occurs only in **extensive polyostotic disease** (>35% skeletal involvement), it is the **most characteristic cardiovascular complication** and represents the direct pathophysiologic consequence of increased bone vascularity. *Osteosarcoma* - While **osteosarcoma** is a serious complication of Paget's disease occurring in approximately **1% of cases**, it is also relatively rare. - Among the listed options, high-output cardiac failure represents the more **direct vascular consequence** of Paget's disease pathophysiology, making it the intended answer for this question about disease mechanisms. *Renal insufficiency* - **Hypercalcemia** can lead to nephrocalcinosis and renal insufficiency, but this patient has **normal calcium levels**, making renal insufficiency due to calcium abnormalities unlikely. - Immobilized Paget's patients can develop hypercalcemia and renal issues, but this is not typical in ambulatory patients. *Impaired hearing* - **Impaired hearing** can occur in Paget's disease when the **skull is affected** (in 30-50% of skull cases), leading to **compression of cranial nerve VIII** or ossicular involvement. - However, this patient's presentation involves **long bone disease** (tibia), and the question focuses on systemic complications of increased bone vascularity rather than localized cranial involvement. *Pancytopenia* - **Pancytopenia** is not a typical complication of Paget's disease. - While severe widespread disease can rarely lead to bone marrow compromise, this is not a recognized primary complication and would not be the most likely outcome.

Question 559: A 67-year-old man with type 2 diabetes mellitus comes to the emergency department because of lightheadedness over the past 2 hours. He reports that he has had similar episodes of lightheadedness and palpitations over the past 3 days. His only medication is metformin. His pulse is 110/min and irregularly irregular. An ECG shows a variable R-R interval and absence of P waves. The patient undergoes transesophageal echocardiography. During the procedure, the tip of the ultrasound probe is angled posteriorly within the esophagus. This view is most helpful for evaluating which of the following conditions?

A. Myxoma in the left atrium
B. Thrombus in the left pulmonary artery
C. Thrombus in the left ventricular apex
D. Tumor in the right main bronchus
E. Aneurysm of the descending aorta (Correct Answer)

Explanation: ***Aneurysm of the descending aorta*** - When the TEE probe is angled **posteriorly within the esophagus**, it optimally visualizes structures directly posterior to the esophagus, particularly the **descending thoracic aorta**. - The descending aorta runs parallel and immediately posterior to the esophagus, making this the ideal view for evaluating **aortic aneurysms, dissections, and atherosclerotic disease** of the descending aorta. - Note: This patient's symptoms (lightheadedness, palpitations) are due to **atrial fibrillation** (irregularly irregular rhythm, absent P waves). The TEE is likely being performed for stroke risk evaluation, but this question tests knowledge of TEE probe positioning and anatomical visualization. *Myxoma in the left atrium* - The left atrium is best visualized using **mid-esophageal views** (especially the 4-chamber view at 0-20 degrees), not a posteriorly angled view. - While TEE is excellent for detecting left atrial myxomas and is commonly performed in AFib patients to evaluate for left atrial appendage thrombus, the posterior angle is not optimal for this structure. *Thrombus in the left pulmonary artery* - The pulmonary arteries are located **anterior** to the esophagus, making them poorly visualized with a posteriorly angled probe. - Pulmonary artery evaluation requires **anterior or superior angulation** of the TEE probe, or CT pulmonary angiography is preferred for pulmonary embolism diagnosis. *Thrombus in the left ventricular apex* - The left ventricular apex is best visualized using **transgastric views** (probe in stomach looking upward), not posterior esophageal views. - LV apex thrombus evaluation requires short-axis and 2-chamber transgastric views at 0-90 degrees. *Tumor in the right main bronchus* - The bronchi are **anterior** to the esophagus and are not adequately visualized with TEE, regardless of probe angle. - TEE is designed for cardiac and great vessel evaluation, not airway pathology; bronchoscopy or CT chest would be appropriate for bronchial tumors.

Question 560: A 44-year-old woman comes to the physician for the evaluation of a 1-month history of fatigue and difficulty swallowing. During this period, she has also had dry skin, thinning hair, and rounding of her face. She has type 1 diabetes mellitus and rheumatoid arthritis. Her father had a thyroidectomy for papillary thyroid cancer. The patient had smoked one pack of cigarettes daily for 20 years but quit 3 years ago. She drinks 2–3 glasses of wine daily. Her current medications include insulin, omeprazole, and daily ibuprofen. She appears well. Her temperature is 36.3°C (97.3°F), pulse is 62/min, and blood pressure is 102/76 mm Hg. Examination of the neck shows a painless, diffusely enlarged thyroid gland. Cardiopulmonary examination shows no abnormalities. Further evaluation is most likely to show which of the following?

A. Positive thyroid peroxidase antibodies and thyroglobulin antibodies in serum (Correct Answer)
B. Diffusely increased uptake on a radioactive iodine scan
C. Increased uptake on radioactive iodine scan in discrete 1-cm area
D. Large irregular nuclei, nuclear grooves, and Psammoma bodies on thyroid biopsy
E. Positive immunohistochemical stain for calcitonin on thyroid biopsy

Explanation: ***Positive thyroid peroxidase antibodies and thyroglobulin antibodies in serum*** - The patient's symptoms (fatigue, dry skin, thinning hair, rounded face, bradycardia) are classic for **hypothyroidism**. - The presence of **Type 1 diabetes mellitus** and **rheumatoid arthritis** suggests an underlying autoimmune diathesis, making **Hashimoto thyroiditis** (autoimmune hypothyroidism) highly likely, which is characterized by positive thyroid peroxidase (TPO) and thyroglobulin antibodies. *Diffusely increased uptake on a radioactive iodine scan* - **Diffusely increased uptake** on a radioactive iodine scan is characteristic of **hyperthyroidism**, such as in **Graves' disease**, which contradicts the patient's hypothyroid symptoms. - In Hashimoto thyroiditis, especially in the hypothyroid phase, uptake is typically **reduced or normal**, not diffusely increased. *Increased uptake on radioactive iodine scan in discrete 1-cm area* - **Increased uptake in a discrete area** (a 'hot nodule') suggests a **toxic adenoma** or a multinodular goiter, which are causes of hyperthyroidism, not hypothyroidism. - This finding would also contradict the patient's clinical presentation of hypothyroidism. *Large irregular nuclei, nuclear grooves, and Psammoma bodies on thyroid biopsy* - These are classic cytologic features seen in **papillary thyroid carcinoma**, not Hashimoto thyroiditis. - While the patient's father had papillary thyroid cancer, her clinical presentation is strongly indicative of hypothyroidism, and her diffusely enlarged, painless gland is more consistent with Hashimoto's than a focal malignant lesion showing these specific cytological features. *Positive immunohistochemical stain for calcitonin on thyroid biopsy* - A positive immunohistochemical stain for **calcitonin** is diagnostic for **medullary thyroid carcinoma**. - This is a neuroendocrine tumor and does not typically present with the generalized hypothyroid symptoms described in the patient.

Question 561: A 47-year-old woman complains of weight gain and irregular menses for the past 2 years. She has gained 13 kg (28.6 lb) and feels that most of the weight gain is in her abdomen and face. She has type 2 diabetes and hypertension for 1 year, and they are difficult to control with medications. Vital signs include a temperature of 36.9°C (98.4°F), blood pressure of 160/100 mm Hg, and pulse of 95/min. The patient's late-night salivary cortisol is elevated. Morning plasma ACTH is high. Brain magnetic resonance imaging shows a 2 cm pituitary adenoma. Which of the following is the optimal therapy for this patient?

A. Unilateral adrenalectomy
B. Bilateral adrenalectomy
C. Pituitary radiotherapy
D. Medical therapy
E. Transsphenoidal pituitary adenomectomy (Correct Answer)

Explanation: ***Transsphenoidal pituitary adenomectomy*** - This patient presents with **Cushing's disease**, characterized by **elevated late-night salivary cortisol** and **high morning plasma ACTH**, coupled with a **pituitary adenoma** on MRI. **Transsphenoidal pituitary adenomectomy** is the first-line and most effective treatment for Cushing's disease, offering the highest chance of remission by directly removing the adenoma. - Successful surgical removal of the tumor can quickly normalize **ACTH** and **cortisol** levels, leading to significant improvement in symptoms like **weight gain**, **hypertension**, **diabetes**, and **menstrual irregularities**. *Unilateral adrenalectomy* - This procedure treats **adrenal adenomas** causing Cushing's syndrome (primary adrenal hypercortisolism), which is characterized by **low or undetectable ACTH levels**. This patient has **high ACTH**, indicating a pituitary source. - Performing a unilateral adrenalectomy in this case would not address the underlying **pituitary tumor** and would not cure Cushing's disease. *Bilateral adrenalectomy* - This is a treatment for severe, refractory Cushing's disease, or as a palliative measure, when **pituitary surgery** has failed or is contraindicated. - While it effectively removes the source of **cortisol**, it leads to **adrenal insufficiency**, requiring lifelong corticosteroid replacement, and carries the risk of **Nelson's Syndrome** (rapid pituitary tumor growth due to loss of negative feedback). *Pituitary radiotherapy* - **Pituitary radiotherapy** is a secondary treatment option, typically used when **transsphenoidal surgery** fails to achieve remission, or if there is residual tumor. - It has a slower onset of action (months to years) compared to surgery, and the patient's severe symptoms require more immediate control. *Medical therapy* - **Medical therapies** (e.g., **ketoconazole**, **mifepristone**, **pasireotide**) are often used as bridging therapy before surgery, when surgery is contraindicated, or for patients with persistent disease after surgery. - They help control **hypercortisolism** but do not cure the underlying **pituitary adenoma**, making **surgical removal** the preferred definitive treatment.

Question 562: A 62-year-old man with a past medical history notable for hemochromatosis now presents for urgent care with complaints of increased thirst and urinary frequency. Physical examination is grossly unremarkable, although there is a bronze discoloration of his skin. His vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, and respiratory rate 14/min. Laboratory analysis reveals fasting blood glucose of 192 mg/dL and subsequently, HbA1c of 8.7. Given the following options, what is the definitive treatment for the patient's underlying disease?

A. Metformin
B. Deferoxamine
C. Basal and bolus insulin
D. Recurrent phlebotomy (Correct Answer)
E. Basal insulin

Explanation: ***Recurrent phlebotomy*** - This patient has signs and symptoms of **hemochromatosis** (bronze skin, history of hemochromatosis) and **diabetes mellitus** (polydipsia, polyuria, elevated fasting glucose, elevated HbA1c). - **Recurrent phlebotomy** is the definitive treatment for hemochromatosis as it removes excess iron from the body by drawing blood. *Metformin* - Metformin is a common initial treatment for **Type 2 Diabetes Mellitus**, but it does not address the underlying iron overload from hemochromatosis. - While it could help manage the diabetes, it is not the **definitive treatment** for the patient's primary underlying disease process. *Deferoxamine* - **Deferoxamine** is an iron chelating agent used to treat iron overload, usually when phlebotomy is contraindicated or ineffective. - While effective, **phlebotomy is generally preferred** as the first-line and most definitive treatment for hereditary hemochromatosis. *Basal and bolus insulin* - This is a treatment for **diabetes mellitus**, especially when oral medications are insufficient or in cases of severe insulin deficiency. - Like metformin, it manages the diabetic symptoms but does not address the **iron overload** that is the root cause of the diabetes in this hemochromatosis patient. *Basal insulin* - **Basal insulin** provides a continuous insulin supply to manage fasting glucose levels in diabetic patients. - This treatment addresses the **diabetes symptoms** but not the underlying hemochromatosis.

Question 563: A 50-year-old man presents with a complaint of pain and swelling of his right leg for the past 2 days. He remembers hitting his leg against a table 3 days earlier. Since then, the pain and swelling of the leg have gradually increased. His past medical history is significant for atopy and pulmonary tuberculosis. The patient reports a 20-pack-year smoking history and currently smokes 2 packs of cigarettes per day. His pulse is 98/min, respiratory rate is 15/min, temperature is 38.4°C (101.2°F), and blood pressure is 100/60 mm Hg. On physical examination, his right leg is visibly swollen up to the groin with moderate erythema and 2+ pitting edema. The peripheral pulses are 2+ in the right leg and there is no discomfort. There is no increased resistance or pain in the right calf in response to forced dorsiflexion of the right foot. Which of the following is the best next step in the management of this patient?

A. Ultrasound of the right leg (Correct Answer)
B. Outpatient management with furosemide
C. Reassurance and supportive treatment
D. D-dimer level
E. CT pulmonary angiography

Explanation: ***Ultrasound of the right leg*** - The patient presents with unilateral **pain, swelling, erythema**, and **pitting edema** of the right leg extending to the groin, which are classic signs of a **deep vein thrombosis (DVT)**. - The absence of a positive Homan's sign (no pain with dorsiflexion) does not rule out DVT, as this sign has poor sensitivity and specificity. - Given the high clinical suspicion based on presentation and risk factors (heavy smoking, recent trauma), an **ultrasound of the right leg** is the most appropriate initial diagnostic step to confirm or rule out DVT, as it is non-invasive, highly accurate, and readily available. *Outpatient management with furosemide* - **Furosemide** is a diuretic primarily used to treat fluid retention associated with conditions like heart failure or kidney disease. - Prescribing a diuretic without a definitive diagnosis would be inappropriate and could mask underlying pathology, especially for a condition like DVT that requires anticoagulation, not diuresis. *Reassurance and supportive treatment* - Reassurance is inappropriate given the patient's symptoms (unilateral leg swelling, erythema, pitting edema, and pain), which strongly suggest a potentially serious condition such as DVT. - Delaying diagnosis and treatment could lead to severe complications, including **pulmonary embolism**. *D-dimer level* - A **D-dimer test** can be useful in ruling out DVT in patients with a low pretest probability, but it has low specificity in patients with moderate to high probability. - Given the patient's significant physical findings and risk factors, a positive D-dimer would still necessitate an ultrasound, making direct imaging more efficient. A negative D-dimer in this high-probability setting would be less reliable. *CT pulmonary angiography* - **CT pulmonary angiography (CTPA)** is the gold standard for diagnosing **pulmonary embolism (PE)**. - While DVT can lead to PE, there are no specific signs or symptoms of PE (e.g., dyspnea, pleuritic chest pain, hemoptysis, hypoxia) mentioned in the patient's presentation that would warrant CTPA as the *initial* step before evaluating the leg.

Question 564: A 55-year-old man presents to the emergency department for chest pain. He states that the pain started last night and has persisted until this morning. He describes the pain as in his chest and radiating into his back between his scapulae. The patient has a past medical history of alcohol abuse and cocaine abuse. He recently returned from vacation on a transatlantic flight. The patient has smoked 1 pack of cigarettes per day for the past 20 years. His temperature is 99.5°F (37.5°C), blood pressure is 167/118 mmHg, pulse is 120/min, and respirations are 22/min. Physical exam reveals tachycardia and clear air movement bilaterally on cardiopulmonary exam. Which of the following is also likely to be found in this patient?

A. Pulmonary artery thrombus
B. Coronary artery thrombus
C. Elevated lipase
D. Asymmetric blood pressures in the upper extremities (Correct Answer)
E. Coronary artery vasospasm

Explanation: ***Asymmetric blood pressures in the upper extremities*** - The patient's presentation with **sudden-onset, severe, tearing chest pain radiating to the back**, combined with **hypertension** and **tachycardia**, is highly suggestive of an **aortic dissection**. Asymmetric blood pressures are a classic sign. - Aortic dissection involves a tear in the intima of the aorta, leading to a false lumen that can compress branch arteries, causing **pulse deficits** or **limb ischemia**, resulting in pressure differences. *Pulmonary artery thrombus* - While a **transatlantic flight** is a risk factor for **pulmonary embolism (PE)**, the described chest pain is typically pleuritic and not usually severe or radiating to the back in this manner. - PE often presents with **dyspnea** and **hypoxia**, which are not prominent features described here. *Coronary artery thrombus* - **Cocaine abuse**, **smoking**, and **hypertension** are risk factors for **myocardial infarction (MI)** due to **coronary artery thrombosis**. However, MI pain is typically crushing or constricting, and radiation to the back between the scapulae is less common than in dissection. - The description of **tearing pain** is more characteristic of aortic dissection than MI. *Elevated lipase* - The patient's history of **alcohol abuse** and **cocaine abuse** are risk factors for **pancreatitis**, which presents with elevated lipase. However, pancreatitis pain is typically **epigastric** and radiates to the back, but it's usually steady, severe, and often associated with nausea/vomiting, not the tearing quality described. - The acute, severe, radiating chest pain pattern is not typical for an initial presentation of pancreatitis. *Coronary artery vasospasm* - **Cocaine abuse** is a known trigger for **coronary artery vasospasm**, leading to angina or MI, and can cause chest pain. - However, the pain from vasospasm is usually anginal in quality, often responsive to nitrates, and less likely to present with the severe, tearing, interscapular back pain and hemodynamic instability suggestive of aortic dissection.

Question 565: A 67-year old woman is brought to the emergency department after she lost consciousness while at home. Her daughter was with her at the time and recalls that her mother was complaining of a diffuse headache and nausea about 2 hours before the incident. The daughter says that her mother has not had any recent falls and was found sitting in a chair when she lost consciousness. She has hypertension. Current medications include amlodipine, a daily multivitamin, and acetaminophen. She has smoked 1/2 pack of cigarettes daily for the past 45 years. Her pulse is 92/min, respirations are 10/min, and blood pressure is 158/100 mm Hg. She is disoriented and unable to follow commands. Examination shows nuchal rigidity. She has flexor posturing to painful stimuli. Fundoscopic examination is notable for bilateral vitreous hemorrhages. Laboratory studies are within normal limits. An emergent non-contrast CT scan of the head is obtained and shows a diffuse hemorrhage at the base of the brain that is largest over the left hemisphere. Which of the following is the most likely cause of this patient's symptoms?

A. Intracranial arterial dissection
B. Ruptured saccular aneurysm (Correct Answer)
C. Ruptured mycotic aneurysm
D. Spinal arteriovenous malformation
E. Intracranial arteriovenous malformation

Explanation: ***Ruptured saccular aneurysm*** - The sudden onset of a "thunderclap" headache, **nuchal rigidity**, diffuse hemorrhage at the base of the brain, and **vitreous hemorrhages (Terson syndrome)** are all highly suggestive of a **subarachnoid hemorrhage (SAH)**, most commonly caused by a ruptured saccular aneurysm. Her history of **hypertension and smoking** are significant risk factors for aneurysm formation and rupture. - The disorientation and flexor posturing indicate severe neurological compromise due to increased **intracranial pressure** and brainstem involvement, consistent with a large SAH. *Intracranial arterial dissection* - While an intracranial arterial dissection can cause hemorrhage, it typically presents with neck pain, lower cranial nerve palsies, or ischemic stroke symptoms due to **thromboembolism**, which are not prominent features here. - The **diffuse hemorrhage at the base of the brain** and bilateral vitreous hemorrhages are more characteristic of a ruptured aneurysm than a dissection. *Ruptured mycotic aneurysm* - A mycotic aneurysm results from an **infectious embolus** lodging in an artery, leading to vessel wall weakening and rupture. This would typically be seen in the context of **endocarditis** or other systemic infections, for which there is no evidence in this patient. - The patient's presentation lacks systemic signs of infection (e.g., fever, new heart murmur, or elevated inflammatory markers) that would point to an infectious etiology. *Spinal arteriovenous malformation* - A spinal arteriovenous malformation (AVM) would present with **spinal cord symptoms** such as back pain, weakness, sensory deficits, or bladder/bowel dysfunction, not primarily with a diffuse intracranial hemorrhage or severe headache. - While it could theoretically cause a hemorrhage, the clinical presentation and CT findings are unequivocally localized to the **brain**, making a spinal origin unlikely. *Intracranial arteriovenous malformation* - An intracranial AVM can cause **intracerebral hemorrhage** or, less commonly, subarachnoid hemorrhage, but the hemorrhages tend to be more localized within the brain parenchyma or along the AVM itself. - Though an AVM could be a differential, the classic presentation including **thunderclap headache**, Terson syndrome, and diffuse basilar hemorrhage is a more classic presentation of a **ruptured saccular aneurysm**.

Question 566: A 33-year-old woman comes to the physician because of left leg pain and swelling for 1 day. She has had two miscarriages but otherwise has no history of serious illness. Physical examination shows stiff, swollen finger joints. The left calf circumference is larger than the right and there is a palpable cord in the left popliteal fossa. Laboratory studies show a prothrombin time of 12 seconds and an activated partial thromboplastin time of 51 seconds. Which of the following is most likely to confirm the diagnosis?

A. Anti-β2 glycoprotein antibodies (Correct Answer)
B. Anti-ribonucleoprotein antibodies
C. Anti-nuclear antibodies
D. Anti-cyclical citrullinated peptide antibodies
E. Anti-synthetase antibodies

Explanation: ***Anti-β2 glycoprotein antibodies*** - This patient presents with recurrent miscarriages, thrombotic events (left leg pain, swelling, palpable cord suggesting **deep vein thrombosis**), and elevated **aPTT**, highly suggestive of **antiphospholipid syndrome (APS)**. - **Anti-β2 glycoprotein I antibodies** are one of the key diagnostic criteria for APS, along with **lupus anticoagulant** and **anticardiolipin antibodies**. *Anti-ribonucleoprotein antibodies* - These antibodies are predominantly associated with **mixed connective tissue disease (MCTD)** and occasionally with lupus or scleroderma. - While there are joint symptoms, the thrombotic events and recurrent miscarriages are not typical primary features of MCTD. *Anti-nuclear antibodies* - **ANA** is a screening test for various autoimmune diseases, particularly **systemic lupus erythematosus (SLE)**. A positive ANA in isolation would not confirm APS. - While APS can occur secondary to SLE, the primary clinical picture directly points to APS, and specific APS antibodies are needed for diagnosis. *Anti-cyclical citrullinated peptide antibodies* - **Anti-CCP antibodies** are highly specific for **rheumatoid arthritis (RA)**. - While the patient has stiff, swollen finger joints, the presence of DVT and recurrent miscarriages are not features of RA. *Anti-synthetase antibodies* - These antibodies are associated with **inflammatory myopathies**, such as **polymyositis** and **dermatomyositis**, especially those with **interstitial lung disease** and **"mechanic's hands."** - The clinical presentation of thrombosis and miscarriages does not align with the typical features of anti-synthetase syndrome.

Question 567: A 57-year-old man comes to the physician two weeks after a blood pressure of 160/92 mm Hg was measured at a routine health maintenance examination. Subsequent home blood pressure measurements since the last visit have been: 159/98 mm Hg, 161/102 mm Hg, and 152/95 mm Hg. Over the past 3 years, the patient has had a 10-kg (22-lb) weight gain. He has type 2 diabetes mellitus. He does not follow any specific diet; he usually eats sandwiches at work and fried chicken or burger for dinner. He says that he has been struggling with a stressful project at work recently. His mother was diagnosed with hypertension at the age of 45. The patient's only medication is metformin. His pulse is 82/min, and blood pressure now is 158/98 mm Hg. The patient is 178 cm (5 ft 10 in) tall and weighs 133 kg (293 lb); BMI is 42 kg/m2. Physical examination shows no other abnormalities except for significant central obesity. Fasting serum studies show: Total cholesterol 220 mg/dL HDL-cholesterol 25 mg/dL Triglycerides 198 mg/dL Glucose 120 mg/dL Which of the following is the most important factor in the development of this patient's condition?

A. Increased dietary salt intake
B. Resistance to insulin (Correct Answer)
C. Accumulation of fat in visceral tissue
D. Release of proinflammatory cytokines
E. Elevation of blood lipids

Explanation: ***Resistance to insulin*** - **Insulin resistance** is a key component of **metabolic syndrome**, which includes **central obesity**, **hypertension**, **dyslipidemia**, and **type 2 diabetes mellitus**, all present in this patient. - It leads to **compensatory hyperinsulinemia**, which contributes to hypertension by increasing **sodium reabsorption**, sympathetic nervous system activity, and vascular smooth muscle proliferation. *Increased dietary salt intake* - While **high dietary salt intake** can contribute to **hypertension**, the patient's diet history (sandwiches, fried chicken, burgers) primarily suggests high fat and calorie intake, not explicitly high sodium. - The patient's **obesity** and **diabetes** point more strongly towards underlying **insulin resistance** as the primary driver of hypertension. *Accumulation of fat in visceral tissue* - **Visceral obesity** is a strong risk factor for hypertension and is evident in this patient (BMI 42 kg/m2, central obesity). - However, **visceral fat accumulation** is itself a major contributor to **insulin resistance**, making insulin resistance the more fundamental pathophysiological factor. *Release of proinflammatory cytokines* - **Chronic inflammation** and the release of **proinflammatory cytokines** from adipose tissue are associated with obesity and insulin resistance. - While contributing to cardiovascular risk, these cytokines are part of the downstream effects of **insulin resistance** and obesity, not the primary initiating factor. *Elevation of blood lipids* - The patient has **dyslipidemia** (high total cholesterol, low HDL, high triglycerides), which is a common comorbidity of metabolic syndrome and increases cardiovascular risk. - However, **dyslipidemia** is often a consequence of **insulin resistance**, which impairs lipid metabolism, rather than the primary cause of the patient's hypertension.

Question 568: A 67-year-old man is brought to the emergency department because of increasing shortness of breath that began while playing outdoors with his grandson. He has a history of asthma but does not take any medications for it. On arrival, he is alert and oriented. He is out of breath and unable to finish his sentences. His pulse is 130/min, respirations are 23/min and labored, and blood pressure is 110/70 mm Hg. Physical examination shows nasal flaring and sternocleidomastoid muscle use. Pulmonary exam shows poor air movement bilaterally but no wheezing. Cardiac examination shows no abnormalities. Oxygen is administered via non-rebreather mask. He is given three albuterol nebulizer treatments, inhaled ipratropium, and intravenous methylprednisolone. The patient is confused and disoriented. Arterial blood gas analysis shows: pH 7.34 Pco2 44 mm Hg Po2 54 mm Hg O2 saturation 87% Which of the following is the most appropriate next step in management?

A. Flexible bronchoscopy
B. Intravenous magnesium sulfate therapy
C. Endotracheal intubation (Correct Answer)
D. Continuous albuterol nebulizer therapy
E. Intravenous theophylline therapy

Explanation: ***Endotracheal intubation*** - The patient's **worsening mental status** (confused and disoriented after initial treatment) and persistent **hypoxemia** (PO2 54 mmHg, O2 sat 87%) despite aggressive therapy indicate impending **respiratory failure** and the need for immediate advanced airway management. - The **normal PCO2** (44 mmHg) in a patient with severe asthma exacerbation is concerning, as it suggests the patient is tiring and unable to maintain adequate ventilation, which can quickly lead to hypercapnia and respiratory arrest. *Flexible bronchoscopy* - This procedure is typically used for **diagnostic purposes** (e.g., investigating foreign body aspiration, airway obstruction, or pneumonia) and is not an immediate life-saving intervention for acute respiratory failure. - It would delay critical airway management and ventilation in a patient with rapidly deteriorating status. *Intravenous magnesium sulfate therapy* - **Magnesium sulfate** is a bronchodilator that can be used as an **adjunctive therapy** in severe asthma exacerbations, particularly in patients not responding to initial bronchodilator treatment. - However, it is not the primary intervention when a patient is showing signs of impending respiratory arrest and requires immediate airway protection and ventilatory support. *Continuous albuterol nebulizer therapy* - The patient has already received three albuterol nebulizer treatments, and while continuous albuterol can be beneficial in severe asthma, the patient's **deteriorating mental status** and **persistent hypoxemia** indicate he needs more aggressive respiratory support than just further bronchodilator therapy. - The immediate priority is to secure the airway and ensure adequate oxygenation and ventilation. *Intravenous theophylline therapy* - **Theophylline** is a bronchodilator with a narrow therapeutic window and significant potential for toxicity, making it a **third-line agent** for severe asthma that is refractory to standard treatments. - Its slow onset of action and potential side effects make it inappropriate as an initial or immediate intervention in a patient with acute respiratory failure.

Question 569: A 25-year-old female comes to the physician because of fever and worsening cough for the past 4-days. She has had several episodes of otitis media, sinusitis, and an intermittent cough productive of green sputum for the past 2-years. She has also noticed some streaks of blood in the sputum lately. Her temperature is 38°C (100.4°F). Auscultation of the chest reveals crackles and rhonchi bilaterally. Heart sounds cannot be heard along the left lower chest. A CT scan of the chest reveals bronchiectasis and dextrocardia. Which of the following additional findings is most likely in this patient?

A. Increased sweat chloride levels
B. Defective interleukin-2 receptor gamma chain
C. Decreased immunoglobulin levels
D. NADPH oxidase deficiency
E. Delayed tubal ovum transit (Correct Answer)

Explanation: ***Delayed tubal ovum transit*** - The patient's symptoms (recurrent upper and lower respiratory infections, bronchiectasis, and dextrocardia) are characteristic of **Kartagener syndrome**, a type of **primary ciliary dyskinesia**. - In Kartagener syndrome, defective cilia throughout the body, including the **fallopian tubes**, lead to impaired ovum transport and often **infertility** in females. *Increased sweat chloride levels* - This finding is characteristic of **cystic fibrosis**, a genetic disorder affecting chloride channels. - While cystic fibrosis can cause recurrent respiratory infections and bronchiectasis, it is not typically associated with **dextrocardia** or situs inversus. *Defective interleukin-2 receptor gamma chain* - This defect is associated with **X-linked severe combined immunodeficiency (SCID)**. - SCID presents with recurrent severe infections early in life due to a profound deficiency in T-lymphocytes and B-lymphocytes, which does not fit the 25-year-old patient's presentation with chronic but non-fatal respiratory issues and structural anomalies like dextrocardia. *Decreased immunoglobulin levels* - This suggests a **humoral immunodeficiency**, such as **common variable immunodeficiency (CVID)**. - While CVID can cause recurrent sinopulmonary infections, it is not associated with **bronchiectasis** in combination with **dextrocardia**, which points more towards a structural or ciliary defect. *NADPH oxidase deficiency* - This is the hallmark of **chronic granulomatous disease (CGD)**, a primary immunodeficiency. - Patients with CGD are prone to recurrent infections with **catalase-positive organisms** and form granulomas, but this condition is not associated with **dextrocardia** or the specific constellation of symptoms seen in this patient.

Question 570: A 12-year-old boy presents with progressive clumsiness and difficulty walking. He walks like a 'drunken-man' and has experienced frequent falls. He was born at term and has gone through normal developmental milestones. His vaccination profile is up to date. He denies fever, chills, nausea, vomiting, chest pain, and shortness of breath. He has no history of alcohol use or illicit drug use. His elder brother experienced the same symptoms. The physical examination reveals normal higher mental functions. His extraocular movements are normal. His speech is mildly dysarthric. His muscle tone and strength in all 4 limbs are normal. His ankle reflexes are absent bilaterally with positive Babinski’s signs. Both vibration and proprioception are absent bilaterally. When he is asked to stand with his eyes closed and with both feet close together, he sways from side to side, unable to stand still. X-ray results show mild scoliosis. Electrocardiogram results show widespread T-wave inversions. His fasting blood glucose level is 143 mg/dL. What is the most likely diagnosis?

A. Charcot-Marie-Tooth disease
B. Myotonic dystrophy
C. Ataxia-telangiectasia
D. Friedreich’s ataxia (Correct Answer)
E. Duchenne muscular dystrophy

Explanation: ***Friedreich's ataxia*** - This diagnosis is strongly supported by the **autosomal recessive inheritance pattern** (elder brother affected), **progressive ataxia** ("drunken-man" walk, clumsiness, frequent falls), **dysarthria**, **absent ankle reflexes**, **positive Babinski's signs**, and loss of **vibration and proprioception**. The additional findings of **scoliosis**, **T-wave inversions** (suggesting hypertrophic cardiomyopathy), and **diabetes mellitus** (fasting blood glucose of 143 mg/dL) are classic features of Friedreich's ataxia. - The **Romberg sign** (swaying with eyes closed and feet together) indicates a **sensory ataxia**, consistent with dorsal column involvement in Friedreich's ataxia. *Charcot-Marie-Tooth disease* - While it can present with gait difficulties and absent reflexes, it is primarily a **peripheral neuropathy** characterized by **distal muscle weakness and atrophy** (e.g., foot drop, "stork-leg" deformity), which are not described in this patient. - It does not typically involve the brainstem or cerebellum, nor does it commonly present with **Babinski's sign**, **dysarthria**, or the specific cardiac and metabolic abnormalities seen here. *Myotonic dystrophy* - This condition is characterized by **myotonia** (delayed muscle relaxation), **progressive muscle weakness**, and multi-system involvement (e.g., cataracts, frontal baldness, endocrine issues). - While it can manifest with gait difficulties and muscle weakness, the classic neurological findings of **sensory ataxia**, **dysarthria**, **absent ankle reflexes with positive Babinski's signs**, and specific cardiac involvement like T-wave inversions are not typical. *Ataxia-telangiectasia* - Key features include **progressive cerebellar ataxia** developing in early childhood, along with **oculocutaneous telangiectasias** (spider veins on eyes and skin), **immunodeficiency**, and increased risk of malignancy. - Although ataxia is present, the absence of telangiectasias, immunodeficiency, and the specific constellation of sensory deficits, cardiac findings, and diabetes make this less likely. *Duchenne muscular dystrophy* - This is an X-linked recessive disorder characterized by **progressive muscle weakness** and **atrophy** predominantly affecting proximal muscles, leading to a **waddling gait**, **Gowers' sign**, and elevated creatine kinase levels. - It does not typically present with **sensory ataxia**, **dysarthria**, **hyperreflexia (Babinski's sign)**, or the specific cardiac and metabolic (diabetes) manifestations seen in this case.

Question 571: A 36-year-old woman presents to the emergency department with chest discomfort and fatigue. She reports that her symptoms began approximately 1 week ago and are associated with shortness of breath, swelling of her legs, and worsening weakness. She’s been having transitory fevers for about 1 month and denies having similar symptoms in the past. Medical history is significant for systemic lupus erythematosus (SLE) treated with hydroxychloroquine. She had a SLE flare approximately 2 weeks prior to presentation, requiring a short course of prednisone. Physical exam was significant for a pericardial friction rub. An electrocardiogram showed widespread ST-segment elevation and PR depression. After extensive work-up, she was admitted for further evaluation, treatment, and observation. Approximately 2 days after admission she became unresponsive. Her temperature is 100°F (37.8°C), blood pressure is 75/52 mmHg, pulse is 120/min, and respirations are 22/min. Heart sounds are muffled. Which of the following is a clinical finding that will most likely be found in this patient?

A. Warm extremities
B. Pericardial knock
C. Decreased systolic blood pressure by 8 mmHg with inspiration
D. Jugular venous distension (Correct Answer)
E. Unequal blood pressure measurements between both arms

Explanation: ***Jugular venous distension*** - The patient's presentation with **muffled heart sounds**, **hypotension**, and a **pericardial friction rub** points towards **cardiac tamponade**, a medical emergency caused by fluid accumulation in the pericardial sac. - **Jugular venous distension** is a key component of **Beck's triad** (along with muffled heart sounds and hypotension) and indicates increased right atrial pressure due to restricted ventricular filling. *Warm extremities* - **Warm extremities** are more characteristic of **vasodilatory shock** (e.g., septic shock), where peripheral vasodilation leads to increased skin temperature. - In **cardiac tamponade**, reduced cardiac output typically results in **cool and clammy extremities** due to compensatory peripheral vasoconstriction. *Pericardial knock* - A **pericardial knock** is an early diastolic sound often heard in **constrictive pericarditis**, caused by the sudden cessation of ventricular filling. - While the patient has pericardial involvement, the acute presentation with signs of shock is more consistent with **cardiac tamponade**, rather than chronic constriction. *Decreased systolic blood pressure by 8 mmHg with inspiration* - **Pulsus paradoxus** (a decrease in systolic blood pressure of **>10 mmHg with inspiration**) is a hallmark sign of **cardiac tamponade**. - While this patient likely has pulsus paradoxus, the value of **8 mmHg falls below the diagnostic threshold** of 10 mmHg and would not be considered pathological pulsus paradoxus. - **Jugular venous distension** is a more reliable and clinically obvious finding in cardiac tamponade. *Unequal blood pressure measurements between both arms* - **Unequal blood pressure measurements between the arms** (>10-15 mmHg difference) are characteristic of conditions like **aortic dissection** or **subclavian artery stenosis**. - This finding is not typically associated with **cardiac tamponade**, which affects global cardiac function.

Question 572: A 54-year-old man presents to the office complaining of recent shortness of breath and fever. He has a history of a chronic cough which is progressively getting worse. His medical history is significant for hypertension and diabetes mellitus, both controlled with medication. He has been working in a sandblasting factory for over 3 decades. His temperature is 37.7°C (99.9°F), the blood pressure is 130/84 mm Hg, the pulse is 98/min, and the respiratory rate is 20/min. Chest X-ray reveals calcified hilar lymph nodes which look like an eggshell. This patient is at increased risk for which of the following conditions?

A. Mesothelioma
B. Chronic obstructive pulmonary disease
C. Pulmonary embolism
D. Adenocarcinoma of the lung
E. Mycobacterium tuberculosis infection (Correct Answer)

Explanation: ***Mycobacterium tuberculosis infection*** - The patient's presentation with a **chronic cough**, **shortness of breath**, and **fever**, coupled with a history of **sandblasting** (suggesting **silicosis** and **eggshell calcifications** on X-ray), places him at a significantly higher risk for **Mycobacterium tuberculosis infection**. - **Silicosis** impairs macrophage function and predisposes individuals to reactivation of latent tuberculosis or increased susceptibility to new TB infections. *Mesothelioma* - **Mesothelioma** is strongly associated with **asbestos exposure**, not typically sandblasting or silica. - While asbestos exposure can involve some construction-related activities, sandblasting specifically points to **silica exposure**. *Chronic obstructive pulmonary disease* - Although the patient's symptoms (chronic cough, dyspnea) could align with **COPD**, the imaging finding of **eggshell calcifications** specifically points to **silicosis**, which has a different primary complication risk, particularly **tuberculosis**. - No information about smoking history or spirometry results is given to confirm COPD. *Pulmonary embolism* - **Pulmonary embolism** typically presents with acute-onset dyspnea, pleuritic chest pain, and sometimes hemoptysis, without the long-standing cough and fever pattern described. The **eggshell calcifications** are not a feature of PE. - The patient's vital signs are not acutely unstable in a way that would strongly suggest an immediate PE. *Adenocarcinoma of the lung* - While **silicosis** can increase the risk of lung cancer, particularly **adenocarcinoma**, the presenting symptoms of fever and the specific finding of **calcified hilar lymph nodes with eggshell calcification** make **tuberculosis** a more immediate concern given the compromised immune status associated with silicosis. - **Silicosis-related lung cancer** typically develops after many years, and while possible, the acute infectious symptoms point to a more immediate etiology.

Question 573: A 72-year-old man is brought to the emergency department after an episode of hemoptysis. He has a chronic cough that is productive of copious sputum. Six years ago, he had a stroke that left him with difficulty swallowing. He smoked one pack of cigarettes daily for 40 years, but quit 2 years ago. His respirations are 25/min and labored. Physical examination shows digital clubbing. An x-ray of the chest shows tram track opacities in the lower lung fields. Which of the following is the most likely diagnosis?

A. Aspiration pneumonia
B. Bronchiectasis (Correct Answer)
C. Emphysema
D. Lung cancer
E. Chronic bronchitis

Explanation: ***Bronchiectasis*** - The combination of **chronic cough with copious sputum**, **hemoptysis**, **digital clubbing**, and **tram track opacities** on chest x-ray is highly characteristic of bronchiectasis. - The patient's history of difficulty swallowing following a stroke suggests a risk factor for recurrent aspirations leading to chronic infection and airway damage characteristic of bronchiectasis. *Aspiration pneumonia* - While the patient has a risk factor for aspiration due to difficulty swallowing, aspiration pneumonia typically presents as an acute infection with fever and infiltrates, rather than chronic symptoms and specific radiographic findings like **tram track opacities** and **digital clubbing**. - Aspiration pneumonia may lead to bronchiectasis if chronic, but it is not the most definitive diagnosis given the full constellation of findings described. *Emphysema* - Emphysema is a form of COPD characterized by destruction of alveolar walls and presents with **dyspnea**, **barrel chest**, and often a history of smoking, but does not typically cause **hemoptysis** or **tram track opacities**. - Chest x-rays in emphysema usually show **hyperinflation** and **flattened diaphragms**, not specific airway dilation. *Lung cancer* - While **hemoptysis** and **chronic cough** can be symptoms of lung cancer, and the patient has a significant smoking history, lung cancer does not typically cause **copious sputum** or **tram track opacities**. - Although digital clubbing can occur with lung cancer as a paraneoplastic syndrome, the presence of **tram track opacities** is pathognomonic for bronchiectasis and points strongly to this diagnosis. *Chronic bronchitis* - Chronic bronchitis is defined by a **chronic productive cough** for at least three months in two consecutive years and is associated with smoking. - However, it does not typically cause **hemoptysis**, **digital clubbing**, or the specific **tram track opacities** seen on x-ray, which indicate bronchial wall thickening and dilation.

Question 574: A 48-year-old male presents to his primary physician with the chief complaints of fever, abdominal pain, weight loss, muscle weakness, and numbness in his lower extremities. UA is normal. A biopsy of the sural nerve reveals transmural inflammation and fibrinoid necrosis of small and medium arteries. Chart review reveals a remote history of cigarette smoking as a teenager and Hepatitis B seropositivity. What is the most likely diagnosis?

A. Raynaud disease
B. Systemic lupus erythematosus
C. Microscopic polyangiitis
D. Thromboangiitis obliterans
E. Polyarteritis nodosa (Correct Answer)

Explanation: ***Polyarteritis nodosa*** - The constellation of **fever, abdominal pain, weight loss, muscle weakness, and numbness in the lower extremities** (suggesting **neuropathy**) along with **Hepatitis B seropositivity**, is highly indicative of **Polyarteritis nodosa (PAN)**. - The **sural nerve biopsy findings of transmural inflammation and fibrinoid necrosis of small and medium arteries** are pathognomonic for PAN, confirming a **necrotizing vasculitis** primarily affecting these vessel types. *Raynaud disease* - This condition involves **vasospasm of small arteries and arterioles**, typically in the fingers and toes, leading to characteristic color changes. - It does not present with systemic symptoms like **fever, weight loss, or abdominal pain**, nor does it cause **transmural inflammation or fibrinoid necrosis** of arteries. *Systemic lupus erythematosus* - SLE is a multisystem autoimmune disease that can cause a wide range of symptoms, but it is not typically characterized by **necrotizing vasculitis of small and medium arteries** with **fibrinoid necrosis** as seen in the biopsy. - While it can cause neuropathy, the specific biopsy findings and the strong association with **Hepatitis B** make PAN a more fitting diagnosis. *Microscopic polyangiitis* - **Microscopic polyangiitis (MPA)** is a **pauci-immune necrotizing vasculitis** that primarily affects **small vessels** (capillaries, venules, arterioles) and is often associated with **ANCA** (anti-neutrophil cytoplasmic antibodies). - While it can cause systemic symptoms and neuropathy, the biopsy finding of **transmural inflammation affecting medium arteries** and the strong link to **Hepatitis B** point away from MPA and towards PAN. *Thromboangiitis obliterans* - This is a **segmental, thrombosing vasculitis** primarily affecting **small and medium arteries and veins of the extremities**, almost exclusively seen in **smokers**. - While the patient has a remote history of smoking, the biopsy finding of **transmural inflammation and fibrinoid necrosis** is typical of PAN, not the thrombosing inflammation of Thromboangiitis obliterans.

Question 575: A previously healthy 64-year-old woman comes to the physician because of a dry cough and progressively worsening shortness of breath for the past 2 months. She has not had fever, chills, or night sweats. She has smoked one pack of cigarettes daily for the past 45 years. She appears thin. Examination of the lung shows a prolonged expiratory phase and end-expiratory wheezing. Spirometry shows decreased FEV1:FVC ratio (< 70% predicted), decreased FEV1, and a total lung capacity of 125% of predicted. The diffusion capacity of the lung (DLCO) is decreased. Which of the following is the most likely diagnosis?

A. Bronchiectasis
B. Interstitial lung disease
C. Chronic obstructive pulmonary disease (Correct Answer)
D. Hypersensitivity pneumonitis
E. Bronchial asthma

Explanation: ***Chronic obstructive pulmonary disease*** - The patient's long history of **smoking (45 pack-years)**, **prolonged expiratory phase**, and **end-expiratory wheezing** are classic signs of airway obstruction. - Spirometry findings of a **decreased FEV1:FVC ratio** (< 70% predicted), **decreased FEV1**, **increased total lung capacity (TLC)**, and **decreased DLCO** are all highly indicative of **emphysema**, a subtype of COPD. *Bronchiectasis* - While it shares symptoms like cough and SOB, **bronchiectasis** is characterized by permanent **dilatation of bronchi** and profuse, chronic **sputum production**, which is not mentioned here. - Spirometry typically shows **obstructive patterns**, but the marked increase in TLC and decreased DLCO are more specific to emphysema. *Interstitial lung disease* - This condition primarily causes a **restrictive lung pattern**, meaning a decreased TLC and normal or increased FEV1:FVC ratio. - The patient's **increased TLC** and **obstructive spirometry** rule out a purely restrictive process. *Hypersensitivity pneumonitis* - This is an inflammatory response to inhaled antigens, often presenting with **recurrent episodes** of fever, chills, and cough, and can lead to restrictive physiology. - The patient lacks a history of specific **antigen exposure** and presents with an obstructive pattern and increased TLC. *Bronchial asthma* - While asthma shares obstructive features like wheezing and a decreased FEV1:FVC ratio, it is characterized by **reversibility** of airway obstruction and typically does not cause a significantly **elevated TLC** or **decreased DLCO** in uncomplicated cases. - The patient's long smoking history points away from asthma as the primary diagnosis.

Question 576: A 63-year-old man comes to the physician because of a 2-day history of a painful rash on his right flank. Two years ago, he underwent cadaveric renal transplantation. Current medications include tacrolimus, mycophenolate mofetil, and prednisone. Examination shows an erythematous rash with grouped vesicles in a band-like distribution over the patient's right flank. This patient is at greatest risk for which of the following complications?

A. Loss of vision
B. Temporal lobe inflammation
C. Postherpetic neuralgia (Correct Answer)
D. Sensory neuropathy
E. Urinary retention

Explanation: ***Postherpetic neuralgia*** - This patient has **herpes zoster (shingles)**, characterized by a painful vesicular rash in a dermatomal distribution. **Postherpetic neuralgia (PHN)** is the most common complication of herpes zoster, defined as persistent neuropathic pain lasting more than 90 days after rash onset. - This patient has **multiple risk factors for PHN**: advanced age (63 years), immunocompromised state (renal transplant on tacrolimus, mycophenolate, and prednisone), and severe acute pain. PHN occurs in **10-18% of all herpes zoster cases** but can affect **50-70% of immunocompromised patients**. - PHN results from nerve damage caused by VZV reactivation and inflammation, leading to chronic neuropathic pain that can persist for months to years after the rash resolves. *Loss of vision* - Loss of vision occurs with **herpes zoster ophthalmicus**, which involves the ophthalmic division of the trigeminal nerve (V1) and can lead to keratitis, uveitis, and vision loss. - This patient's rash is on the **right flank** (thoracic/lumbar dermatome), not the ophthalmic distribution, making vision loss unlikely. *Temporal lobe inflammation* - **Temporal lobe encephalitis** is a rare complication of disseminated VZV infection, typically occurring in severely immunocompromised patients (AIDS, chemotherapy). - While this transplant patient is immunosuppressed, localized dermatomal zoster rarely causes CNS complications. Encephalitis would present with altered mental status, seizures, and focal neurological deficits. *Urinary retention* - Urinary retention can occur when herpes zoster affects the **sacral dermatomes (S2-S4)**, involving autonomic nerves that innervate the bladder. - This patient's rash is on the **right flank** (thoracic or lumbar dermatome), making sacral involvement and urinary retention unlikely. *Sensory neuropathy* - While herpes zoster does cause sensory nerve damage, "sensory neuropathy" is not a standard clinical term for herpes zoster complications. The specific consequence of this nerve damage that persists as a complication is **postherpetic neuralgia** (PHN). - All nerve damage from zoster is essentially sensory in nature, but when asking about the greatest risk for complications, **postherpetic neuralgia** is the recognized and most common complication, especially in elderly immunocompromised patients.

Question 577: A 23-year-old female presents to the emergency department with monocular blindness. She states that early this morning she lost her vision seemingly "out of nowhere." She denies trauma or any precipitating factors. She does state though that over the past year she has had occasional episodes of weakness and even an episode of urinary incontinence, which always resolve on their own. On exam, pain is elicited with eye movement and nystagmus is appreciated. The emergency physician performs a lumbar puncture. What is most likely to be observed in the CSF of this patient?

A. Increased lymphocyte count
B. Normal findings
C. Albuminocytologic dissociation
D. Oligoclonal bands (Correct Answer)
E. Increased opening pressure

Explanation: ***Oligoclonal bands*** - The patient's presentation with **monocular blindness**, **pain with eye movement**, **nystagmus**, and a history of resolving neurological symptoms like weakness and urinary incontinence is highly suggestive of **multiple sclerosis (MS)**. - **Oligoclonal bands** in the CSF, representing intrathecal immunoglobulin production, are a hallmark finding supportive of an MS diagnosis, found in over 90% of patients. *Increased lymphocyte count* - While there can be a mild increase in **lymphocytes** in the CSF of MS patients during acute exacerbations, a significant increase is more characteristic of infectious meningoencephalitis. - A definitive diagnostic marker like oligoclonal bands is more specific for MS than a general increase in lymphocytes alone. *Normal findings* - Given the patient's symptoms and the strong clinical suspicion for **multiple sclerosis**, a completely normal CSF analysis is unlikely. - MS is characterized by distinct immunological changes in the CSF, making a normal result improbable for diagnosis. *Albuminocytologic dissociation* - **Albuminocytologic dissociation**, characterized by a high protein count with a normal cell count, is a classic finding in **Guillain-Barré Syndrome (GBS)**. - The patient's symptoms (monocular blindness, nystagmus, resolving neurological deficits) are not typical of GBS, which usually presents with ascending paralysis. *Increased opening pressure* - **Increased opening pressure** in the CSF is primarily associated with conditions like **idiopathic intracranial hypertension (pseudotumor cerebri)** or space-occupying lesions. - While some MS patients might have mild elevations, it is not a hallmark diagnostic feature and the clinical picture does not point to conditions primarily causing increased intracranial pressure.

Question 578: A 52-year-old man presents to his primary care physician to discuss laboratory results that were obtained during his annual checkup. He has no symptoms or concerns and denies changes in eating or urination patterns. Specifically, the physician ordered a panel of metabolic laboratory tests to look for signs of diabetes, hyperlipidemia, or other chronic disorders. A spot glucose check from a random blood sample showed a glucose level of 211 mg/dL. A hemoglobin A1c level was obtained at the same time that showed a level of 6.3%. A fasting blood glucose was obtained that showed a blood glucose level of 125 mg/dL. Finally, a 2-hour glucose level was obtained after an oral glucose tolerance test that showed a glucose level of 201 mg/dL. Which of the following statements is most accurate for this patient?

A. This patient does not have type 2 diabetes
B. This patient has type 2 diabetes as diagnosed by his fasting blood glucose
C. This patient has type 2 diabetes as diagnosed by his oral tolerance blood glucose (Correct Answer)
D. This patient has type 2 diabetes as diagnosed by his random blood glucose
E. This patient has type 2 diabetes as diagnosed by his hemoglobin A1c

Explanation: **This patient has type 2 diabetes as diagnosed by his oral tolerance blood glucose** - A 2-hour plasma glucose of **200 mg/dL or higher** during an Oral Glucose Tolerance Test (OGTT) is a diagnostic criterion for diabetes. This patient's 2-hour glucose level of **201 mg/dL** meets this criterion. - The combination of this elevated OGTT result with a random glucose over 200 mg/dL further supports the diagnosis, even in an asymptomatic individual. *This patient does not have type 2 diabetes* - The patient has multiple laboratory values that meet or exceed diagnostic thresholds for diabetes, including a random glucose of **211 mg/dL**, an HbA1c of **6.3%**, and a 2-hour OGTT glucose of **201 mg/dL**. - While one individual threshold might not be conclusive, the overall pattern of results clearly indicates diabetes. *This patient has type 2 diabetes as diagnosed by his fasting blood glucose* - A fasting plasma glucose (FPG) of **126 mg/dL or higher** is diagnostic for diabetes. This patient's FPG of **125 mg/dL** is just below this threshold. - While concerning, an FPG of 125 mg/dL alone is considered **impaired fasting glucose** (pre-diabetes), not diabetes. *This patient has type 2 diabetes as diagnosed by his random blood glucose* - A random plasma glucose of **200 mg/dL or higher** in a symptomatic patient is diagnostic for diabetes. However, this patient is **asymptomatic**. - In an asymptomatic patient, an elevated random glucose requires confirmation by another diagnostic test (e.g., FPG, OGTT, or HbA1c) on a subsequent day, or concurrent with another positive test (like the OGTT in this case). *This patient has type 2 diabetes as diagnosed by his hemoglobin A1c* - An HbA1c level of **6.5% or higher** is diagnostic for diabetes. This patient's HbA1c of **6.3%** is below this cutoff. - An HbA1c between 5.7% and 6.4% indicates **pre-diabetes**, specifically increased risk for diabetes.

Question 579: A 32-year-old woman presents to the clinic with the complaint of excessive fatigue for the past few weeks. After returning home from the office, she feels too tired to climb up the stairs, comb her hair, or chew her food. She has occasionally experienced double vision. She denies any history of fever, cough, weight loss, night sweats, or snoring. Past history is unremarkable. Physical examination reveals: blood pressure 124/86 mm Hg, heart rate 85/min, respiratory rate 14/min, temperature 37.0°C (98.6°F), and body mass index (BMI) 22.6 kg/m2. On examination, the right upper eyelid is slightly drooping when compared to the left side. Her eye movements are normal. Flexion of the neck is mildly weak. Muscle strength is 5/5 in all 4 limbs. When she is asked to alternately flex and extend her shoulder continuously for 5 minutes, the power in the proximal upper limb muscles becomes 4/5. The muscle tone and deep tendon reflexes are normal. What is the most appropriate test to diagnose this condition?

A. CT scan chest
B. Plasmapheresis
C. Tensilon test
D. Single-fiber electromyography (Correct Answer)
E. Presynaptic calcium channel antibodies

Explanation: ***Single-fiber electromyography*** - This patient presents with symptoms highly suggestive of **myasthenia gravis**, including **fatigue**, **ptosis**, **diplopia**, and **fatigable weakness** of proximal muscles exacerbated by repetitive use. - **Single-fiber electromyography (SFEMG)** is the **most sensitive** electrodiagnostic test for myasthenia gravis, detecting impaired neuromuscular transmission with a sensitivity of **95-99%**. - While **acetylcholine receptor (AChR) antibodies** are often the first-line test in clinical practice (85-90% sensitivity), SFEMG is superior when antibody tests are negative or when the highest diagnostic sensitivity is required, making it the most appropriate test overall. *CT scan chest* - A CT scan of the chest is used to look for a **thymoma**, which is associated with myasthenia gravis in 10-15% of cases, but it is not a diagnostic test for the condition itself. - While important for prognostication and treatment planning (particularly in patients with confirmed MG), it does not confirm the diagnosis of myasthenia gravis. *Plasmapheresis* - **Plasmapheresis** is a treatment for myasthenia gravis, particularly in myasthenic crisis or during exacerbations, by removing anti-acetylcholine receptor antibodies. - It is not a diagnostic test; diagnostic tests are performed to identify the condition before treatment initiation. *Tensilon test* - The **Tensilon (edrophonium) test** was historically used to diagnose myasthenia gravis by transiently improving muscle weakness upon administration of the anticholinesterase drug. - However, due to potential side effects (e.g., **bradycardia, syncope**) and the availability of more sensitive and safer diagnostic methods like SFEMG and antibody testing, it is **less commonly used** as a primary diagnostic tool today. *Presynaptic calcium channel antibodies* - Presynaptic calcium channel antibodies (specifically **P/Q-type voltage-gated calcium channel antibodies**) are characteristic of **Lambert-Eaton myasthenic syndrome (LEMS)**, a disorder of the neuromuscular junction distinct from myasthenia gravis. - LEMS typically presents with **proximal weakness that improves with exercise** (unlike MG where weakness worsens), autonomic dysfunction, and association with small cell lung cancer. - This patient's symptoms (fatigable weakness worsening with activity, ptosis, diplopia) are more consistent with myasthenia gravis, which involves postsynaptic acetylcholine receptor antibodies.

Question 580: A 25-year-old woman presents into the clinic complaining of worsening malaise, hair loss, and a rash on her face. The patient states that she has been avoiding daylight because the rash becomes painful, and she has not been able to go to classes because of debilitating arthralgia in her fingers and ankles. No significant past medical history. She takes no medication. At the time of the consult, the patient has a fever of 39.0°C (102.2 °F). The presence of which of the following is most commonly seen on diagnostic labs in this patient’s most likely condition?

A. Anti-smith antibody
B. Anti-dsDNA
C. Anti-Ro antibody
D. Antinuclear antibody (Correct Answer)
E. Anti-histone antibody

Explanation: ***Antinuclear antibody*** - The patient's symptoms (malaise, hair loss, photosensitive malar rash, arthralgia, fever) are highly suggestive of **Systemic Lupus Erythematosus (SLE)**. - An **antinuclear antibody (ANA)** test is the **most sensitive screening test** for SLE and is present in over 95% of patients with the condition. *Anti-dsDNA* - While **anti-dsDNA antibodies** are highly specific for SLE and often correlate with disease activity, particularly **lupus nephritis**, they are present in only about 70-80% of SLE patients, making them less common than ANA. - This antibody is more specific than ANA but **not as sensitive** as ANA for initial diagnosis. *Anti-smith antibody* - **Anti-Smith antibodies** are highly specific for SLE (pathognomonic), meaning their presence strongly indicates SLE, but they are found in only about 20-30% of SLE patients, making them relatively uncommon. - Their presence is **not as common** as ANA or even anti-dsDNA in the general SLE population. *Anti-Ro antibody* - **Anti-Ro/SSA antibodies** are associated with specific manifestations of SLE, such as **subacute cutaneous lupus erythematosus**, neonatal lupus, and Sjögren's syndrome, but are not present in all SLE patients. - This antibody is present in approximately 25-30% of SLE patients, and its diagnostic significance is more often for specific subsets rather than overall disease presence. *Anti-histone antibody* - **Anti-histone antibodies** are primarily associated with **drug-induced lupus (DIL)**, although they can also be present in a small percentage of idiopathic SLE cases. - Given that the patient takes no medication and her symptoms are more consistent with idiopathic SLE, this antibody is **less likely to be the most commonly seen** diagnostic marker.

Question 581: A 40-year-old woman comes to the physician for the evaluation of fatigue, poor appetite, and an unintentional 10-kg (22-lb) weight loss over the past 6 months. The patient also reports several episodes of nausea and two episodes of non-bloody vomiting. There is no personal or family history of serious illness. Menses occur at regular 27-day intervals and last 6 days. Her last menstrual period was 3 weeks ago. She is sexually active with her husband, but states that she has lost desire in sexual intercourse lately. Her temperature is 37°C (98.6°F), pulse is 100/min, and blood pressure is 96/70 mm Hg. Physical examination shows no abnormalities. Laboratory studies show: Hemoglobin 13.5 g/dL Leukocyte count 7,000/mm3 Serum Na+ 128 mEq/L Cl- 96 mEq/L K+ 5.8 mEq/L HCO3- 23 mEq/L Glucose 70 mg/dL AM Cortisol 2 μg/dL Which of the following is the most appropriate next step in management?

A. Hydrocortisone administration
B. Adrenal imaging
C. TSH measurement
D. Urine aldosterone level measurement
E. Cosyntropin administration (Correct Answer)

Explanation: ***Cosyntropin administration*** - The patient presents with symptoms such as **fatigue, weight loss, hypotension, hyponatremia, hyperkalemia, and a low morning cortisol level** (2 μg/dL), highly suggestive of **adrenal insufficiency**. - A **cosyntropin (ACTH stimulation) test** is the most appropriate next step to confirm adrenal insufficiency and differentiate between primary and secondary causes. *Hydrocortisone administration* - While hydrocortisone is used to treat adrenal insufficiency, it should only be administered **after a definitive diagnosis** has been established, especially if the patient is not in an acute adrenal crisis. - Administering corticosteroids before diagnostic testing can **interfere with the results** of the cosyntropin stimulation test. *Adrenal imaging* - Adrenal imaging (e.g., CT or MRI) may be considered *after* a diagnosis of primary adrenal insufficiency is confirmed by biochemical testing to identify the underlying cause (e.g., **adrenal hemorrhage, tumor, or atrophy**). - It is **not the initial diagnostic step** for suspected adrenal insufficiency based on these lab findings. *TSH measurement* - While thyroid dysfunction can cause nonspecific symptoms like fatigue and weight changes, the **hyponatremia, hyperkalemia, and profoundly low cortisol** are more indicative of adrenal pathology. - Ruling out adrenal insufficiency is a higher priority given the potentially life-threatening nature of an **adrenal crisis**. *Urine aldosterone level measurement* - Measuring urine aldosterone might be useful in the workup for primary adrenal insufficiency (Addison's disease) to assess **mineralocorticoid deficiency**, which often coexists with glucocorticoid deficiency. - However, the **cosyntropin stimulation test** is the gold standard for diagnosing adrenal insufficiency and evaluating the adrenal reserve, making it the more appropriate initial diagnostic step.

Question 582: A 32-year-old African American woman presents to her family physician complaining of fevers, fatigue, weight loss, joint pains, night sweats and a rash on her face that extends over the bridge of her nose. She has also had multiple sores in her mouth over the past few weeks. She recently had a root canal procedure done without complications. She has no significant past medical history, but has recently had a urinary tract infection. She denies tobacco, alcohol, and illicit drug use. Laboratory evaluation reveals hemolytic anemia. If she were found to have a cardiac lesion, what would be the most likely pathogenetic cause?

A. Left atrial mass causing a ball valve-type outflow obstruction
B. Immune complex deposition and subsequent inflammation (Correct Answer)
C. Bacteremia secondary to a recent dental procedure
D. Bacteremia secondary to a urinary tract infection
E. Aberrant flow causing platelet-fibrin thrombus formation secondary to hypercoagulability and malignancy.

Explanation: ***Immune complex deposition and subsequent inflammation*** - The patient's symptoms (fevers, fatigue, weight loss, joint pains, "butterfly" rash, oral sores, hemolytic anemia, and recent UTI) are highly suggestive of **Systemic Lupus Erythematosus (SLE)**. SLE is an autoimmune disease characterized by the formation of **immune complexes** that deposit in various tissues, including the heart. - Cardiac involvement in SLE often manifests as **pericarditis**, **myocarditis**, or **Libman-Sacks endocarditis**, all of which are inflammatory conditions caused by immune complex deposition. *Left atrial mass causing a ball valve-type outflow obstruction* - This description is characteristic of a **left atrial myxoma**, which is a primary cardiac tumor. - While myxomas can cause systemic symptoms, the constellation of symptoms (rash, oral sores, hemolytic anemia, etc.) is not typical for a myxoma, which does not involve immune complex formation. *Abberent flow causing platelet-fibrin thrombus formation secondary to hypercoagulability and malignancy.* - This describes marantic endocarditis (nonbacterial thrombotic endocarditis), which is associated with **hypercoagulable states** and **malignancy**. - While patients with SLE can have hypercoagulability, the primary cardiac pathology in SLE-related endocarditis is due to immune complex deposition, not simply aberrant flow or malignancy. *Bacteremia secondary to a recent dental procedure* - This would lead to **infective endocarditis** (IE) caused by bacterial colonization of heart valves. - While a dental procedure can be a risk factor for IE, the patient's wide array of systemic autoimmune symptoms (rash, joint pain, hemolytic anemia) points away from a simple bacterial infection as the sole or primary cause of cardiac lesion in this context. *Bacteremia secondary to a urinary tract infection* - Similar to the dental procedure, a UTI could potentially lead to **sepsis** and **infective endocarditis** in some cases. - However, the overall clinical picture, especially the characteristic "butterfly" rash, oral ulcers, and hemolytic anemia, strongly suggests an autoimmune process like SLE, making immune complex deposition the more likely underlying cause of a cardiac lesion than a standard bacterial infection.

Question 583: A 71-year old man is brought to the emergency department because of progressively worsening shortness of breath and fatigue for 3 days. During the last month, he has also noticed dark colored urine. He had an upper respiratory infection 6 weeks ago. He underwent a cholecystectomy at the age of 30 years. He has hypertension, hyperlipidemia, and type 2 diabetes mellitus. He immigrated to the US from Italy 50 years ago. Current medications include simvastatin, lisinopril, and metformin. He appears pale. His temperature is 37.1°C (98.8°F), pulse is 96/min, respirations are 21/min, and blood pressure is 150/80 mm Hg. Auscultation of the heart shows a grade 4/6 systolic murmur over the right second intercostal space that radiates to the carotids. Laboratory studies show: Leukocyte count 9,000/mm3 Hemoglobin 8.3 g/dL Hematocrit 24% Platelet count 180,000/mm3 LDH 212 U/L Haptoglobin 15 mg/dL (N=41–165) Serum Na+ 138 mEq/L K+ 4.5 mEq/L CL- 102 mEq/L HCO3- 24 mEq/L Urea nitrogen 20 mg/dL Creatinine 1.2 mg/dL Total bilirubin 1.8 mg/dL Stool testing for occult blood is negative. Direct Coombs test is negative. Echocardiography shows an aortic jet velocity of 4.2 m/s and a mean pressure gradient of 46 mm Hg. Which of the following is the most appropriate next step in management to treat this patient's anemia?

A. Aortic valve replacement (Correct Answer)
B. Administration of corticosteroids
C. Discontinuation of medication
D. Administration of hydroxyurea
E. Supplementation with iron

Explanation: ***Aortic valve replacement*** - The patient's **severe aortic stenosis** (aortic jet velocity >4.0 m/s and mean pressure gradient >40 mmHg) is causing **shear stress** on red blood cells, leading to **microangiopathic hemolytic anemia**. This is characterized by low hemoglobin, high LDH, low haptoglobin, and negative Coombs test. - **Aortic valve replacement** is the definitive treatment to reduce the shear stress, resolve the hemolysis, and improve the patient's symptoms of anemia and heart failure. *Administration of corticosteroids* - Corticosteroids are primarily used in **autoimmune hemolytic anemia** (positive Coombs test), which is not the case here as the direct Coombs test is negative. - They would not address the underlying **mechanical destruction of red blood cells** due to aortic stenosis. *Discontinuation of medication* - The patient's current medications (simvastatin, lisinopril, metformin) are for managing his chronic conditions and are **not associated with hemolytic anemia**. Discontinuing them would be inappropriate and potentially harmful. - There is no evidence to suggest a **drug-induced hemolytic anemia** in this case. *Administration of hydroxyurea* - Hydroxyurea is used in conditions like **sickle cell anemia** or **polycythemia vera** to modify red blood cell production or reduce cell counts, respectively. - It has no role in treating **mechanical hemolytic anemia** caused by valvular heart disease. *Supplementation with iron* - While the patient has anemia, it is a **hemolytic anemia**, not an iron deficiency anemia, as indicated by the low haptoglobin and elevated LDH. - Iron supplementation would **not stop the destruction of red blood cells** caused by the turbulent flow across the aortic valve.

Question 584: A 65-year-old man is brought to the emergency department because of a fall that occurred while he was taking a shower earlier that morning. His wife heard him fall and entered the bathroom to find all four of his extremities twitching. The episode lasted approximately 30 seconds. He was unsure of what had happened and was unable to answer simple questions on awakening. He has regained orientation since that time. He has hypertension and hyperlipidemia. Current medications include metoprolol and atorvastatin. His temperature is 37.1°C (98.8°F), pulse is 72/min, respirations are 19/min, and blood pressures is 130/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Cranial nerve examination shows no abnormalities. He has 5/5 strength in all extremities. Examination shows full muscle strength. Sensation to pinprick, light touch, and vibration is normal and symmetrical. A noncontrast head CT is performed and shows a slightly hyperdense mass. Follow-up MRI shows a homogeneous, well-circumscribed 4-cm mass with compression of the adjacent white matter, and a hyperintense rim around the mass on T2 weighted imaging. Which of the following is the most likely diagnosis?

A. Meningioma (Correct Answer)
B. Hemangioblastoma
C. Schwannoma
D. Glioblastoma multiforme
E. Oligodendroglioma

Explanation: ***Meningioma*** - This is the most likely diagnosis due to the **solitary, well-circumscribed, supratentorial mass** found in an elderly patient, which is a classic presentation. The **dural tail sign** (hyperintense rim on T2 MRI) and **homogeneous enhancement** are characteristic features. - The patient's presentation with a **fall due to a focal seizure** (twitching extremities, post-ictal confusion) is a common symptom of a slow-growing mass like a meningioma that can irritate the cerebral cortex. *Hemangioblastoma* - These are typically found in the **cerebellum** or spinal cord, not supratentorially as described in the case. - They often present as a **cystic lesion with a mural nodule**, which is different from the solid, well-circumscribed mass described here. *Schwannoma* - Schwannomas usually arise from cranial nerves, most commonly the **vestibulocochlear nerve** (**acoustic neuroma**). - While they can be homogeneous and well-circumscribed, they are typically **extra-axial (arising from nerves)** rather than from the brain parenchyma or dura. *Glioblastoma multiforme* - Glioblastoma multiforme (GBM) is characterized by an **aggressive, infiltrative mass** with **heterogeneous enhancement**, central necrosis, and significant surrounding edema. - The MRI description of a **homogeneous, well-circumscribed mass** does not fit the typical appearance of a GBM. *Oligodendroglioma* - Oligodendrogliomas are often characterized by **calcifications** and typically occur in the frontal lobes, but they tend to be **infiltrative** rather than well-circumscribed. - The description of a homogeneous, well-circumscribed mass with a hyperintense rim is not typical for an oligodendroglioma.

Question 585: A 53-year-old woman presents to her primary care physician with joint pain. She reports a 6-month history of progressive pain in her hands that is worse around her knuckles. The pain is symmetric bilaterally and seems to improve after she starts working in the morning at her job in a local grocery store. She has also lost 10 pounds over the past 6 months despite no changes in her diet or exercise regimen. Her past medical history is notable for seasonal allergies, hypertension, and intermittent constipation. She takes losartan and a laxative as needed. She had adolescent idiopathic scoliosis as a child and underwent a spinal fusion at the age of 14. She does not smoke or drink alcohol. Her temperature is 98.6°F (37°C), blood pressure is 135/75 mmHg, pulse is 92/min, and respirations are 16/min. On examination, she appears well and is appropriately interactive. Strength is 5/5 and sensation to light touch is intact in the bilateral upper and lower extremities. An examination of her hands demonstrates symmetric swelling of the metacarpophalangeal joints bilaterally. This patient's condition is most strongly characterized by which of the following?

A. HLA-DR2
B. HLA-B8
C. HLA-DR3
D. HLA-B27
E. HLA-DR4 (Correct Answer)

Explanation: ***HLA-DR4*** - The patient's symptoms, including **symmetric polyarthritis** of the **small joints** (knuckles), morning stiffness that improves with activity, and weight loss, are highly suggestive of **rheumatoid arthritis (RA)**. - **HLA-DR4** is the **MHC class II allele most strongly associated with rheumatoid arthritis** and is found in the majority of patients with seropositive RA. *HLA-DR2* - **HLA-DR2** is associated with other autoimmune diseases such as **multiple sclerosis**, **narcolepsy**, and **Goodpasture's syndrome**, but not typically with rheumatoid arthritis. - There is no clinical evidence in the patient's presentation to suggest these conditions. *HLA-B8* - **HLA-B8** is primarily associated with diseases like **myasthenia gravis**, **celiac disease**, and **Dermatitis herpetiformis**. - It does not have a strong association with rheumatoid arthritis. *HLA-DR3* - **HLA-DR3** is linked with diseases such as **celiac disease**, **Type 1 diabetes mellitus**, and **systemic lupus erythematosus**. - While autoimmune, these conditions do not align with the patient's specific pattern of joint and systemic symptoms. *HLA-B27* - **HLA-B27** is strongly associated with **spondyloarthropathies**, such as **ankylosing spondylitis** and **reactive arthritis**. - This patient's symptoms of symmetric small joint polyarthritis are inconsistent with spondyloarthropathies, which typically affect the spine and larger joints.

Question 586: A 60-year-old woman presents to the emergency department due to progressive shortness of breath and a dry cough for the past week. She notes that her symptoms are exacerbated by physical activity and relieved by rest. The woman was diagnosed with chronic kidney disease 2 years ago and was recently started on regular dialysis treatment. Her pulse rate is 105/min, blood pressure is 110/70 mm Hg, respiratory rate is 30/min, and temperature is 37.8°C (100.0°F). On examination of the respiratory system, there is dullness on percussion, decreased vocal tactile fremitus, and decreased breath sounds over the right lung base. The rest of the physical exam is within normal limits. Which of the following is the most likely cause of this patient’s symptoms?

A. Primary spontaneous pneumothorax (PSP)
B. Pleural effusion (Correct Answer)
C. Acute bronchitis
D. Pneumonia
E. Pulmonary tuberculosis (TB)

Explanation: ***Pleural effusion*** - The patient's symptoms of **progressive shortness of breath**, **dry cough**, and physical exam findings of **dullness to percussion**, **decreased vocal tactile fremitus**, and **decreased breath sounds** over the right lung base are classic signs of a **pleural effusion**. - Given her history of **chronic kidney disease** and recent initiation of **dialysis**, she is at high risk for fluid overload, which can lead to **transudative pleural effusions** due to **increased hydrostatic pressure**. *Primary spontaneous pneumothorax (PSP)* - PSP typically presents with **sudden onset of pleuritic chest pain** and **shortness of breath**, not a progressive onset over a week. - Physical exam findings for pneumothorax include **hyperresonance to percussion** and **absent or diminished breath sounds**, but **vocal tactile fremitus would be decreased or absent**, which is similar to pleural effusion. However, the patient's presentation of gradual onset and risk factors for fluid overload point away from a PSP. *Acute bronchitis* - Acute bronchitis usually presents with a **productive cough**, and symptoms are often preceded by an **upper respiratory tract infection**. - Physical exam findings typically include **wheezing** or **rhonchi**, with normal percussion and fremitus, differing from the described findings. *Pneumonia* - Pneumonia would typically present with a **productive cough**, **fever**, and signs of consolidation on lung exam, such as **bronchial breath sounds** and **increased vocal fremitus**, along with dullness to percussion. - While dullness and decreased breath sounds can be present, the **decreased vocal tactile fremitus** observed here strongly suggests fluid in the pleural space rather than consolidation. *Pulmonary tuberculosis (TB)* - Pulmonary TB often presents with **chronic cough (often productive)**, **night sweats**, **weight loss**, and **low-grade fever**, which are not the primary symptoms described. - While CXR findings can vary, the acute presentation with clear signs of fluid accumulation in a patient with kidney disease makes TB less likely without other predisposing factors or prolonged symptomatology.

Question 587: A 72-year-old man is brought to the emergency department by his daughter because he was found to have decreased alertness that has gotten progressively worse. Three weeks ago he was diagnosed with an infection and given an antibiotic, though his daughter does not remember what drug was prescribed. His medical history is also significant for benign prostatic hyperplasia and hypertension, for which he was prescribed tamsulosin, a thiazide, and an ACE inhibitor. He has not sustained any trauma recently, and no wounds are apparent. On presentation, he is found to be confused. Labs are obtained with the following results: Serum: Na+: 135 mEq/L BUN: 52 mg/dL Creatinine: 2.1 mg/dL Urine: Osmolality: 548 mOsm/kg Na+: 13 mEq/L Creatinine: 32 mg/dL Which of the following etiologies would be most likely given this patient's presentation?

A. Forgetting to take tamsulosin
B. Overdiuresis by thiazides (Correct Answer)
C. Toxic reaction to antibiotic
D. Allergic reaction to antibiotic
E. Hemorrhage

Explanation: ***Overdiuresis by thiazides*** - The patient exhibits elevated **BUN** and **creatinine** (52 mg/dL and 2.1 mg/dL respectively), suggestive of **prerenal acute kidney injury**. The low **urine sodium** (13 mEq/L) and high **urine osmolality** (548 mOsm/kg) indicate appropriate renal response to hypovolemia, reflecting reduced renal perfusion. - **Thiazide diuretics** can cause significant volume depletion, leading to prerenal injury, and the patient's decreased alertness is consistent with dehydration and potential electrolyte imbalances from aggressive diuresis. *Forgetting to take tamsulosin* - **Tamsulosin** is an alpha-blocker used for benign prostatic hyperplasia; forgetting it would lead to worsening urinary symptoms, not acute kidney injury or decreased alertness. - While it can cause orthostatic hypotension, skipping a dose would likely improve, not worsen, blood pressure, and would not explain the observed lab values. *Toxic reaction to antibiotic* - While some antibiotics can cause **nephrotoxicity** (e.g., aminoglycosides, vancomycin), this would typically manifest with **acute tubular necrosis**, characterized by a high **urine sodium** and low **urine osmolality**, which contradicts the patient's lab findings. - The patient was diagnosed with an infection three weeks ago; a toxic reaction usually occurs shortly after administration or with chronic high doses, not with such a delayed presentation without specific signs of organ damage beyond kidney injury. *Allergic reaction to antibiotic* - An **allergic reaction** to an antibiotic would likely present with symptoms such as rash, urticaria, angioedema, or anaphylaxis, none of which are described. - An allergic reaction would not directly cause the patient's specific pattern of **prerenal acute kidney injury** as indicated by the urine and serum labs. *Hemorrhage* - A **hemorrhage** could cause **prerenal acute kidney injury** due to hypovolemia, but there is no mention of trauma or signs of bleeding (e.g., melena, hematochezia, ecchymoses), and the patient's daughter did not report any. - While hemorrhage is a possibility in elderly patients, the history of recent diuretic use provides a more direct and plausible explanation for the observed fluid status and renal parameters.

Question 588: A 69-year-old man is brought to the emergency room by his wife 30 minutes after losing consciousness while they were working in their garden together. The patient says that time seemed to slow down, his vision went dark, and he had a sensation of falling. After 3–5 seconds, he awoke slightly disoriented but quickly regained his baseline mental status. The patient says he has had a few similar episodes that occurred 1–2 months ago for which he did not seek any medical treatment. He says overall he has been more tired than usual and feeling out of breath on his morning walks. He denies any chest pain or palpitations. Past medical history is significant for type 1 diabetes mellitus. Current medications are atorvastatin and insulin. His family history is significant for his father who died of myocardial infarction in his 70’s. His blood pressure is 110/85 mm Hg and pulse is 82/min. On physical examination, there is a 3/6 systolic murmur best heard over the right sternal border with radiation to the carotids. S1 is normal but there is a soft unsplit S2. The lungs are clear to auscultation bilaterally. The remainder of the exam is unremarkable. Which of the following physical exam findings would also most likely be present in this patient?

A. A decrease in systolic blood pressure ≥ 10 mmHg during inspiration
B. A carotid biphasic pulse
C. Increased capillary pulsations of the fingertips
D. Distant heart sounds
E. A slow-rising and delayed upstroke of the carotid pulse (Correct Answer)

Explanation: ***A slow-rising and delayed upstroke of the carotid pulse*** - The patient's symptoms (syncope, dyspnea, fatigue) coupled with the **systolic murmur radiating to the carotids**, **soft unsplit S2**, and **type 1 diabetes mellitus** (a risk factor) are highly suggestive of **aortic stenosis**. - **Pulsus parvus et tardus** (small, slow-rising, and delayed carotid pulse) is a classic physical exam finding in severe **aortic stenosis** due to the obstruction of left ventricular outflow. *A decrease in systolic blood pressure ≥ 10 mmHg during inspiration* - This finding, known as **pulsus paradoxus**, is characteristic of **cardiac tamponade** or severe **obstructive lung disease**. - The patient's presentation of exertional syncope and a significant systolic ejection murmur does not align with these conditions. *A carotid biphasic pulse* - A **bisferiens pulse** (biphasic pulse) is typically observed in conditions that cause a rapid ejection followed by a second, smaller pulse, such as **aortic regurgitation** with or without **aortic stenosis**, or **hypertrophic obstructive cardiomyopathy**. - While there is a systolic murmur, the overall clinical picture, particularly the unsplit S2, is more consistent with isolated **aortic stenosis**. *Increased capillary pulsations of the fingertips* - **Quincke's sign**, or capillary pulsations in the nail beds, is a characteristic finding of **severe aortic regurgitation** due to the wide pulse pressure. - The patient’s symptoms and the murmur are more indicative of **aortic stenosis**, which is an outflow obstruction, rather than regurgitation. *Distant heart sounds* - **Distant heart sounds** are typically associated with conditions that create a barrier between the heart and the stethoscope, such as **pericardial effusion**, obesity, or emphysema. - While common in a range of pathologies, it is not a specific or classic finding for **aortic stenosis**, and the other findings strongly point towards valvular disease rather than pericardial issues.

Question 589: A 67-year-old man comes to the physician for a follow-up examination. He feels well. His last visit to a physician was 3 years ago. He has chronic obstructive pulmonary disease, coronary artery disease, and hypertension. Current medications include albuterol, atenolol, lisinopril, and aspirin. He has smoked one pack of cigarettes daily for 18 years but stopped 20 years ago. He had a right lower extremity venous clot 15 years ago that required 3 months of anticoagulation therapy. A colonoscopy performed 3 years ago demonstrated 2 small, flat polyps that were resected. He is 175 cm (5 ft 9 in) tall and weighs 100 kg (220 lb); BMI is 32.5 kg/m2. His pulse is 85/min, respirations are 14/min, and blood pressure is 150/80 mm Hg. Examination shows normal heart sounds and no carotid or femoral bruits. Scattered minimal expiratory wheezing and rhonchi are heard throughout both lung fields. Which of the following health maintenance recommendations is most appropriate at this time?

A. Bone densitometry scan
B. Abdominal ultrasonography (Correct Answer)
C. CT scan of the chest
D. Pulmonary function testing
E. Lower extremity ultrasonography

Explanation: ***Abdominal ultrasonography*** - This patient has a **history of smoking, obesity, hypertension, and coronary artery disease**, all of which are significant risk factors for **abdominal aortic aneurysm (AAA)**. - Current **USPSTF guidelines** recommend a **one-time screening abdominal ultrasound** for men aged 65-75 who have ever smoked to detect AAA. - This patient is 67 years old with an 18 pack-year smoking history (quit 20 years ago), making him eligible for this Grade B recommendation. *Bone densitometry scan* - **Osteoporosis screening** with bone densitometry is recommended for women aged 65 and older, but for men, it is typically recommended only if they have specific risk factors like chronic steroid use or hypogonadism, which are not present here. - While his COPD might contribute to some bone loss risk, it's not the most immediate or strongly indicated screening compared to AAA. *CT scan of the chest* - Although the patient has a smoking history, a **CT scan of the chest** for lung cancer screening is recommended for individuals aged 50-80 with a **20 pack-year smoking history** who currently smoke or have quit within the past 15 years. - This patient has only **18 pack-years** and quit smoking **20 years ago**, placing him outside the criteria for lung cancer screening. *Pulmonary function testing* - The patient has a known diagnosis of **COPD** and is already on appropriate medication (albuterol). - While monitoring **pulmonary function** is important for COPD management, routine PFTs are not indicated at every follow-up unless there is a change in symptoms or treatment, and it is not a primary preventive screening recommendation. *Lower extremity ultrasonography* - The patient had a **deep venous thrombosis (DVT)** 15 years ago, which was fully treated with 3 months of anticoagulation. - There are **no current symptoms of DVT** (e.g., leg pain, swelling, erythema), so a lower extremity ultrasound is not warranted as routine screening in the absence of new symptoms.

Question 590: A 33-year-old woman presents to her primary care physician for a wellness check-up. She states that recently she has been feeling well other than headaches that occur occasionally, which improve with ibuprofen and rest. She has a past medical history of hypertension and headaches and is currently taking hydrochlorothiazide. Her temperature is 99.2°F (37.3°C), blood pressure is 157/108 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals a young woman who appears healthy. A normal S1 and S2 are auscultated on cardiac exam, and her lungs are clear with good air movement bilaterally. From her previous visit, it was determined that she has an elevated aldosterone and low renin level. Laboratory values are ordered as seen below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 3.7 mEq/L HCO3-: 29 mEq/L BUN: 20 mg/dL Creatinine: 1.1 mg/dL Which of the following is the most likely diagnosis?

A. Benign essential hypertension
B. Pheochromocytoma
C. Cushing syndrome
D. Narrowing of the renal arteries
E. Primary hyperaldosteronism (Correct Answer)

Explanation: ***Primary hyperaldosteronism*** - The patient presents with **hypertension**, **mild hypokalemia (K+ of 3.7 mEq/L)**, and **metabolic alkalosis (HCO3- of 29 mEq/L)**, which are classic signs of primary hyperaldosteronism. - The elevated aldosterone and low renin levels, as noted from her previous visit, are diagnostic for primary hyperaldosteronism. *Benign essential hypertension* - While essential hypertension is common, the presence of **hypokalemia**, **metabolic alkalosis**, and particularly the **elevated aldosterone with low renin** points away from benign essential hypertension, which typically has normal renin-aldosterone ratios. - This patient's hypertension is likely **secondary** due to a specific endocrine imbalance. *Pheochromocytoma* - This condition presents with **episodic or paroxysmal hypertension**, **tachycardia**, **sweating**, and headaches, often in a more dramatic fashion. - The patient's blood pressure is consistently elevated, and she lacks the typical paroxysmal symptoms and signs of catecholamine excess. *Cushing syndrome* - Cushing syndrome is characterized by **hypertension**, central obesity, moon facies, buffalo hump, and striae, none of which are described. - While it can cause hypertension, it is due to cortisol excess and does not typically present with the specific aldosterone-renin profile seen in this patient. *Narrowing of the renal arteries* - **Renal artery stenosis** causes **renovascular hypertension** and is associated with **elevated renin levels** as the kidney perceives hypoperfusion and activates the renin-angiotensin-aldosterone system. - This patient presents with **low renin levels**, which directly contradicts the pathophysiology of renal artery stenosis.

Question 591: A 66-year-old man is brought into the emergency department by his daughter for a change in behavior. Yesterday the patient seemed more confused than usual and was asking the same questions repetitively. His symptoms have not improved over the past 24 hours, thus the decision to bring him in today. Last year, the patient was almost completely independent but he then suffered a "series of falls," after which his ability to care for himself declined. After this episode he was no longer able to cook for himself or pay his bills but otherwise had been fine up until this episode. The patient has a past medical history of myocardial infarction, hypertension, depression, diabetes mellitus type II, constipation, diverticulitis, and peripheral neuropathy. His current medications include metformin, insulin, lisinopril, hydrochlorothiazide, sodium docusate, atorvastatin, metoprolol, fluoxetine, and gabapentin. On exam you note a confused man who is poorly kept. He has bruises over his legs and his gait seems unstable. He is alert to person and place, and answers some questions inappropriately. The patient's pulse is 90/minute and his blood pressure is 170/100 mmHg. Which of the following is the most likely diagnosis?

A. Normal aging
B. Lewy body dementia
C. Vascular dementia (Correct Answer)
D. Pseudodementia (depression-related cognitive impairment)
E. Alzheimer's dementia

Explanation: ***Vascular dementia*** - This diagnosis is strongly supported by the patient's **stepwise decline** in cognitive function following a "series of falls" (likely small strokes or transient ischemic attacks) and his extensive history of **vascular risk factors** including hypertension, diabetes, and previous myocardial infarction. - The acute worsening of confusion over 24 hours, coupled with pre-existing impaired executive function (inability to cook or pay bills), is characteristic of **vascular dementia's fluctuating course** and presentation often linked to new cerebrovascular events. *Incorrect: Normal aging* - **Normal aging** involves a very gradual and mild decline in cognitive functions, primarily affecting processing speed and memory recall, without significant impairment in daily activities. - This patient's rapid, stepwise decline and inability to perform instrumental activities of daily living (IADLs) such as cooking and managing finances go beyond what is considered normal cognitive changes with aging. *Incorrect: Lewy body dementia* - **Lewy body dementia** is characterized by prominent **fluctuations in attention and alertness**, recurrent visual hallucinations, and spontaneous parkinsonism, none of which are explicitly mentioned as primary features in this patient's presentation. - While fluctuations in confusion are present, the history of a clear stepwise decline post-falls and significant vascular risk factors points away from Lewy body dementia as the most likely primary cause. *Incorrect: Pseudodementia (depression-related cognitive impairment)* - **Pseudodementia** refers to cognitive impairment that occurs in the context of **major depression**, where patients may exhibit poor concentration, memory difficulties, and psychomotor slowing that mimics dementia. - While this patient is on fluoxetine for depression, the **stepwise decline** after clear vascular events (falls), multiple vascular risk factors, and impaired executive function point to a true neurodegenerative process rather than depression-induced cognitive changes, which typically improve with treatment of the underlying mood disorder. *Incorrect: Alzheimer's dementia* - **Alzheimer's dementia** typically presents with a **gradual and progressive decline** in memory, particularly episodic memory, followed by other cognitive domains over several years. - The patient's history of a clear **stepwise decline** in function after acute events (falls) and the strong presence of **vascular risk factors** make vascular dementia a more fitting diagnosis than Alzheimer's, which is not typically associated with such a sudden, step-like progression.

Question 592: A 33-year-old African American woman presents to the office complaining of blurry vision and headache for the past 2 weeks. She states that she has not been feeling herself lately and also fell down once after a dizzy episode. Her medical history is remarkable for hypertension and pulmonary sarcoidosis treated with hydralazine and prednisone respectively. She had a recent bout of acute optic neuritis, requiring high-dose IV methylprednisolone. Her temperature is 37°C (98.6°F), the blood pressure is 112/76 mm Hg, the pulse is 78/min, and the respirations are 14/min. On examination, the patient is mildly disoriented. Head and neck examination reveals a soft, supple neck and a right-sided facial droop. There is 5/5 muscle strength in all extremities. VDRL test is negative. A head MRI is pending. What is the most appropriate next step in the management of this patient?

A. Methotrexate
B. Plasmapheresis
C. High-dose methylprednisolone (Correct Answer)
D. Heparin
E. Methotrexate and azathioprine

Explanation: ***High-dose methylprednisolone*** - The patient's symptoms (blurry vision, headache, disorientation, facial droop, recent optic neuritis) are highly suggestive of a **central nervous system (CNS) demyelinating event**, possibly related to **neuroinflammation** in the setting of sarcoidosis or a new demyelinating disease. - **High-dose intravenous corticosteroids** like methylprednisolone are the cornerstone treatment for acute exacerbations of demyelinating diseases (e.g., multiple sclerosis) and neuroinflammatory conditions like **neurosarcoidosis**, effectively reducing inflammation and neurological deficits. *Methotrexate* - **Methotrexate** is an immunosuppressant used as a **corticosteroid-sparing agent** in chronic inflammatory conditions, including sarcoidosis, but it is not the primary treatment for acute neurological exacerbations. - Its onset of action is relatively slow, making it unsuitable for immediate management of acute neurological symptoms. *Plasmapheresis* - **Plasmapheresis** is typically considered for severe inflammatory demyelinating events that are **refractory to high-dose corticosteroids**, or in specific conditions like Guillain-Barré syndrome or myasthenia gravis crisis. - It is not the initial treatment strategy when corticosteroids have not yet been adequately trialed for the current acute episode. *Heparin* - **Heparin** is an anticoagulant used to prevent or treat **thromboembolic events**, such as deep vein thrombosis, pulmonary embolism, or stroke due to clotting. - There is no clinical evidence in the patient's presentation (e.g., focal neurological deficits without clear vascular territory involvement, normal blood pressure) to suggest an acute thrombotic event warranting heparin. *Methotrexate and azathioprine* - This combination represents a **dual immunosuppressive therapy** typically used for **chronic, severe, or refractory autoimmune and inflammatory conditions**, often as steroid-sparing agents or for long-term disease control. - While relevant for chronic management of sarcoidosis, neither individually nor in combination are they appropriate for the **immediate treatment of acute neurological symptoms** which require rapid anti-inflammatory intervention.

Question 593: A 74-year-old man presents to the emergency department by paramedics for slurred speech and weakness in the left arm and leg for 1 hour. The patient was playing with his grandson when the symptoms started and his wife immediately called an ambulance. There is no history of head trauma or recent surgery. The patient takes captopril for hypertension. The vital signs include: pulse 110/min, respiratory rate 22/min, and blood pressure 200/105 mm Hg. The physical examination shows that the patient is alert and conscious, but speech is impaired. Muscle strength is 0/5 in the left arm and leg and 5/5 in the right arm and leg. A non-contrast CT of the head shows no evidence of intracranial bleeding. The lab results are as follows: Serum glucose 90 mg/dL Sodium 140 mEq/L Potassium 4.1 mEq/L Chloride 100 mEq/L Serum creatinine 1.3 mg/dL Blood urea nitrogen 20 mg/dL Cholesterol, total 240 mg/dL HDL-cholesterol 38 mg/dL LDL-cholesterol 100 mg/dL Triglycerides 190 mg/dL Hemoglobin (Hb%) 15.3 g/dL Mean corpuscular volume (MCV) 83 fL Reticulocyte count 0.8% Erythrocyte count 5.3 million/mm3 Platelet count 130,000/mm3 Partial thromboplastin time (aPTT) 30 sec Prothrombin time (PT) 12 sec Although he is within the time frame for the standard therapy of the most likely condition, the treatment cannot be started because of which of the following contraindications?

A. A platelet count of 130,000/mm3
B. Age of 74 years
C. Cholesterol level of 240 mg/dL
D. Creatinine level of 1.3 mg/dL
E. Systolic blood pressure of 200 mm Hg (Correct Answer)

Explanation: ***Systolic blood pressure of 200 mm Hg*** - The patient presents with symptoms highly suggestive of an **acute ischemic stroke**, including **slurred speech** and **left-sided weakness**. - For patients with acute ischemic stroke who are candidates for **thrombolytic therapy (e.g., alteplase)**, a **systolic blood pressure consistently >185 mm Hg or diastolic >110 mm Hg is a contraindication** due to increased risk of hemorrhagic transformation. *A platelet count of 130,000/mm3* - A platelet count of 130,000/mm³ is above the **contraindication threshold for thrombolytic therapy**, which is typically <100,000/mm³. - Therefore, this platelet count would **not prevent** the initiation of tPA. *Age of 74 years* - While older age was once considered a relative contraindication, current guidelines **do not consider age alone (including 74 years old) as an absolute contraindication** for thrombolytic therapy in acute ischemic stroke. - Eligibility is determined by a comprehensive risk-benefit assessment, not solely by age. *Cholesterol level of 240 mg/dL* - An elevated **cholesterol level** is a **risk factor for atherosclerosis** and ischemic stroke, but it is **not a contraindication for acute thrombolytic therapy**. - It relates to the underlying cause of the stroke rather than the immediate treatment decision. *Creatinine level of 1.3 mg/dL* - A **creatinine level of 1.3 mg/dL** indicates **mild renal impairment**, but it is **not a contraindication for thrombolytic therapy**. - Renal function more significantly impacts the use of certain anticoagulants, but not typically alteplase in the acute setting.

Question 594: A 40-year-old man comes to the physician because of a 2-year history of gradually worsening shortness of breath. He smoked half a pack of cigarettes daily for 10 years but stopped 8 years ago. His pulse is 72/min, blood pressure is 135/75 mm Hg, and respirations are 20/min. Examination shows an increased anteroposterior diameter of the chest. Diminished breath sounds are heard on auscultation of the chest. An x-ray of the chest shows widened intercostal spaces, a flattened diaphragm, and bilateral hyperlucency of the lung bases. This patient's condition puts him at greatest risk for which of the following conditions?

A. Antineutrophil cytoplasmic antibody-positive vasculitis
B. Bronchiolitis obliterans
C. IgA nephropathy
D. Bronchogenic carcinoma (Correct Answer)
E. Hepatocellular carcinoma

Explanation: ***Bronchogenic carcinoma*** - The patient's presentation with **shortness of breath**, history of **smoking**, and chest X-ray findings (increased AP diameter, flattened diaphragm, hyperlucency) are highly suggestive of **emphysema**, a strong risk factor for bronchogenic carcinoma. - While he stopped smoking 8 years ago, his past smoking history significantly increases his lifetime risk for lung cancer, and emphysema itself is an independent risk factor for malignancies. *Antineutrophil cytoplasmic antibody-positive vasculitis* - This condition involves systemic inflammation of blood vessels, often affecting the **lungs and kidneys**, but there are no clinical or radiological findings suggestive of vasculitis here. - There is no mention of symptoms like **hematuria**, **rash**, or other systemic inflammatory signs that would point towards ANCA-positive vasculitis. *Bronchiolitis obliterans* - This is a rare, severe obstructive lung disease often caused by toxic inhalant exposure (e.g., **sulfur mustard**, **diacetyl**) or as a complication of **lung transplantation** or **rheumatoid arthritis**, none of which are indicated in this patient. - While it can cause shortness of breath, the characteristic imaging findings in this patient (hyperlucency, flattened diaphragm) are more indicative of **emphysema**, not bronchiolitis obliterans. *IgA nephropathy* - This is a **primary glomerulonephritis** characterized by IgA deposits in the glomeruli, leading to **hematuria** and **proteinuria**, and is not related to the patient's respiratory symptoms or imaging findings. - There is no clinical information provided that would suggest renal involvement. *Hepatocellular carcinoma* - This is a **primary liver cancer** typically associated with chronic liver diseases like **hepatitis B** or **C infections**, **cirrhosis**, or **alcohol abuse**, none of which are suggested in the patient's history. - The patient's symptoms and diagnostic findings are entirely focused on the respiratory system, with no indication of liver disease.

Question 595: A 45-year-old man presents to the emergency department with decreased exercise tolerance and shortness of breath which has progressed slowly over the past month. The patient recalls that shortly before the onset of these symptoms, he had a low-grade fever, malaise, and sore throat which resolved after a few days with over the counter medications. He does not have any chronic illnesses and denies recent travel or illicit habits. His vital signs include: blood pressure 120/80 mm Hg, temperature 37.0°C (98.6°F), and regular radial pulse 90/min. While checking his blood pressure manually, the difference between the systolic pressure at which the first Korotkoff sounds are heard during expiration and the pressure at which they are heard throughout the respiratory cycle is less than 10 mm Hg. On physical examination, he is in mild distress with jugular venous pressure (JVP) of 13 cm, and his heart sounds are muffled. His echocardiography shows a fluid collection in the pericardial sac with no evidence of right ventricular compression. Which of the following is the best initial step for the treatment of this patient?

A. Prednisone
B. Surgical drainage
C. Pericardiectomy
D. Pericardiocentesis
E. Observation and anti-inflammatory medicines (Correct Answer)

Explanation: ***Observation and anti-inflammatory medicines*** - The patient presents with symptoms suggestive of acute pericarditis (dyspnea, decreased exercise tolerance, prior viral illness) with pericardial effusion, but critically, he does **not exhibit signs of hemodynamic compromise** (pulsus paradoxus <10 mm Hg, stable blood pressure, no right ventricular compression on echo). - Given the absence of **cardiac tamponade** or severe symptomatic effusion, initial management typically involves conservative measures such as **NSAIDs and colchicine** to reduce pain and inflammation, along with close observation. *Prednisone* - **Corticosteroids** like prednisone are generally reserved for patients with **recurrent pericarditis resistant to NSAID treatment**, inflammatory causes (e.g., autoimmune), or those with contraindications to NSAIDs. - Using prednisone as a first-line treatment for acute pericarditis can increase the risk of **recurrence**. *Surgical drainage* - **Surgical drainage** (pericardial window) is indicated for **recurrent cardiac tamponade**, effusions unresponsive to pericardiocentesis, or when a **diagnostic biopsy** of the pericardium is required. - It's a more invasive procedure than justified for stable, non-compressive pericardial effusions. *Pericardiectomy* - **Pericardiectomy**, the surgical removal of the pericardium, is indicated for **constrictive pericarditis** or **recurrent effusions** that are not controlled by less invasive means. - This patient does not show signs of constriction, making it an overly aggressive initial treatment. *Pericardiocentesis* - **Pericardiocentesis** is indicated for **cardiac tamponade** (hemodynamic compromise), large effusions causing significant symptoms, or for diagnostic purposes when a specific etiology is suspected (e.g., bacterial, malignant). - The patient's lack of pulsus paradoxus (<10 mm Hg) and no evidence of right ventricular compression suggest no tamponade, thus negating the need for immediate pericardiocentesis.

Question 596: A 51-year-old woman presents for her annual wellness visit. She says she feels healthy and has no specific concerns. Past medical history is significant for bipolar disorder, hypertension, and diabetes mellitus type 2, managed with lithium, lisinopril, and metformin, respectively. Her family history is significant for hypertension and diabetes mellitus type 2 in her father, who died from lung cancer at age 67. Her vital signs include: temperature 36.8°C (98.2°F), pulse 97/min, respiratory rate 16/min, blood pressure 120/75 mm Hg. Physical examination is unremarkable. Mammogram findings are labeled breast imaging reporting and data system-3 (BIRADS-3) (probably benign). Which of the following is the next best step in management in this patient?

A. Follow-up mammogram in 6 months (Correct Answer)
B. Follow-up mammogram in 1 year
C. Treatment
D. Biopsy
E. Breast MRI

Explanation: ***Follow-up mammogram in 6 months*** - A **BIRADS-3** (Breast Imaging Reporting and Data System 3) classification indicates a **probably benign finding**, with a less than 2% chance of malignancy. - The recommended management for BIRADS-3 is a **short-interval follow-up mammogram in 6 months** to assess for stability or changes. *Follow-up mammogram in 1 year* - This follow-up interval is typically recommended for **BIRADS-1 (negative)** or **BIRADS-2 (benign)** findings, not for BIRADS-3. - Waiting a full year would delay the detection of any potential malignancy in a BIRADS-3 lesion. *Treatment* - Treatment is indicated for confirmed malignancy, typically after a biopsy has confirmed cancerous cells. - Starting treatment at the BIRADS-3 stage would be premature given the low probability of malignancy. *Biopsy* - A biopsy is generally warranted for **BIRADS-4 (suspicious)** or **BIRADS-5 (highly suggestive of malignancy)** lesions. - While biopsy can be considered for BIRADS-3 if there are high-risk factors or patient preference, **short-interval follow-up** is the standard and preferred initial approach. *Breast MRI* - Breast MRI is often used for high-risk patients, for **staging known breast cancer**, or to evaluate **dense breast tissue**. - It is not the standard next step for a BIRADS-3 finding in a patient with no specific high-risk indications beyond the mammogram result.

Question 597: A 35-year-old woman presents as a new patient to a primary care physician. She hasn't seen a doctor in many years and came in for a routine check-up. She has no specific complaints, although she has occasional shortness of breath with mild activity. On physical exam, her vital signs are as follows: HR 80, BP 110/70, RR 14. On auscultation, her lungs are clear with equal breath sounds bilaterally. When listening over the precordium, the physician hears a mid-systolic click followed by a late systolic murmur that is loudest over the apex. Valsalva increases the murmur. Which of the following is NOT a possible complication of this patient's underlying problem?

A. Cerebral embolism
B. Infective endocarditis
C. Atrial fibrillation
D. Bleeding from acquired von Willebrand disease (Correct Answer)
E. Sudden death

Explanation: ***Bleeding from acquired von Willebrand disease*** - The patient's presentation of a **mid-systolic click** followed by a **late systolic murmur** that increases with Valsalva maneuver is characteristic of **mitral valve prolapse (MVP)**. - While acquired **von Willebrand syndrome (AVWS)** has been rarely reported with MVP, it is **not a characteristic complication** and is far more commonly associated with **aortic stenosis** and other high-shear cardiac lesions. - Among the listed options, AVWS is the **least typical** complication of MVP, making this the correct answer to a "NOT" question. *Cerebral embolism* - Patients with MVP are at a slightly increased risk of **thromboembolic events**, including **cerebral embolism**, particularly in those with mitral regurgitation or atrial fibrillation. - The structural abnormalities of the valve can promote **platelet aggregation** or the formation of small thrombi that can embolize. *Infective endocarditis* - MVP increases the risk of **infective endocarditis**, particularly in cases with significant mitral regurgitation or thickened, redundant valve leaflets (**myxomatous degeneration**). - The damaged valve surface provides a site for bacterial attachment and colonization. *Atrial fibrillation* - MVP, especially when associated with significant **mitral regurgitation** or **left atrial enlargement**, can lead to the development of **atrial fibrillation**. - The altered hemodynamics and increased atrial pressure can predispose to arrhythmias. *Sudden death* - Although rare, **sudden cardiac death** is a recognized complication of MVP, particularly in patients with severe forms, complex ventricular arrhythmias, or significant mitral regurgitation. - This complication is often linked to serious ventricular arrhythmias, which can be triggered by leaflet elongation, myocardial fibrosis, or papillary muscle abnormalities.

Question 598: A 62-year-old man comes to the physician because of a 5-day history of swelling in his left arm. Two months ago, he was diagnosed with a deep venous thrombosis in the left calf. He has had a 7-kg (15-lb) weight loss in the last 3 months. He has smoked 1 pack of cigarettes daily for the past 25 years. His only medication is warfarin. Physical examination shows warm edema of the left forearm with overlying erythema and a tender, palpable cord-like structure along the medial arm. His lungs are clear to auscultation bilaterally. Duplex sonography shows thrombosis of the left basilic and external jugular veins. Which of the following is the most appropriate next step to confirm the underlying diagnosis?

A. CT scan of the chest
B. X-ray of the chest (Correct Answer)
C. Transesophageal echocardiography
D. Serum antiphospholipid antibody level
E. Serum D-dimer level

Explanation: **X-ray of the chest** - The patient presents with **recurrent deep venous thrombosis (DVT)**, specifically in an unusual location (upper extremity), combined with **unexplained weight loss** and a **significant smoking history**. These are strong indicators of an underlying malignancy. - A **chest x-ray** is a readily available and cost-effective initial screening tool to evaluate for **lung cancer**, which is common in smokers and can present with paraneoplastic phenomena like hypercoagulability (Trousseau phenomenon) leading to DVT. *CT scan of the chest* - While a **CT scan of the chest** is more sensitive than an X-ray for detecting lung masses, an **X-ray is the more appropriate initial step** for screening given the clinical context. - A **CT scan** would typically be performed after an abnormal chest X-ray or if clinical suspicion remains high despite a normal X-ray. *Transesophageal echocardiography* - **Transesophageal echocardiography (TEE)** is primarily used to evaluate **cardiac structures**, valve function, and to detect intracardiac thrombi or vegetations. - It is not indicated as a primary screening tool for an underlying malignancy or in the workup of a **venous thrombosis** not directly related to cardiac pathology. *Serum antiphospholipid antibody level* - **Antiphospholipid antibody syndrome** is a cause of recurrent thrombosis, but the patient's other symptoms (weight loss, smoking history, unusual DVT location) point more strongly towards an underlying malignancy. - While it might be considered in a broader workup for hypercoagulability, it is not the most immediate next step given the constellation of findings strongly suggestive of cancer. *Serum D-dimer level* - A **serum D-dimer level** is a marker of fibrin degradation and is useful for **excluding DVT/PE** in low-probability patients. - In this patient, a DVT has already been diagnosed by duplex sonography, so a D-dimer level would not provide additional diagnostic information regarding the presence of thrombosis, nor would it help in identifying the underlying cause of the recurrent thrombosis.

Question 599: A 28-year-old woman presents to the emergency department with fever, cough, and difficulty in breathing for the last 6 hours. She also mentions that she noticed some blood in her sputum an hour ago. She denies nasal congestion or discharge, sneezing, wheezing, chest pain, or palpitation. Her past history does not suggest any chronic medical condition, including respiratory disease, cardiovascular disease, or cancer. There is no history of pulmonary embolism or deep vein thrombosis in the past. Her temperature is 38.3°C (101.0°F), the pulse is 108/min, the blood pressure is 116/80 mm Hg, and the respirations are 28/min. Auscultation of her lungs reveals the presence of localized crackles over the right inframammary region. Edema is present over her left leg and tenderness is present over her left calf region. When her left foot is dorsiflexed, she complains of calf pain. The emergency department protocol mandates the use of a modified Wells scoring system in all patients presenting with the first episode of breathlessness when there is no history of a cardiorespiratory disorder in the past. According to the modified Wells scoring system, which of the following risk factors, if present, would contribute the most points toward a high clinical probability of pulmonary embolism?

A. History of surgery within the last 30 days (Correct Answer)
B. Use of oral contraceptives within last 90 days
C. Intravenous drug use within last 14 days
D. History of travel of 2 hours in 30 days
E. History of smoking for more than 1 year

Explanation: ***History of surgery within the last 30 days*** - Recent surgery (within the previous 4 weeks) is a significant **risk factor for venous thromboembolism (VTE)** due to immobility, endothelial damage, and hypercoagulability, and contributes **1.5 points** in the modified Wells score. - Among the options listed, this is the **only risk factor that actually contributes points** to the modified Wells score, making it the correct answer for the highest individual contribution. - In this scoring system, scores are categorized as: ≤1 point (low probability), 2-6 points (moderate probability), and ≥7 points (high probability). *Use of oral contraceptives within last 90 days* - While **oral contraceptives** are a known risk factor for VTE in epidemiological studies, they are **not included as a scored component** in the modified Wells criteria for pulmonary embolism. - The Wells score focuses on acute clinical factors rather than chronic predisposing conditions like hormonal contraception. *Intravenous drug use within last 14 days* - **Intravenous drug use** is not a component of the modified Wells score for pulmonary embolism. - It may lead to other complications (such as septic emboli or endocarditis) but does not directly increase the score for PE risk in this specific diagnostic tool. *History of travel of 2 hours in 30 days* - **Prolonged immobilization** (≥3 days of bed rest or travel exceeding 4-6 hours) is a risk factor for VTE and would contribute **1.5 points** as part of the immobilization criterion. - However, travel of only **2 hours** does not meet the threshold for significant immobilization and would **not contribute points** to the modified Wells score. *History of smoking for more than 1 year* - **Smoking** is a general risk factor for various cardiovascular and pulmonary diseases but is **not a component** of the modified Wells score for assessing the acute probability of pulmonary embolism. - While it contributes to overall cardiovascular risk, it does not add points in this specific diagnostic tool for PE.

Question 600: A 67-year-old man comes to the physician because of a 6-month history of increasing shortness of breath on exertion, dry cough, and fatigue. He has not had any fevers or night sweats. He worked in a glass manufacturing factory for 15 years and retired 2 years ago. Pulmonary examination shows diffuse crackles bilaterally. An x-ray of the chest shows well-defined calcification of the rims of hilar lymph nodes and scattered nodules in both upper lung fields. This patient is most likely to develop which of the following complications?

A. Pneumocystis pneumonia
B. Pulmonary tuberculosis (Correct Answer)
C. Invasive aspergillosis
D. Malignant mesothelioma
E. Spontaneous pneumothorax

Explanation: ***Pulmonary tuberculosis*** * The description of **shortness of breath**, **dry cough**, and fatigue in a patient with a history of working in a **glass manufacturing factory** (exposing him to silica) with specific radiographic findings such as **egg-shell calcification of hilar lymph nodes** and scattered nodules in the upper lung fields is highly suggestive of **silicosis**. * Patients with **silicosis** have an increased risk of developing **pulmonary tuberculosis** due to impaired macrophage function, leading to reduced clearance of *Mycobacterium tuberculosis*. *Pneumocystis pneumonia* * This infection primarily affects **immunocompromised individuals**, such as those with HIV/AIDS or those on immunosuppressive medications. * There is no information in the vignette to suggest the patient is immunocompromised in a way that would predispose him to *Pneumocystis* pneumonia. *Invasive aspergillosis* * This is typically an opportunistic infection found in severely **immunocompromised patients** (e.g., those with hematologic malignancies, transplant recipients, or prolonged neutropenia) or those with pre-existing lung cavitations. * While lung pathology due to silicosis could potentially create an environment for fungal colonization, invasive aspergillosis is not the most common or direct complication. *Malignant mesothelioma* * **Malignant mesothelioma** is primarily associated with **asbestos exposure**, not silica exposure. * The patient's history of working in a **glass manufacturing factory** indicates **silica exposure**, not asbestos. *Spontaneous pneumothorax* * While some types of interstitial lung disease, including advanced silicosis, can increase the risk of pneumothorax, it is not as classically or directly associated as tuberculosis. * **Tuberculosis** reactivation is a well-established and significant complication of **silicosis** due to altered immune response.

Question 601: A 71-year-old man presents to the emergency department for shortness of breath. The patient was returning from a business trip to China, when he suddenly felt short of breath during the taxi ride home from the airport. The patient has a past medical history of poorly controlled diabetes mellitus and a 50 pack-year smoking history. The patient is non-compliant with his medications and is currently only taking ibuprofen. An initial ECG demonstrates sinus tachycardia. A chest radiograph is within normal limits. Laboratory values are notable for a creatinine of 2.4 mg/dL and a BUN of 32 mg/dL as compared to his baseline creatinine of 0.9 mg/dL. His temperature is 98.8°F (37.1°C), pulse is 122/min, blood pressure is 145/90 mmHg, respirations are 19/min, and oxygen saturation is 93% on room air. On physical exam, you note an older gentleman in distress. Cardiac exam is notable only for tachycardia. Pulmonary exam is notable for expiratory wheezes. Which of the following is the best confirmatory test for this patient?

A. Ventilation perfusion scan
B. Lower extremity ultrasound with Doppler
C. CT angiogram (Correct Answer)
D. Arterial blood gas
E. D-dimer

Explanation: ***CT angiogram*** - This patient presents with multiple risk factors for **pulmonary embolism (PE)**, including a recent long-haul flight and acute onset of dyspnea with tachycardia and hypoxemia. CT pulmonary angiography (CTPA) is the **gold standard confirmatory test** for PE, directly visualizing thrombi in the pulmonary arteries with high sensitivity (>90%) and specificity. - While this patient has **acute kidney injury** (creatinine elevated from 0.9 to 2.4 mg/dL), raising concerns about contrast-induced nephropathy, the **high clinical probability of PE** (recent long flight, acute dyspnea, tachycardia, hypoxemia) makes urgent diagnosis critical. In hemodynamically stable patients with intermediate-to-high PE probability and renal insufficiency, CTPA with appropriate precautions (IV hydration, minimizing contrast dose, avoiding nephrotoxic agents) is still preferred as it provides the most definitive diagnosis. - The patient's hemodynamic stability (BP 145/90) allows time for renal protective measures before contrast administration. *Ventilation perfusion scan* - A V/Q scan is an important **alternative** for diagnosing PE, particularly valuable in patients with severe renal insufficiency (CKD Stage 4-5) or contrast allergy where CTPA is truly contraindicated. - However, in this patient with **expiratory wheezes** suggesting possible underlying obstructive lung disease (50 pack-year smoking history), a V/Q scan has higher likelihood of **indeterminate results** (intermediate probability), which would not confirm or exclude PE and might necessitate additional testing anyway. - V/Q scans also have lower sensitivity than CTPA and require the patient to cooperate with breathing maneuvers, which may be difficult in an acutely dyspneic patient. *Lower extremity ultrasound with Doppler* - This test diagnoses **deep vein thrombosis (DVT)**, the most common source of PE. While a positive DVT in a patient with suspected PE would support treatment, a **negative study does not rule out PE** since the thrombus may have already completely embolized. - This is a supportive test, not a confirmatory test for PE itself. The patient's symptoms require direct assessment of the pulmonary vasculature. *Arterial blood gas* - An ABG typically shows **hypoxemia and respiratory alkalosis** in PE due to V/Q mismatch and hyperventilation, but these findings are **non-specific** and occur in many cardiopulmonary conditions (pneumonia, asthma, COPD exacerbation, heart failure). - ABG is a supportive tool that may guide oxygen therapy but does not confirm PE diagnosis. *D-dimer* - D-dimer has excellent **negative predictive value** and is useful to exclude PE in patients with **low clinical probability** (Wells score <2 or PERC rule negative). - In this patient with **high clinical probability** of PE (recent long flight, acute symptoms, risk factors), D-dimer would almost certainly be elevated and thus **not helpful for confirmation**. Elevated D-dimer occurs in many conditions including infection, inflammation, malignancy, recent surgery, and advanced age, making it non-specific in this context.

Question 602: A 77-year-old woman is brought to the physician for gradually increasing confusion and difficulty walking for the past 4 months. Her daughter is concerned because she has been forgetful and seems to be walking more slowly. She has been distracted during her weekly bridge games and her usual television shows. She has also had increasingly frequent episodes of urinary incontinence and now wears an adult diaper daily. She has hyperlipidemia and hypertension. Current medications include lisinopril and atorvastatin. Her temperature is 36.8°C (98.2°F), pulse is 84/min, respirations are 15/min, and blood pressure is 139/83 mmHg. She is confused and oriented only to person and place. She recalls 2 out of 3 words immediately and 1 out of 3 after five minutes. She has a broad-based gait and takes short steps. Sensation is intact and muscle strength is 5/5 throughout. Laboratory studies are within normal limits. Which of the following is the most likely diagnosis in this patient?

A. Pseudodementia
B. Normal pressure hydrocephalus (Correct Answer)
C. Creutzfeldt-Jakob disease
D. Frontotemporal dementia
E. Dementia with Lewy-bodies

Explanation: ***Normal pressure hydrocephalus*** - The constellation of **gradually increasing confusion**, an **ataxic gait** (broad-based, short steps), and **urinary incontinence** in an elderly patient is the classic triad of **normal pressure hydrocephalus (NPH)**. - Lumbar puncture with temporary symptom improvement or **neuroimaging** showing ventriculomegaly without significant sulcal atrophy would further support this diagnosis. *Pseudodementia* - **Pseudodementia** is a cognitive impairment primarily caused by **depression**, characterized by rapid onset of symptoms and often a history of mood disturbances. - The patient's progressive decline over 4 months and lack of overt depressive symptoms make this less likely. *Creutzfeldt-Jakob disease* - **Creutzfeldt-Jakob disease (CJD)** is a rapidly progressive and fatal neurodegenerative disorder characterized by a very fast decline in cognitive function, typically over months, along with **myoclonus**, ataxia, and other neurological signs. - The slower, more subtle progression of symptoms and absence of myoclonus make CJD less likely. *Frontotemporal dementia* - **Frontotemporal dementia (FTD)** usually presents with prominent early changes in **personality, behavior**, or **language (aphasia)**, rather than the classic NPH triad. - While confusion can occur, gait disturbance and incontinence are not typically primary or early features. *Dementia with Lewy-bodies* - **Dementia with Lewy bodies (DLB)** is characterized by **fluctuating cognition**, **recurrent visual hallucinations**, and **spontaneous parkinsonism**. - While gait disturbance can occur (parkinsonism), the absence of hallucinations and significant cognitive fluctuations makes NPH a more fitting diagnosis for the specific triad presented.

Question 603: A 32-year-old woman comes to the physician because of a 6-week history of fatigue and weakness. Examination shows marked pallor of the conjunctivae. The spleen tip is palpated 2 cm below the left costal margin. Her hemoglobin concentration is 9.5 g/dL, serum lactate dehydrogenase concentration is 750 IU/L, and her serum haptoglobin is undetectable. A peripheral blood smear shows multiple spherocytes. When anti-IgG antibodies are added to a sample of the patient's blood, there is clumping of the red blood cells. Which of the following is the most likely predisposing factor for this patient's condition?

A. Bicuspid aortic valve
B. Epstein-Barr virus infection
C. Mycoplasma pneumoniae infection
D. Systemic lupus erythematosus (Correct Answer)
E. Hereditary spectrin defect

Explanation: ***Systemic lupus erythematosus*** - The patient's presentation with **fatigue, weakness, pallor, splenomegaly**, and laboratory findings of **hemolytic anemia** (low hemoglobin, elevated LDH, undetectable haptoglobin, spherocytes) along with a **positive direct antiglobulin test** (clumping with anti-IgG antibodies) is highly suggestive of **autoimmune hemolytic anemia (AIHA)**. - **Systemic lupus erythematosus (SLE)** is a common cause of secondary AIHA, where the immune system mistakenly attacks red blood cells, leading to their destruction. *Bicuspid aortic valve* - A **bicuspid aortic valve** is a congenital heart defect that can lead to increased stress on red blood cells, but it typically causes **mechanical hemolysis**, not autoimmune hemolysis. - Mechanical hemolysis would not explain the **positive direct antiglobulin test** and the presence of **spherocytes** as the hallmark of immune-mediated destruction. *Epstein-Barr virus infection* - **Epstein-Barr virus (EBV) infection** can cause various hematologic complications, including anemia, but it is more commonly associated with cold agglutinin disease (a type of AIHA where IgM antibodies are involved), not warm AIHA (IgG-mediated) with spherocytes. - While EBV can cause lymphoproliferation and autoimmune phenomena, it is not the most direct or common predisposing factor for this specific presentation of warm AIHA. *Mycoplasma pneumoniae infection* - **Mycoplasma pneumoniae infection** is a well-known cause of **cold agglutinin disease**, where **IgM antibodies** (specifically anti-I antibodies) cause clumping of red blood cells at lower temperatures. - This patient's direct antiglobulin test is positive for **IgG antibodies**, indicating a warm AIHA, which is typically not caused by Mycoplasma. *Hereditary spectrin defect* - A **hereditary spectrin defect** is characteristic of **hereditary spherocytosis**, a genetic disorder causing red blood cell membrane abnormalities and spherocyte formation. - While hereditary spherocytosis leads to spherocytes and hemolysis, it is associated with a **negative direct antiglobulin test** because the hemolysis is due to intrinsic red blood cell defects, not autoimmune processes.

Question 604: A 59-year-old woman comes to the emergency department because of a 2-day history of worsening fever, chills, malaise, productive cough, and difficulty breathing. Three days ago, she returned from a trip to South Africa. She has type 2 diabetes mellitus, hypertension, and varicose veins. Her current medications include metformin, lisinopril, and atorvastatin. Her temperature is 39.4°C (102.9°F), pulse is 102/minute, blood pressure is 94/68 mm Hg, and respirations are 31/minute. Pulse oximetry on 2 L of oxygen via nasal cannula shows an oxygen saturation of 91%. Examination reveals decreased breath sounds and dull percussion over the left lung base. The skin is very warm and well-perfused. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 11.6 g/dL Leukocyte count 15,400/mm3 platelet count 282,000/mm3 Serum Na+ 144 mEq/L Cl- 104 mEq/L K+ 4.9 mEq/L Creatinine 1.5 mg/dL Blood and urine for cultures are obtained. Intravenous fluid resuscitation is begun. Which of the following is the next best step in management?

A. Erythromycin
B. Intravenous ceftriaxone and azithromycin (Correct Answer)
C. External cooling and intravenous acetaminophen
D. Intravenous vancomycin and ceftriaxone
E. CT of the chest with contrast

Explanation: ***Intravenous ceftriaxone and azithromycin*** * This patient presents with **severe community-acquired pneumonia (CAP)** meeting criteria for ICU-level care, including hypotension (94/68 mm Hg), hypoxemia requiring supplemental oxygen, tachypnea (31/min), and altered mental status indicators. The presentation meets multiple **severe CAP criteria** (CURB-65 score ≥3 or IDSA/ATS major criteria). * **Intravenous ceftriaxone** (a third-generation cephalosporin) provides broad-spectrum coverage against common bacterial causes of CAP, including *Streptococcus pneumoniae* and *Haemophilus influenzae*. **Azithromycin** (a macrolide) is crucial to cover atypical pathogens like *Mycoplasma pneumoniae*, *Chlamydophila pneumoniae*, and *Legionella pneumoniae*. * This combination represents the **standard empiric therapy for severe CAP** per IDSA/ATS guidelines. The patient's recent travel to South Africa and severe symptoms increase the likelihood of atypical pathogens or resistant strains, making dual therapy essential. *Erythromycin* * While erythromycin is a macrolide that covers atypical pathogens, its use is generally limited due to higher rates of gastrointestinal side effects and a less favorable dosing profile compared to newer macrolides like azithromycin. It does not provide adequate coverage for typical bacterial causes of CAP. * In severe CAP with signs of sepsis, monotherapy with erythromycin would be insufficient and would not address the need for broad-spectrum coverage against both typical and atypical bacteria. Dual antibiotic therapy is required for severe cases. *External cooling and intravenous acetaminophen* * These interventions are appropriate for **fever reduction** but do not address the underlying severe infection (pneumonia with sepsis). While important for symptomatic relief, they are not the "next best step in management" for a life-threatening condition. * Treating the infection with appropriate antibiotics is paramount to prevent further deterioration and organ damage. In severe sepsis from pneumonia, **source control through antimicrobial therapy takes precedence** over symptomatic fever management. *Intravenous vancomycin and ceftriaxone* * **Vancomycin** is primarily used to cover **methicillin-resistant *Staphylococcus aureus* (MRSA)**. While MRSA can cause severe pneumonia, there are no specific risk factors for MRSA in this patient (e.g., recent hospitalization, IV drug use, prior MRSA infection, severe influenza, cavitary lesions, hemoptysis). * Adding vancomycin without specific indications for MRSA coverage would represent unnecessary broad-spectrum antibiotic use and could contribute to antibiotic resistance. The combination of **ceftriaxone and azithromycin is the standard empiric therapy** for severe CAP without MRSA risk factors. *CT of the chest with contrast* * A CT scan of the chest might be useful for further characterizing the pneumonia, identifying complications (e.g., empyema, abscess), or differentiating from other conditions **after initial stabilization**. However, in a patient with severe pneumonia, hypoxemia, and hypotension, the immediate priority is stabilization and initiation of empiric antibiotic therapy. * Delaying life-saving antibiotic treatment to obtain a CT scan could worsen the patient's prognosis and violate the principle of **early appropriate antibiotics in sepsis** (ideally within 1 hour). Clinical diagnosis with chest X-ray is sufficient to initiate treatment, and further imaging can be obtained after stabilization if needed.

Question 605: A 75-year-old woman presents to the physician with a complaint of a frequent need to void at nighttime, which has been disrupting her sleep. She notes embarrassingly that she is often unable to reach the bathroom in time, and experiences urinary leakage throughout the night as well as during the day. The patient undergoes urodynamic testing and a urinalysis is obtained which is normal. She is instructed by the physician to perform behavioral training to improve her bladder control. Which of the following is the most likely diagnosis contributing to this patient’s symptoms?

A. Urinary tract infection
B. Stress incontinence
C. Urge incontinence (Correct Answer)
D. Overflow incontinence
E. Total incontinence

Explanation: ***Urge incontinence*** - The patient's symptoms of a **frequent need to void**, inability to reach the bathroom in time (urgency), and **nocturnal leakage** (nocturia with incontinence) are classic for urge incontinence. - This condition is characterized by **detrusor overactivity**, leading to sudden, strong urges to urinate that are difficult to defer. *Urinary tract infection* - While UTIs can cause urgency and frequency, the patient's **normal urinalysis** rules out an active infection as the cause of her symptoms. - UTIs typically present with dysuria, hematuria, or suprapubic pain, which are not mentioned. *Stress incontinence* - This type of incontinence is characterized by **involuntary urine leakage with increased intra-abdominal pressure**, such as coughing, sneezing, or laughing. - The patient's description of sudden urges and inability to reach the bathroom in time does not align with stress incontinence. *Overflow incontinence* - This condition is due to **incomplete bladder emptying**, leading to a constantly full bladder and continuous leakage. - It often presents with weak stream, hesitancy, and a feeling of incomplete voiding, which are not described here. *Total incontinence* - Total incontinence involves the **continuous and unpredictable leakage** of urine, day and night, without any discernible pattern. - While the patient experiences significant leakage, her symptoms point more specifically to the urge component rather than a complete absence of bladder control.

Question 606: A 68-year old woman presents with recurring headaches and pain while combing her hair. Her past medical history is significant for hypertension, glaucoma and chronic deep vein thrombosis in her right leg. Current medication includes rivaroxaban, latanoprost, and benazepril. Her vitals include: blood pressure 130/82 mm Hg, pulse 74/min, respiratory rate 14/min, temperature 36.6℃ (97.9℉). Physical examination reveals neck stiffness and difficulty standing up due to pain in the lower limbs. Strength is 5 out of 5 in the upper and lower extremities bilaterally. Which of the following is the next best step in the management of this patient?

A. Erythrocyte sedimentation rate (Correct Answer)
B. CK-MB
C. Fundoscopic examination
D. Lumbar puncture
E. Temporal artery biopsy

Explanation: ***Erythrocyte sedimentation rate*** - The patient's symptoms of recurring headaches, pain while combing hair, and neck stiffness are highly suggestive of **giant cell arteritis (GCA)**, a vasculitis requiring prompt diagnosis. - An elevated **erythrocyte sedimentation rate (ESR)** is a hallmark laboratory finding in GCA and is the most appropriate initial diagnostic test to support the clinical suspicion. *CK-MB* - **CK-MB** (creatine kinase-myocardial band) is a marker primarily used to diagnose myocardial injury, such as a heart attack. - The patient's symptoms are not consistent with an acute cardiac event; therefore, CK-MB measurement would not be the next best step. *Fundoscopic examination* - While **fundoscopic examination** can reveal signs of vasculitis or optic nerve ischemia in GCA, it is not the primary diagnostic test and may not show abnormalities early in the disease. - It would be part of a more extensive workup once GCA is suspected and initial lab tests are supportive. *Lumbar puncture* - A **lumbar puncture** is used to analyze cerebrospinal fluid, typically to diagnose conditions like meningitis, encephalitis, or subarachnoid hemorrhage. - The patient's symptoms do not point towards these neurological emergencies, making a lumbar puncture an inappropriate initial step. *Temporal artery biopsy* - A **temporal artery biopsy** is the gold standard for confirming the diagnosis of giant cell arteritis. - However, it is an invasive procedure and is typically performed *after* initial laboratory tests, such as ESR, support the clinical suspicion, and often after the initiation of empiric steroid treatment.

Question 607: A 59-year-old woman comes to the physician because of a 1-year history of pain and stiffness in her fingers and knees. The stiffness lasts for about 10 minutes after she wakes up in the morning. She also reports that her knee pain is worse in the evening. She drinks one glass of wine daily. Her only medication is acetaminophen. She is 175 cm (5 ft 9 in) tall and weighs 102 kg (225 lb); BMI is 33 kg/m2. Physical examination shows firm nodules on the distal interphalangeal joints of the index, ring, and little fingers of both hands. Which of the following is the most likely diagnosis?

A. Septic arthritis
B. Pseudogout
C. Gout
D. Rheumatoid arthritis
E. Osteoarthritis (Correct Answer)

Explanation: ***Osteoarthritis*** * The patient's age (59 years), obesity (BMI 33 kg/m2), short duration of morning stiffness (10 minutes), evening worsening of knee pain, and the presence of **firm nodules on the distal interphalangeal joints** (Heberden's nodes) are classic signs of **osteoarthritis**. * This condition is a common **degenerative joint disease** associated with wear and tear, often affecting weight-bearing joints and small joints of the hands. *Septic arthritis* * **Septic arthritis** typically presents with an acutely painful, hot, and swollen joint, often with systemic symptoms like fever and chills, which are absent here. * The chronic, progressive nature of the patient's symptoms and the presence of bony nodules point away from an infectious cause. *Pseudogout* * **Pseudogout**, or calcium pyrophosphate deposition disease, involves the deposition of calcium pyrophosphate crystals, leading to episodes of acute, painful arthritis, often in larger joints like the knee. * While it can affect the knee, the insidious onset, chronic pain, and specific hand nodules seen in this case are not typical features of pseudogout. *Gout* * **Gout** is characterized by sudden, severe attacks of pain, redness, and swelling, often affecting a single joint (commonly the great toe) due to **uric acid crystal deposition**. * The patient's chronic pain pattern, multiple joint involvement (fingers and knees), and the description of firm nodules (not tophi) make gout less likely. *Rheumatoid arthritis* * **Rheumatoid arthritis** typically presents with morning stiffness lasting longer than 30 minutes, symmetrical polyarthritis, and often affects the **proximal interphalangeal (PIP)** and **metacarpophalangeal (MCP) joints** of the hands, sparing the DIP joints. * The patient's short morning stiffness, DIP joint involvement, and the absence of systemic inflammatory signs argue against rheumatoid arthritis.

Question 608: One day after undergoing total knee replacement for advanced degenerative osteoarthritis, a 66-year-old man has progressive lower abdominal pain. The surgery was performed under general anesthesia and the patient was temporarily catheterized for perioperative fluid balance. Several hours after the surgery, the patient began to have decreasing voiding volumes, nausea, and progressive, dull lower abdominal pain. He has Sjögren syndrome. He is sexually active with his wife and one other woman and uses condoms inconsistently. He does not smoke and drinks beer occasionally. Current medications include pilocarpine eye drops. He appears uncomfortable and is diaphoretic. His temperature is 37.3°C (99.1°F), pulse is 90/min, and blood pressure is 130/82 mm Hg. Abdominal examination shows a pelvic mass extending to the umbilicus. It is dull on percussion and diffusely tender to palpation. His hemoglobin concentration is 13.9 g/dL, leukocyte count is 9,000/mm3, a platelet count is 230,000/mm3. An attempt to recatheterize the patient transurethrally is unsuccessful. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Neurogenic bladder
B. Adverse effect of pilocarpine
C. Urethral stricture
D. Prostate cancer
E. Benign prostatic enlargement (Correct Answer)

Explanation: ***Benign prostatic enlargement*** - The patient's symptoms of **decreasing voiding volumes**, **lower abdominal pain**, and a **palpable bladder** after surgery are highly suggestive of **acute urinary retention**. The most common cause of acute urinary retention in older men is **benign prostatic hyperplasia (BPH)**, leading to bladder outlet obstruction. - The **failed attempt to recatheterize** transurethrally further points to a mechanical obstruction at the level of the bladder neck or urethra, which is consistent with an enlarged prostate. *Neurogenic bladder* - While neurogenic bladder can cause urinary retention, it typically presents with a history of neurological deficits or risk factors (e.g., spinal cord injury, diabetes, multiple sclerosis), which are not mentioned here. - The **acute onset** post-surgery and the **failed catheterization** strongly favor a mechanical obstruction over a purely neurogenic cause. *Adverse effect of pilocarpine* - Pilocarpine is a **muscarinic agonist** used to treat dry mouth/eyes from Sjögren syndrome and can increase bladder contractility, potentially *improving* urination, not causing retention. - Its side effects generally include increased salivation, sweating, and gastrointestinal upset, not urinary retention. *Urethral stricture* - A urethral stricture could explain the resistance to catheterization and urinary retention but is less common acutely after simple catheterization for surgery, unless there was prior urethral trauma or infection. - The presence of a **pelvic mass** (distended bladder) and the patient's age make BPH a more common and likely cause of obstruction. *Prostate cancer* - Prostate cancer can cause bladder outlet obstruction, but it typically presents more insidiously with urinary symptoms, and acute urinary retention as a sole initial presentation is less common than with BPH. - While possible, the acute onset post-surgery in an elderly male without other symptoms (e.g., bone pain, weight loss) makes **benign prostatic enlargement** a more probable and immediate cause of obstruction.

Question 609: A 33-year-old man presents to the emergency department after an episode of syncope. He states that for the past month ever since starting a new job he has experienced an episode of syncope or near-syncope every morning while he is getting dressed. The patient states that he now gets dressed, shaves, and puts on his tie sitting down to avoid falling when he faints. He has never had this before and is concerned it is stress from his new job as he has been unemployed for the past 5 years. He is wondering if he can get a note for work since he was unable to head in today secondary to his presentation. The patient has no significant past medical history and is otherwise healthy. His temperature is 99.2°F (37.3°C), blood pressure is 122/83 mmHg, pulse is 92/min, respirations are 16/min, and oxygen saturation is 100% on room air. Cardiopulmonary and neurologic exams are within normal limits. An initial ECG and laboratory values are unremarkable as well. Which of the following is the most likely diagnosis?

A. Malingering
B. Hypertrophic obstructive cardiomyopathy
C. Aortic stenosis
D. Carotid hypersensitivity syndrome (Correct Answer)
E. Anxiety

Explanation: ***Carotid hypersensitivity syndrome*** - This patient's symptoms of recurrent syncope/near-syncope during activities like **shaving or putting on a tie**, which involve pressure on the neck where the **carotid sinus** is located, are classic for carotid sinus hypersensitivity. - The maneuvers he is taking to avoid falling (getting dressed, shaving, and putting on his tie while sitting down) further support this diagnosis, as they show an adaptive behavior to a precise, reproducible trigger. *Malingering* - While the patient's request for a work note might raise some suspicion, there are **clear, physiologically plausible triggers** for his syncope, and his adaptive behavior suggests a genuine effort to cope with real symptoms rather than feigning illness for external gain. - Malingering would typically involve less specific or consistent symptoms, and often a more overt attempt to obtain a specific outcome (e.g., disability benefits) without the accompanying adaptive behaviors seen here. *Hypertrophic obstructive cardiomyopathy* - This condition can cause exertional syncope due to outflow tract obstruction, but it's less likely to present with syncope triggered by distinct neck maneuvers like **shaving or tying a tie**. - An initial **ECG and physical exam** would likely show abnormalities (e.g., prominent S waves in V1-V3, left ventricular hypertrophy, murmur) which are absent in this case. *Aortic stenosis* - Syncope in aortic stenosis is typically **exertional** and caused by reduced cerebral perfusion during physical activity, not by specific neck movements. - Aortic stenosis would also likely present with a **characteristic systolic ejection murmur** and ECG changes that were not noted in this otherwise healthy patient, and is less common in a 33-year-old without other risk factors. *Anxiety* - While anxiety can cause symptoms like lightheadedness or hyperventilation leading to near-syncope, it typically does not cause **true syncope with loss of consciousness** with such a consistent and specific trigger (neck compression). - The regular daily occurrence tied to specific actions and the body's physiological response points away from anxiety as the primary cause for the syncope itself, although anxiety about the events could be secondary.

Question 610: Three days after undergoing open surgery to repair a bilateral inguinal hernia, a 66-year-old man has new, intermittent upper abdominal discomfort that worsens when he walks around. He also has new shortness of breath that resolves with rest. There were no complications during surgery or during the immediate postsurgical period. Ambulation was restarted on the first postoperative day. He has type 2 diabetes mellitus, hypercholesterolemia, and hypertension. He has smoked one pack of cigarettes daily for 25 years. Prior to admission, his medications included metformin, simvastatin, and lisinopril. His temperature is 37°C (98.6°F), pulse is 80/min, respirations are 16/min, and blood pressure is 129/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. The abdomen is soft and shows two healing surgical scars with moderate serous discharge. Cardiopulmonary examination shows no abnormalities. An ECG at rest shows no abnormalities. Cardiac enzyme levels are within the reference range. An x-ray of the chest and abdominal ultrasonography show no abnormalities. Which of the following is the most appropriate next step in diagnosis?

A. Culture swab from the surgical site
B. Cardiac pharmacological stress test (Correct Answer)
C. Magnetic resonance imaging of the abdomen
D. Obtain serum D-dimer level
E. Coronary angiography

Explanation: ***Cardiac pharmacological stress test*** - The patient's symptoms of **intermittent upper abdominal discomfort** during activity and **shortness of breath** that improves with rest are highly suggestive of **angina equivalent**, especially given his multiple cardiovascular risk factors (type 2 diabetes, hypercholesterolemia, hypertension, and 25 pack-year smoking history). - A **pharmacological stress test** is appropriate to uncover **demand ischemia** in a patient with normal resting ECG and cardiac enzymes. - The patient cannot perform an exercise stress test shortly after abdominal surgery, making pharmacological stress testing the preferred non-invasive approach. *Culture swab from the surgical site* - While there is **serous discharge** from the surgical site, the patient's primary symptoms are systemic (new upper abdominal discomfort, shortness of breath) and are not typical of a localized surgical site infection, which would usually present with pain, erythema, and purulent discharge. - A surgical site infection would not explain the **activity-related symptoms** that resolve with rest. *Magnetic resonance imaging of the abdomen* - Abdominal MRI is not indicated as the initial step for these symptoms. His abdominal discomfort is activity-related and associated with shortness of breath, pointing away from a primary intra-abdominal issue. - **Abdominal ultrasonography** was already performed and was unremarkable, making further abdominal imaging unlikely to yield a diagnosis. *Obtain serum D-dimer level* - While **postoperative patients** are at risk for **venous thromboembolism (VTE)**, the symptoms of activity-related chest discomfort (angina equivalent) and shortness of breath are not classic for pulmonary embolism, especially with **98% oxygen saturation** and no tachycardia or respiratory distress. - A D-dimer would require further imaging (CT pulmonary angiography) if elevated, but the clinical picture points more strongly to cardiac ischemia. *Coronary angiography* - **Coronary angiography** is an invasive procedure and should not be the initial diagnostic step. - It is typically reserved for patients with a high pretest probability of **coronary artery disease** after non-invasive tests (such as a stress test) have indicated ischemia or for acute coronary syndromes. - Performing a stress test first is a safer and more appropriate initial approach to confirm or rule out ischemia.

Question 611: A 35-year-old woman who was recently ill with an upper respiratory infection presents to the emergency department with weakness in her lower limbs and difficulty breathing. Her symptoms began with a burning sensation in her toes along with numbness. She claims that the weakness has been getting worse over the last few days and now involving her arms and face. Currently, she is unable to get up from the chair without some assistance. Her temperature is 37.0°C (98.6°F), the blood pressure is 145/89 mm Hg, the heart rate is 99/min, the respiratory rate is 12/min, and the oxygen saturation is 95% on room air. On physical examination, she has diminished breath sounds on auscultation of bilateral lung fields with noticeably poor inspiratory effort. Palpation of the lower abdomen reveals a palpable bladder. Strength is 3 out of 5 symmetrically in the lower extremities bilaterally. The sensation is intact. What is the most likely diagnosis?

A. Guillain-Barré syndrome (Correct Answer)
B. Adrenoleukodystrophy
C. Myasthenia Gravis
D. Multiple sclerosis
E. Acute disseminated encephalomyelitis

Explanation: ***Guillain-Barré syndrome*** - The patient presents with **ascending paralysis** (weakness starting in lower limbs and progressing upwards to arms and face) following an **upper respiratory infection**, which is a classic presentation of GBS. - The presence of **respiratory compromise** (difficulty breathing, diminished breath sounds, poor inspiratory effort), **dysautonomia** (palpable bladder due to urinary retention), and the pattern of **symmetrical weakness with intact sensation** are characteristic features of GBS. - GBS typically presents with areflexia and shows albumino-cytologic dissociation on CSF analysis (elevated protein with normal cell count). *Adrenoleukodystrophy* - This is a rare, **X-linked genetic disorder** that primarily affects white matter in the brain and spinal cord, typically presenting in childhood with neurological deficits, not an acute ascending paralysis after an infection. - It involves demyelination and adrenal insufficiency, which are not suggested by the acute onset and progressive neurological symptoms described. *Myasthenia Gravis* - Myasthenia gravis typically presents with **fluctuating muscle weakness** that worsens with activity and improves with rest, often affecting ocular and bulbar muscles first. - The progression of weakness in this case is constant and ascending, not fluctuating, and there is no mention of characteristic findings like ptosis or diplopia. *Multiple sclerosis* - MS is characterized by **demyelinating lesions** in the central nervous system, leading to neurological symptoms that are often **disseminated in space and time**, meaning they affect different parts of the body at different times. - While it can cause weakness, the acute onset of rapidly progressive, ascending, symmetrical paralysis following an infection is not typical for MS; MS symptoms are usually more insidious or relapsing-remitting. *Acute disseminated encephalomyelitis* - ADEM is an **acute inflammatory demyelinating disease** of the central nervous system that typically follows an infection or vaccination, but it usually presents with **encephalopathy** (altered mental status), multifocal neurological deficits, and often affects the brain and spinal cord diffusely. - While it can cause weakness, the prominent ascending paralysis, intact sensation, and lack of encephalopathy make GBS a more fitting diagnosis.

Question 612: A 56-year-old woman presents with sudden-onset severe headache, nausea, vomiting, and neck pain for the past 90 minutes. She describes her headache as a ‘thunderclap’, followed quickly by severe neck pain and stiffness, nausea and vomiting. She denies any loss of consciousness, seizure, or similar symptoms in the past. Her past medical history is significant for an episode 6 months ago where she suddenly had trouble putting weight on her right leg, which resolved within hours. The patient denies any history of smoking, alcohol or recreational drug use. On physical examination, the patient has significant nuchal rigidity. Her muscle strength in the lower extremities is 4/5 on the right and 5/5 on the left. The remainder of the physical examination is unremarkable. A noncontrast CT scan of the head is normal. Which of the following is the next best step in the management of this patient?

A. Diffusion-weighted magnetic resonance imaging of the brain
B. IV tPA
C. Placement of a ventriculoperitoneal (VP) shunt
D. T1/T2 MRI of the head
E. Lumbar puncture (Correct Answer)

Explanation: ***Lumbar puncture*** - A **thunderclap headache**, nuchal rigidity, nausea, and vomiting despite a normal noncontrast CT scan, is highly suspicious for **subarachnoid hemorrhage (SAH)**. A lumbar puncture is the next diagnostic step to look for **xanthochromia** or **red blood cells** in the cerebrospinal fluid. - The previous episode of transient leg weakness could indicate a prior **warning leak** from an **aneurysm**, increasing the suspicion for SAH. *Diffusion-weighted magnetic resonance imaging of the brain* - This imaging is primarily used to detect **acute ischemic stroke**, which presents differently. - While helpful for ischemic events, it is **not the primary diagnostic test** for suspected SAH after a normal CT. *IV tPA* - **Intravenous tissue plasminogen activator (IV tPA)** is a thrombolytic used in acute ischemic stroke, characterized by focal neurological deficits. - It is **contraindicated** in SAH due to the significant risk of exacerbating intracranial bleeding. *Placement of a ventriculoperitoneal (VP) shunt* - A **VP shunt** is a surgical procedure to drain excess cerebrospinal fluid, typically used to treat **hydrocephalus**. - This is a treatment for a complication (hydrocephalus) that may arise from SAH, but it is **not the initial diagnostic or management step** for an acute SAH. *T1/T2 MRI of the head* - While MRI can detect SAH, especially if performed with specific sequences (FLAIR), a **lumbar puncture is more sensitive for detecting SAH** when a CT scan is negative and clinical suspicion remains high. - MRI is generally less accessible and more time-consuming than lumbar puncture in an emergency setting for suspected SAH.

Question 613: A 72-year-old woman with hypertension comes to the physician because of swelling and pain in both legs for the past year. The symptoms are worse at night and improve in the morning. Current medications include losartan and metoprolol. Her temperature is 36°C (96.8°F), pulse is 67/min, and blood pressure is 142/88 mm Hg. Examination shows normal heart sounds; there is no jugular venous distention. Her abdomen is soft and the liver edge is not palpable. Examination of the lower extremities shows bilateral pitting edema and prominent superficial veins. The skin is warm and there is reddish-brown discoloration of both ankles. Laboratory studies show a normal serum creatinine and normal urinalysis. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Decreased arteriolar resistance
B. Increased venous valve reflux (Correct Answer)
C. Decreased intravascular oncotic pressure
D. Decreased lymphatic flow
E. Increased capillary permeability

Explanation: ***Increased venous valve reflux*** - The patient presents with **bilateral pitting edema**, **prominent superficial veins**, and **reddish-brown discoloration of the ankles**, which are classic signs of **chronic venous insufficiency**. - **Venous valve reflux** leads to increased hydrostatic pressure in the capillaries, causing fluid transudation into the interstitial space, leading to edema that is worse at night and improves with elevation. *Decreased arteriolar resistance* - **Decreased arteriolar resistance** can lead to increased blood flow to the capillaries, but it typically causes edema that is **warm and erythematous**, often in the context of inflammation or certain medications (e.g., dihydropyridine calcium channel blockers), which is not the primary mechanism here. - While some medications can cause edema, the full clinical picture points more specifically to venous stasis. *Decreased intravascular oncotic pressure* - **Decreased intravascular oncotic pressure** (e.g., due to low albumin from liver disease or nephrotic syndrome) causes **generalized edema** that is often symmetrical, but it would not typically cause prominent superficial veins or reddish-brown ankle discoloration. - The patient's normal liver exam and creatinine/urinalysis make this less likely. *Decreased lymphatic flow* - **Decreased lymphatic flow** results in **lymphedema**, which is typically **non-pitting**, unilateral, and does not cause prominent superficial veins or pigment changes initially. - Lymphedema often leads to a "woody" texture and can be associated with skin thickening over time. *Increased capillary permeability* - **Increased capillary permeability** can cause edema, often due to **inflammation**, allergic reactions, or sepsis, and typically presents with warmth, erythema, and localized swelling. - This mechanism is usually acute and does not primarily explain the chronic skin changes and prominent veins seen in this patient.

Question 614: A 50-year-old morbidly obese woman presents to a primary care clinic for the first time. She states that her father recently died due to kidney failure and wants to make sure she is healthy. She works as an accountant, is not married or sexually active, and drinks alcohol occasionally. She currently does not take any medications. She does not know if she snores at night but frequently feels fatigued. She denies any headaches but reports occasional visual difficulties driving at night. She further denies any blood in her urine or increased urinary frequency. She does not engage in any fitness program. She has her period every 2 months with heavy flows. Her initial vital signs reveal that her blood pressure is 180/100 mmHg and heart rate is 70/min. Her body weight is 150 kg (330 lb). On physical exam, the patient has droopy eyelids, a thick neck with a large tongue, no murmurs or clicks on cardiac auscultation, clear lungs, a soft nontender, albeit large abdomen, and palpable pulses in her distal extremities. She can walk without difficulty. A repeat measurement of her blood pressure shows 155/105 mmHg. Which among the following is part of the most appropriate next step in management?

A. Renal artery doppler ultrasonography
B. Polysomnography
C. Urinalysis (Correct Answer)
D. Thyroid-stimulating hormone
E. Cortisol levels

Explanation: ***Urinalysis*** - Given the patient's strong family history of **kidney failure**, current presentation with **hypertension (BP 180/100 mmHg, confirmed at 155/105 mmHg)**, and concern for her health, a urinalysis is a crucial initial step to look for signs of kidney damage or disease. - Urinalysis can detect **proteinuria**, **hematuria**, or other abnormalities indicative of renal pathology, helping to assess her kidney health. *Renal artery doppler ultrasonography* - While **renal artery stenosis** can cause hypertension, it is usually considered after initial non-invasive tests and if there are specific signs of secondary hypertension like a **renal bruit** or **unexplained renal insufficiency**, which are not explicitly described here as a first step. - This is a more advanced diagnostic test and not typically the *most appropriate next step* before basic screening like urinalysis. *Polysomnography* - The patient's **morbid obesity**, **fatigue**, and physical exam findings like a **thick neck with a large tongue** suggest **obstructive sleep apnea (OSA)**, for which polysomnography is the diagnostic test. - However, while important, addressing the immediate concern of **hypertension** and assessing **kidney health** (given the family history) is a higher priority in the *initial* workup. *Thyroid-stimulating hormone* - Symptoms like **fatigue**, **heavy menstrual periods (menorrhagia)**, and features like a **thick tongue** could suggest **hypothyroidism**. - However, **hypertension** and the urgent need to evaluate **kidney function** (due to family history and current high blood pressure) make urinalysis a more immediate and critical step before an extensive endocrine workup. *Cortisol levels* - Elevated blood pressure, obesity, and menstrual irregularities could, in some contexts, raise suspicion for **Cushing's syndrome**. - However, there are no classic features like **buffalo hump**, **moon facies**, or **striae** mentioned, and assessing renal involvement given the family history and current hypertension is a more direct next step.

Question 615: A 32-year-old woman comes to the physician because of a 4-day history of low-grade fever, joint pain, and muscle aches. The day before the onset of her symptoms, she was severely sunburned on her face and arms during a hike with friends. She also reports being unusually fatigued over the past 3 months. Her only medication is a combined oral contraceptive pill. Her temperature is 37.9°C (100.2°F). Examination shows bilateral swelling and tenderness of the wrists and metacarpophalangeal joints. There are multiple nontender superficial ulcers on the oral mucosa. The detection of antibodies directed against which of the following is most specific for this patient's condition?

A. Nuclear Sm proteins (Correct Answer)
B. Fc region of IgG
C. Single-stranded DNA
D. Cell nucleus
E. Histones

Explanation: ***Nuclear Sm proteins*** - Antibodies to **Sm proteins** (anti-Sm antibodies) are highly specific for **Systemic Lupus Erythematosus (SLE)**, although present in only a minority of patients. - The patient's symptoms, including **photosensitivity (exacerbation by sunburn)**, **arthritis**, **oral ulcers**, and **fatigue**, are classic manifestations of SLE. *Fc region of IgG* - Antibodies directed against the **Fc region of IgG** are known as **rheumatoid factor (RF)**. - While RF can be positive in a small percentage of SLE patients, it is most characteristic of **rheumatoid arthritis** and is not specific for SLE. *Single-stranded DNA* - Antibodies to **single-stranded DNA (anti-ssDNA antibodies)** are found in various autoimmune diseases, including SLE, but are **less specific** than anti-dsDNA or anti-Sm antibodies for SLE diagnosis. - These antibodies can also be seen in drug-induced lupus and other conditions, making them a less definitive marker. *Cell nucleus* - Antibodies directed against the **cell nucleus** (antinuclear antibodies or **ANA**) are present in nearly all patients with SLE and are highly sensitive for the disease. - However, ANA can also be positive in many other autoimmune conditions, infections, and even healthy individuals, making it **not specific** enough for a definitive diagnosis without other criteria. *Histones* - Antibodies to **histones** are most commonly associated with **drug-induced lupus erythematosus**. - While they can be present in some cases of SLE, the patient's presentation does not strongly suggest drug-induced lupus, and anti-histone antibodies are not the most specific marker for typical SLE.

Question 616: A 67-year-old man presents to his primary care physician complaining of frequent urination overnight. He states that for several years he has had trouble maintaining his urine stream along with the need for frequent urination, but the nighttime urination has only recently started. The patient also states that he has had 2 urinary tract infections in the last year, which he had never had previously. On exam, his temperature is 98.8°F (37.1°C), blood pressure is 124/68 mmHg, pulse is 58/min, and respirations are 13/min. On digital rectal exam, the prostate is enlarged but feels symmetric and smooth. Which of the following is a possible consequence of this condition?

A. Increased serum creatinine (Correct Answer)
B. Malignant transformation
C. Increased serum AFP
D. Increased serum hCG
E. Increased serum ALP

Explanation: ***Increased serum creatinine*** - Chronic **urinary retention** due to benign prostatic hyperplasia (BPH) can lead to **hydronephrosis** and **renal parenchymal damage**, impairing kidney function and increasing serum creatinine. - The patient's symptoms of difficulty maintaining urine stream, frequent urination, and recurrent UTIs suggest BPH, which can progress to urinary obstruction and subsequent kidney dysfunction. *Malignant transformation* - **Benign prostatic hyperplasia (BPH)** is a non-malignant condition and does not directly undergo **malignant transformation** into prostate cancer. - While both BPH and prostate cancer can coexist, BPH itself is not considered a premalignant lesion. *Increased serum AFP* - **Alpha-fetoprotein (AFP)** is a tumor marker primarily associated with **hepatocellular carcinoma** and **germ cell tumors** (e.g., testicular cancer). - It is not associated with benign prostatic hyperplasia (BPH) or its complications. *Increased serum hCG* - **Human chorionic gonadotropin (hCG)** is a tumor marker most notably elevated in **choriocarcinoma** and some **germ cell tumors**. - It has no association with benign prostatic hyperplasia (BPH) or urinary obstruction. *Increased serum ALP* - **Alkaline phosphatase (ALP)** can be elevated in conditions affecting the **liver** (e.g., cholestasis) or **bones** (e.g., Paget's disease, osteoblastic metastases). - While significantly elevated ALP can indicate prostate cancer with **bone metastases**, it is not a direct consequence of uncomplicated benign prostatic hyperplasia (BPH).

Question 617: A 49-year-old male presents with a primary complaint of several recent episodes of severe headache, sudden anxiety, and a "racing heart". The patient originally attributed these symptoms to stress at work; however, these episodes are becoming more frequent and severe. Laboratory evaluation during such an episode reveals elevated plasma free metanephrines. Which of the following additional findings in this patient is most likely?

A. Anhidrosis
B. Diarrhea
C. Episodic hypertension (Correct Answer)
D. Hypoglycemia
E. Decreased 24 hour urine vanillylmandelic acid (VMA) levels

Explanation: ***Episodic hypertension*** - The patient's symptoms of severe headache, sudden anxiety, a "racing heart," and **elevated plasma free metanephrines** are classic presentations of a **pheochromocytoma**, a tumor that produces catecholamines. These catecholamines cause **paroxysmal (episodic) hypertension**. - **Hypertensive episodes** are a hallmark symptom of pheochromocytoma, often triggered by stress, exercise, or changes in body position. *Anhidrosis* - **Anhidrosis** (lack of sweating) is not a typical manifestation of pheochromocytoma; rather, patients often experience **diaphoresis (excessive sweating)** due to overstimulation of adrenergic receptors. - Anhidrosis can be a feature of certain neuropathies or autonomic dysfunction, but it does not align with the hyperadrenergic state described. *Diarrhea* - While pheochromocytoma can cause gastrointestinal symptoms due to altered autonomic tone, **diarrhea** is uncommon; **constipation** is more frequently reported because of catecholamine effects on gut motility. - Diarrhea is more commonly associated with conditions like carcinoid syndrome or irritable bowel syndrome. *Hypoglycemia* - **Hypoglycemia** is generally not associated with pheochromocytoma; the excess catecholamines typically promote **glycogenolysis and gluconeogenesis**, leading to **hyperglycemia**. - Hypoglycemia could be caused by an insulinoma or certain endocrine deficiencies. *Decreased 24 hour urine vanillylmandelic acid (VMA) levels* - **Elevated plasma free metanephrines** indicate excessive catecholamine production, which would lead to **elevated 24-hour urine VMA** (a catecholamine metabolite), not decreased levels. - Decreased VMA levels would suggest conditions with reduced catecholamine production, which contradicts the clinical picture of hyperadrenergic symptoms.

Question 618: A 37-year-old female presents to her primary care physician with constipation and abdominal pain. She notes that the pain has been present for several days and is not related to food. She also reports increased urinary frequency without incontinence, as well as increased thirst. She takes no medications, but notes taking vitamin supplements daily. Her vital signs are: BP 130/72 mmHg, HR 82 bpm, T 97.0 degrees F, and RR 12 bpm. Lab studies reveal: Na 139, K 4.1, Cl 104, HCO3 25, Cr 0.9, and Ca 12.4. Further studies show an increased ionized calcium, decreased PTH, and normal phosphate. What is the most likely cause of this patient's symptoms?

A. Vitamin overdose (Correct Answer)
B. Vitamin deficiency
C. Inherited disorder
D. Plasma cell neoplasm
E. Primary endocrine dysfunction

Explanation: ***Vitamin overdose*** - The patient's symptoms of **constipation**, **abdominal pain**, **increased urinary frequency**, and **thirst** are classic signs of **hypercalcemia**. - The lab findings of **hypercalcemia (Ca 12.4)**, **increased ionized calcium**, **decreased PTH**, and increased phosphate, coupled with a history of daily vitamin supplements, strongly suggest **Vitamin D toxicity** from overdose, which leads to increased calcium absorption and bone resorption. *Vitamin deficiency* - Vitamin deficiencies typically do not cause **hypercalcemia**; in fact, severe **Vitamin D deficiency** can lead to **hypocalcemia** and **secondary hyperparathyroidism**. - Symptoms associated with common vitamin deficiencies (e.g., scurvy, rickets) are not consistent with this patient's presentation. *Inherited disorder* - While some **inherited disorders** (e.g., **Familial Hypocalciuric Hypercalcemia**) can cause hypercalcemia, the distinguishing feature is typically a **normal or mildly elevated PTH** and **low urinary calcium excretion**, which is not entirely aligned with the presented PTH and phosphate levels and the acute onset suggested by symptoms. - The patient's history of **vitamin supplement** use provides a more direct and likely explanation for acute hypercalcemia. *Plasma cell neoplasm* - **Plasma cell neoplasms** like **multiple myeloma** can cause **hypercalcemia** due to increased bone resorption from osteoclast-activating factors. - However, hypercalcemia from these conditions is often accompanied by other signs of malignancy such as **renal failure**, **anemia**, or **bone lesions**, which are not reported in this case, and the **decreased PTH** points away from malignancy-associated humorally mediated hypercalcemia. *Primary endocrine dysfunction* - **Primary hyperparathyroidism** is a common cause of **hypercalcemia**, but it is characterized by **elevated or inappropriately normal PTH levels** in the presence of hypercalcemia, which contradicts the **decreased PTH** found in this patient. - Other endocrine causes of hypercalcemia, such as **thyrotoxicosis** or **adrenal insufficiency**, present with distinct clinical features not described here.

Question 619: A 34-year-old woman is brought to the emergency department following a motor vehicle accident. She was walking on the sidewalk when a car traveling at high speed knocked her off her feet. She did not sustain any obvious injury but has painful breathing. An X-ray of the chest is taken to exclude a rib fracture and contusion of the lungs. The X-ray is found to be normal except for a solitary calcified nodule located in the left hilar region. The physician then asks the patient if she is or was a smoker, or has any pertinent medical history to explain the nodule. Her past medical history is insignificant, including any previous lung infections. Physical examination does not reveal any significant signs indicative of a tumor. A chest CT is ordered and a solitary nodule of 0.5 cm is confirmed. Which of the following is the most appropriate next step in the management of this patient?

A. Mediastinoscopy
B. CT scan of abdomen
C. Positron emission scan
D. Repeat chest CT scan in 6 months (Correct Answer)
E. Sputum cytology

Explanation: ***Repeat chest CT scan in 6 months*** - A **solitary pulmonary nodule (SPN)** that is **calcified**, smaller than **1 cm**, and found in a patient with a **low pre-test probability** of malignancy (e.g., non-smoker, no history of cancer) generally warrants **serial imaging** to monitor for growth. - The **0.5-cm size** and **calcification** make malignancy less likely, so deferring invasive procedures and opting for a follow-up CT in 6 months is the most appropriate initial step. *Mediastinoscopy* - This is an **invasive surgical procedure** used to biopsy **mediastinal lymph nodes**, usually for staging lung cancer or diagnosing other mediastinal masses. - It is **not indicated** for an asymptomatic, small, calcified solitary pulmonary nodule without suspicion of malignancy or lymphadenopathy. *CT scan of abdomen* - A CT scan of the abdomen would be performed to look for **metastatic disease** if there were a high suspicion of primary lung cancer. - Given the features of the nodule (small, calcified) and the patient's low-risk profile, there is no immediate indication for metastatic workup. *Positron emission scan* - A **PET scan** is used to evaluate the metabolic activity of a nodule and can help differentiate between benign and malignant lesions. - However, for nodules that are **smaller than 0.8-1 cm** or are **calcified**, PET scans often have **limited sensitivity** and are not typically the first-line diagnostic tool. *Sputum cytology* - **Sputum cytology** involves examining cells from sputum for malignant cells, and its utility is highest for **central tumors** that shed cells into the airways. - For a **solitary pulmonary nodule**, especially one that is small and peripheral or calcified, sputum cytology has a very **low diagnostic yield**.

Question 620: A 13-year-old girl presents after losing consciousness during class 30 minutes ago. According to her friends, she was doing okay since morning, and nobody noticed anything abnormal. The patient’s mother says that her daughter does not have any medical conditions. She also says that the patient has always been healthy but has recently lost weight even though she was eating as usual. Her vital signs are a blood pressure of 100/78 mm Hg, a pulse of 89/min, and a temperature of 37.2°C (99.0°F). Her breathing is rapid but shallow. Fingerstick glucose is 300 mg/dL. Blood is drawn for additional lab tests, and she is started on intravenous insulin and normal saline. Which of the following HLA subtypes is associated with this patient’s most likely diagnosis?

A. DR3 (Correct Answer)
B. A3
C. B8
D. DR5
E. B27

Explanation: ***DR3*** - The patient's presentation with **recent weight loss despite normal eating**, rapid but shallow breathing (**Kussmaul respiration** hinting at **metabolic acidosis**), elevated blood glucose (300 mg/dL), and loss of consciousness strongly suggests **Type 1 Diabetes Mellitus (T1DM)** presenting as **diabetic ketoacidosis (DKA)**. - **HLA-DR3** and **HLA-DR4** are the primary genetic markers most strongly associated with an increased susceptibility to Type 1 Diabetes Mellitus, an **autoimmune disease** affecting pancreatic beta cells. - **HLA-DR3** is the most direct answer as it is one of the two strongest HLA-DR associations with T1DM. *A3* - **HLA-A3** is primarily associated with **hemochromatosis**, a disorder of iron metabolism, and is not a common genetic marker for Type 1 Diabetes Mellitus. - The symptoms described in the patient (weight loss, hyperglycemia, DKA) are not characteristic of hemochromatosis. *B8* - **HLA-B8** is actually associated with Type 1 Diabetes Mellitus as part of the **extended haplotype A1-B8-DR3**, which shows strong linkage disequilibrium. - However, **HLA-B8 is not as directly or specifically associated with T1DM** as the HLA-DR subtypes (DR3 and DR4), which are considered the primary genetic markers. - When asking about HLA subtypes associated with T1DM, **DR3 or DR4** are the best answers as they show the strongest and most direct association. - HLA-B8 is also associated with other autoimmune conditions like **myasthenia gravis** and **Graves' disease**. *DR5* - While part of the **HLA-DR family**, **HLA-DR5** is less commonly associated with **Type 1 Diabetes Mellitus** compared to DR3 and DR4. - This subtype is more frequently linked with conditions like **pernicious anemia** or increased risk of certain infections. *B27* - **HLA-B27** is strongly associated with **seronegative spondyloarthropathies**, such as **ankylosing spondylitis** and **reactive arthritis**. - It has no known direct association with **Type 1 Diabetes Mellitus**.

Question 621: A 58-year-old woman comes to the physician because of a 3-month history of recurring chest discomfort. The symptoms occur when walking up the stairs to her apartment or when walking quickly for 5 minutes on level terrain. She has not had shortness of breath, palpitations, or dizziness. She has hypertension and hyperlipidemia. Current medications include estrogen replacement therapy, metoprolol, amlodipine, lisinopril, hydrochlorothiazide, and rosuvastatin. She drinks 3–4 cups of coffee per day. She does not drink alcohol. Her pulse is 65/min, respirations are 21/min, and blood pressure is 145/90 mm Hg. Physical examination shows no abnormalities. A resting ECG shows normal sinus rhythm. She is scheduled for a cardiac exercise stress test in 2 days. Discontinuation of which of the following is the most appropriate next step in management at this time?

A. Metoprolol and amlodipine (Correct Answer)
B. Lisinopril and hydrochlorothiazide
C. Estrogen and hydrochlorothiazide
D. Estrogen and amlodipine
E. Metoprolol and rosuvastatin

Explanation: ***Metoprolol and amlodipine*** - **Beta-blockers** (metoprolol) and **calcium channel blockers** (amlodipine) used to treat angina can mask ischemia during a stress test, leading to a falsely negative result. - Temporarily discontinuing these medications allows for a more accurate assessment of the heart's response to stress and diagnosis of **ischemic heart disease**. *Lisinopril and hydrochlorothiazide* - **ACE inhibitors** (lisinopril) and **diuretics** (hydrochlorothiazide) primarily manage blood pressure and do not significantly interfere with the diagnostic capabilities of a cardiac exercise stress test for detecting ischemia. - While they can lower blood pressure, their impact on the heart's ischemic response during stress is less direct and less problematic than that of beta-blockers or calcium channel blockers. *Estrogen and hydrochlorothiazide* - **Estrogen replacement therapy** generally does not interfere with the results or interpretation of an exercise stress test for ischemia. - **Hydrochlorothiazide** is a diuretic primarily affecting blood pressure and fluid balance; it does not significantly alter cardiac physiology in a way that would obscure ischemic findings during stress. *Estrogen and amlodipine* - While **amlodipine** (a calcium channel blocker) needs to be held before a stress test, **estrogen replacement therapy** does not affect the diagnostic accuracy of the test. - Combining these two would be partially correct regarding amlodipine but introduces an unnecessary and incorrect action regarding estrogen. *Metoprolol and rosuvastatin* - **Metoprolol** (a beta-blocker) should be discontinued as it can mask ischemia during a stress test. - However, **rosuvastatin** (a statin) is crucial for managing hyperlipidemia and preventing cardiovascular events; there is no medical reason to discontinue it before a stress test, as it does not interfere with the test's diagnostic accuracy.

Question 622: A previously healthy 21-year-old man is brought to the emergency department for the evaluation of an episode of unconsciousness that suddenly happened while playing football 30 minutes ago. He was not shaking and regained consciousness after about 30 seconds. Over the past three months, the patient has had several episodes of shortness of breath while exercising as well as sensations of a racing heart. He does not smoke or drink alcohol. He takes no medications. His vital signs are within normal limits. On mental status examination, he is oriented to person, place, and time. Cardiac examination shows a systolic ejection murmur that increases with valsalva maneuver and standing and an S4 gallop. The remainder of the examination shows no abnormalities. An ECG shows a deep S wave in lead V1 and tall R waves in leads V5 and V6. Echocardiography is most likely to show which of the following findings?

A. Mitral valve leaflet thickening ≥ 5 mm
B. Ventricular septum defect
C. Abnormal movement of the mitral valve (Correct Answer)
D. Reduced left ventricular ejection fraction
E. Symmetric left ventricular wall thickening

Explanation: ***Abnormal movement of the mitral valve*** - This patient's presentation with exercise-induced syncope, shortness of breath, palpitations, a systolic ejection murmur that increases with **Valsalva maneuver** and **standing**, and ECG findings of **left ventricular hypertrophy** (deep S in V1, tall R in V5-V6) is highly suggestive of **hypertrophic cardiomyopathy (HCM)**. - In HCM, the **hypertrophied septum** obstructs outflow, leading to **systolic anterior motion (SAM) of the mitral valve**, which an echocardiogram would reveal as abnormal movement. *Mitral valve leaflet thickening ≥ 5 mm* - Marked **mitral valve leaflet thickening** is typically associated with **rheumatic heart disease** or significant valvular degeneration. - While HCM can affect mitral valve function, significant structural thickening to this extent is not its primary or diagnostic echocardiographic feature. *Ventricular septum defect* - A **ventricular septum defect (VSD)** is a congenital heart defect characterized by a hole in the septum separating the ventricles. - While VSDs can cause murmurs, the characteristic murmur variations with Valsalva and standing, and the ECG findings in this case, are not typical of an isolated VSD. *Reduced left ventricular ejection fraction* - **Hypertrophic cardiomyopathy** is usually characterized by a **preserved or even hyperdynamic left ventricular ejection fraction** in the early stages, despite impaired diastolic function. - **Reduced LVEF** is seen in **dilated cardiomyopathy** or advanced stages of other heart diseases. *Symmetric left ventricular wall thickening* - While there is **left ventricular wall thickening** in HCM, it is characteristically **asymmetric**, primarily affecting the **interventricular septum**. - **Symmetric wall thickening** is more indicative of conditions like **hypertensive heart disease** or **athlete's heart**, rather than HCM.

Question 623: A 26-year-old woman presents with blood in her urine for the past 2 days. She says she has had increasing urinary frequency at night for the past several days and recently noticed a reddish tinge in her urine. She is also concerned that her feet are beginning to swell, and she has been feeling increasingly fatigued for the past week. She gives no history of joint pains, rashes, or skin changes. Past medical history is relevant for an occasional bluish discoloration of her fingers during exposure to cold. Her vital signs are a pulse of 80/min, a respiratory rate of 14/min, and blood pressure of 140/88 mm Hg. On physical examination, the patient has 1+ pitting edema of her feet bilaterally. Remainder of examination is unremarkable. Laboratory findings are significant for the following: Serum glucose (fasting) 88 mg/dL Sodium 143 mEq/L Potassium 3.7 mEq/L Chloride 102 mEq/L Serum creatinine 1.7 mg/dL Blood urea nitrogen 32 mg/dL Cholesterol, total 180 mg/dL HDL-cholesterol 43 mg/dL LDL-cholesterol 75 mg/dL Triglycerides 135 mg/dL Hemoglobin (Hb%) 12.5 g/dL Mean corpuscular volume (MCV) 80 fL Reticulocyte count 1% Erythrocyte count 5.1 million/mm3 Thyroid stimulating hormone 4.5 μU/mL Urinalysis: Glucose negative Protein +++ Ketones negative Nitrites negative RBCs negative Casts +++ A renal biopsy is performed which reveals findings consistent with lupus nephritis. Which of the following is the next best step in treatment of this patient?

A. Cyclophosphamide
B. Mycophenolic acid (Correct Answer)
C. Corticosteroids
D. Cyclosporine
E. Azathioprine

Explanation: ***Mycophenolic acid*** - **Mycophenolic acid** (mycophenolate mofetil or mycophenolate sodium) is the **first-line induction therapy** for **lupus nephritis Class III, IV, and V** according to current **KDIGO, ACR, and EULAR guidelines** (2012-2023). - This patient has biopsy-proven lupus nephritis with active disease (proteinuria +++, casts +++, elevated creatinine, hypertension, edema). - Mycophenolate is typically given **in combination with high-dose corticosteroids** for induction therapy, followed by maintenance therapy. - It has **superior efficacy** and **lower toxicity** (particularly reduced gonadal toxicity and malignancy risk) compared to cyclophosphamide. - Given as **2-3 g/day** for induction over 6 months, then reduced for maintenance. *Corticosteroids* - While **high-dose corticosteroids** are essential in lupus nephritis treatment, they are **never used as monotherapy** for proliferative or membranous lupus nephritis. - Steroids alone are insufficient to control active renal inflammation and prevent progression to end-stage renal disease. - They must be combined with an immunosuppressant like **mycophenolate** or **cyclophosphamide** for induction therapy. *Cyclophosphamide* - **Cyclophosphamide** remains an alternative induction agent for severe lupus nephritis, particularly Class III or IV. - However, it has been largely replaced by **mycophenolate** as first-line therapy due to mycophenolate's better side effect profile. - Cyclophosphamide is now reserved for cases with **severe renal dysfunction**, **rapidly progressive disease**, or **failure of mycophenolate therapy**. - Significant toxicities include **gonadal failure** (infertility concerns in young women), **hemorrhagic cystitis**, and increased **malignancy risk**. *Cyclosporine* - **Cyclosporine** is a calcineurin inhibitor occasionally used for **membranous lupus nephritis (Class V)** or as second-line therapy. - It is **not recommended for proliferative nephritis** (Class III or IV) due to risk of **nephrotoxicity** and inferior efficacy compared to mycophenolate or cyclophosphamide. - May be considered in special circumstances such as pregnancy or contraindications to other agents. *Azathioprine* - **Azathioprine** is primarily used for **maintenance therapy** after successful induction with mycophenolate or cyclophosphamide. - It has a **slower onset of action** and is **less potent** than mycophenolate for treating active lupus nephritis. - Not appropriate as initial induction therapy for moderate-to-severe lupus nephritis with active renal inflammation.

Question 624: A 66-year-old woman with no significant past medical, past surgical, or family history presents with new symptoms of chest pain, an oral rash, and pain with swallowing. She lost her husband several months earlier and has moved into an elderly assisted living community. She states that her symptoms began several weeks earlier. Physical examination reveals numerous white plaques on her buccal mucosa and tongue, raising suspicion for oral candidiasis. What is the next step in the patient’s management?

A. CD4 count (Correct Answer)
B. Single contrast esophagram with barium sulfate contrast
C. Single contrast esophagram with water soluble iodine contrast
D. Denture fitting assessment
E. Modified barium swallow

Explanation: ***CD4 count*** - This patient presents with **oral candidiasis** (thrush) and symptoms suggestive of **esophageal candidiasis** including **odynophagia** (painful swallowing) and chest discomfort. - While oral candidiasis can occur in elderly patients due to dentures, medications, or transient immune changes, the presence of **presumed esophageal involvement** in a previously healthy 66-year-old woman raises concern for **underlying immunosuppression**. - **HIV infection** is an important cause of esophageal candidiasis and should not be missed. The next step is to evaluate for immunodeficiency with **HIV testing and CD4 count**. - Recent psychosocial stress alone does not typically cause severe candidiasis; an underlying immune defect should be investigated. *Single contrast esophagram with water soluble iodine contrast* - Esophagram has **low sensitivity** for diagnosing esophageal candidiasis and is not the standard diagnostic approach. - There is no clinical indication for **perforation** in this case (no instrumentation, severe vomiting, or trauma), so water-soluble contrast is unnecessary. - If imaging were needed, **upper endoscopy (EGD)** would be far superior for visualizing candidal plaques and obtaining tissue diagnosis. *Single contrast esophagram with barium sulfate contrast* - As noted above, esophagram is **not the test of choice** for esophageal candidiasis. - **EGD with biopsy/brushings** provides direct visualization and allows for definitive diagnosis. - Barium studies have been largely replaced by endoscopy for evaluating esophageal infections. *Denture fitting assessment* - While ill-fitting dentures can contribute to **oral candidiasis**, they do not explain the **esophageal symptoms** (chest pain and odynophagia). - The presence of systemic symptoms warrants investigation for immunosuppression rather than focusing solely on local oral factors. - This would not address the patient's most concerning symptoms. *Modified barium swallow* - A **modified barium swallow** assesses **swallowing mechanics** and aspiration risk, typically used for neurological or structural dysphagia. - The patient has **odynophagia** (painful swallowing) rather than **dysphagia** (difficulty swallowing), indicating mucosal pathology rather than a motility or coordination disorder. - This test would not help diagnose or manage candidal esophagitis.

Question 625: A 24-year-old man comes to the physician because of severe lower back pain for the past 2 days. The pain is constant and non-radiating, and he describes it as 7 out of 10 in intensity. The pain began after he helped a friend move into a new apartment. Three weeks ago, he was diagnosed with urethritis and was treated with azithromycin and ceftriaxone. He has a history of intravenous heroin use. He takes no medications. His temperature is 37°C (98.6°F), pulse is 98/min, and blood pressure is 128/90 mm Hg. Examination shows old track marks on the cubital fossae bilaterally. His lumbar paraspinal muscles are firm and tense on palpation. There is no midline spinal tenderness. Flexing the hip and extending the knee while raising the leg to 70° does not cause any pain. Urinalysis shows no abnormalities. Which of the following is the most appropriate next step in management?

A. MRI of the spine
B. Broad-spectrum antibiotic therapy
C. Spinal traction
D. Analgesia and regular activity (Correct Answer)
E. Measurement of serum HLA-B27

Explanation: ***Analgesia and regular activity*** - The patient's presentation with acute low back pain following exertion (helping a friend move), the absence of **red flag symptoms** (fever, neurological deficits, severe spinal tenderness, constitutional symptoms), and normal vital signs suggest a **mechanical cause** of back pain. - Initial management for acute, uncomplicated mechanical back pain involves **analgesia** (e.g., NSAIDs, acetaminophen) and encouraging **continued light activity** rather than strict bed rest, as this promotes faster recovery. *MRI of the spine* - An **MRI of the spine** is generally reserved for patients with suspected serious spinal pathology, such as **neurological deficits**, persistent pain despite conservative management, or suspicion of infection/malignancy. - The absence of these **red flag symptoms** and the acute, exertional onset of pain make immediate MRI unnecessary. *Broad-spectrum antibiotic therapy* - While the patient has a history of IV heroin use (a risk factor for infection) and recent urethritis, his current presentation does not strongly suggest an active infection (no fever, normal WBC count implied by history, no localized signs of infection other than muscle tension). - Initiating **broad-spectrum antibiotics** empirically for back pain without clear evidence of infection (e.g., fever, elevated inflammatory markers, positive blood cultures, or imaging suggestive of osteomyelitis/abscess) is not indicated. *Spinal traction* - **Spinal traction** is a therapy that has shown **limited efficacy** for acute low back pain and is generally not recommended as a primary treatment. - Evidence-based guidelines do not support its routine use for mechanical back pain. *Measurement of serum HLA-B27* - **HLA-B27** is associated with **spondyloarthropathies** (e.g., ankylosing spondylitis), which typically present with chronic inflammatory back pain (worse with rest, improves with activity, morning stiffness). - The patient's acute, exertion-related pain and the absence of inflammatory features make **spondyloarthropathy** unlikely as the primary diagnosis in this acute setting.

Question 626: A 21-year-old woman comes to the physician for the evaluation of dry cough and some chest tightness for the past several weeks. The cough is worse at night and while playing volleyball. She frequently has a runny nose and nasal congestion. Her mother has systemic lupus erythematosus. The patient has smoked one pack of cigarettes daily for the last 5 years. She does not drink alcohol. Her only medication is cetirizine. Her vital signs are within normal limits. Pulse oximetry on room air shows an oxygen saturation of 98%. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?

A. CT scan of the chest
B. Spirometry (Correct Answer)
C. Laboratory studies
D. Methacholine challenge test
E. Blood gas analysis

Explanation: ***Spirometry*** - The patient's symptoms (dry cough, chest tightness, worse at night and with activity) are highly suggestive of **asthma**. - **Spirometry** is the initial recommended diagnostic test to assess for reversible airway obstruction, which is characteristic of asthma. *CT scan of the chest* - A CT scan of the chest is generally reserved for evaluating structural lung diseases, persistent or atypical symptoms, or when other diagnoses (e.g., malignancy, interstitial lung disease) are suspected. - Given the classic asthma-like symptoms, a **less invasive and more direct physiological test** is indicated first. *Laboratory studies* - Routine laboratory studies are typically **not helpful** in the initial diagnosis of asthma. - While allergy testing or inflammatory markers might be considered later, they do not directly assess airway function to confirm asthma. *Methacholine challenge test* - A **methacholine challenge test** is used to diagnose **asthma** when spirometry results are normal but asthma is still strongly suspected. - It is often considered if initial spirometry with bronchodilator reversal is inconclusive, rather than as a first-line diagnostic step. *Blood gas analysis* - Blood gas analysis measures oxygen and carbon dioxide levels in the blood and is used to assess the severity of respiratory failure or acid-base status. - It is **not a primary diagnostic tool for asthma**, especially in a patient with normal vital signs and pulse oximetry.

Question 627: A 50-year-old man with a remote history of intravenous drug use and a past medical history of AIDS presents to his primary care provider with several weeks of productive cough and a mild fever. He was in his normal state of health and slowly started to develop these symptoms. He is hoping to be prescribed an antibiotic so he can get back to “normal”. Family history is significant for cardiovascular disease and diabetes. He takes antiviral medication and a multivitamin daily. His heart rate is 90/min, respiratory rate is 19/min, blood pressure is 135/85 mm Hg, and temperature is 38.3°C (100.9°F). On physical examination, he looks uncomfortable. A chest examination reveals consolidation in the right lower lung. Chest radiography confirms right lower lobe pneumonia. Of the following options, which is the most likely cause of the patient’s pneumonia?

A. Pulmonary sequestration
B. Pneumocystis pneumonia
C. Aspiration pneumonia
D. Community-acquired pneumonia (Correct Answer)
E. Disseminated cutaneous infection

Explanation: ***Community-acquired pneumonia*** - This patient, despite having AIDS, presents with typical symptoms of **community-acquired pneumonia (CAP)**, including productive cough, fever, and classic consolidation on chest examination and radiography. - While HIV/AIDS patients are at higher risk for opportunistic infections, CAP caused by common bacterial pathogens like *Streptococcus pneumoniae* is still a frequent cause of pneumonia and should be considered, especially with a **lobar consolidation pattern**. *Pulmonary sequestration* - **Pulmonary sequestration** is a rare congenital malformation where a segment of lung tissue is not connected to the tracheobronchial tree and receives systemic blood supply. It typically presents with recurrent infections in the same location or as an asymptomatic mass. - It would not explain the acute onset of symptoms like fever and productive cough, nor the classic signs of pneumonia like consolidation in an otherwise healthy adult (aside from AIDS). *Pneumocystis pneumonia* - **Pneumocystis pneumonia (PJP)**, caused by *Pneumocystis jirovecii*, is a classic opportunistic infection in patients with AIDS, especially those with low CD4 counts. - However, PJP typically presents with a **subacute onset** of dyspnea, non-productive cough, and diffuse interstitial infiltrates on chest radiography, not focal consolidation. *Aspiration pneumonia* - **Aspiration pneumonia** occurs when foreign material, often gastric contents or oral flora, is inhaled into the lungs, leading to inflammation and infection. - There is no clinical indication of aspiration in this patient (e.g., dysphagia, impaired consciousness, reflux), and the history does not suggest risk factors for aspiration. *Disseminated cutaneous infection* - A **disseminated cutaneous infection** involves widespread skin lesions caused by an infection. - This patient's symptoms are localized to the respiratory system (productive cough, lung consolidation) and do not suggest a primary cutaneous infection.

Question 628: A previously healthy 21-year-old man is brought to the emergency department 4 hours after the sudden onset of shortness of breath and pleuritic chest pain. He has smoked 1 pack of cigarettes daily for the past 3 years. He is 188 cm (6.2 ft) tall and weighs 70 kg (154 lb); BMI is 19.8 kg/m2. Physical examination shows decreased tactile fremitus and diminished breath sounds over the left lung. Which of the following is the most likely cause of this patient's symptoms?

A. Embolic occlusion of the pulmonary artery
B. Inflammation of the costal cartilage
C. Rupture of a subpleural bleb (Correct Answer)
D. Infection with gram-positive diplococci
E. Hyperresponsiveness of the bronchial system

Explanation: ***Rupture of a subpleural bleb*** - The patient's presentation with **sudden onset shortness of breath**, **pleuritic chest pain**, and physical findings of **decreased tactile fremitus** and **diminished breath sounds** on one side are classic for **spontaneous pneumothorax**. - A **tall, thin young male smoker** is a typical demographic for a **primary spontaneous pneumothorax**, which results from the rupture of subpleural blebs. *Embolic occlusion of the pulmonary artery* - While **pulmonary embolism** can cause sudden shortness of breath and pleuritic chest pain, it wouldn't typically manifest with **decreased tactile fremitus** or **diminished breath sounds** as a primary finding. - Pulmonary embolism is less likely without risk factors like prolonged immobility, surgery, or hypercoagulable states, although smoking is a minor risk factor. *Inflammation of the costal cartilage* - **Costochondritis** causes localized chest pain, often reproducible with palpation, but does not present with **sudden onset dyspnea** or significant changes in lung examination findings like **diminished breath sounds**. - Systemic symptoms like shortness of breath and physical exam findings of reduced lung sounds are not characteristic of costochondritis. *Infection with gram-positive diplococci* - This suggests **bacterial pneumonia**, which typically presents with fever, productive cough, and more gradual onset of symptoms. - While pneumonia can cause pleuritic chest pain and shortness of breath, the physical exam would likely show **bronchial breath sounds** or **crackles**, not diminished breath sounds, and tactile fremitus would be increased, not decreased. *Hyperresponsiveness of the bronchial system* - This refers to **asthma**, which causes **wheezing**, cough, and shortness of breath due to bronchoconstriction. - Asthma would typically present with **diffuse wheezing** on auscultation, not diminished breath sounds on one side, and wouldn't lead to decreased tactile fremitus.

Question 629: A 32-year-old woman comes to the physician because of a 2-month history of fatigue, muscle weakness, paresthesias, headache, and palpitations. Her pulse is 75/min and blood pressure is 152/94 mm Hg. Physical examination shows no abnormalities. Serum studies show: Sodium 144 mEq/L Potassium 2.9 mEq/L Bicarbonate 31 mEq/L Creatinine 0.7 mg/dL Further evaluation shows low serum renin activity. Which of the following is the most likely diagnosis?

A. Aldosteronoma (Correct Answer)
B. Cushing syndrome
C. Renal artery stenosis
D. Pheochromocytoma
E. Laxative abuse

Explanation: ***Aldosteronoma*** - The patient presents with **hypertension**, **hypokalemia**, and **metabolic alkalosis** (elevated bicarbonate), which are classic signs of primary hyperaldosteronism. - **Low serum renin activity** in conjunction with these findings points directly to an **aldosterone-producing adenoma (aldosteronoma)** as the most likely cause. *Cushing syndrome* - While Cushing syndrome can cause **hypertension** and **hypokalemia**, it is primarily characterized by features of **hypercortisolism** such as central obesity, moon facies, striae, and muscle wasting, which are not described here. - The primary defect in Cushing syndrome relates to cortisol excess, not primary aldosterone overproduction leading to low renin. *Renal artery stenosis* - **Renal artery stenosis** causes **secondary hyperaldosteronism**, typically presenting with **hypertension** and **elevated renin activity** due to decreased renal perfusion. - This contradicts the patient's low serum renin activity, making it an unlikely diagnosis. *Pheochromocytoma* - **Pheochromocytoma** presents with paroxysmal or sustained **hypertension**, **palpitations**, **headaches**, and **sweating** due to catecholamine excess. - It does not typically cause **hypokalemia** or **metabolic alkalosis** as seen in this patient. *Laxative abuse* - **Laxative abuse** can cause hypokalemia and metabolic alkalosis, but it is typically associated with **chronic diarrhea** and volume depletion, which are not mentioned. - It does not directly cause **hypertension** and is not associated with low renin activity in the context of aldosterone excess.

Question 630: A 12-year-old boy presents to the emergency department with a swollen and painful knee. He says that he was exploring with his friends when he tripped and hit his knee against the ground. He didn't feel like he hit it very hard but it started swelling and becoming very painful. His mom reports that he has always been prone to bleeding from very minor trauma and that others in the family have had similar problems. Based on clinical suspicion a coagulation panel was obtained showing a prothrombin time (PT) of 10 seconds (normal range 9-11 seconds), a partial thromboplastin time (PTT) of 45 seconds (normal 20-35 seconds), and a normal ristocetin cofactor assay (equivalent to bleeding time). Mixing tests with factor IX and XI do not show complementation, but mixing with factor VIII reverses the coagulation abnormality. Which of the following is the most likely diagnosis for this patient?

A. Glanzmann thrombasthenia
B. Hemophilia B
C. von Willebrand disease
D. Bernard-Soulier disease
E. Hemophilia A (Correct Answer)

Explanation: ***Hemophilia A*** - The **prolonged PTT** that corrects with the addition of **Factor VIII** in the mixing study strongly indicates Factor VIII deficiency, which is characteristic of **Hemophilia A**. - The history of **easy bleeding** from minor trauma and reports of similar problems in other family members also align with the **X-linked recessive inheritance** pattern and clinical presentation of Hemophilia A. *Glanzmann thrombasthenia* - This condition is characterized by a defect in **platelet aggregation** due to an abnormality in **glycoprotein IIb/IIIa**, which would typically manifest with a **normal PT and PTT** but an **abnormal bleeding time** (reflected by the ristocetin cofactor assay equivalent), which is not the case here. - Patients typically present with **mucocutaneous bleeding** (e.g., epistaxis, petechiae) rather than deep joint bleeds. *Hemophilia B* - While Hemophilia B also causes a **prolonged PTT** and is inherited in an **X-linked recessive** pattern, the mixing study specifically showed correction with **Factor VIII**, not Factor IX, thus ruling out Hemophilia B (which is Factor IX deficiency). - The clinical presentation of spontaneous bleeding into joints (hemarthrosis) is consistent with both Hemophilia A and B, but the specific lab findings differentiate them. *von Willebrand disease* - This disease typically presents with a **prolonged bleeding time** (or abnormal ristocetin cofactor assay), which was noted as normal in this patient. - While it can cause a **mildly prolonged PTT** due to its role in stabilizing Factor VIII, the primary diagnostic indicator of an abnormal ristocetin cofactor is absent here. *Bernard-Soulier disease* - This is a rare **platelet disorder** characterized by large platelets and a deficiency or defect in the **glycoprotein Ib-IX-V complex**, leading to impaired platelet adhesion. - It would typically present with a **normal PT and PTT** but a **prolonged bleeding time** (abnormal ristocetin cofactor assay), differentiating it from the findings in this case.

Question 631: A 54-year-old woman presents to the emergency ward with a chief complaint of chest pain. The pain is sharp and present in the anterior part of the chest. There is no radiation of the pain; however, the intensity is decreased while sitting and leaning forward. There is no associated shortness of breath. Vital signs are the following: blood pressure is 132/84 mm Hg; pulse rate is 82/min, rhythmic, and regular. Lungs are clear on auscultation and cardiovascular examination demonstrates scratchy and squeaking sounds at the left sternal border. Kussmaul sign is positive and ECG shows new widespread ST segment elevation and PR depression. The most likely cause for these findings in this patient is?

A. Restrictive cardiomyopathy
B. Acute pericarditis (Correct Answer)
C. Pleurisy
D. Right ventricular myocardial infarction
E. Cardiac tamponade

Explanation: ***Acute pericarditis*** - The classic presentation includes **sharp, pleuritic chest pain** that **improves with leaning forward** and **worsens with lying down**. The presence of a **pericardial friction rub** (scratchy and squeaking sounds) and specific ECG findings like **widespread ST elevation** and **PR depression** are highly indicative. - **Kussmaul sign** (paradoxical rise in jugular venous pressure on inspiration) is unusual in uncomplicated acute pericarditis but may suggest associated pericardial effusion or early constrictive physiology. The clinical picture remains most consistent with acute pericarditis given the characteristic chest pain, friction rub, and ECG changes. *Restrictive cardiomyopathy* - Characterized by **diastolic dysfunction** and impaired ventricular filling, leading to symptoms like dyspnea and edema. While Kussmaul sign can be present, the chest pain characteristics, friction rub, and widespread ST elevation with PR depression are not typical. - The ECG findings in restrictive cardiomyopathy usually involve **low voltage** and non-specific ST-T wave changes, not diffuse ST elevation and PR depression. *Pleurisy* - Pleurisy causes **sharp, pleuritic chest pain** that can worsen with breathing and movement, similar to pericarditis. However, it does not typically present with a pericardial friction rub or the characteristic ECG changes of widespread ST elevation and PR depression. - Pleurisy is an inflammation of the pleura, often indicated by **pleural friction rubs** and usually associated with pulmonary conditions, which are not suggested by this patient's findings. *Right ventricular myocardial infarction* - While it can cause chest pain and positive Kussmaul sign due to elevated right atrial pressure, the chest pain is typically more anginal-like and not relieved by leaning forward. - The ECG would show **ST elevation primarily in right-sided leads (V4R)** and inferior leads (II, III, aVF), but would **not typically show widespread ST elevation or PR depression** in multiple lead distributions or a pericardial friction rub. *Cardiac tamponade* - Characterized by the **Beck's triad** (hypotension, muffled heart sounds, and elevated jugular venous pressure) and pulsus paradoxus. Chest pain can be present, but the pain's amelioration with leaning forward and the specific ECG changes with widespread ST elevation and PR depression are not typical. - While a pericardial friction rub might precede tamponade, **cardiac tamponade itself typically develops from a significant pericardial effusion**, leading to compression of the heart and does not directly manifest with diffuse ST elevation and PR depression.

Question 632: A previously healthy 33-year-old woman comes to the emergency department 1 hour after falling from a ladder. She is conscious. She does not smoke, drink alcohol, or use illicit drugs. There is no family history of serious illness. Her pulse is 72/min, respirations are 17/min, and blood pressure is 110/72 mm Hg. Physical examination shows ecchymosis and point tenderness over the right clavicle. An x-ray of the chest shows a nondisplaced fracture of the midshaft of the right clavicle and a 3.5-mm pulmonary nodule in the central portion of the left upper lung field. No previous x-rays of the patient are available. The fracture is treated with pain management and immobilization with a sling. A CT scan of the chest shows that the pulmonary nodule is solid and has well-defined, smooth borders. Which of the following is the most appropriate next step in management of this patient's pulmonary nodule?

A. Follow-up CT scan of the chest in 6–12 months (Correct Answer)
B. CT-guided transthoracic biopsy
C. Follow-up x-ray of the chest in 6–12 months
D. Bronchoscopy with biopsy
E. Reassurance

Explanation: ***Follow-up CT scan of the chest in 6–12 months*** - This patient has a **small (3.5 mm)**, **solid**, **well-defined**, **smooth-bordered pulmonary nodule** discovered incidentally in a **low-risk patient** (33-year-old, non-smoker, no malignancy history, no suspicious symptoms). - Per **Fleischner Society guidelines**, small solid nodules <6mm in low-risk patients generally require minimal or no routine follow-up. However, **conservative management with follow-up CT** at 6–12 months is a reasonable approach to ensure stability, especially when baseline imaging is not available for comparison. - **CT scan** (not X-ray) is the appropriate imaging modality due to superior resolution for detecting subtle changes in nodule size and characteristics. - The nodule's benign features (small size, smooth borders, well-defined margins) suggest low malignancy risk, making watchful waiting the most appropriate strategy. *CT-guided transthoracic biopsy* - This invasive procedure carries significant risks including **pneumothorax** (15-30% risk) and **hemorrhage**. - Reserved for nodules with **high suspicion of malignancy**: typically larger (>8mm), spiculated, irregular borders, or in high-risk patients (heavy smokers, older age, cancer history). - Given the **benign features** and **low-risk profile**, immediate biopsy would expose the patient to unnecessary procedural risks. *Follow-up x-ray of the chest in 6–12 months* - While follow-up is appropriate, **chest X-ray has poor sensitivity** for detecting small nodules and interval changes, especially for nodules <5mm. - **CT scan** provides detailed information on nodule size (to the millimeter), morphology, density (Hounsfield units), and interval growth, which is essential for proper surveillance. - X-ray follow-up would be inadequate for this small nodule. *Bronchoscopy with biopsy* - **Bronchoscopy** is typically used for centrally located endobronchial lesions or when navigational bronchoscopy can safely access peripheral nodules. - While the nodule is described as "central portion of left upper lung field," this likely means medial, not necessarily endobronchial. - The **small size (3.5mm)**, **benign characteristics**, and **low pretest probability of malignancy** make bronchoscopy with its associated risks (bleeding, pneumothorax, infection) an overtreatment. - Diagnostic yield for nodules <10mm via bronchoscopy is generally low. *Reassurance* - While the nodule has benign features and current **Fleischner 2017 guidelines** suggest no routine follow-up may be needed for solid nodules <6mm in low-risk patients, this is an **incidental finding without prior imaging for comparison**. - Complete reassurance without any follow-up or documentation of stability would not be the most prudent approach in clinical practice. - At minimum, **one follow-up study** is reasonable to confirm stability and document benign behavior, particularly in a medicolegal context.

Question 633: A 72-year-old man with longstanding history of diabetes mellitus and hypertension presents to the emergency department with sudden-onset numbness. On your neurological exam, you note that he has loss of sensation on the left side of his face, arm, and leg. His motor strength exam is normal, as are his cranial nerves. Which of the following is the most likely explanation for his presentation?

A. Middle cerebral artery stroke
B. Thalamic stroke (Correct Answer)
C. Conversion disorder
D. Anterior cerebral artery stroke
E. Basilar artery stroke

Explanation: ***Thalamic stroke*** - A **thalamic stroke** classically presents with pure sensory deficits, often affecting the **contralateral** side of the body without significant motor weakness or cranial nerve involvement. - The patient's history of **diabetes mellitus** and **hypertension** are significant risk factors for this type of **lacunar stroke**. *Middle cerebral artery stroke* - An **MCA stroke** typically causes **contralateral hemiparesis/hemiplegia** (motor weakness), sensory loss, and possibly **aphasia** (if dominant hemisphere) or **hemineglect** (if non-dominant hemisphere). - The patient's preserved motor strength and normal cranial nerves make a pure MCA stroke unlikely. *Conversion disorder* - **Conversion disorder** involves neurological symptoms that are inconsistent with known neurological conditions, often linked to psychological stress. - While it can manifest as numbness, the specific pattern of **pure sensory loss** and the patient's strong vascular risk factors suggest a physiological rather than psychological cause. *Anterior cerebral artery stroke* - An **ACA stroke** primarily affects the **contralateral leg** more than the arm, often with **urinary incontinence** and **abulia** (lack of initiative). - The patient's involvement of the face, arm, and leg equally, without leg predominance or behavioral changes, is atypical for an ACA stroke. *Basilar artery stroke* - A **basilar artery stroke** typically manifests with a wide range of severe neurological deficits, including **ataxia**, **dysarthria**, **diplopia**, **vertigo**, and often with **quadriparesis** or **locked-in syndrome**. - The patient's isolated sensory loss without other brainstem signs makes a basilar artery stroke highly improbable.

Question 634: A 72-year-old man presents to the physician with blood in his sputum for 3 days. He also mentions that he has had a cough for the last 3 months but thought that it was because of the winter season. He also has often experienced fatigue recently. His temperature is 37.0°C (98.6°F), the respiratory rate is 15/min, the pulse is 67/min, and the blood pressure is 122/98 mm Hg. Auscultation of his chest reveals normal heart sounds but localized rhonchi over the right infrascapular region. A detailed diagnostic evaluation including a complete blood count and other serum biochemistry, chest radiogram, computed tomography of chest and abdomen, magnetic resonance imaging of the brain, bone scan, and pulmonary function tests are ordered, which confirm a diagnosis of limited-disease small cell lung cancer of 2.5 cm (1 in) in diameter, located in the lower lobe of the right lung, with the involvement of ipsilateral hilar lymph nodes and intrapulmonary lymph nodes. The mediastinal, subcarinal, scalene or supraclavicular lymph nodes are not involved, and there is no distant metastasis. There is no additional comorbidity and his performance status is good. The patient does not have any contraindication to any chemotherapeutic agents or radiotherapy. Which of the following is the best treatment option for this patient?

A. Thoracic radiation therapy followed by prophylactic cranial irradiation
B. Platinum-based chemotherapy plus etoposide and thoracic radiation therapy (Correct Answer)
C. Lobectomy with adjuvant topotecan-based chemotherapy
D. Pneumonectomy with adjuvant platinum-based chemotherapy and thoracic radiation therapy
E. Topotecan-based chemotherapy plus thoracic radiation therapy

Explanation: ***Platinum-based chemotherapy plus etoposide and thoracic radiation therapy*** - For **limited-stage small cell lung cancer (SCLC)**, combined modality treatment with **platinum-based chemotherapy (cisplatin or carboplatin) and etoposide** given concurrently with **thoracic radiation therapy** is the standard of care as it improves survival. - This patient has limited-stage disease, defined as disease confined to one hemithorax and regional lymph nodes that can be encompassed within a tolerable radiation field. *Thoracic radiation therapy followed by prophylactic cranial irradiation* - While **prophylactic cranial irradiation (PCI)** is indicated for limited-stage SCLC after systemic therapy to reduce brain metastases, it's not the initial primary treatment by itself. - **Chemotherapy** is a mandatory component of initial treatment for SCLC due to its highly metastatic nature. *Lobectomy with adjuvant topotecan-based chemotherapy* - **Surgery (lobectomy or pneumonectomy)** is generally not indicated for SCLC, even in limited stages, because it is a highly aggressive and systemic disease that responds better to chemotherapy and radiation. - **Topotecan** is typically used as a second-line agent for recurrent or refractory SCLC, not as adjuvant therapy after surgery. *Pneumonectomy with adjuvant platinum-based chemotherapy and thoracic radiation therapy* - **Pneumonectomy** is an extensive surgery with significant morbidity and mortality and is rarely, if ever, performed for SCLC. - While chemotherapy and radiation are components of treatment, **surgical resection (pneumonectomy in this case)** is not the standard primary therapy for SCLC given its systemic nature. *Topotecan-based chemotherapy plus thoracic radiation therapy* - **Topotecan** is generally reserved for **relapsed or refractory SCLC** as a second-line or later agent. - The standard first-line chemotherapy for limited-stage SCLC involves a **platinum agent (cisplatin or carboplatin) with etoposide**.

Question 635: A 29-year-old woman comes to the physician for the evaluation of progressive loss of vision in her left eye and gradual blurring of vision in her right eye over the past 2 months. She also says that she has had occasional headaches and has noticed a decrease in her sense of smell lately. The patient's only medication is fexofenadine for seasonal allergies. She is 158 cm (5 ft 2 in) tall and weighs 61 kg (135 lbs); BMI is 24.7 kg/m2. Vital signs are within normal limits. Visual acuity is 20/40 in the right eye and there is minimal light perception in the left eye. In the swinging flashlight test, both of her eyes dilate as the light moves from the right to left eye. Fundoscopy shows papilledema in the right optic disc and a pale left optic disc. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Meningioma (Correct Answer)
B. Pseudotumor cerebri
C. Hereditary optic neuropathy
D. Multiple sclerosis
E. Anterior ischemic optic neuropathy

Explanation: ***Meningioma*** - Progressive **vision loss**, **headaches**, and **anosmia** (loss of smell) in a young woman suggest an anterior cranial fossa mass compressing the **optic nerves** and **olfactory bulbs**. Papilledema in one eye and a pale optic disc in the other (Foster Kennedy syndrome) is a classic presentation of a meningioma at the **olfactory groove** or **sphenoid wing**. - The **relative afferent pupillary defect** (RAPD) on the swinging flashlight test (both pupils dilating when light moves from the right to left eye) indicates significant damage to the left optic nerve. *Pseudotumor cerebri* - This condition primarily affects **obese young women** and typically presents with **bilateral papilledema**, headaches, and visual disturbances, but **anosmia is not a characteristic feature**. - Affects intracranial pressure, but focal neurological deficits like unilateral severe vision loss and anosmia are less common. *Hereditary optic neuropathy* - Conditions like **Leber hereditary optic neuropathy** typically present with **painless, subacute bilateral vision loss**, often in young males, and do not usually involve headaches or anosmia. - Fundoscopy might show hyperemia of the optic disc in the acute phase, followed by optic atrophy, but not usually the mixed picture of papilledema and pallor seen here. *Multiple sclerosis* - **Optic neuritis** in multiple sclerosis causes **sudden, painful unilateral vision loss**, rather than gradual, painless loss, and is usually an acute inflammatory event. - While headaches can occur, anosmia is rare, and the specific fundoscopic findings and RAPD pattern are not typical for MS optic neuritis alone. *Anterior ischemic optic neuropathy* - Typically causes **sudden, painless, monocular vision loss** in older individuals with vascular risk factors. - The gradual progression, presence of anosmia, and the specific fundoscopic findings (papilledema in one eye, pallor in the other) are not characteristic of this condition.

Question 636: A 55-year-old woman who is an established patient presents to your office. She is complaining of increased urination and increased thirst. She has recently began taking several over-the-counter vitamins and supplements. On further review, she reports she has also been having abdominal pain and constipation. She denies significant weight changes. Her fingerstick blood glucose in your office is 96 mg/dL. Which of the following test is most likely to provide the diagnosis?

A. Niacin levels
B. Pyridoxine levels
C. Hemoglobin A1C
D. Free T4 levels
E. Calcium level (Correct Answer)

Explanation: ***Calcium level*** - The constellation of **polyuria**, **polydipsia**, **abdominal pain**, and **constipation** is classic for **hypercalcemia** (remembered by "stones, bones, groans, and psychiatric overtones"). - **Hypercalcemia** causes **nephrogenic diabetes insipidus** (leading to polyuria and polydipsia) and **GI dysmotility** (causing constipation and abdominal pain). - The key clinical clue is **recent supplement use** - excessive intake of **calcium-containing supplements** or **vitamin D** (which increases calcium absorption) can cause **hypercalcemia**. - Other causes include **primary hyperparathyroidism** and **malignancy**, but the supplement history makes iatrogenic hypercalcemia most likely. *Niacin levels* - **Niacin** (Vitamin B3) deficiency causes **pellagra** (dermatitis, diarrhea, dementia), while toxicity causes flushing and hepatotoxicity. - These symptoms are not present in this patient, making niacin levels an unlikely diagnostic test. *Pyridoxine levels* - **Pyridoxine** (Vitamin B6) deficiency causes peripheral neuropathy and sideroblastic anemia; toxicity causes sensory neuropathy. - Neither deficiency nor toxicity explains polyuria, polydipsia, abdominal pain, and constipation. *Hemoglobin A1C* - While polyuria and polydipsia suggest **diabetes mellitus**, the **normal fingerstick blood glucose of 96 mg/dL** makes diabetes unlikely. - An A1C assesses long-term glycemic control but would not explain the abdominal pain, constipation, or supplement connection. *Free T4 levels* - **Hypothyroidism** causes constipation, but not typically polyuria or polydipsia. - **Hyperthyroidism** can cause increased thirst but does not explain the full symptom complex, particularly the abdominal pain and supplement history. - Thyroid dysfunction is less likely than hypercalcemia given the clinical presentation.

Question 637: A 15-year-old girl comes to the physician for a well-child examination. She feels well. Her father has coronary artery disease and hypertension. Her mother has type 2 diabetes mellitus, hypercholesterolemia, and had a myocardial infarction at the age of 52 years. She is at the 25th percentile for height and above the 95th percentile for weight. Her BMI is 32 kg/m2. Her temperature is 37°C (98.6°F), pulse is 99/min, and blood pressure is 140/88 mm Hg. Physical examination shows no abnormalities. Random serum studies show: Glucose 160 mg/dL Creatinine 0.8 mg/dL Total cholesterol 212 mg/dL HDL-cholesterol 32 mg/dL LDL-cholesterol 134 mg/dL Triglycerides 230 mg/dL In addition to regular aerobic physical activity, which of the following is the most appropriate next step in management?

A. Atorvastatin therapy
B. Reduced-calorie diet (Correct Answer)
C. Fenofibrate therapy
D. Metformin therapy
E. Niacin therapy

Explanation: ***Reduced-calorie diet*** - Given the patient's **obesity (BMI 32 kg/m2)**, **elevated blood pressure (140/88 mmHg)**, **impaired fasting glucose (160 mg/dL)**, and **dyslipidemia (high triglycerides, low HDL)**, lifestyle modifications, particularly a **reduced-calorie diet**, are the cornerstone of initial management. This approach aims to address the underlying metabolic cluster contributing to her risk. - A **reduced-calorie diet** combined with regular aerobic physical activity can lead to weight loss, which in turn can improve blood pressure, glucose levels, and lipid profiles, thereby mitigating her significant risk factors for cardiovascular disease and type 2 diabetes. *Atorvastatin therapy* - **Atorvastatin (a statin)** is typically indicated for severe dyslipidemia, particularly elevated LDL-cholesterol, or in patients with established cardiovascular disease in adults. For adolescents, statin use is reserved for those with **severe primary hypercholesterolemia** unresponsive to lifestyle changes. - While her **LDL is elevated (134 mg/dL)**, given her age and the multifactorial nature of her metabolic abnormalities, initial management should focus on lifestyle modifications before considering pharmacotherapy like statins. *Fenofibrate therapy* - **Fenofibrate** is primarily used to treat **severe hypertriglyceridemia** and to improve low HDL-cholesterol. While her **triglycerides are elevated (230 mg/dL)**, similar to statins, pharmacologic interventions for dyslipidemia in adolescents usually follow a trial of intensive lifestyle modifications. - Addressing the patient's overall metabolic syndrome through weight loss and dietary changes is a more comprehensive initial approach, as it can simultaneously improve her dyslipidemia, hyperglycemia, and hypertension. *Metformin therapy* - **Metformin** is used to manage **type 2 diabetes mellitus** and often for **insulin resistance**, particularly in obese individuals. While her **random glucose is elevated (160 mg/dL)**, indicating impaired glucose regulation, a definitive diagnosis of type 2 diabetes or prediabetes requiring metformin typically involves fasting glucose levels, oral glucose tolerance tests, or HbA1c. - For a 15-year-old with these findings, intensive lifestyle intervention to achieve weight loss is the **first-line therapy** to improve glucose metabolism and prevent the progression to type 2 diabetes. *Niacin therapy* - **Niacin** is used to reduce LDL-cholesterol and triglycerides, and to increase HDL-cholesterol. However, it can have significant side effects like flushing and hepatotoxicity. - Its role in the management of dyslipidemia, especially in adolescents, is generally limited and considered after other agents or in specific conditions, as lifestyle modification remains the initial and most appropriate step.

Question 638: A 39-year-old male is rushed to the emergency department after he developed a sudden-onset severe headache with ensuing nausea, vomiting, vision changes, and loss of consciousness. Past medical history is unattainable. He reports that the headache is worse than any he has experienced before. Noncontrast CT of the head is significant for an intracranial hemorrhage. Follow-up cerebral angiography is performed and shows a ruptured anterior communicating artery aneurysm. Which of the following has the strongest association with this patient's current presentation?

A. Abdominal CT suggestive of renal cell carcinoma
B. Kidney ultrasound showing numerous bilateral renal cysts (Correct Answer)
C. Brain MRI showing a butterfly glioma with a central necrotic core
D. History of renal transplantation at 8 years of age
E. History of multiple hemangioblastomas of the retina and spine as well as pheochromocytoma

Explanation: ***Kidney ultrasound showing numerous bilateral renal cysts*** - This finding is highly suggestive of **Autosomal Dominant Polycystic Kidney Disease (ADPKD)**, which is strongly associated with an increased risk of **intracranial aneurysms**. - Ruptured intracranial aneurysms, like the one described in the patient, are a major cause of morbidity and mortality in individuals with ADPKD. *Abdominal CT suggestive of renal cell carcinoma* - While renal cell carcinoma can be associated with certain genetic syndromes (e.g., von Hippel-Lindau disease), it does not have a direct strong association with **intracranial aneurysms** causing a sudden-onset severe headache in the manner described. - The primary presentation here is a ruptured cerebral aneurysm, making other associations less likely. *Brain MRI showing a butterfly glioma with a central necrotic core* - A **butterfly glioma with a central necrotic core** is characteristic of **glioblastoma multiforme**, a primary brain tumor. - While brain tumors can cause headaches, they typically lead to a more gradual onset of symptoms and do not directly predispose to the formation and rupture of **intracranial aneurysms**. *History of renal transplantation at 8 years of age* - A history of renal transplantation suggests prior **end-stage renal disease**, which can have various underlying causes. - While some causes of kidney disease (like ADPKD) are linked to aneurysms, transplantation itself is not a direct risk factor for aneurysm rupture; rather, it's the *underlying cause* of kidney disease that might be relevant. *History of multiple hemangioblastomas of the retina and spine as well as pheochromocytoma* - This constellation of symptoms is indicative of **von Hippel-Lindau disease**, which is associated with various tumors, including **hemangioblastomas** of the central nervous system. - While von Hippel-Lindau disease is linked to CNS lesions, it is **not primarily associated with an increased risk of intracranial saccular aneurysms** leading to subarachnoid hemorrhage.

Question 639: A 54-year-old man is brought to the emergency department because of progressive tingling and weakness in both of his legs for the past two days. The patient reports that his symptoms interfere with his ability to walk. Two weeks ago, he had an upper respiratory tract infection, which resolved spontaneously. His vital signs are within normal limits. Examination shows weakness in the lower extremities with absent deep tendon reflexes. Reflexes are 1+ in the upper extremities. Sensation to pinprick and light touch is intact. Romberg's test is negative. Laboratory studies show a leukocyte count of 12,000/mm3. Cerebrospinal fluid analysis results show: Opening pressure normal Protein 200 mg/dL Glucose 70 mg/dL White blood cells 4/mm3 This patient is at increased risk for which of the following conditions?

A. Respiratory failure (Correct Answer)
B. Dementia
C. Hypertrophic cardiomyopathy
D. Thymoma
E. Urinary incontinence

Explanation: ***Respiratory failure*** - The patient's presentation is consistent with **Guillain-Barré Syndrome (GBS)**, characterized by **ascending paralysis**, areflexia, and a history of preceding infection. - As the paralysis ascends, it can affect the **respiratory muscles** (diaphragm and intercostal muscles), leading to life-threatening respiratory failure requiring mechanical ventilation. *Dementia* - **Dementia** is a chronic neurodegenerative condition characterized by progressive cognitive decline, memory impairment, and functional deficits. - It does not present with acute, rapidly progressing **motor weakness** and **areflexia** as seen in this patient. *Hypertrophic cardiomyopathy* - **Hypertrophic cardiomyopathy** is a genetic heart condition causing thickening of the heart muscle, leading to impaired diastolic filling and potential arrhythmias. - It does not explain the patient's neurological symptoms of **progressive weakness**, **areflexia**, or the characteristic CSF findings. *Thymoma* - A **thymoma** is a tumor of the thymus gland, most commonly associated with **myasthenia gravis**, an autoimmune disorder causing fluctuating muscle weakness that worsens with activity. - The patient's symptoms of progressive, ascending paralysis with absent reflexes are **inconsistent with myasthenia gravis**. *Urinary incontinence* - While urinary symptoms can be seen in some neurological conditions, **urinary incontinence** is not a primary or hallmark feature of **Guillain-Barré Syndrome** in its acute phase unless severe autonomic dysfunction or profound flaccid paralysis affecting the bladder occurs. - The most immediate and life-threatening complication in GBS is respiratory compromise due to ascending paralysis.

Question 640: A 62-year-old Caucasian male presents to your office with hemoptysis and hematuria. On physical exam you note a saddle nose deformity. Laboratory results show an elevated level of cytoplasmic antineutrophil cytoplasmic antibody. Which of the following interventions is most appropriate for this patient?

A. Smoking cessation
B. Corticosteroids (Correct Answer)
C. IV immunoglobulin
D. Discontinuation of ibuprofen
E. Isoniazid

Explanation: ***Corticosteroids*** - The patient's presentation with **hemoptysis**, **hematuria**, and **saddle nose deformity**, coupled with a **positive c-ANCA**, is highly suggestive of **granulomatosis with polyangiitis (GPA)**, a severe vasculitis. - **Corticosteroids** are a cornerstone of treatment for GPA, especially during acute flares, to suppress the inflammatory response and prevent organ damage. *Smoking cessation* - While **smoking cessation** is important for overall health, particularly in cases of hemoptysis, it does not directly treat the underlying autoimmune vasculitis in GPA. - It would be a supportive measure, but not the primary or most appropriate intervention for the acute, life-threatening aspects of GPA. *IV immunoglobulin* - **Intravenous immunoglobulin (IVIG)** may be used in certain autoimmune conditions, but it is **not the primary treatment for GPA**. - While it can modulate the immune system, its role in GPA is generally limited to cases refractory to conventional therapy or in specific situations like severe neurologic involvement, which is not indicated here. *Discontinuation of ibuprofen* - **Ibuprofen**, an NSAID, might contribute to renal dysfunction or gastrointestinal bleeding, but discontinuing it alone would **not address the systemic autoimmune vasculitis**. - It would be a symptomatic management, potentially alleviating some non-specific inflammation or pain, but would not halt the progression of GPA. *Isoniazid* - **Isoniazid** is an antibiotic primarily used for the treatment and prophylaxis of **tuberculosis**. - There is no indication of tuberculosis in this patient's presentation, and isoniazid has no role in the treatment of systemic vasculitis like GPA.

Question 641: A 5-year-old girl with an aortic stenosis correction comes to the office for a follow-up visit for acute lymphoblastic leukemia. She initiated chemotherapy a week before through a peripherally inserted central line. She reports being 'tired all the time' and has been bruising easily. Her vital signs are within normal limits. Physical examination shows several tender, non-blanching petechiae on the pads of the fingers and toes; several dark, non-tender petechiae on her palms and soles; and small, linear hemorrhages under her fingernails. Fundoscopic examination shows various small areas of hemorrhage on the retinae bilaterally. Cardiac examination is notable for a II/VI systolic ejection murmur that seems to have worsened in comparison to the last visit. Which of the following is the most likely cause?

A. Dilated cardiomyopathy
B. Acute rheumatic fever
C. Infective endocarditis (Correct Answer)
D. Hypertrophic cardiomyopathy
E. Bleeding diathesis secondary to thrombocytopenia

Explanation: ***Infective endocarditis*** - The patient's history of **aortic stenosis correction** and a recently placed **PICC line** are significant risk factors for **infective endocarditis**. - The presence of **petechiae on fingers/toes/palms/soles**, **splinter hemorrhages** (under fingernails), and **retinal hemorrhages** (Roth spots) are classic peripheral stigmata of infective endocarditis. The worsening systolic ejection murmur suggests new or worsening valvular dysfunction. *Dilated cardiomyopathy* - While it can cause fatigue and a murmur, **dilated cardiomyopathy** does not typically present with the specific peripheral dermatological and ophthalmological findings seen in this patient (petechiae, splinter hemorrhages, Roth spots). - It is often associated with a dilated ventricle and reduced ejection fraction, which is not suggested by the classic signs in the question. *Acute rheumatic fever* - **Acute rheumatic fever** typically occurs after a Group A Streptococcus infection and presents with migratory polyarthritis, carditis, chorea, erythema marginatum, and subcutaneous nodules according to the **Jones criteria**. - The presence of petechiae and splinter hemorrhages is not characteristic of acute rheumatic fever. *Hypertrophic cardiomyopathy* - **Hypertrophic cardiomyopathy** is characterized by left ventricular hypertrophy and can cause systolic murmurs, but it does not explain the widespread petechiae, splinter hemorrhages, or retinal hemorrhages observed. - Its symptoms often include dyspnea, palpitations, chest pain, and syncope, which are distinct from the current presentation. *Bleeding diathesis secondary to thrombocytopenia* - **Thrombocytopenia** could explain easy bruising and petechiae due to platelet deficiency, which is possible in a patient undergoing chemotherapy for ALL. However, thrombocytopenia alone would not cause the specific signs of **splinter hemorrhages** or **retinal hemorrhages (Roth spots)** particularly with a worsening cardiac murmur. - The combination of peripheral embolic phenomena and cardiac involvement strongly points away from a simple bleeding diathesis and towards an infectious cardiac source.

Question 642: A 57-year-old man comes to the physician because of a 2-month history of worsening shortness of breath with walking. He has not had any cough, fevers, or recent weight loss. He has hypercholesterolemia, for which he takes simvastatin, but otherwise is healthy. For 35 years he has worked for a demolition company. He has smoked 1 pack of cigarettes daily for the past 33 years. Pulmonary examination shows fine bibasilar end-expiratory crackles. An x-ray of the chest shows diffuse bilateral infiltrates predominantly in the lower lobes and bilateral calcified pleural plaques. The patient is most likely to develop which of the following conditions?

A. Tuberculosis
B. Thyroid carcinoma
C. Sarcoidosis
D. Mesothelioma (Correct Answer)
E. Bronchogenic carcinoma

Explanation: ***Mesothelioma*** - The patient has **asbestosis** (interstitial lung disease from asbestos exposure causing bilateral lower lobe infiltrates and bibasilar crackles) due to 35 years working in **demolition** with asbestos exposure. - **Calcified pleural plaques** are pathognomonic for asbestos exposure and indicate significant cumulative exposure. - Patients with asbestosis and pleural plaques have markedly increased risk of **malignant mesothelioma**, a highly specific asbestos-related malignancy of the pleura. - While bronchogenic carcinoma is statistically more common, **mesothelioma is virtually pathognomonic** for asbestos exposure and is the classic malignancy tested in this clinical context. *Tuberculosis* - TB typically presents with **cough, fevers, night sweats, and weight loss**, which are absent in this patient. - Chest x-ray in TB shows **upper lobe cavitations or consolidation**, not bilateral lower lobe interstitial infiltrates with pleural plaques. - No epidemiologic risk factors for TB are present. *Thyroid carcinoma* - Thyroid cancer presents with a **thyroid nodule or mass**, not pulmonary symptoms. - No association with asbestos exposure or the clinical findings described. *Sarcoidosis* - Sarcoidosis typically shows **bilateral hilar lymphadenopathy** and upper/middle lobe involvement on chest x-ray. - Not associated with asbestos exposure or calcified pleural plaques. - Occurs more commonly in younger patients (20-40 years old). *Bronchogenic carcinoma* - While this patient's **smoking history** increases lung cancer risk, and asbestos exposure synergistically increases this risk further, bronchogenic carcinoma would present with a **focal mass or nodule**, not diffuse bilateral infiltrates. - The **calcified pleural plaques** and diffuse interstitial pattern point more specifically toward asbestos-related pathology (asbestosis now, mesothelioma risk in future). - Mesothelioma is more specific to asbestos exposure in this clinical scenario.

Question 643: A 43-year-old woman presents to the physician with the complaint of worsening fatigue over the past several months. She has found that she requires nearly double the amount of coffee consumption each day to stay awake at work and that despite maintaining a balanced, healthy diet, she has experienced significant weight gain. A blood test confirms the presence of anti-thyroid peroxidase antibodies. Which of the following additional findings would be most consistent with the underlying pathophysiology of her condition?

A. Galactorrhea (Correct Answer)
B. Constipation
C. Brisk deep tendon reflexes
D. Diarrhea
E. Heat intolerance

Explanation: ***Galactorrhea*** - This patient has **Hashimoto's thyroiditis**, an autoimmune hypothyroidism, given the fatigue, weight gain, and positive **anti-thyroid peroxidase antibodies**. - **Hypothyroidism** can lead to **hyperprolactinemia** due to increased **TRH** (thyrotropin-releasing hormone), which stimulates both TSH and prolactin release from the anterior pituitary. - Elevated prolactin can manifest as **galactorrhea**, representing a less commonly recognized endocrine consequence of primary hypothyroidism. *Constipation* - **Constipation** is a common symptom of **hypothyroidism** due to decreased gastrointestinal motility. - While consistent with hypothyroidism, it is a direct consequence of reduced metabolic activity rather than a secondary endocrine effect. - This is a well-known, expected finding rather than an additional pathophysiologic manifestation. *Brisk deep tendon reflexes* - **Hypothyroidism** typically causes **delayed relaxation of deep tendon reflexes** (hung-up reflexes), not brisk reflexes. - **Brisk reflexes** are characteristic of **hyperthyroidism** due to increased neuromuscular excitability. *Diarrhea* - **Diarrhea** is typically associated with **hyperthyroidism** due to increased gastrointestinal motility from elevated metabolic rate. - **Hypothyroidism** more commonly causes **constipation** due to decreased GI motility. *Heat intolerance* - **Heat intolerance** is a classic symptom of **hyperthyroidism** due to an elevated metabolic rate and increased thermogenesis. - Patients with **hypothyroidism** usually experience **cold intolerance** due to decreased metabolic heat production.

Question 644: A 48-year-old woman comes to the physician because of a 6-month history of muscle stiffness, myalgia, and a 7-kg (15-lb) weight gain. Her last menstrual period was 4 months ago. Physical examination shows cold, dry skin, and proximal muscle weakness. Deep tendon reflexes are 2+ bilaterally, with delayed relaxation. The creatine kinase level is 2,940 U/L. Which of the following is the most appropriate next step in diagnosis?

A. Thyroid function tests (Correct Answer)
B. Repetitive nerve stimulation
C. Serum electrolytes
D. Muscle biopsy
E. Serum assay for muscle specific tyrosine kinase antibody

Explanation: ***Thyroid function tests*** - The patient's symptoms (muscle stiffness, myalgia, weight gain, cold/dry skin, proximal muscle weakness, delayed deep tendon reflex relaxation, and elevated CK) are highly suggestive of **hypothyroidism**. - Measuring **TSH** and **free T4** is crucial to confirm or rule out this diagnosis and it is the most appropriate next step in the diagnostic workup. *Repetitive nerve stimulation* - This test is primarily used to diagnose disorders of the **neuromuscular junction**, such as **myasthenia gravis** or **Lambert-Eaton syndrome**. - The patient's clinical picture, particularly the delayed deep tendon reflex relaxation and muscle stiffness, is not typical for these conditions. *Serum electrolytes* - While electrolytes can be abnormal in various conditions, they are unlikely to directly explain the constellation of symptoms (muscle stiffness, weight gain, cold/dry skin, delayed reflexes) and the high **creatine kinase** level in this patient. - While a basic metabolic panel is often part of a general workup, it is not the most specific or appropriate *next step* for this clinical presentation. *Muscle biopsy* - A muscle biopsy is an **invasive procedure** typically reserved for diagnosing specific **myopathies** (e.g., inflammatory myopathies, muscular dystrophies) when less invasive tests have not yielded a diagnosis. - Given the strong indicators for hypothyroidism, a muscle biopsy would be premature before evaluating thyroid function. *Serum assay for muscle specific tyrosine kinase antibody* - This antibody is a marker for a subtype of **myasthenia gravis** (**MuSK-associated myasthenia gravis**), a disorder of the neuromuscular junction. - As with repetitive nerve stimulation, the patient's symptoms, especially the delayed deep tendon reflexes and myxedema-like features, do not primarily point towards myasthenia gravis.

Question 645: A 9-year-old girl is admitted to the hospital with a one-day history of acute abdominal pain and vomiting. She also has a two-day history of fever, headache, and neck pain. Her immunizations are up-to-date. She is confused and oriented only to place and person. Her temperature is 39.7°C (103.5°F), pulse is 148/min, blood pressure is 90/50 mm Hg, and respiratory rate is 28/min. Cervical range of motion is limited by pain. The remainder of the neurologic examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.9 g/dL Leukocyte count 44,000/mm3 Serum pH 7.33 Na+ 130 mEq/L Cl- 108 mEq/L K+ 6.1 mEq/L HCO3- 20 mEq/L Urea nitrogen 34 mg/dL Glucose 180 mg/dL Creatinine 2.4 mg/dL Urine ketones negative A CT scan of the head shows enhancement of the arachnoid and pia mater. Cerebrospinal fluid analysis shows a leukocyte count of 3,400/μL (90% neutrophils), a glucose concentration of 50 mg/dL, protein concentration of 81 mg/dL, and no erythrocytes. Gram stain of the CSF shows gram-negative diplococci. This patient is at increased risk for which of the following complications?

A. Vesicular skin eruptions
B. Adrenal hemorrhage (Correct Answer)
C. Pancreatitis
D. Temporal lobe inflammation
E. Deep neck abscess

Explanation: **Adrenal hemorrhage** - The clinical picture of **fever, acute abdominal pain, confusion, hypotension, and a high WBC count (44,000/mm³)**, along with **Gram-negative diplococci in CSF**, indicates **meningococcal meningitis with sepsis**. This rapidly progressive infection by *Neisseria meningitidis* can lead to **Waterhouse-Friderichsen syndrome**, characterized by **adrenal hemorrhage** and profound shock. - The **elevated potassium (6.1 mEq/L)** and **hyponatremia (130 mEq/L)** are consistent with **adrenal insufficiency** resulting from adrenal hemorrhage. *Vesicular skin eruptions* - **Vesicular skin eruptions** are characteristic of viral infections such as **herpes simplex virus (HSV)** or **varicella-zoster virus**, which would present differently (e.g., HSV encephalitis often causes temporal lobe involvement). - While various infections can cause skin rashes, this specific presentation with extensive meningeal inflammation and septic shock points away from typical vesicular eruptions. *Pancreatitis* - **Pancreatitis** is characterized by severe epigastric pain radiating to the back, often with nausea and vomiting, and elevated lipase/amylase. While **abdominal pain** is present, other symptoms like **neck stiffness, confusion, and CSF findings of bacterial meningitis** are not typical for pancreatitis. - There is no specific evidence, such as imaging findings or elevated pancreatic enzymes, to suggest pancreatitis in this case. *Temporal lobe inflammation* - **Temporal lobe inflammation** is a hallmark of **HSV encephalitis**, which often presents with seizures, bizarre behavior, and specific MRI findings in the temporal lobes. While a CT scan showed arachnoid and pia mater enhancement, this indicates **meningeal inflammation**, not specifically temporal lobe parenchymal inflammation (encephalitis). - The presence of **Gram-negative diplococci in the CSF** strongly indicates bacterial meningitis, not viral encephalitis, making temporal lobe inflammation less likely. *Deep neck abscess* - A **deep neck abscess** would typically cause localized neck pain, swelling, dysphagia, and stridor, potentially with fever, but would not explain the widespread CNS symptoms (confusion, meningeal signs, CSF findings) or systemic signs of shock and coagulopathy seen here. - While the patient has neck pain, it is due to **meningismus**, not a localized abscess, and there is no mention of local swelling or airway compromise.

Question 646: A 69-year-old woman is rushed to the emergency room by her daughter after she found her unconscious. Bruises are visible on the patient’s torso and limbs, and it is evident that she has epistaxis. Her daughter says that the patient was diagnosed with immune thrombocytopenic purpura at 61 years of age and has not had a normal thrombocyte count since the time of diagnosis. She was treated with corticosteroids, which were discontinued several weeks ago. Her current platelet count is 4,000/mm3. Which of the following is the best next step in the treatment of this patient?

A. Administration of intravenous immunoglobulins (Correct Answer)
B. Splenectomy
C. Platelet transfusion
D. Continuation of corticosteroids
E. Stem cell transplantation

Explanation: ***Administration of intravenous immunoglobulins*** - Given the patient's **severe thrombocytopenia (platelet count 4,000/mm3)**, **active bleeding (epistaxis)**, and unconsciousness indicating a potential severe bleeding event (e.g., intracranial hemorrhage), **IVIG** is the most appropriate first-line treatment to rapidly increase platelet count. - **IVIG acts quickly** (within 24-48 hours) by blocking macrophage Fc receptors, preventing the destruction of antibody-coated platelets, and is preferred as the primary intervention in acute, life-threatening ITP with bleeding. - While platelet transfusion may be given concurrently in life-threatening bleeding, **IVIG addresses the underlying immune destruction** and is the definitive acute intervention. *Splenectomy* - While **splenectomy** is an effective treatment for chronic ITP unresponsive to corticosteroids or IVIG, it is an **invasive surgical procedure** and not suitable for immediate stabilization in a patient with severe, acute bleeding. - It takes time to arrange and perform and carries surgical risks, which are heightened in an actively bleeding patient. - Typically considered for **chronic refractory ITP** after failure of medical management. *Platelet transfusion* - **Platelet transfusions** in ITP are **rapidly destroyed by autoantibodies**, making them generally ineffective as monotherapy. - However, they **may be used as a temporizing measure** in life-threatening bleeding (such as suspected intracranial hemorrhage) while awaiting the effect of IVIG or corticosteroids. - They do not address the underlying immune-mediated platelet destruction and should be given **in conjunction with** immunosuppressive therapy (IVIG or corticosteroids), not as a standalone intervention. - **IVIG remains the best answer** as it treats the cause of thrombocytopenia rather than just temporarily supplementing platelet numbers. *Continuation of corticosteroids* - The patient has already received corticosteroids, which were discontinued, suggesting either **lack of sustained response** or inability to tolerate long-term use. - While high-dose corticosteroids may be restarted in acute ITP with bleeding, they have a **slower onset of action** (days to weeks) compared to IVIG (24-48 hours) and are less suitable as the primary intervention for an acute, severe bleeding emergency. *Stem cell transplantation* - **Stem cell transplantation** is a highly invasive and high-risk procedure reserved for **severe refractory autoimmune conditions** when multiple other treatments have failed. - It is not a first-line treatment for acute ITP exacerbations and would not be considered in an emergency setting for immediate management of severe bleeding.

Question 647: A 57-year-old woman presents to her family physician because of sinusitis and nasal drainage for 3 months. The nasal drainage is purulent and occasionally hemorrhagic. She has only temporary improvement after trying multiple over the counter medications. Over the last 2 weeks, she also has fatigue and joint pain, mainly affecting the ankles, knees, and wrists. Vital signs include: temperature 36.9°C (98.4°F), blood pressure 142/91 mm Hg, and pulse 82/min. On examination, there is inflammation and bleeding of the nasal mucosa, along with tenderness to percussion over the maxillary sinuses. Urine dipstick reveals 4+ microscopic hematuria and 2+ proteinuria. Which of the following is the most likely diagnosis?

A. Granulomatosis with polyangiitis (Correct Answer)
B. Polyarteritis nodosa
C. Churg-Strauss syndrome
D. Immunoglobulin A nephropathy
E. Sarcoidosis

Explanation: ***Granulomatosis with polyangiitis*** - This patient presents with **upper airway inflammation** (chronic sinusitis, hemorrhagic purulent nasal drainage, inflamed nasal mucosa), **joint pain**, and **renal involvement** (hematuria, proteinuria), which are classic features of granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis. - GPA is a **small vessel vasculitis** often associated with **ANCA** (specifically PR3-ANCA/c-ANCA) and characterized by granulomatous inflammation of the respiratory tract and glomerulonephritis. *Polyarteritis nodosa* - **Polyarteritis nodosa (PAN)** typically involves **medium-sized arteries** and presents with systemic symptoms, but it **spares the lungs** and **kidneys initially**, unlike the prominent renal and upper respiratory manifestations seen here. - PAN is **not associated with ANCA** and does not typically involve the upper respiratory tract with granulomatous inflammation. *Churg-Strauss syndrome* - Also known as **Eosinophilic Granulomatosis with Polyangiitis (EGPA)**, this condition is characterized by **asthma**, **eosinophilia**, and **allergic rhinitis**, which are not the primary features in this patient. - While it can involve the upper respiratory tract and kidneys, the absence of **asthma** and **high eosinophil count** makes it less likely. *Immunoglobulin A nephropathy* - This is a **primary glomerular disease** characterized by **IgA deposition** in the mesangium, presenting often with recurrent macroscopic hematuria following an upper respiratory or gastrointestinal infection. - It does **not cause systemic vasculitis** with prominent upper airway inflammation, granulomas, or destructive sinusitis. *Sarcoidosis* - **Sarcoidosis** is a multi-system granulomatous disease, often affecting the lungs and lymph nodes, and sometimes the skin, eyes, and joints. - While it can cause some nasal symptoms, it generally **does not cause destructive sinonasal disease** with purulent and hemorrhagic drainage or severe glomerulonephritis with 4+ hematuria, and it is **not a vasculitis**.

Question 648: A 79-year-old woman is brought to the emergency department by her husband 20 minutes after losing consciousness. She was walking briskly with her husband when she collapsed suddenly. Her husband says that she regained consciousness after 1 minute. She has had episodes of mild chest pain for the past 2 months, especially when working in the garden. Physical examination shows a grade 3/6 systolic ejection murmur. The intensity of the murmur decreases with the handgrip maneuver and does not change with inspiration. Which of the following is the most likely cause of this patient's symptoms?

A. Infected fibrin aggregates on the tricuspid valve
B. Dystrophic calcification on the aortic valve (Correct Answer)
C. Sterile platelet thrombi on the mitral valve
D. Granulomatous nodules on the mitral valve
E. Cystic medial degeneration of the aortic root

Explanation: ***Dystrophic calcification on the aortic valve*** - The patient's age (79 years), history of **exertional chest pain**, **syncopal episode**, and a **systolic ejection murmur** are classic signs of **aortic stenosis**. - The decrease in murmur intensity with a **handgrip maneuver** (which increases afterload and reduces stroke volume in aortic stenosis) further supports this diagnosis, with **dystrophic calcification** being the most common cause of aortic stenosis in the elderly. *Infected fibrin aggregates on the tricuspid valve* - This description is consistent with **infective endocarditis** affecting the tricuspid valve, which typically occurs in intravenous drug users and presents with fever, chills, and symptoms of right-sided heart failure or septic emboli. - The patient's history and symptoms are not suggestive of infective endocarditis, and a tricuspid murmur would typically be loudest during inspiration (Carvallo's sign), which is not observed here. *Sterile platelet thrombi on the mitral valve* - This describes **nonbacterial thrombotic endocarditis** (NBTE), also known as marantic endocarditis, which is associated with hypercoagulable states, systemic lupus erythematosus, or advanced malignancy. - While it can lead to embolic events, NBTE typically does not cause significant valvular obstruction resulting in a prominent systolic ejection murmur and exertional symptoms like those described. *Granulomatous nodules on the mitral valve* - This type of valvular lesion is characteristic of **rheumatic heart disease**, which is a consequence of acute rheumatic fever. - While rheumatic heart disease commonly affects the mitral valve and can cause stenosis, the patient's age and acute presentation do not align with a primary diagnosis of new-onset severe rheumatic mitral valve disease, which usually manifests earlier in life or from long-standing disease. *Cystic medial degeneration of the aortic root* - This condition is associated with **aortic root dilation** and **aortic insufficiency** (regurgitation) rather than stenosis. - It would typically result in a diastolic murmur and symptoms related to volume overload, which are not present in this patient's presentation of a systolic ejection murmur and syncopal episodes.

Question 649: A 21-year-old woman is evaluated for dry cough, shortness of breath, and chest tightness which occur episodically 1–2 times per week. She notes that she develops significant shortness of breath when running, especially during cool weather. She also says she has 1 episode of coughing attacks during the night per month. She denies any history of tobacco use. Medical history is significant for atopic dermatitis as a child, although she now rarely experiences skin flares. Family history is non-contributory. Vital signs include a temperature of 37.0°C (98.6°F), blood pressure of 115/75 mm Hg, and heart rate of 88/min. Her pulse oximetry is 98% on room air. Physical examination reveals normal air entry and no wheezes. A chest X-ray is normal. Spirometry findings are within normal parameters. Which of the following is the best next step in the management of this patient’s condition?

A. Skin-prick testing
B. Methacholine challenge test (Correct Answer)
C. Sweat chloride test
D. Clinical observation without further evaluation
E. Ciliary studies

Explanation: ***Methacholine challenge test*** - This patient presents with classic symptoms of **asthma**, including episodic dry cough, shortness of breath, chest tightness, exercise-induced symptoms in cool weather, and nocturnal coughing. Given her normal spirometry but high suspicion for asthma, a **methacholine challenge test** is the most appropriate next step to confirm **bronchial hyperreactivity** [1]. - A positive methacholine challenge test (a decrease in FEV1 by ≥20% at a methacholine concentration of ≤16 mg/mL) would confirm the diagnosis of asthma [1]. *Skin-prick testing* - While helpful in identifying **allergic triggers** for asthma, skin-prick testing does not directly diagnose asthma itself or assess the degree of bronchial hyperreactivity [2]. - Identifying allergens is secondary to establishing the diagnosis of asthma and would be considered after a confirmed diagnosis, if allergic asthma is suspected [2]. *Sweat chloride test* - A **sweat chloride test** is used to diagnose **cystic fibrosis**, a condition typically presenting with recurrent respiratory infections, pancreatic insufficiency, and failure to thrive, none of which are described in this patient. - The patient's symptoms are episodic and responsive to specific triggers, unlike the persistent symptoms of cystic fibrosis. *Clinical observation without further evaluation* - Given the patient's classic and frequent symptoms, along with a significant impact on her daily life (exercise limitation, nocturnal symptoms), further evaluation is warranted to establish a definitive diagnosis and initiate appropriate treatment. - Without a diagnosis, the patient's symptoms could worsen or lead to complications, especially since her symptoms are suggestive of a treatable condition like asthma [3]. *Ciliary studies* - **Ciliary studies** are used to diagnose **primary ciliary dyskinesia (PCD)**, a rare genetic disorder characterized by chronic sinopulmonary infections, situs inversus, and infertility. - The patient's presentation with episodic symptoms and specific triggers is not consistent with the chronic, progressive nature of PCD.

Question 650: A 47-year-old woman presents to the emergency department with pain in her right knee. She states that the pain started last night and rapidly worsened, prompting her presentation for care. The patient has a past medical history of rheumatoid arthritis and osteoarthritis. Her current medications include corticosteroids, infliximab, ibuprofen, and aspirin. The patient denies any recent trauma to the joint. Her temperature is 99.5°F (37.5°C), pulse is 112/min, blood pressure is 100/70 mmHg, respirations are 18/min, and oxygen saturation is 98% on room air. On physical exam, you note erythema and edema of the right knee. There is limited range of motion due to pain of the right knee. Which of the following is the best initial step in management?

A. Conservative therapy
B. Broad spectrum antibiotics
C. Surgical drainage
D. Aspiration (Correct Answer)
E. CT scan

Explanation: ***Aspiration*** - The patient's presentation with acute, severe **monoarticular arthritis**, especially in the context of **immunosuppressive medications** (corticosteroids, infliximab) and a history of rheumatoid arthritis (which increases the risk), strongly suggests **septic arthritis**. - **Joint aspiration** is the most crucial initial diagnostic and therapeutic step to confirm the diagnosis (via synovial fluid analysis for cell count, gram stain, culture) and guide subsequent treatment immediately. *Conservative therapy* - This approach, involving rest, ice, compression, and elevation, is generally insufficient and potentially harmful when an **infectious etiology** like septic arthritis is suspected. - Delaying definitive diagnosis and treatment for septic arthritis can lead to rapid **joint destruction** and systemic complications. *Broad spectrum antibiotics* - While antibiotics are critical for treating septic arthritis, they should be initiated **after joint aspiration** and Gram stain results to optimize treatment based on the most likely pathogen. - Administering antibiotics prior to aspiration may **sterilize the joint fluid**, making culture results unreliable and hindering pathogen identification. *Surgical drainage* - **Surgical drainage** is indicated for septic arthritis that does not respond to conservative aspiration and antibiotics, or if there are extensive loculations or involvement of prosthetic joints. - It is not the **initial step** in management for acute septic arthritis unless complications are already present or aspiration is unsuccessful. *CT scan* - A CT scan can assess **bone or soft tissue damage** or detect foreign bodies, but it is not the initial or most definitive diagnostic tool for septic arthritis. - **Arthrocentesis** (aspiration) is superior for diagnosing joint infection by directly analyzing synovial fluid.

Question 651: A 53-year-old woman comes to the physician because of a 3-month history of intermittent severe left neck, shoulder, and arm pain and paresthesias of the left hand. The pain radiates to the radial aspect of her left forearm, thumb, and index finger. She first noticed her symptoms after helping a friend set up a canopy tent. There is no family history of serious illness. She appears healthy. Vital signs are within normal limits. When the patient extends and rotates her head to the left and downward pressure is applied, she reports paresthesias along the radial aspect of her left forearm and thumb. There is weakness when extending the left wrist against resistance. The brachioradialis reflex is 1+ on the left and 2+ on the right. The radial pulse is palpable bilaterally. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Carpal tunnel syndrome
B. Syringomyelia
C. Amyotrophic lateral sclerosis
D. C5-C6 disc herniation (Correct Answer)
E. Thoracic outlet syndrome

Explanation: ***C5-C6 disc herniation*** - The patient's symptoms of neck, shoulder, and arm pain, along with paresthesias radiating to the **radial aspect of the forearm, thumb, and index finger**, are consistent with **C6 dermatomal distribution**. - The positive **Spurling's maneuver** (extension, rotation, and downward pressure causing paresthesias) and decreased **brachioradialis reflex** (C5-C6 reflex) strongly suggest **cervical radiculopathy**, most likely due to a disc herniation affecting the C6 nerve root. *Carpal tunnel syndrome* - Characterized by **median nerve compression** at the wrist, causing paresthesias and pain primarily in the **thumb, index, middle, and radial half of the ring finger**, typically worsening at night. - Would not explain the neck, shoulder, or upper arm pain, or the positive Spurling's maneuver, which indicates a more proximal nerve root compression. *Syringomyelia* - A rare chronic progressive disorder where a **syrinx (fluid-filled cyst)** forms within the spinal cord, often presenting with a **cape-like distribution of sensory loss** (loss of pain and temperature sensation) over the shoulders and upper extremities. - Motor weakness can occur but the pain and paresthesia pattern, along with the positive Spurling's maneuver, are not typical for syringomyelia. *Amyotrophic lateral sclerosis* - A progressive neurodegenerative disease affecting **upper and lower motor neurons**, leading to widespread muscle weakness, atrophy, fasciculations, and spasticity. - It does not typically present with acute, radicular pain and paresthesias restricted to a specific dermatome, and sensory involvement is absent. *Thoracic outlet syndrome* - Involves compression of the **brachial plexus** and/or subclavian vessels in the thoracic outlet, causing neurogenic symptoms (pain, paresthesias) primarily in the **ulnar nerve distribution** and vascular symptoms (edema, discoloration). - The pain and paresthesias in the radial aspect of the hand and forearm, along with the specific reflex changes and positive neck maneuver, are not characteristic of thoracic outlet syndrome.

Question 652: A 43-year-old man presents to his primary care provider with concerns about general weakness and decreased concentration over the past several months. He reports constipation and unintentional weight loss of about 9.1 kg (20 lb). The past medical history is noncontributory. He works as a bank manager and occasionally drinks alcohol but does not smoke tobacco. Today, the vital signs include blood pressure 145/90 mm Hg, heart rate 60/min, respiratory rate 19/min, and temperature 36.6°C (97.9°F). On physical examination, the patient looks fatigued. His heart has a regular rate and rhythm, and his lungs are clear to auscultation bilaterally. Laboratory studies show: Calcium 14.5 mg/dL Phosphate 2.2 mg/dL Parathyroid hormone (PTH) 18 pg/mL Parathyroid hormone-related protein (PTHrP) 4 pmol/L Normal value: < 2 pmol/L Calcitriol 46 pg/mL Normal value: 25–65 pg/mL T3 120 ng/mL T4 10.2 mcg/dL Taking into account the clinical and laboratory findings, what is the most likely cause of this patient's hypercalcemia?

A. Hyperparathyroidism
B. Hypervitaminosis D
C. Malignancy (Correct Answer)
D. Thyrotoxicosis
E. Chronic kidney disease

Explanation: **Malignancy** - The patient exhibits significant **hypercalcemia (14.5 mg/dL)**, **low normal PTH (18 pg/mL)**, elevated **PTHrP (4 pmol/L)**, and **unintentional weight loss**, all of which are highly suggestive of **humoral hypercalcemia of malignancy (HHM)**. PTHrP acts like PTH, leading to increased calcium reabsorption from bones and kidneys. - The constellation of **weakness, decreased concentration, constipation**, and especially the **unexplained weight loss**, are classic paraneoplastic symptoms often associated with underlying malignancy, as opposed to primary endocrine disorders. *Hyperparathyroidism* - This condition is characterized by **elevated PTH levels** (typically > 65 pg/mL) in the presence of hypercalcemia, which is not seen here as the PTH is low normal. - While it causes hypercalcemia, it typically does **not present with elevated PTHrP** or significant unexplained weight loss. *Hypervitaminosis D* - This would present with **elevated calcitriol (1,25-dihydroxyvitamin D)** levels, but in this patient, calcitriol is within the normal range. - PTH levels would be suppressed, but **PTHrP would not be elevated**, which is a key differentiator in this case. *Thyrotoxicosis* - While hypercalcemia can sometimes be a feature of hyperthyroidism (thyrotoxicosis) due to increased bone turnover, it is usually **mild** and less severe than observed here (14.5 mg/dL). - The patient's **T3 and T4 levels are within the normal range**, ruling out hyperthyroidism as the cause of hypercalcemia. *Chronic kidney disease* - In chronic kidney disease, hypercalcemia is less common; **hypocalcemia is more typical** due to impaired vitamin D activation and phosphate retention. - While PTH can be elevated in secondary hyperparathyroidism of CKD, it would be in response to hypocalcemia, and **PTHrP would not be elevated**.

Question 653: A 49-year-old male presents to the emergency room with dyspnea and pulmonary edema. He reports that he has been smoking 2 packs a day for the past 25 years and has difficulty breathing during any sustained physical activity. His blood pressure is normal, and he reports a history of COPD. An echocardiogram was ordered as part of a cardiac workup. Which of the following would be the most likely finding?

A. Right ventricular hypertrophy (Correct Answer)
B. Left ventricular hypertrophy
C. Mitral valve insufficiency
D. Right atrial enlargement
E. Tricuspid regurgitation

Explanation: ***Right ventricular hypertrophy*** - The patient's history of **COPD** and heavy smoking leads to **pulmonary hypertension**, which increases the afterload on the right ventricle, causing it to hypertrophy. - While the patient has pulmonary edema, the normal blood pressure and history of COPD point toward **cor pulmonale**, where RVH is a hallmark, rather than primary left-sided heart failure. *Left ventricular hypertrophy* - **Left ventricular hypertrophy** is typically caused by systemic hypertension, aortic stenosis, or hypertrophic cardiomyopathy, none of which are strongly suggested here. - The patient's **normal blood pressure** makes LVH due to chronic hypertension less likely. *Mitral valve insufficiency* - **Mitral valve insufficiency** would primarily cause pulmonary edema due to backflow into the left atrium and pulmonary veins, but it is not directly linked to the patient's COPD and smoking history. - Clinical findings such as a **pansystolic murmur** and specific echocardiographic evidence of valvular dysfunction are not mentioned. *Right atrial enlargement* - **Right atrial enlargement** often accompanies right ventricular hypertrophy due to increased pressure and volume load, but RVH is the more direct consequence of chronic pulmonary hypertension. - While possible, it is secondary to the elevated right ventricular pressure and usually seen with significant RV remodeling. *Tricuspid regurgitation* - **Tricuspid regurgitation** can develop secondary to severe pulmonary hypertension and right ventricular dilation, but it is a consequence of RV dysfunction, not the primary finding. - The initial compensatory mechanism to increased afterload is **RV hypertrophy**, which precedes significant dilation and regurgitation.

Question 654: A 42-year-old man comes to the physician for the evaluation of episodic headaches involving both temples for 5 months. The patient has been taking acetaminophen, but it has not provided relief. He has also had double vision. Ophthalmic examination shows impaired peripheral vision bilaterally. Contrast MRI of the head shows a 14 x 10 x 8-mm intrasellar mass. Further evaluation is most likely to show which of the following findings?

A. Polyuria
B. Impotence (Correct Answer)
C. Galactorrhea
D. Macroglossia
E. Diarrhea

Explanation: ***Impotence*** - The patient's symptoms of **headaches**, **double vision**, and **impaired peripheral vision** with a **14x10x8 mm intrasellar mass** are consistent with a **prolactinoma**, the most common functional pituitary adenoma. - In **men**, hyperprolactinemia from prolactinomas most commonly presents with **hypogonadotropic hypogonadism**, causing **decreased libido**, **erectile dysfunction (impotence)**, and **infertility**. - Elevated prolactin suppresses **GnRH secretion**, leading to decreased **LH and FSH**, resulting in low testosterone levels and sexual dysfunction. - **Impotence is the most likely finding** in a male patient with a prolactinoma of this size. *Galactorrhea* - While galactorrhea is a classic manifestation of hyperprolactinemia in **women**, it is **rare in men** due to lack of developed breast tissue. - When it occurs in men, it is usually with very high prolactin levels and is less common than sexual dysfunction. - This would not be the "most likely" finding in a male patient with prolactinoma. *Polyuria* - Polyuria suggests **diabetes insipidus** from posterior pituitary dysfunction or compression of the pituitary stalk. - While large pituitary masses can cause this, it is not the primary manifestation of a **prolactinoma**. - More commonly seen with infiltrative lesions or after pituitary surgery. *Macroglossia* - **Macroglossia** is a feature of **acromegaly**, caused by excess **growth hormone** secretion from a GH-secreting pituitary adenoma. - The patient shows no other acromegalic features (frontal bossing, hand/foot enlargement, prognathism). - Not consistent with the clinical presentation of a prolactinoma. *Diarrhea* - Diarrhea is not a typical manifestation of pituitary adenomas including prolactinomas. - No direct pathophysiologic link between hyperprolactinemia and gastrointestinal symptoms exists.

Question 655: A 65-year-old man presents to the physician for the evaluation of increasing dyspnea and swelling of the lower extremities over the past year. He has no cough. He also complains of frequent awakenings at night and excessive daytime sleepiness. He has no history of a serious illness. He takes no medications other than zolpidem before sleep. He is a 35-pack-year smoker. His blood pressure is 155/95 mm Hg. His BMI is 37 kg/m2. Oropharyngeal examination shows a small orifice and an enlarged tongue and uvula. The soft palate is low-lying. The examination of the nasal cavity shows no septal deviation or polyps. Symmetric pitting edema is seen below the knee, bilaterally. The lungs are clear to auscultation. Echocardiography shows a mildly dilated right ventricle and an elevated systolic pulmonary artery pressure with no abnormalities of the left heart. A ventilation-perfusion scan shows no abnormalities. Which of the following is the most likely cause of this patient’s symptoms?

A. Chronic obstructive pulmonary disease
B. Pulmonary thromboembolism
C. Idiopathic pulmonary artery hypertension
D. Obstructive sleep apnea (Correct Answer)
E. Heart failure with a preserved ejection fraction

Explanation: ***Obstructive sleep apnea*** - This patient's symptoms of **dyspnea, lower extremity swelling, frequent nocturnal awakenings, and excessive daytime sleepiness**, in conjunction with **obesity (BMI 37)**, **hypertension**, and specific **oropharyngeal abnormalities** (small orifice, enlarged tongue and uvula, low-lying soft palate), are highly suggestive of **obstructive sleep apnea (OSA)**. - The echocardiographic findings of a **mildly dilated right ventricle** and **elevated systolic pulmonary artery pressure** (cor pulmonale) without left heart abnormalities are a common consequence of chronic hypoxia and hypercapnia associated with severe OSA. *Chronic obstructive pulmonary disease* - While the patient is a 35-pack-year smoker, the absence of a **cough** and **clear lungs to auscultation** make COPD less likely. - A Ventilation-Perfusion scan showing **no abnormalities** further decreases the likelihood of significant parenchymal lung disease often seen in COPD. *Pulmonary thromboembolism* - Although dyspnea is a symptom of pulmonary thromboembolism, the **insidious onset over a year** and the absence of acute symptoms like pleuritic chest pain or hemoptysis make it unlikely. - A **normal ventilation-perfusion scan** effectively rules out significant pulmonary thromboembolism. *Idiopathic pulmonary artery hypertension* - This diagnosis typically presents with **progressive dyspnea** and signs of **right heart failure**, similar to the patient's presentation. - However, the patient's severe **risk factors for OSA (obesity, oropharyngeal features)** provide a more specific and likely underlying cause for the observed pulmonary hypertension, rather than idiopathic. *Heart failure with a preserved ejection fraction* - This condition is characterized by dyspnea and edema with normal or near-normal left ventricular ejection fraction. - However, the echocardiogram specifically states **no abnormalities of the left heart**, which would typically show some signs of diastolic dysfunction in HFpEF. The primary findings point to right heart strain.

Question 656: A 30-year-old man presents to his primary care physician complaining of headaches. He states that over the past month he has been trying to study for an accounting exam, but he finds it increasingly more difficult to focus due to his headaches. He also complains of lower extremity muscle cramping. He has no significant past medical history and takes ibuprofen and acetaminophen as needed. The patient’s temperature is 98°F (36.7°C), blood pressure is 168/108 mmHg, and pulse is 75/min. Labs are obtained, as shown below: Serum: pH (VBG): 7.50 Na: 146 mEq/L K+: 3.2 mEq/L Cl-: 104 mEq/L HCO3-: 32 mEq/L Urea nitrogen: 20 mg/dL Creatinine: 1.1 mg/dL Glucose: 85 mg/dL An ultrasound reveals a hypoechoic lesion within the right adrenal gland. A 2 cm right-sided homogeneous adrenal mass is confirmed with computed tomography. Which of the following findings is associated with the patient’s most likely diagnosis?

A. Low plasma renin (Correct Answer)
B. High plasma renin
C. Low aldosterone level
D. High adrenocorticotropic hormone
E. Elevated 17-hydroxyprogesterone

Explanation: ***Low plasma renin*** - The patient's presentation of hypertension, hypokalemia, metabolic alkalosis, and an adrenal mass strongly points towards **primary hyperaldosteronism**, often caused by an aldosterone-producing adrenal adenoma (Conn's syndrome). - In primary hyperaldosteronism, the excess aldosterone production by the adrenal gland occurs **independently of the renin-angiotensin-aldosterone system**, leading to **suppression of renin secretion** due to negative feedback inhibition. - This is the key diagnostic finding: **low plasma renin with elevated aldosterone**, resulting in an elevated aldosterone-to-renin ratio. *High plasma renin* - This would be expected in **secondary hyperaldosteronism**, where a condition outside the adrenal gland (e.g., renal artery stenosis, renovascular hypertension) stimulates renin production, which then drives aldosterone synthesis. - Given the **adrenal mass** and **low potassium**, primary hyperaldosteronism is more likely, in which renin should be suppressed, not elevated. *Low aldosterone level* - The patient's symptoms (hypertension, hypokalemia, metabolic alkalosis, muscle cramping) are classic signs of **aldosterone excess**, not deficiency. - A **hypoechoic adrenal lesion** further supports the diagnosis of an aldosteronoma, which produces too much aldosterone. - Low aldosterone would cause hyperkalemia and hypotension, not the findings seen here. *High adrenocorticotropic hormone* - **ACTH primarily regulates cortisol production** and, to a lesser extent, adrenal androgens. It does not directly regulate aldosterone production in primary hyperaldosteronism. - Conditions like **Cushing's disease** (due to a pituitary adenoma) would cause high ACTH leading to high cortisol, presenting with different features such as central obesity, striae, and glucose intolerance. - Aldosterone secretion is primarily regulated by the renin-angiotensin system and serum potassium, not ACTH. *Elevated 17-hydroxyprogesterone* - Elevated 17-hydroxyprogesterone is characteristic of **congenital adrenal hyperplasia (CAH)**, particularly **21-hydroxylase deficiency**, the most common form. - CAH presents with different clinical features including **ambiguous genitalia** in females, **virilization**, salt wasting, or hypertension with hypokalemia in 11β-hydroxylase deficiency (not 21-hydroxylase deficiency). - This patient's presentation with an isolated adrenal adenoma and classic hyperaldosteronism findings does not suggest CAH.

Question 657: A 53-year-old female presents with worsening shortness of breath with activity. Physical exam reveals a diastolic murmur with an opening snap. The patient’s medical history is significant for a left hip replacement 10 years ago, and she vaguely recalls an extended period of illness as a child described as several severe episodes of sore throat followed by rash, fever, and joint pains. Administration of which of the following treatments at that time would have been most effective in reducing her risk of developing cardiac disease?

A. Ciprofloxacin
B. Vancomycin
C. Penicillin (Correct Answer)
D. Acyclovir
E. Aspirin

Explanation: ***Penicillin*** - The patient's childhood history of recurrent sore throats, rash, fever, and joint pains is highly suggestive of **rheumatic fever**, a sequela of untreated **Group A Streptococcal (GAS) pharyngitis**. - **Penicillin** is the most effective antibiotic for treating GAS pharyngitis and preventing subsequent rheumatic fever and its associated **valvular heart disease**, such as the **mitral stenosis** suggested by the diastolic murmur and opening snap. *Ciprofloxacin* - **Ciprofloxacin** is a fluoroquinolone antibiotic primarily used for gram-negative bacterial infections and some gram-positive infections, but it is **not the first-line treatment for GAS pharyngitis**. - Its broad spectrum and potential side effects make it unsuitable for routine use in preventing rheumatic fever. *Vancomycin* - **Vancomycin** is a powerful antibiotic reserved for serious infections caused by gram-positive bacteria, particularly **MRSA** and **_Clostridioides difficile_**. - While it has activity against GAS, it is **not appropriate for treating GAS pharyngitis** due to its reserved status for resistant infections, requirement for IV administration, and potential side effects, making it unsuitable for preventing rheumatic fever. *Acyclovir* - **Acyclovir** is an antiviral medication used to treat herpes simplex and varicella-zoster virus infections. - It has **no antibacterial activity** and would be completely ineffective in treating GAS pharyngitis or preventing rheumatic heart disease. *Aspirin* - **Aspirin** is an anti-inflammatory and antiplatelet agent used to manage symptoms of rheumatic fever like **arthralgia** and fever, but it **does not treat the underlying streptococcal infection**. - While it can alleviate some acute symptoms, it **does not prevent the development of permanent cardiac damage**.

Question 658: A 63-year-old man presents to the emergency department because of progressive difficulty with breathing. He has a history of diabetes, hypertension, and chronic bronchitis. He has been receiving medications to moderate his conditions and reports being compliant with his schedule. He reports a recent difficulty with tackling simple chores in the house. He has not been able to walk for more than 1 block over the past few days. His persistent cough has also been worsening with more formation of sputum. During his diagnosis of bronchitis, about a year ago, he had a 40-pack-year smoking history. The patient is in evident distress and uses his accessory muscles to breathe. The vital signs include: temperature 38.6°C (101.5°F), blood pressure 120/85 mm Hg, pulse 100/min, respiratory rate 26/min, and oxygen (O2) saturation 87%. A decrease in breathing sounds with expiratory wheezes is heard on auscultation of the lungs. The arterial blood gas (ABG) analysis shows: PCO2 60 mm Hg PO2 45 mm Hg pH 7.3 HCO3– 25 mEq/L Which of the following is the most appropriate next step in the treatment?

A. O2 supplementation (Correct Answer)
B. Aminophylline
C. Methylprednisolone
D. Albuterol
E. Levofloxacin

Explanation: ***O2 supplementation*** - The patient presents with **severe hypoxemia** (SpO2 87%, PO2 45 mm Hg), which is a life-threatening condition requiring immediate intervention. **Oxygen supplementation** is critical to improve tissue oxygenation and prevent organ damage. - The patient's presentation is consistent with an acute exacerbation of COPD, likely triggered by infection, where *initial management focuses on correcting hypoxemia* and *relieving bronchospasm*. - In COPD patients, **controlled oxygen therapy** is essential (target SpO2 88-92%) to avoid worsening CO2 retention, but with SpO2 of 87% and severe hypoxemia, oxygen remains the immediate priority. *Aminophylline* - Aminophylline is a **methylxanthine** with bronchodilatory effects, but its **narrow therapeutic index** and significant side effect profile (e.g., arrhythmias, seizures) make it a less favored first-line treatment for acute exacerbations of COPD. - While it can be considered in severe cases unresponsive to other therapies, it is not the most appropriate immediate next step given the patient's critical hypoxemia, where oxygen is paramount. *Methylprednisolone* - **Corticosteroids** like methylprednisolone are important in reducing inflammation during COPD exacerbations and improving lung function. - However, their full therapeutic effect takes hours to develop, and they do not immediately address the acute, life-threatening hypoxemia present in this patient. *Albuterol* - Albuterol is a **short-acting beta-agonist (SABA)**, which is crucial for *bronchodilation* in COPD exacerbations. It should be administered promptly to relieve airway obstruction. - While essential in managing the exacerbation, addressing the *severe hypoxemia* with oxygen takes immediate precedence to prevent organ damage, as albuterol will not directly increase oxygen saturation to a safe level alone. *Levofloxacin* - **Antibiotics** like levofloxacin are indicated when there's evidence of a bacterial infection triggering the COPD exacerbation, as suggested by increased sputum purulence and fever. - While important for treating the underlying infection, administering antibiotics does not immediately address the *acute respiratory distress* and *severe hypoxemia*, which are the most urgent concerns.

Question 659: A 66-year-old woman with hypertension comes to the physician because of crampy, dull abdominal pain and weight loss for 1 month. The pain is located in the epigastric region and typically occurs within the first hour after eating. She has had a 7-kg (15.4-lb) weight loss in the past month. She has smoked 1 pack of cigarettes daily for 20 years. Physical examination shows a scaphoid abdomen and diffuse tenderness to palpation. Laboratory studies including carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA), and lipase concentrations are within the reference range. Which of the following is the most likely cause of this patient's symptoms?

A. Focal wall thickening in the colon
B. Narrowing of the celiac artery (Correct Answer)
C. Decreased motility of gastric smooth muscle
D. Embolus in the superior mesenteric artery
E. Malignant mass at the head of the pancreas

Explanation: ***Narrowing of the celiac artery*** - This presentation, with postprandial epigastric pain, weight loss, and a history of hypertension and smoking, is highly suggestive of **chronic mesenteric ischemia**, often caused by **atherosclerotic narrowing** of the celiac or mesenteric arteries. - The pain occurring consistently within an hour of eating is known as "intestinal angina," as the increased metabolic demand of digestion is unmet by the compromised blood supply. *Focal wall thickening in the colon* - This finding would more likely point to conditions such as **diverticulitis**, **inflammatory bowel disease**, or **colorectal cancer**. - While these can cause abdominal pain and weight loss, the classic postprandial timing of the pain in the epigastric region is not typical. *Decreased motility of gastric smooth muscle* - This condition, known as **gastroparesis**, primarily causes symptoms like nausea, vomiting, early satiety, and bloating. - While weight loss can occur, the prominent **crampy, dull epigastric pain** that consistently appears after eating is not typical of gastroparesis. *Embolus in the superior mesenteric artery* - An **acute arterial embolus** typically causes sudden onset, severe, diffuse abdominal pain with signs of acute abdomen or shock, often leading to rapid bowel ischemia and infarction. - This patient's symptoms are chronic (lasting 1 month) and progressive, inconsistent with an acute embolic event. *Malignant mass at the head of the pancreas* - Pancreatic cancer often causes **epigastric pain**, **weight loss**, and sometimes **jaundice** if it obstructs the bile duct. - However, the absence of elevated CA 19-9 and the very specific postprandial nature of the pain point away from pancreatic cancer as the *most likely* cause, although it remains a differential for epigastric pain and weight loss.

Question 660: A 72-year-old man presents to his primary care physician for a wellness visit. He says that he has been experiencing episodes of chest pain and lightheadedness. Approximately 1 week ago he fell to the ground after abruptly getting up from the bed. Prior to the fall, he felt lightheaded and his vision began to get blurry. According to his wife, he was unconscious for about 5 seconds and then spontaneously recovered fully. He experiences a pressure-like discomfort in his chest and lightheadedness with exertion. At times, he also experiences shortness of breath when climbing the stairs. Medical history is significant for hypertension and hypercholesterolemia. He does not smoke cigarettes or drink alcohol. Cardiac auscultation demonstrates a systolic ejection murmur at the right upper border and a normal S1 and soft S2. Which of the following is most likely found in this patient?

A. Pulsus paradoxus
B. Decreased murmur intensity with squatting
C. Bicuspid aortic valve
D. High bounding pulses
E. Increased blood flow velocity through the aortic valve (Correct Answer)

Explanation: ***Increased blood flow velocity through the aortic valve*** - The patient's symptoms of **chest pain**, **lightheadedness (syncope)**, and **shortness of breath (dyspnea)** with exertion, along with a **systolic ejection murmur** at the right upper sternal border, are classic for **aortic stenosis**. - In aortic stenosis, the narrowed aortic valve orifice causes a significant increase in the **velocity of blood flow** through the valve to maintain cardiac output, which can be detected by Doppler echocardiography. *Pulsus paradoxus* - This is a decrease in systolic blood pressure by more than 10 mmHg during inspiration, typically associated with conditions like **cardiac tamponade** or **severe asthma/COPD**, not aortic stenosis. - It results from increased right ventricular filling and bowing of the interventricular septum into the left ventricle during inspiration, impairing left ventricular filling. *Decreased murmur intensity with squatting* - Squatting increases **venous return** and **systemic vascular resistance**, which typically *increases* the intensity of murmurs associated with forward flow lesions like aortic stenosis. - A *decrease* in murmur intensity with squatting is characteristic of **hypertrophic obstructive cardiomyopathy (HOCM)**, which becomes less obstructive with increased left ventricular filling. *Bicuspid aortic valve* - While a **bicuspid aortic valve** is a common *cause* of aortic stenosis, it is a congenital anomaly and not a *finding* directly observed in the physical exam or a physiological consequence in a 72-year-old presenting with acquired calcific aortic stenosis. - The question asks for what is *most likely found* in this patient *given the current presentation*, not the underlying etiology in an elderly patient where calcific degeneration is more prevalent. *High bounding pulses* - **High bounding pulses** (e.g., **Corrigan's pulse**) are characteristic of **aortic regurgitation**, where there is a wide pulse pressure due to rapid runoff from the aorta. - In aortic stenosis, the pulse is typically **parvus et tardus** (small and delayed) due to the obstruction to outflow.

Question 661: A 57-year-old man presents to his family physician for a routine exam. He feels well and reports no new complaints since his visit last year. Last year, he had a colonoscopy which showed no polyps, a low dose chest computerized tomography (CT) scan that showed no masses, and routine labs which showed a fasting glucose of 93 mg/dL. He is relatively sedentary and has a body mass index (BMI) of 24 kg/m^2. He has a history of using methamphetamines, alcohol (4-5 drinks per day since age 30), and tobacco (1 pack per day since age 18), but he joined Alcoholics Anonymous and has been in recovery, not using any of these for the past 7 years. Which of the following is indicated at this time?

A. Colonoscopy
B. Chest computerized tomography (CT) scan (Correct Answer)
C. Abdominal ultrasound
D. Chest radiograph
E. Fasting glucose

Explanation: ***Chest computerized tomography (CT) scan*** - This patient has a significant **smoking history** (1 pack per day since age 18 = **39 pack-years**) and is 57 years old, placing him in a high-risk group for **lung cancer**. - Annual low-dose CT screening for lung cancer is recommended for individuals aged 50-80 with a 20 pack-year smoking history who currently smoke or have quit within the past 15 years. - He meets all criteria: age 57, 39 pack-years, and quit only 7 years ago (within the 15-year window). - Since he had screening **last year** with no masses, this year's visit represents the appropriate time for his **annual follow-up screening**. *Colonoscopy* - The patient had a colonoscopy last year with **no polyps**, suggesting he is at average risk for colorectal cancer. - For individuals at average risk with normal findings, repeat screening colonoscopy is typically recommended every **10 years** (or every 5 years for flexible sigmoidoscopy), not annually. *Abdominal ultrasound* - One-time abdominal ultrasound screening for **abdominal aortic aneurysm (AAA)** is recommended for men aged 65-75 who have ever smoked. - This patient is only 57 years old and does not yet meet the age criteria for AAA screening. *Chest radiograph* - While a chest radiograph can identify some lung abnormalities, a **low-dose CT scan** is far more sensitive and specific for detecting early-stage lung cancer in high-risk populations. - Chest radiography is **not recommended** as a screening tool for lung cancer due to its lower sensitivity and lack of mortality benefit in trials. *Fasting glucose* - The patient had a **normal fasting glucose** of 93 mg/dL last year, and there are no new symptoms suggestive of diabetes. - For asymptomatic adults with normal glucose, diabetes screening is typically repeated every **3 years**. - Annual re-screening is not indicated without new risk factors or symptoms.

Question 662: A 59-year-old man presents to his primary care physician with a 5-month history of breathing difficulties. He says that he has been experiencing exertional dyspnea that is accompanied by a nonproductive cough. His past medical history is significant for a solitary lung nodule that was removed surgically 10 years ago and found to be benign. He works as a coal miner, does not smoke, and drinks socially with friends. His family history is significant for autoimmune diseases. Physical exam reveals fine bibasilar inspiratory crackles in both lungs, and laboratory testing is negative for antinuclear antibody and rheumatoid factor. Which of the following is associated with the most likely cause of this patient's symptoms?

A. Caplan's syndrome
B. Centrilobular emphysema
C. Restrictive lung physiology
D. Coal macules and fibrosis (Correct Answer)
E. Progressive massive fibrosis

Explanation: ***Coal macules and fibrosis*** (Keep the correct option at the top and the incorrect options in the order they are provided in the input) - The patient's history of working for a **coal mining company**, combined with **dyspnea**, nonproductive cough, and **bibasilar inspiratory crackles**, is highly suggestive of **coal workers' pneumoconiosis (CWP)**. - The initial stages of CWP are characterized by the formation of **coal macules (anthracosis)** and subsequent **fibrosis** in the lungs, leading to symptoms. *Caplan's syndrome* - This syndrome is a rare complication of coal workers' pneumoconiosis (or other pneumoconioses), characterized by the presence of **rheumatoid nodules** in the lungs. - The patient's **negative rheumatoid factor** makes Caplan's syndrome less likely, as it is typically associated with rheumatoid arthritis. *Centrilobular emphysema* - **Centrilobular emphysema** is predominantly caused by **smoking** and affects the central portion of the lobule. - The patient explicitly states he **does not smoke**, making this diagnosis unlikely. *Restrictive lung physiology* - While coal workers' pneumoconiosis *does* cause **restrictive lung physiology**, this option describes a physiological consequence rather than the underlying pathological cause. - This answer defines the *type* of lung disease, but not the specific **etiology** as requested by the question. *Progressive massive fibrosis* - **Progressive massive fibrosis (PMF)** represents an advanced stage of coal workers' pneumoconiosis, characterized by large fibrotic masses in the lungs. - While it's a possibility given the occupational exposure, the initial presentation of symptoms and findings are more consistent with the **earlier stages** of coal macule formation and fibrosis, which precedes PMF.

Question 663: A 75-year-old woman comes to the physician because of generalized weakness for 6 months. During this period, she has also had a 4-kg (8.8-lb) weight loss and frequent headaches. She has been avoiding eating solids because of severe jaw pain. She has hypertension and osteoporosis. She underwent a total left-sided knee arthroplasty 2 years ago because of osteoarthritis. The patient does not smoke or drink alcohol. Her current medications include enalapril, metoprolol, low-dose aspirin, and a multivitamin. She appears pale. Her temperature is 37.5°C (99.5°F), pulse is 82/min, and blood pressure is 135/80 mm Hg. Physical examination shows no abnormalities. Laboratory studies show: Hemoglobin 10 g/dL Mean corpuscular volume 87 μm3 Leukocyte count 8,500/mm3 Platelet count 450,000/mm3 Erythrocyte sedimentation rate 90 mm/h Which of the following is the most appropriate next step in management?

A. Temporal artery biopsy only
B. Intravenous methylprednisolone only
C. Intravenous methylprednisolone and temporal artery biopsy
D. Oral prednisone and temporal artery biopsy (Correct Answer)
E. Oral prednisone only

Explanation: ***Oral prednisone and temporal artery biopsy*** - The patient's symptoms (generalized weakness, weight loss, headaches, **jaw claudication**) and elevated **ESR** are highly suggestive of **giant cell arteritis**. Prompt initiation of high-dose oral corticosteroids (prednisone) is crucial to prevent irreversible vision loss. - A **temporal artery biopsy** is necessary to confirm the diagnosis, but treatment should not be delayed while awaiting the biopsy results. *Temporal artery biopsy only* - While a **temporal artery biopsy** is essential for diagnosis, delaying treatment until after the biopsy significantly increases the risk of permanent complications, particularly **vision loss**. - **Giant cell arteritis** is a medical emergency requiring immediate corticosteroid therapy. *Intravenous methylprednisolone only* - **Intravenous methylprednisolone** is typically reserved for cases with **severe vision loss** or other critical ischemic complications, which are not described here. - While treatment should be initiated immediately, an **oral corticosteroid** generally suffices for initial management in the absence of severe symptoms, and it still requires a follow-up **biopsy**. *Intravenous methylprednisolone and temporal artery biopsy* - As mentioned, **IV methylprednisolone** is usually for more severe, vision-threatening cases. For this patient's presentation, **oral prednisone** is the appropriate initial corticosteroid. - While both elements are part of management, the *route* of corticosteroid administration is typically oral for uncomplicated cases. *Oral prednisone only* - Initiating **oral prednisone** is appropriate to prevent complications like vision loss, but a definitive diagnosis requires a **temporal artery biopsy**. - Without a biopsy, long-term corticosteroid therapy without histologic confirmation could lead to unnecessary side effects or mask an alternative diagnosis.

Question 664: A 47-year-old woman comes to her primary care doctor because of a new, pruritic rash. She was gardening in her yard two days ago and now has an eczematous papulovesicular rash on both ankles. You also note a single, 5 mm brown lesion with a slightly raised border on her left thigh. You prescribe a topical corticosteroid for contact dermatitis. Which of the following is the appropriate next step for the thigh lesion?

A. Further questioning (Correct Answer)
B. Full thickness biopsy
C. Simple shave biopsy
D. Reassurance
E. Topical corticosteroid

Explanation: ***Further questioning*** - **Obtaining a thorough history** about the brown lesion is crucial to assess for features suspicious for melanoma or other skin cancers (**A**symmetry, **B**order irregularity, **C**olor variation, **D**iameter >6mm, **E**volving). - This step helps determine the urgency and type of subsequent diagnostic procedures, such as whether a biopsy is immediately needed and if so, what kind. *Full thickness biopsy* - A full-thickness biopsy, also known as an **excisional biopsy**, is generally reserved for lesions highly suspicious for melanoma where complete removal and accurate staging are desired. - Performing an invasive procedure without first gathering more information about the lesion's history and characteristics is premature. *Simple shave biopsy* - A shave biopsy samples only the superficial layers of the skin and is appropriate for lesions that are primarily epidermal and raised, such as **seborrheic keratoses** or **basal cell carcinomas** not suspected of deep invasion. - It is generally **contraindicated for pigmented lesions suspicious for melanoma**, as it may interfere with accurate staging if the lesion is malignant. *Reassurance* - Reassurance is inappropriate given the description of a **new, pigmented lesion with a slightly raised border**, which could indicate a potential malignancy. - All suspicious skin lesions warrant further investigation to rule out serious conditions. *Topical corticosteroid* - Topical corticosteroids are used to treat inflammatory skin conditions like eczema or contact dermatitis, which is the diagnosis for the patient's ankle rash. - Applying a corticosteroid to a **pigmented lesion of unknown etiology** is incorrect and potentially harmful, as it would not address a neoplastic process and could mask symptoms.

Question 665: A 45-year-old woman presents to her physician with a four-month history of headache. Her headache is nonfocal but persistent throughout the day without any obvious trigger. She was told that it was a migraine but has never responded to sumatriptan, oxygen, or antiemetics. She takes amlodipine for hypertension. She does not smoke. She denies any recent weight loss or constitutional symptoms. Her temperature is 98°F (36.7°C), blood pressure is 180/100 mmHg, pulse is 70/min, and respirations are 15/min. She is obese with posterior cervical fat pads and central abdominal girth. Her neurological exam is unremarkable. In her initial laboratory workup, her fasting blood glucose level is 200 mg/dL. The following additional lab work is obtained and is as follows: Serum: Na+: 142 mEq/L Cl-: 102 mEq/L K+: 4.1 mEq/L HCO3-: 24 mEq/L BUN: 20 mg/dL Glucose: 135 mg/dL Creatinine: 1.3 mg/dL Ca2+: 10.0 mg/dL AST: 8 U/L ALT: 8 U/L 24-hour urinary cortisol: 500 µg (reference range < 300 µg) Serum cortisol: 25 µg/mL (reference range 5-23 µg/dL) 24-hour low dose dexamethasone suppression test: Not responsive High dose dexamethasone suppression test: Responsive Adrenocorticotropin-releasing hormone (ACTH): 20 pg/mL (5-15 pg/mL) Imaging reveals a 0.5 cm calcified pulmonary nodule in the right middle lobe that has been present for 5 years but an otherwise unremarkable pituitary gland, mediastinum, and adrenal glands. What is the best next step in management?

A. Pituitary resection
B. CT-guided biopsy of the pulmonary nodule
C. Inferior petrosal sinus sampling (Correct Answer)
D. Pulmonary nodule resection
E. Repeat high dose dexamethasone suppression test

Explanation: ***Inferior petrosal sinus sampling*** - The patient exhibits clear signs of **Cushing's syndrome** (hypertension, obesity with central fat distribution, hyperglycemia, elevated cortisol, lack of suppression with low-dose dexamethasone). - The elevated ACTH and suppression with high-dose dexamethasone point towards **Cushing's disease** (pituitary ACTH overproduction). However, with an unremarkable pituitary MRI, **inferior petrosal sinus sampling (IPSS)** is crucial to differentiate ectopic ACTH production (e.g., from a bronchial carcinoid, lung nodule) from pituitary disease. *Pituitary resection* - This is a treatment for **Cushing's disease** (pituitary adenoma), but it should only be performed after definitive localization of the ACTH-producing tumor. - Since the pituitary gland appears unremarkable on imaging and the patient has a lung nodule, **IPSS** is needed to confirm the source of ACTH overexpression before surgery. *CT-guided biopsy of the pulmonary nodule* - While the patient has a calcified pulmonary nodule, it has been stable for 5 years and calcified, suggesting it is likely **benign**. - Without evidence that this nodule is the source of **ectopic ACTH production** (which IPSS would help determine), a biopsy is premature and may not yield a definitive answer for the Cushing's presentation. *Pulmonary nodule resection* - Resection is a treatment for **ectopic ACTH-producing tumors**, typically **carcinoid tumors** in the lung. - However, the nodule is calcified and stable, making it unlikely to be the cause of Cushing's syndrome, and further, the diagnosis of ectopic ACTH needs to be confirmed with **IPSS** before considering such an invasive procedure. *Repeat high dose dexamethasone suppression test* - The results already indicate responsiveness to the high-dose dexamethasone suppression test, suggesting a **pituitary source** of ACTH. - Repeating the test would not add more diagnostic value and would only delay the necessary localization studies like **IPSS** or imaging.

Question 666: A 23-year-old man presents to the emergency department brought in by police. He was found shouting at strangers in the middle of the street. The patient has no significant past medical history, and his only medications include a short course of prednisone recently prescribed for poison ivy exposure. His temperature is 77°F (25°C), blood pressure is 90/50 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. The patient is only wearing underwear, and he is occasionally mumbling angrily about the government. He appears to be responding to internal stimuli, and it is difficult to obtain a history from him. Which of the following is the next best step in management?

A. Haloperidol IM
B. Warmed IV normal saline and warm blankets (Correct Answer)
C. Lorazepam and discontinue steroids
D. Warm air recirculator
E. Risperidone and warm blankets

Explanation: ***Warmed IV normal saline and warm blankets*** - The patient's core body temperature of **77°F (25°C)** indicates severe **hypothermia**. The immediate priority is to rewarm the patient to prevent further physiological compromise. - **Warmed IV normal saline** and **warm blankets** are essential interventions for **passive external rewarming** and **active core rewarming**, helping to gradually increase the patient's body temperature and stabilize hemodynamic status. *Haloperidol IM* - While the patient exhibits agitation and psychotic-like symptoms, addressing severe **hypothermia** is the immediate life-saving priority. Administering an antipsychotic without first stabilizing core temperature could be dangerous. - Furthermore, **haloperidol** can have sedative effects that might mask the neurological signs of worsening hypothermia or other underlying conditions. *Lorazepam and discontinue steroids* - The patient's altered mental status and agitation are likely due to **hypothermia**, not necessarily an adverse effect of **prednisone** or an isolated psychiatric emergency requiring benzodiazepines. - Discontinuing **steroids** abruptly can lead to **adrenal insufficiency**, which could further complicate the patient's critical condition, especially in the context of stress from severe hypothermia. *Warm air recirculator* - A **warm air recirculator** (e.g., forced-air warming blanket) is a form of **active external rewarming**. While beneficial, it is often used in conjunction with or after initiating **active core rewarming** with warmed IV fluids in cases of severe hypothermia. - Relying solely on external rewarming might not be sufficient to rapidly correct **severe hypothermia** (core temperature < 28°C) and address associated **hemodynamic instability**. *Risperidone and warm blankets* - Similar to haloperidol, **risperidone** is an antipsychotic used for agitation and psychosis. However, the patient's primary and life-threatening issue is severe **hypothermia**. - While **warm blankets** are appropriate for rewarming, addressing the underlying cause of the patient's presentation (hypothermia) takes precedence over immediate pharmacological management of psychiatric symptoms.

Question 667: A 19-year-old man with a history of type 1 diabetes presents to the emergency department for the evaluation of a blood glucose level of 492 mg/dL. Laboratory examination revealed a serum bicarbonate level of 13 mEq/L, serum sodium level of 122 mEq/L, and ketonuria. Arterial blood gas demonstrated a pH of 6.9. He is admitted to the hospital and given bicarbonate and then started on an insulin drip and intravenous fluid. Seven hours later when his nurse is making rounds, he is confused and complaining of a severe headache. Repeat sodium levels are unchanged, although his glucose level has improved. His vital signs include a temperature of 36.6°C (98.0°F), pulse 50/min, respiratory rate 13/min and irregular, and blood pressure 177/95 mm Hg. What other examination findings would be expected in this patient?

A. Hypoglycemia
B. Pupillary constriction
C. Papilledema (Correct Answer)
D. Pancreatitis
E. Peripheral edema

Explanation: ***Papilledema*** - This patient's symptoms (confusion, severe headache, bradycardia, irregular respiration, hypertension) following treatment for **diabetic ketoacidosis (DKA)** are highly suggestive of **cerebral edema**. - **Papilledema** is a retinal finding resulting from increased intracranial pressure (ICP), which is a characteristic sign of cerebral edema. *Hypoglycemia* - While the patient's glucose level has improved, it is not described as being low enough to cause hypoglycemia, and the symptoms are more consistent with **increased ICP**. - Symptoms of hypoglycemia (e.g., tremors, sweating, hunger, anxiety) are different from the patient's current presentation of confusion and severe headache. *Pupillary constriction* - **Pupillary constriction** (miosis) is typically not associated with cerebral edema; instead, **pupillary dilation** (mydriasis) can occur with severe increase in ICP due to uncal herniation. - The combination of bradycardia, irregular respiration, and hypertension (Cushing's triad) is indicative of increased ICP, which would likely cause pupillary changes related to brainstem compression. *Pancreatitis* - Pancreatitis is a known complication of DKA, but it typically presents with **severe abdominal pain**, nausea, and vomiting, rather than cerebral symptoms. - Although the patient had DKA, the current neurological symptoms point directly to an intracranial process rather than an abdominal issue. *Peripheral edema* - **Peripheral edema** results from fluid accumulation in peripheral tissues and is not a direct consequence or expected finding in cerebral edema. - While fluid administration can cause some peripheral fluid retention, it typically does not lead to the acute neurological deterioration seen in this patient.

Question 668: A 25-year-old mother presents to her primary care physician for wrist pain. The patient recently gave birth to a healthy newborn at 40 weeks gestation. Beginning one week ago, she started having pain over her wrist that has steadily worsened. The patient notes that she also recently fell while walking and broke the fall with her outstretched arm. The patient is an accountant who works from home and spends roughly eight hours a day typing or preparing financial statements. Recreationally, the patient is a competitive cyclist who began a rigorous training routine since the birth of her child. The patient's past medical history is notable for hypothyroidism that is treated with levothyroxine. On physical exam, inspection of the wrist reveals no visible or palpable abnormalities. Pain is reproduced when the thumb is held in flexion, and the wrist is deviated toward the ulna. The rest of the patient's physical exam is within normal limits. Which of the following is the best next step in management?

A. Thumb spica cast
B. Rest and ibuprofen (Correct Answer)
C. Repositioning of the wrist while cycling
D. Wrist guard to be worn during work and at night
E. Radiography of the wrist

Explanation: ***Rest and ibuprofen*** - This patient presents with symptoms consistent with **De Quervain tenosynovitis**, characterized by pain over the radial side of the wrist, especially with activities involving thumb movement, and a positive **Finkelstein test** (pain with ulnar deviation of the wrist while the thumb is flexed). - Initial management for **De Quervain tenosynovitis** typically involves conservative measures like **rest**, **NSAIDs** (e.g., ibuprofen), and **splinting** to immobilize the thumb and wrist. *Thumb spica cast* - A **thumb spica cast** provides more rigid immobilization than typically needed for initial management of uncomplicated De Quervain tenosynovitis. - While immobilization is important, a full cast is usually reserved for cases that fail to improve with less restrictive measures, or for specific conditions like **scaphoid fractures**. *Repositioning of the wrist while cycling* - While proper ergonomics can help prevent occupational injuries, simply repositioning the wrist while cycling does not address the underlying **inflammation** of the **extensor pollicis brevis** and **abductor pollicis longus tendons**. - This measure alone is insufficient for treating an actively inflamed and painful tenosynovitis. *Wrist guard to be worn during work and at night* - A wrist guard or splint can be helpful for immobilization in De Quervain tenosynovitis, but the question asks for the **best next step** in management, which includes addressing the **inflammation** and **pain** in acute cases. - A wrist guard alone without **rest** or **anti-inflammatory medication** may not provide adequate relief or promote healing effectively. *Radiography of the wrist* - Radiography is useful for ruling out **bony injuries** (e.g., fractures), but the patient's presentation, particularly the positive Finkelstein test, strongly points to a **soft tissue inflammation** (tenosynovitis). - Given no reported acute trauma to the wrist itself (only falling on an outstretched hand, which would often localize pain differently for a fracture) and no visible deformity, X-rays are not typically the immediate next step for presumed **De Quervain tenosynovitis**.

Question 669: A 78-year-old man presents to the hospital because of shortness of breath and chest pain that started a few hours ago. 3 weeks ago he had surgery for a total hip replacement with a prosthesis. The patient was treated with prophylactic doses of low-molecular-weight heparin until he was discharged. He did not have a fever, expectoration, or any accompanying symptoms. He has a history of right leg deep vein thrombosis that occurred 5 years ago. His vital signs include: heart rate 110/min, respiratory rate 22/min, and blood pressure 150/90 mm Hg. There were no significant findings on the physical exam. Chest radiography was within normal limits. What is the most likely diagnosis?

A. Myocardial infarction
B. Pneumonia
C. Pneumothorax
D. Exacerbation of chronic lung disease
E. Pulmonary thromboembolism (Correct Answer)

Explanation: ***Pulmonary thromboembolism*** - The patient's recent **hip replacement surgery**, a history of **DVT**, and the acute onset of **shortness of breath** and **chest pain** strongly suggest a pulmonary embolism. - The elevated heart rate and respiratory rate, despite a normal chest X-ray and absence of fever/expectoration, align with the presentation of a **pulmonary embolism**. - **Normal chest X-ray** is common in PE, as radiography is often non-specific. - The **3-week post-operative period** represents peak risk for venous thromboembolism following orthopedic surgery. *Myocardial infarction* - While chest pain is present, the clinical context of **recent orthopedic surgery** and **prior DVT** makes PE more likely than MI. - MI would typically present with ECG changes and elevated cardiac biomarkers. - The absence of typical cardiovascular risk factors in the stem and the **tachypnea** more strongly suggest pulmonary rather than cardiac pathology. *Pneumonia* - **Absence of fever**, expectoration, and a **normal chest X-ray** effectively rule out pneumonia. - Pneumonia typically presents with cough, fever, productive sputum, and infiltrates on chest imaging. *Pneumothorax* - A pneumothorax would present with **sudden, sharp chest pain** and shortness of breath, often with diminished breath sounds and hyperresonance on the affected side. - However, the **normal chest X-ray** makes pneumothorax highly unlikely, as it would show visceral pleural line and absence of lung markings peripherally. *Exacerbation of chronic lung disease* - There is **no mention of a prior diagnosis of chronic lung disease** (e.g., COPD, asthma) in the patient's history. - The **acute, sudden onset** of symptoms in the context of recent surgery with known VTE risk factors is more indicative of an acute thrombotic event rather than an exacerbation of chronic disease.

Question 670: A 74-year-old man is rushed to the emergency department with left-sided weakness, facial deviation, and slurred speech. His wife first noticed these changes about an hour ago. The patient is having difficulty communicating. He can answer questions by nodding his head, and his wife is providing detailed information. He denies fever, loss of consciousness, head injury, bleeding, or seizures. Past medical history is significant for diabetes mellitus, hypertension, hyperlipidemia, ischemic heart disease, chronic kidney disease, and osteoarthritis. He had a heart attack 6 weeks ago. Baseline creatinine is 2.5 mg/dL, and he is not on hemodialysis. Medications include aspirin, clopidogrel, metoprolol, ramipril, rosuvastatin, and insulin detemir. Blood pressure is 175/95 mm Hg and the heart rate is 121/min. Muscle strength is decreased in both the upper and lower extremities on the left-side. A forehead sparing left sided facial weakness is also appreciated. An ECG reveals atrial fibrillation. An urgent head CT shows a hypodense area in the right parietal cortex with no indication of hemorrhage. Treatment with tissue plasminogen activator (tPA) is deferred due to which condition?

A. History of myocardial infarction 6 weeks ago (Correct Answer)
B. Chronic kidney disease
C. Atrial fibrillation on electrocardiogram
D. Raised blood pressures
E. Aspirin and clopidogrel use

Explanation: ***History of myocardial infarction 6 weeks ago*** - Recent **myocardial infarction (MI)**, especially within the last 3 months, is a relative contraindication for tPA due to the increased risk of hemorrhage. The patient's MI 6 weeks ago falls within this critical window. - While not an absolute contraindication, the increased risk of hemorrhagic complications from tPA outweighs potential benefits in this specific scenario. *Chronic kidney disease* - **Chronic kidney disease (CKD)** itself is not a contraindication to tPA administration. - The elevated creatinine and CKD stage do not directly increase the risk of hemorrhage from tPA in the absence of other bleeding diatheses. *Atrial fibrillation on electrocardiogram* - **Atrial fibrillation (AFib)** is a common cause of embolic stroke and does not contraindicate tPA. - In fact, identifying AFib helps confirm the likely cardioembolic etiology of the stroke, making tPA a potentially beneficial treatment if other contraindications are absent. *Raised blood pressures* - While BP above 185/110 mm Hg is an absolute contraindication for tPA, the patient's current BP of **175/95 mm Hg** can typically be managed pharmacologically to below the threshold before tPA administration. - **Hypertension** itself can be treated to enable tPA, it is not an intrinsic contraindication provided it can be lowered. *Aspirin and clopidogrel use* - Concurrent use of **antiplatelet agents** like aspirin and clopidogrel is not an absolute or relative contraindication for tPA. - The combination of antiplatelets does not significantly increase the risk of hemorrhage with tPA to the extent that it would prompt deferral.

Question 671: A 45-year-old woman presents to her primary care provider complaining of daytime drowsiness and fatigue. She reports that she can manage at most a couple of hours of work before needing a nap. She has also noted impaired memory and a 6.8 kg (15 lb) weight gain. She denies shortness of breath, chest pain, lightheadedness, or blood in her stool. At the doctor’s office, the vital signs include: pulse 58/min, blood pressure 104/68 mm Hg, and oxygen saturation 99% on room air. The physical exam is notable only for slightly dry skin. The complete blood count (CBC) is within normal limits. Which of the following is a likely additional finding in this patient?

A. Tremor
B. Anxiety
C. Hypercholesterolemia (Correct Answer)
D. Lid lag
E. Palpitations

Explanation: ***Hypercholesterolemia*** - The patient's symptoms of **fatigue, weight gain, impaired memory, daytime drowsiness, dry skin, and bradycardia** are classic for **hypothyroidism**. - **Hypothyroidism** leads to a decrease in the breakdown of **lipids**, resulting in elevated **LDL cholesterol and triglycerides**. *Tremor* - A **fine tremor** is commonly associated with **hyperthyroidism**, not hypothyroidism, due to sympathetic overactivity. - It is a sign of an **overactive metabolic state**, which is the opposite of the patient's presentation. *Anxiety* - While anxiety can be a symptom of many conditions, it is more typically associated with **hyperthyroidism** due to increased metabolic activity and sympathetic tone. - Patients with **hypothyroidism** tend to experience **depression, lethargy, and slowed mentation** rather than anxiety. *Lid lag* - **Lid lag** (Graefe's sign) is a classic ophthalmic sign of **hyperthyroidism**, often seen in **Graves' ophthalmopathy**. - It is caused by increased sympathetic stimulation of the **levator palpebrae superioris muscle**, not a feature of hypothyroidism. *Palpitations* - **Palpitations** are a common symptom of **hyperthyroidism** due to increased heart rate and contractility. - In contrast, **hypothyroidism** is usually associated with **bradycardia** and a *slowed heart rate*, as seen in this patient.

Question 672: A 48-year-old woman is transferred from her primary care physician's office to the emergency department for further evaluation of hypokalemia to 2.5 mEq/L. She was recently diagnosed with hypertension 2 weeks ago and started on medical therapy. The patient said that she enjoys all kinds of food and exercises regularly, but has not been able to complete her workouts as she usually does. Her temperature is 97.7°F (36.5°C), blood pressure is 107/74 mmHg, pulse is 80/min, respirations are 15/min, and SpO2 is 94% on room air. Her physical exam is unremarkable. Peripheral intravenous (IV) access is obtained. Her basic metabolic panel is obtained below. Serum: Na+: 135 mEq/L Cl-: 89 mEq/L K+: 2.2 mEq/L HCO3-: 33 mEq/L BUN: 44 mg/dL Glucose: 147 mg/dL Creatinine: 2.3 mg/dL Magnesium: 2.0 mEq/L What is the next best step in management?

A. Obtain an electrocardiogram (Correct Answer)
B. Obtain urine sodium and creatinine
C. Administer isotonic saline 1 liter via peripheral IV
D. Administer potassium chloride 40mEq via peripheral IV
E. Administer potassium bicarbonate 50mEq per oral

Explanation: ***Obtain an electrocardiogram*** - The patient has severe **hypokalemia** (K+ 2.2 mEq/L), which requires urgent assessment for cardiac complications before initiating treatment. - An **ECG is the mandatory first step** in severe hypokalemia (K+ <2.5 mEq/L) to evaluate for life-threatening arrhythmias and ECG changes including U waves, T wave flattening, ST depression, and QT prolongation. - The patient is **hemodynamically stable** with only mild symptoms (exercise intolerance), so immediate potassium administration is not required before obtaining an ECG. - ECG findings will guide the urgency and route of potassium repletion and determine the need for cardiac monitoring during treatment. *Administer potassium chloride 40mEq via peripheral IV* - While **IV potassium chloride** will be needed for repletion, it should be administered after ECG assessment in a stable patient. - IV potassium administration carries risks including phlebitis, infiltration, and potential cardiac complications if given too rapidly without monitoring. - In severe hypokalemia without cardiac arrest or documented life-threatening arrhythmias, obtaining an ECG first is standard practice. *Obtain urine sodium and creatinine* - Measuring **urine electrolytes** helps identify the cause of hypokalemia (likely diuretic-induced given recent hypertension treatment with metabolic alkalosis and hypochloremia). - However, this diagnostic workup should follow the immediate assessment and treatment of severe hypokalemia. - While useful for long-term management, it does not take priority over assessing cardiac risk with an ECG. *Administer potassium bicarbonate 50mEq per oral* - **Potassium bicarbonate** is contraindicated in this patient with **metabolic alkalosis** (HCO3- 33 mEq/L), as it would worsen the alkalosis. - The correct form for repletion in metabolic alkalosis is **potassium chloride**, which addresses both the hypokalemia and hypochloremia. - Oral repletion is also too slow for severe hypokalemia and may cause gastrointestinal side effects. *Administer isotonic saline 1 liter via peripheral IV* - While the patient shows signs of volume depletion (elevated BUN/Cr ratio, likely prerenal azotemia from diuretic use), the immediate priority is assessing the cardiac impact of severe hypokalemia. - **Isotonic saline** without potassium supplementation could potentially worsen hypokalemia through dilution and increased renal potassium excretion. - Volume resuscitation should be considered after ECG assessment and in conjunction with potassium repletion.

Question 673: A 22-year-old woman presents to the emergency department with a chief concern of shortness of breath. She was hiking when she suddenly felt unable to breathe and had to take slow deep breaths to improve her symptoms. The patient is a Swedish foreign exchange student and does not speak any English. Her past medical history and current medications are unknown. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 90% on room air. Physical exam is notable for poor air movement bilaterally and tachycardia. The patient is started on treatment. Which of the following best describes this patient's underlying pathology? FEV1 = Forced expiratory volume in 1 second FVC = Forced vital capacity DLCO = Diffusing capacity of carbon monoxide

A. Increased FVC
B. Increased FEV1
C. Increased FEV1/FVC
D. Decreased airway tone
E. Normal DLCO (Correct Answer)

Explanation: ***Normal DLCO*** - This patient presents with an acute exacerbation of what is likely **asthma**, showing symptoms of **shortness of breath**, **tachycardia**, poor air movement bilaterally, and improvement with slow deep breaths. **Asthma** characteristically affects the airways and not the alveoli, thus the **diffusing capacity of carbon monoxide (DLCO)**, which measures gas exchange across the alveolar-capillary membrane, would be expected to be normal. - In asthma, the primary problem is **bronchoconstriction** and **airway inflammation**, which restricts airflow but does not typically impair the diffusion of gases like carbon monoxide across the alveolar-capillary membrane. *Increased FVC* - **Forced vital capacity (FVC)** is often normal or even slightly reduced in asthma due to **air trapping** and early airway closure, not increased. - An increased FVC is usually not associated with obstructive lung diseases like asthma but could potentially be seen in conditions where lung volumes are pathologically large, which is not the case here. *Increased FEV1* - **Forced expiratory volume in 1 second (FEV1)** is typically **decreased** in obstructive lung diseases like asthma due to **airflow limitation**. - An increased FEV1 would indicate better-than-average expiratory flow, which contradicts the symptoms of shortness of breath and poor air movement in this patient. *Increased FEV1/FVC* - The **FEV1/FVC ratio** is characteristically **decreased** in obstructive lung diseases like asthma, indicating that a disproportionately smaller amount of air can be exhaled in the first second relative to the total forced vital capacity. - An increased FEV1/FVC ratio would be a sign of a restrictive lung disease or normal lung function, not an exacerbation of an obstructive process. *Decreased airway tone* - The underlying pathology in asthma is typically **bronchoconstriction**, which means an **increased airway tone** and narrowing of the airways, rather than decreased. - Decreased airway tone would imply bronchodilation, which would alleviate, not cause, the patient's symptoms of shortness of breath and poor air movement.

Question 674: A 34-year-old man presents with multiple painful ulcers on his penis. He says that the ulcers all appeared suddenly at the same time 3 days ago. He reports that he is sexually active with multiple partners and uses condoms inconsistently. He is afebrile and his vital signs are within normal limits. Physical examination reveals multiple small shallow ulcers with an erythematous base and without discharge. There is significant inguinal lymphadenopathy present. Which of the following is the most likely etiologic agent of this patient’s ulcers?

A. Human papillomavirus
B. Chlamydia trachomatis
C. Treponema pallidum
D. Haemophilus ducreyi
E. Herpes simplex virus (Correct Answer)

Explanation: ***Herpes simplex virus*** - This patient's presentation of multiple **painful shallow ulcers** with an **erythematous base** that appeared suddenly, along with significant **inguinal lymphadenopathy**, is highly consistent with **genital herpes** caused by HSV. - HSV lesions typically appear in **clusters** and are often painful, in contrast to the single, painless chancre of syphilis. *Human papillomavirus* - HPV infection primarily causes **genital warts (condyloma acuminata)**, which are usually soft, fleshy, and non-painful growths, not ulcers. - While HPV can cause epithelial lesions, they are not typically described as painful, shallow ulcers. *Chlamydia trachomatis* - *Chlamydia trachomatis* typically causes **urethritis**, cervicitis, or **lymphogranuloma venereum (LGV)**, the latter of which involves painful inguinal lymphadenopathy and sometimes secondary ulcers, but the initial lesion is often a small, transient, painless ulcer or papule. - The sudden onset of multiple painful shallow ulcers is not characteristic of typical *C. trachomatis* infections. *Treponema pallidum* - *Treponema pallidum* (syphilis) causes a **painless, firm, singular chancre** in the primary stage, which is very different from the multiple painful shallow ulcers described. - While syphilis can cause lymphadenopathy, the ulcer itself is usually not painful. *Haemophilus ducreyi* - *Haemophilus ducreyi* causes **chancroid**, which presents as **deep, painful ulcers** with ragged, undermined borders and frequently causes **suppurative (pus-forming) inguinal lymphadenopathy**. - Although painful ulcers are present, the description of "shallow ulcers" with an erythematous base is less typical for chancroid.

Question 675: A 35-year-old woman presents to the clinic for a several-month history of heat intolerance. She lives in a small apartment with her husband and reports that she always feels hot and sweaty, even when their air conditioning is on high. On further questioning, she's also had a 4.5 kg (10 lb) unintentional weight loss. The vital signs include: heart rate 102/min and blood pressure 150/80 mm Hg. The physical exam is notable for warm and slightly moist skin. She also exhibits a fine tremor in her hands when her arms are outstretched. Which of the following laboratory values is most likely low in this patient?

A. Triiodothyronine (T3)
B. Thyroxine (T4)
C. Calcitonin
D. Glucose
E. Thyroid-stimulating hormone (Correct Answer)

Explanation: ***Thyroid-stimulating hormone*** - The patient's symptoms (heat intolerance, weight loss, tachycardia, hypertension, warm/moist skin, fine tremor) are classic for **hyperthyroidism**. - In primary hyperthyroidism, the thyroid gland overproduces T3 and T4, which **negatively feedbacks** on the pituitary, leading to a **low TSH** level. *Triiodothyronine (T3)* - In hyperthyroidism, **T3 levels are typically elevated**, not low, as the thyroid gland is overactive. - T3 is one of the primary thyroid hormones responsible for the patient's metabolic symptoms. *Thyroxine (T4)* - In hyperthyroidism, **T4 levels are typically elevated**, not low, alongside T3. - T4 is the other key thyroid hormone produced in excess, contributing to the hypermetabolic state. *Calcitonin* - Calcitonin is a hormone involved in **calcium regulation** and is produced by the parafollicular C cells of the thyroid gland. - Its levels are not directly affected by hyperthyroidism and would not be consistently low in this scenario. *Glucose* - While hyperthyroidism can affect glucose metabolism, causing increased gluconeogenesis and glycogenolysis, it more commonly leads to **elevated or normal glucose levels**, not consistently low levels. - Low glucose would typically suggest other conditions like insulinoma or adrenal insufficiency.

Question 676: A 64-year-old man presents with a complaint of prominent stiffness in his legs which is causing a difficulty in ambulation. He is not able to relax his trunk area and has frequent, painful muscle spasms. He denies diplopia, swallowing difficulties, and urinary or bowel problems. He has a medical history of stage IV lung cancer. He has received 4 sessions of chemotherapy. The neurological examination reveals an increased generalized muscle tone. He has a spastic gait with exaggerated lumbar lordosis. The needle electromyography (EMG) studies show continuous motor unit activity that persists at rest. Which paraneoplastic antibody is most likely associated with the symptoms of this patient?

A. Anti-Hu
B. Anti-Ri
C. Glutamic acid decarboxylase
D. Voltage-gated calcium channel
E. Amphiphysin (Correct Answer)

Explanation: ***Amphiphysin*** - The patient's symptoms of **stiffness in the legs**, inability to relax the trunk, **painful muscle spasms**, and **continuous motor unit activity at rest** are characteristic of **Stiff-Person Syndrome (SPS)**. - While Glutamic Acid Decarboxylase (GAD) is the most common antibody in classic SPS, **Amphiphysin antibodies** are strongly associated with **paraneoplastic SPS**, particularly in the context of **lung cancer** (as seen in this patient). *Anti-Hu* - **Anti-Hu antibodies** are primarily associated with paraneoplastic **encephalomyelitis** and **sensory neuronopathy**. - Symptoms usually include multifocal neurological deficits, often with significant sensory loss, which is not the prominent feature in this case. *Anti-Ri* - **Anti-Ri antibodies** are linked to **paraneoplastic opsoclonus-myoclonus syndrome**, characterized by rapid, irregular eye movements (opsoclonus) and involuntary muscle jerks (myoclonus). - These specific eye and movement disorders are not observed in the patient's presentation. *Glutamic acid decarboxylase* - Antibodies to **glutamic acid decarboxylase (GAD)** are the most common autoantibodies found in **classic Stiff-Person Syndrome (SPS)**. - However, in the context of a **paraneoplastic syndrome associated with lung cancer**, amphiphysin antibodies are a more specific and likely cause. *Voltage-gated calcium channel* - Antibodies to **voltage-gated calcium channels** are characteristic of **Lambert-Eaton Myasthenic Syndrome (LEMS)**. - LEMS typically presents with **proximal muscle weakness** that improves with activity and autonomic dysfunction, differentiating it from the spasticity and muscle spasms seen here.

Question 677: A 55-year-old woman sees her family doctor for a follow-up appointment to discuss her imaging studies. She previously presented with chest pain and shortness of breath for the past 2 months. Her CT scan shows a 3.5 cm mass in the lower lobe of her right lung. The mass has irregular borders. Saddle/hilar lymph nodes are enlarged. No distant metastases are identified with PET imaging. The patient has been a smoker for over 35 years (1.5 packs per day), but she has recently quit. This patient is referred to the Pulmonary Diseases Center. What is the most effective step in appropriately managing her case?

A. Paclitaxel
B. CT scan in 3 months
C. Sputum cytology
D. Radiotherapy
E. Tissue biopsy (Correct Answer)

Explanation: ***Tissue biopsy*** - A **tissue biopsy** is the most effective step for definitive diagnosis of lung cancer, which is strongly suspected given the patient's smoking history, CT findings (irregular mass, enlarged hilar lymph nodes), and symptoms. - This procedure allows for **histopathological examination** to confirm malignancy, determine the specific type of lung cancer, and guide further treatment decisions. *Paclitaxel* - **Paclitaxel** is a chemotherapy agent used in the treatment of various cancers, including lung cancer, but it is not the initial diagnostic step. - Chemotherapy is administered *after* a definitive diagnosis is made and the stage of cancer is determined. *CT scan in 3 months* - Repeating a **CT scan in 3 months** would delay the diagnosis and treatment of a potentially aggressive cancer, which is not appropriate given the high suspicion of malignancy. - While follow-up imaging is used in surveillance, it is not the appropriate first step for a suspicious new mass in a high-risk patient. *Sputum cytology* - **Sputum cytology** can sometimes detect lung cancer cells, especially in central tumors, but its sensitivity is generally low (around 30-50%) compared to tissue biopsy. - Given the patient's 3.5 cm mass with irregular borders and enlarged lymph nodes, a more definitive diagnostic method is required. *Radiotherapy* - **Radiotherapy** is a treatment modality for lung cancer, either curative in early stages or palliative in advanced disease. - Similar to chemotherapy, it is administered *after* a definitive diagnosis is established through biopsy and the disease stage and treatment goals are determined.

Question 678: A 53-year-old woman presents to her primary care provider complaining of fatigue for the last several months. She reports feeling tired all day, regardless of her quality or quantity of sleep. On further questioning, she has also noted constipation and a 4.5 kg (10 lb) weight gain. She denies shortness of breath, chest pain, lightheadedness, or blood in her stool. At the doctor’s office, the vital signs include: pulse 58/min, blood pressure 104/68 mm Hg, and oxygen saturation 98% on room air. The physical exam shows only slightly dry skin. The complete blood count (CBC) is within normal limits. Which of the following best describes the pathogenesis of this patient's condition?

A. Chronic blood loss
B. Bone marrow failure
C. Autoimmune attack on endocrine tissue (Correct Answer)
D. Nutritional deficiency
E. Iatrogenesis

Explanation: ***Autoimmune attack on endocrine tissue*** - The patient's symptoms of **fatigue**, **constipation**, **weight gain**, **bradycardia**, and dry skin are classic signs of **hypothyroidism**. - The most common cause of hypothyroidism in developed countries is **Hashimoto's thyroiditis**, an **autoimmune disease** where the immune system attacks the thyroid gland (endocrine tissue). *Chronic blood loss* - This typically leads to **iron deficiency anemia**, which would likely manifest as a **low hemoglobin** or hematocrit on the CBC. - While fatigue can be a symptom, constipation and weight gain are not typical presentations of chronic blood loss, and the CBC is within normal limits. *Bone marrow failure* - Bone marrow failure would result in **pancytopenia** (low red blood cells, white blood cells, and platelets), which would be evident on the CBC. - The patient's CBC is normal, ruling out this condition as the primary cause of her symptoms. *Nutritional deficiency* - While certain nutritional deficiencies (e.g., **Vitamin B12 deficiency**) can cause fatigue and constipation, they do not typically cause weight gain or bradycardia. - The patient's symptom constellation points more specifically to an endocrine disorder. *Iatrogenesis* - Iatrogenic causes refer to conditions resulting from medical intervention or treatment. - There is no information in the vignette to suggest any recent medical procedures or medications that would account for this specific constellation of symptoms.

Question 679: A 43-year-old man is brought to the emergency department because of severe retrosternal pain radiating to the back and left shoulder for 4 hours. The pain began after attending a farewell party for his coworker at a local bar. He had 3–4 episodes of nonbilious vomiting before the onset of the pain. He has hypertension. His father died of cardiac arrest at the age of 55 years. He has smoked one pack of cigarettes daily for the last 23 years and drinks 2–3 beers daily. His current medications include amlodipine and valsartan. He appears pale. His temperature is 37° C (98.6° F), pulse is 115/min, and blood pressure is 90/60 mm Hg. There are decreased breath sounds over the left base and crepitus is palpable over the thorax. Abdominal examination shows tenderness to palpation in the epigastric region; bowel sounds are normal. Laboratory studies show: Hemoglobin 16.5 g/dL Leukocyte count 11,100/mm3 Serum Na+ 133 mEq/L K+ 3.2 mEq/L Cl- 98 mEq/L HCO3- 30 mEq/L Creatinine 1.4 mg/dL An ECG shows sinus tachycardia with left ventricular hypertrophy. Intravenous fluid resuscitation and antibiotics are begun. Which of the following is the most appropriate test to confirm the diagnosis in this patient?

A. Aortography
B. Transthoracic echocardiography
C. Abdominal ultrasound
D. CT scan of the chest (Correct Answer)
E. Esophagogastroduodenoscopy

Explanation: ***CT scan of the chest*** - This patient's presentation of **severe retrosternal pain after forceful vomiting** (Mackler's triad: vomiting, chest pain, subcutaneous emphysema) strongly suggests **Boerhaave syndrome** (spontaneous esophageal perforation). - The presence of **subcutaneous crepitus** (indicating pneumomediastinum) and **decreased breath sounds** (pleural effusion) are key findings. - **CT scan of the chest with oral contrast is the gold standard** for diagnosing esophageal perforation, demonstrating **pneumomediastinum, pleural effusion, esophageal wall thickening**, and extravasation of contrast. - CT is **highly sensitive (>90%) and specific**, non-invasive, and provides comprehensive evaluation of the mediastinum and pleural spaces. *Esophagogastroduodenoscopy* - While EGD can directly visualize esophageal mucosa, it is **relatively contraindicated** in suspected acute esophageal perforation. - Insufflation during endoscopy risks **extending the perforation** and worsening mediastinal contamination. - EGD may be considered after CT confirmation for therapeutic intervention or if diagnosis remains unclear, but is **not the initial confirmatory test**. *Aortography* - **Aortography** is used to diagnose aortic dissection, which can present with retrosternal pain radiating to the back. - However, aortic dissection typically presents with **sudden tearing pain** without preceding vomiting, and would not explain the **crepitus** or timing after vomiting episodes. - The clinical picture here is classic for esophageal perforation, not aortic pathology. *Transthoracic echocardiography* - **TTE** is useful for cardiac evaluation and can detect some aortic pathologies or pericardial effusion. - It **cannot visualize the esophagus or mediastinum** adequately to diagnose esophageal perforation. - While useful in ruling out cardiac causes of chest pain, it does not address the primary diagnosis suggested by this presentation. *Abdominal ultrasound* - **Abdominal ultrasound** evaluates intra-abdominal organs and free fluid but **cannot assess the esophagus or mediastinum**. - It would miss the diagnosis of esophageal perforation entirely, as the pathology is located in the **thorax**, not the abdomen. - Not useful for this clinical presentation despite epigastric tenderness.

Question 680: A 57-year-old man presents to his primary care provider with progressive right foot swelling, redness, and malaise. He reports seeing a blister on his forefoot several months ago after he started using new work boots. He has dressed the affected area daily with bandages; however, healing has not occurred. He has a history of type 2 diabetes mellitus and stage 2 chronic kidney disease. He has smoked 20 to 30 cigarettes daily for the past 25 years. Vital signs are a temperature of 38.1°C (100.58°F), blood pressure of 110/70 mm Hg, and pulse of 102/minute. On physical examination, there is a malodorous right foot ulcer overlying the first metatarsophalangeal joint. Fluctuance and erythema extend 3 cm beyond the ulcer border. Moderate pitting edema is notable over the remaining areas of the foot and ankle. Which of the following is the best initial step for this patient?

A. Minor amputation
B. Graded compression stockings
C. Antibiotics and supportive care (Correct Answer)
D. Superficial swabs
E. Endovascular intervention

Explanation: ***Antibiotics and supportive care*** - The patient presents with clear signs of **infection**, including fever, tachycardia, local erythema extending beyond the ulcer, fluctuance, and a malodorous ulcer, warranting immediate initiation of **empiric broad-spectrum antibiotics**. - His history of **diabetes mellitus** and long-standing ulcer makes him highly susceptible to serious foot infections, including potential osteomyelitis, which requires prompt medical management to prevent progression and sepsis. - **Supportive care** including wound care, glycemic control, and hemodynamic monitoring is essential alongside antibiotics. *Minor amputation* - While amputation might be considered in severe, limb-threatening infections or cases with extensive non-viable tissue, it is an **invasive procedure** and premature as an initial step when less invasive medical management has not yet been attempted. - **Initial medical management** with antibiotics is crucial to control the infection before considering surgical interventions like amputation. *Graded compression stockings* - **Compression therapy** is typically used to manage chronic venous insufficiency or lymphedema, where the primary issue is venous hypertension or lymphatic fluid accumulation. - In this patient, the prominent issue is an **active infection** with systemic signs, making compression stockings inappropriate as an initial intervention, as they do not address the infection and could potentially worsen tissue perfusion in the setting of arterial disease. *Superficial swabs* - Superficial swabs of ulcers are **unreliable** for identifying causative pathogens in deep-seated diabetic foot infections, as they typically only detect colonizing organisms rather than true pathogens. - While appropriate **deep tissue cultures or bone biopsy** may be obtained to guide targeted therapy, empiric broad-spectrum antibiotics should be initiated immediately in a patient with systemic signs of infection rather than delaying treatment pending culture results. - The best initial step is to start antibiotics first, with cultures obtained concurrently or shortly thereafter. *Endovascular intervention* - **Endovascular intervention** (e.g., angioplasty, stenting) addresses peripheral arterial disease (PAD) by improving blood flow to the limb, which is important for long-term wound healing in ischemic ulcers. - However, the immediate priority in this patient is to **control the active infection**, which is manifesting with systemic inflammatory response. Revascularization may be considered later to aid healing once the infection is stabilized, as performing vascular procedures during acute infection carries increased risks of complications.

Question 681: A 40-year-old man comes to the physician because of weight gain over the past 3 months. During this period, he has gained 10 kg (22 lb) unintentionally. He also reports decreased sexual desire, oily skin, and sleeping difficulties. There is no personal or family history of serious illness. He has smoked one pack of cigarettes daily for the past 10 years. The patient appears lethargic. His temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 150/90 mm Hg. Physical examination shows central obesity, acne, and thin, easily bruisable skin with stretch marks on the abdomen. There is darkening of the mucous membranes and the skin creases. Examination of the muscles shows atrophy and weakness of proximal muscle groups. His serum glucose concentration is 240 mg/dL. Which of the following findings would most likely be present on imaging?

A. Pituitary microadenoma (Correct Answer)
B. Decreased thyroid size
C. Multiple kidney cysts
D. Kidney tumor
E. Adrenal carcinoma

Explanation: ***Pituitary microadenoma*** * The patient's symptoms, including **weight gain, central obesity, oily skin, acne, thin and easily bruisable skin with stretch marks, proximal muscle weakness, hypertension, and hyperglycemia**, are classic for **Cushing's syndrome**. * A common cause of Cushing's syndrome is **Cushing's disease**, which is caused by an **ACTH-secreting pituitary adenoma** (often a microadenoma). *Decreased thyroid size* * **Decreased thyroid size** would be associated with conditions like **atrophic thyroiditis** or **iodine deficiency**, typically leading to **hypothyroidism**. * **Hypothyroidism** would present with **weight gain** and **fatigue**, but not with **hypertension, hyperglycemia, central obesity, skin bruising, or proximal muscle weakness** as seen in this patient. *Multiple kidney cysts* * **Multiple kidney cysts** are characteristic of **polycystic kidney disease**, which can cause **hypertension** and sometimes **renal failure**. * However, polycystic kidney disease does not typically cause **central obesity, skin changes (bruising, stretch marks, acne), proximal muscle weakness, or hyperglycemia** seen in this patient. *Kidney tumor* * A **kidney tumor** (e.g., **renal cell carcinoma**) can cause **hypertension** and **weight loss** but is not associated with the full spectrum of symptoms presented here like **central obesity, skin fragility, stretch marks, muscle atrophy, or hyperglycemia**. * Some kidney tumors can produce **erythropoietin** leading to **polycythemia**, but not the endocrine features of Cushing's syndrome. *Adrenal carcinoma* * While an **adrenal carcinoma** can cause Cushing's syndrome by directly producing **cortisol**, it is typically a **large tumor** visible on imaging and often presents with more rapid and severe symptom onset. * The presence of **skin darkening (hyperpigmentation)** in this patient, due to increased ACTH stimulation of melanocytes, suggests an **ACTH-dependent Cushing's syndrome**, making a pituitary adenoma more likely than a primary adrenal tumor which would suppress ACTH.

Question 682: A 26-year-old woman comes to the physician for a pre-employment examination. She has no complaints. She has a history of polycystic ovarian syndrome. She exercises daily and plays soccer recreationally on the weekends. Her mother was diagnosed with hypertension at a young age. She does not smoke and drinks 2 glasses of wine on the weekends. Her current medications include an oral contraceptive pill and a daily multivitamin. Her vital signs are within normal limits. Cardiac examination shows a grade 1/6 decrescendo diastolic murmur heard best at the left sternal border. Her lungs are clear to auscultation bilaterally. Peripheral pulses are normal and there is no lower extremity edema. An electrocardiogram shows sinus rhythm with a normal axis. Which of the following is the most appropriate next step in management?

A. Exercise stress test
B. No further testing
C. CT scan of the chest with contrast
D. Transthoracic echocardiogram (Correct Answer)
E. X-ray of the chest

Explanation: ***Transthoracic echocardiogram*** - A **grade 1/6 decrescendo diastolic murmur** heard best at the **left sternal border** is consistent with **aortic regurgitation** and warrants further investigation with a **transthoracic echocardiogram** to evaluate for potential cardiac abnormalities, such as **bicuspid aortic valve** or **aortic regurgitation**, which can be congenital and lead to complications. - Given the patient's young age, active lifestyle, and family history of hypertension, even a subtle cardiac finding should be thoroughly investigated to rule out underlying structural heart disease. - **All diastolic murmurs are pathological** and require imaging evaluation. *Exercise stress test* - An **exercise stress test** is typically used to evaluate **ischemic heart disease** or exercise-induced arrhythmias, neither of which are suggested by the patient's presentation or murmur. - It would not provide diagnostic information regarding the **etiology of a diastolic murmur**. *No further testing* - A **diastolic murmur** is almost always pathological and should be further investigated, even if the patient is asymptomatic. - Ignoring a diastolic murmur could lead to delayed diagnosis and treatment of a potentially serious underlying cardiac condition. *CT scan of the chest with contrast* - A **CT scan of the chest** is not the primary imaging modality for evaluating heart murmurs. - It is more commonly used for evaluating pulmonary diseases, aortic aneurysms, or aortic dissection, none of which are indicated here. *X-ray of the chest* - A **chest X-ray** can show gross cardiac enlargement or pulmonary congestion but will not provide the detailed anatomical and functional information needed to diagnose the cause of a diastolic murmur. - It has low sensitivity for diagnosing specific valvular abnormalities.

Question 683: An obese 37-year-old woman is brought to the emergency department 2 hours after the onset of weakness in her left arm and leg. She fell from the stairs the day prior but did not have any loss of consciousness or nausea after the fall. She travels to Asia regularly on business; her last trip was 4 days ago. She has no history of serious illness. Her only medication is an oral contraceptive. Her temperature is 37.8°C (100°F), pulse is 113/min and regular, and blood pressure is 162/90 mm Hg. Examination shows decreased muscle strength on the left side. Deep tendon reflexes are 4+ on the left. Babinski sign is present on the left. The right lower leg is swollen, erythematous, and tender to palpation. Further evaluation is most likely to show which of the following?

A. Atrial fibrillation
B. Patent foramen ovale (Correct Answer)
C. Atrial myxoma
D. Ventricular septal defect
E. Carotid artery dissection

Explanation: ***Patent foramen ovale*** - This patient presents with a **cryptogenic stroke** (stroke of undetermined cause) in the context of being **obese**, taking **oral contraceptives**, recent **long-distance travel**, and symptoms of a **deep vein thrombosis (DVT)** in her right leg. - A **paradoxical embolism** through a **patent foramen ovale (PFO)** is a strong possibility, where a clot from the DVT could bypass the pulmonary circulation and enter the systemic circulation, leading to a stroke. *Atrial fibrillation* - While **atrial fibrillation** is a common cause of **embolic stroke**, the patient's pulse is described as **regular**, making this diagnosis less likely. - There are no other indications of atrial fibrillation on physical exam, such as an irregularly irregular pulse. *Atrial myxoma* - An **atrial myxoma** can cause **embolic stroke** due to tumor fragments breaking off, but this is a rare cause. - There are no other signs or symptoms suggestive of a cardiac tumor, such as constitutional symptoms or cardiac murmurs. *Ventricular septal defect* - A **ventricular septal defect (VSD)** typically causes a left-to-right shunt and is associated with a **loud holosystolic murmur** at the lower left sternal border. - While a **right-to-left shunt** can occur in the presence of **pulmonary hypertension (Eisenmenger syndrome)**, there is no mention of a murmur or signs of pulmonary hypertension. *Carotid artery dissection* - **Carotid artery dissection** can cause stroke, often preceded by **neck pain** or **headache**, which is not reported by the patient. - The presence of a **DVT** and associated risk factors for thromboembolism makes a paradoxical embolism a more probable cause in this clinical scenario.

Question 684: A 35-year-old man is brought to the emergency department because of a 2-week history of abdominal cramps, vomiting, and constipation. He also reports having to urinate frequently and occasional leg pain. He has had similar episodes in the past. He has hypertension and peptic ulcer disease. Current medications include captopril and ranitidine. He appears depressed. Physical examination shows weakness in the extremities. Abdominal examination shows mild epigastric tenderness. There is no rebound or guarding. He has a restricted affect. Laboratory studies show elevated serum parathyroid hormone levels; serum calcium is 14.2 mg/dL. Abdominal ultrasonography shows multiple small calculi in the right kidney. Which of the following is most likely to provide rapid relief in this patient?

A. Normal saline and intravenous calcitonin therapy (Correct Answer)
B. Intravenous pamidronate therapy
C. Normal saline and intravenous fentanyl therapy
D. Normal saline and intravenous furosemide therapy
E. Reduction of dietary intake of calcium

Explanation: ***Normal saline and intravenous calcitonin therapy*** - The patient presents with **severe hypercalcemia** (14.2 mg/dL) and symptoms like abdominal cramps, vomiting, constipation, polyuria, leg pain, and weakness. **Normal saline** effectively rehydrates the patient and promotes renal calcium excretion, while **intravenous calcitonin** rapidly reduces serum calcium by inhibiting osteoclast activity. - This combination provides a **rapid reduction in serum calcium**, which is crucial for symptomatic relief in severe hypercalcemia. *Intravenous pamidronate therapy* - **Bisphosphonates** like pamidronate are effective in treating hypercalcemia, but their **onset of action is slower** (2-4 days) compared to calcitonin. - While ultimately helpful, pamidronate would not provide the immediate relief needed for this patient's acute symptoms. *Normal saline and intravenous fentanyl therapy* - **Fentanyl** is an opioid pain reliever and does not address the underlying **hypercalcemia** or its symptoms. - While it could help with acute pain (e.g., from renal calculi), it doesn't provide symptomatic relief for hypercalcemia-related issues like vomiting, constipation, or weakness, and it won't lower calcium levels. *Normal saline and intravenous furosemide therapy* - **Loop diuretics** like furosemide can increase renal calcium excretion but should only be used *after* adequate rehydration with normal saline to prevent volume depletion and worsening hypercalcemia. - Furosemide alone is not sufficient to rapidly correct severe hypercalcemia and can potentially lead to dehydration if not managed carefully alongside vigorous fluid resuscitation. *Reduction of dietary intake of calcium* - While appropriate for long-term management of hypercalcemia, reducing dietary calcium intake has an **insignificant and slow effect** on severe hypercalcemia. - It would not provide the rapid relief necessary for the patient's acute and symptomatic hypercalcemic crisis.

Question 685: A 60-year-old man with a long-standing history of type 2 diabetes and hypertension managed with lisinopril and metformin presents with itchy skin. He also describes moderate nausea, vomiting, muscle weakness, and fatigue. The vital signs include: temperature 36.8°C (98.2°F), heart rate 98/min, respiratory rate 15/min, blood pressure 135/85 mm Hg, oxygen saturation 100% on room air. Physical exam is notable for pale conjunctivae, pitting edema, and ascites. Laboratory findings are shown below: BUN 78 mg/dL pCO2 25 mm Hg Creatinine 7.2 mg/dL Glucose 125 mg/dL Serum chloride 102 mmol/L Serum potassium 6.3 mEq/L Serum sodium 130 mEq/L Total calcium 1.3 mmol/L Magnesium 1.2 mEq/L Phosphate 1.9 mmol/L Hemoglobin 9.5 g/dL MCV 86 μm3 Bicarbonate (HCO3) 10 mmol/L Shrunken kidneys are identified on renal ultrasound. The doctor explains to the patient that he will likely need dialysis due to his significant renal failure until a renal transplant can be performed. The patient is concerned because he is very busy and traveling a lot for work. Given his lifestyle requirements, what is a potential complication of the most appropriate dialysis modality for this patient?

A. Excessive bleeding
B. Muscle cramping
C. Hypotension
D. Hypertriglyceridemia (Correct Answer)
E. Hypoglycemia

Explanation: ***Hypertriglyceridemia*** - The patient's **lifestyle requirements** (busy, traveling a lot) suggest **peritoneal dialysis (PD)** as the most appropriate modality due to its flexibility and home-based nature. - **Hypertriglyceridemia** is a common complication of PD due to the absorption of glucose from the dialysate, which stimulates hepatic triglyceride synthesis. *Excessive bleeding* - This is a rare complication in both hemodialysis and peritoneal dialysis. - While **anti-coagulation** is used in hemodialysis, it's carefully monitored, and significant bleeding is not a typical long-term complication of the chosen modality (PD). *Muscle cramping* - **Muscle cramps** can occur with hemodialysis, typically due to rapid fluid and electrolyte shifts. - This is less common in peritoneal dialysis, which involves a slower and more continuous exchange process. *Hypotension* - **Hypotension** can be a complication of hemodialysis due to rapid fluid removal. - Peritoneal dialysis, with its gradual fluid exchange, is generally less associated with significant hypotensive episodes. *Hypoglycemia* - The **glucose-rich dialysate** used in peritoneal dialysis can actually lead to **hyperglycemia**, not hypoglycemia, especially in diabetic patients. - Regular insulin adjustments are often required for diabetic patients on PD.

Question 686: Twelve days after undergoing a cadaveric renal transplant for adult polycystic kidney disease, a 23-year-old man has pain in the right lower abdomen and generalized fatigue. During the past 4 days, he has had decreasing urinary output. Creatinine concentration was 2.3 mg/dL on the second postoperative day. Current medications include prednisone, cyclosporine, azathioprine, and enalapril. His temperature is 38°C (100.4°F), pulse is 103/min, and blood pressure is 168/98 mm Hg. Examination reveals tenderness to palpation on the graft site. Creatinine concentration is 4.3 mg/dL. A biopsy of the transplanted kidney shows tubulitis. C4d staining is negative. Which of the following is the most likely cause of this patient's findings?

A. Drug-induced nephrotoxicity
B. Allorecognition with T cell activation (Correct Answer)
C. Irreversible fibrosis of the glomerular vessels
D. Donor T cells from the graft
E. Preformed cytotoxic antibodies against class I HLA

Explanation: ***Allorecognition with T cell activation*** - The patient's symptoms (pain at graft site, fatigue, decreasing urinary output, elevated creatinine) 12 days post-transplant, along with **tubulitis on biopsy** and negative **C4d staining**, are indicative of acute cellular rejection, mediated primarily by **T-cell recognition of donor HLA antigens**. - **Hypertension** and **fever** also support acute rejection, and the immunosuppressive regimen may not be fully effective in preventing this T-cell mediated response. *Drug-induced nephrotoxicity* - While cyclosporine and enalapril can cause kidney injury, the **histological finding of tubulitis** is highly specific for acute cellular rejection, not typically seen with drug-induced nephrotoxicity alone. - Drug-induced nephrotoxicity usually presents with a more **gradual rise in creatinine** and may lack the systemic signs like fever or the specific pathological features of rejection. *Irreversible fibrosis of the glomerular vessels* - This description is more consistent with **chronic allograft nephropathy** or long-term damage, which typically develops months to years after transplantation, not within 12 days. - The findings described (pain, fever, tubulitis) point to an acute process, not chronic fibrosis. *Donor T cells from the graft* - This scenario describes **graft-versus-host disease (GVHD)**, which is rare in solid organ transplantation due to the much smaller lymphocyte load compared to bone marrow transplants. - GVHD typically affects the skin, liver, and gut, and while it involves T-cell mediated injury, the primary damage in renal transplant rejection is directed at the transplanted kidney by the recipient's immune system. *Preformed cytotoxic antibodies against class I HLA* - This describes **hyperacute rejection**, which occurs within minutes to hours of transplantation due to pre-existing antibodies in the recipient against donor antigens. - The patient's symptoms developing 12 days post-transplant, along with the biopsy showing tubulitis and negative C4d staining (indicating absence of significant antibody-mediated complement activation), rule out hyperacute rejection.

Question 687: A 67-year-old Caucasian female presents to her primary care physician after a screening DEXA scan reveals a T-score of -3.0. Laboratory work-up reveals normal serum calcium, phosphate, vitamin D, and PTH levels. She smokes 1-2 cigarettes per day. Which of the following measures would have reduced this patient's risk of developing osteoporosis?

A. Weight loss
B. Reduced physical activity to decrease the chance of a fall
C. Initiating a swimming exercise program three days per week
D. Calcium and vitamin D supplementation
E. Smoking cessation (Correct Answer)

Explanation: ***Smoking cessation*** - **Smoking** is a well-established, modifiable risk factor for osteoporosis that directly impairs bone metabolism - Cigarette smoking **decreases osteoblast activity**, increases **bone resorption**, and reduces intestinal calcium absorption - This patient is **actively smoking 1-2 cigarettes per day**, making cessation the most relevant preventive measure for her specific situation - **Smoking cessation** would have directly addressed a harmful exposure that contributed to her bone loss *Calcium and vitamin D supplementation* - While important for bone health, this patient's laboratory work-up shows **normal serum calcium and vitamin D levels** - Supplementation beyond adequate levels has **limited additional benefit** for osteoporosis prevention in patients with normal baseline values - Supplementation is most beneficial in patients with documented **deficiency** or inadequate dietary intake *Weight loss* - **Weight loss** and being underweight are actually **risk factors for osteoporosis** - Lower body weight reduces mechanical loading on bones, which is necessary for maintaining bone density - Weight-bearing stress stimulates bone formation through mechanotransduction *Initiating a swimming exercise program three days per week* - While **swimming** is excellent for cardiovascular fitness and overall health, it is **not a weight-bearing exercise** - Osteoporosis prevention requires **weight-bearing or resistance exercises** such as walking, jogging, dancing, or strength training - These activities provide the mechanical stress needed to stimulate bone formation *Reduced physical activity to decrease the chance of a fall* - **Reducing physical activity** accelerates bone loss due to decreased mechanical loading - While fall prevention is important in osteoporosis management, it should focus on **environmental modifications** and **balance training**, not activity reduction - Maintaining appropriate physical activity is essential for preserving bone density

Question 688: A 65-year-old man is brought to the emergency department because of a 3-day history of increasing shortness of breath and chest pain. He has had a productive cough with foul-smelling sputum for 1 week. He has gastritis as well as advanced Parkinson disease and currently lives in an assisted-living community. He smoked one pack of cigarettes daily for 40 years but quit 5 years ago. He has a 30-year history of alcohol abuse but has not consumed any alcohol in the past 5 years. His temperature is 39.3°C (102.7°F), he is tachycardic and tachypneic and his oxygen saturation is 77% on room air. Auscultation of the lung shows rales and decreased breath sounds over the right upper lung field. Examination shows a resting tremor. Laboratory studies show: Hematocrit 38% Leukocyte count 17,000/mm3 Platelet count 210,000/mm3 Lactic acid 4.1 mmol/L (N=0.5–1.5) A x-ray of the chest shows infiltrates in the right upper lobe. Which of the following is the most significant predisposing factor for this patient's respiratory symptoms?

A. Tobacco use history
B. Parkinson disease (Correct Answer)
C. Past history of alcohol abuse
D. Gastritis
E. Living in an assisted-living community

Explanation: ***Parkinson disease*** - **Parkinson disease** impairs the normal swallowing reflex, leading to **dysphagia** and an increased risk of **aspiration**, which is the most likely cause of the patient's **foul-smelling sputum** (indicating anaerobic organisms from oral flora). - The **right upper lobe infiltrate** can occur with aspiration pneumonia, particularly involving the **posterior segment** in patients who aspirate while supine or semi-recumbent, which is common in patients with advanced Parkinson disease. - The resting tremor mentioned in the physical exam further confirms the diagnosis of Parkinson disease, linking it directly to his aspiration risk. *Tobacco use history* - While a significant **smoking history** increases the risk of chronic obstructive pulmonary disease (COPD) and lung cancer, it does not directly lead to **foul-smelling sputum** and the acute aspiration event described. - The patient quit smoking 5 years ago, reducing his immediate risk compared to an active smoker. *Past history of alcohol abuse* - **Chronic alcohol abuse** can compromise the immune system and increase the risk of pneumonia, but this patient has not consumed alcohol in the past 5 years. - Alcohol abuse does not specifically predispose to **aspiration events** in the same direct way Parkinson disease does through impaired swallowing mechanisms. *Gastritis* - **Gastritis** primarily affects the stomach lining and is not a direct predisposing factor for severe respiratory infections like pneumonia, especially aspiration pneumonia with **foul-smelling sputum**. - It does not impact swallowing reflexes or increase the risk of aspiration. *Living in an assisted-living community* - Living in a communal setting like an **assisted-living facility** can increase exposure to infectious agents and healthcare-associated pneumonia, but it does not specifically explain the risk of **aspiration pneumonia** with **foul-smelling sputum**. - This factor is less specific to the underlying pathophysiological mechanism of his current illness compared to Parkinson disease.

Question 689: A 62-year-old woman with type 2 diabetes mellitus comes to the physician because of a 3-month history of fatigue and weakness. Her hemoglobin A1c concentration was 13.5% 12 weeks ago. Her blood pressure is 152/92 mm Hg. Examination shows lower extremity edema. Serum studies show: K+ 5.1 mEq/L Phosphorus 5.0 mg/dL Ca2+ 7.8 mg/dL Urea nitrogen 60 mg/dL Creatinine 2.2 mg/dL Which of the following is the best parameter for early detection of this patient’s renal condition?

A. Serum total protein
B. Serum creatinine
C. Urinary red blood cell casts
D. Serum urea nitrogen
E. Urinary albumin (Correct Answer)

Explanation: ***Urinary albumin*** - **Microalbuminuria** is often the earliest detectable sign of **diabetic nephropathy**, occurring before changes in GFR or serum creatinine become apparent. - Regular screening for urinary albumin in diabetic patients allows for early intervention to slow the progression of **renal damage**. *Serum total protein* - **Hypoalbuminemia** can be seen in advanced renal disease due to significant proteinuria, but it is not an early marker. - Other conditions like **liver disease** or **malnutrition** can also cause altered serum total protein, making it less specific for early renal damage. *Serum creatinine* - **Serum creatinine** levels rise significantly only after a substantial portion of kidney function (around 50%) has been lost. - Therefore, it is a marker of established renal dysfunction rather than an early indicator. *Urinary red blood cell casts* - The presence of **red blood cell casts** in urine indicates **glomerulonephritis** or other inflammatory conditions affecting the glomeruli. - While concerning, it is not the typical or earliest presentation of **diabetic nephropathy**, which primarily involves proteinuria. *Serum urea nitrogen* - **Blood urea nitrogen (BUN)** levels, like creatinine, increase with declining kidney function and are used to assess the severity of **renal impairment**. - However, BUN levels can also be influenced by factors like **hydration status** and **protein intake**, and they are not an early marker of nascent renal disease.

Question 690: A 10-year-old boy is brought to the pediatrician by his father because of recent changes in his behavior. His father states that he has noticed that the boy has begun to appear less coordinated than normal and has had frequent falls. On exam, the pediatrician observes pes cavus and hammer toes. The pediatrician makes a presumptive diagnosis based on these findings and recommends a formal echocardiogram. The pediatrician is most likely concerned about which of the following cardiovascular defects?

A. Tetralogy of Fallot
B. Aortic cystic medial necrosis
C. Hypertrophic cardiomyopathy (Correct Answer)
D. Coarctation of the aorta
E. Endocardial cushion defect

Explanation: **Hypertrophic cardiomyopathy** - The constellation of **neurological symptoms** (ataxia, frequent falls) and **skeletal deformities** (**pes cavus**, **hammer toes**) is classic for **Friedreich ataxia**. - **Hypertrophic cardiomyopathy** is a common and severe cardiac complication in patients with **Friedreich ataxia**, making the recommended echocardiogram highly pertinent for screening and management. *Tetralogy of Fallot* - This is a **cyanotic congenital heart defect** typically presenting in infancy with **cyanosis**, **dyspnea**, and **tet spells**, not usually associated with later-onset neurological and skeletal issues like those described. - While it can manifest with exercise intolerance, it does not directly lead to **pes cavus** or **hammer toes** as part of a systemic syndrome. *Aortic cystic medial necrosis* - This condition is associated with disorders like **Marfan syndrome** due to underlying connective tissue defects, predisposing to **aortic dissection** or **aneurysm**. - It does not present with the specific neurological and skeletal findings seen here, and its cardiac manifestations (e.g., aortic root dilation) are distinct from hypertrophic cardiomyopathy. *Coarctation of the aorta* - This is a **narrowing of the aorta**, typically presenting with **hypertension in the upper extremities**, **diminished femoral pulses**, and sometimes **heart failure** or **murmurs**. - It is not directly linked to neurological degeneration, **pes cavus**, or **hammer toes**, and is not a common complication of Friedreich ataxia. *Endocardial cushion defect* - Also known as **atrioventricular septal defect**, this is a **congenital heart defect** common in children with **Down syndrome**. - It typically presents with symptoms of **heart failure** in infancy or early childhood due to large shunts, and does not cause the described neurological and skeletal abnormalities.

Question 691: A 55-year-old man is brought to the emergency department 30 minutes after the sudden onset of severe, migrating anterior chest pain, shortness of breath, and sweating at rest. He has hypertension, hypercholesterolemia, and type 2 diabetes mellitus. Medications include atorvastatin, hydrochlorothiazide, lisinopril, and metformin. He has smoked one pack of cigarettes daily for 25 years. He is in severe distress. His pulse is 110/min, respirations are 20/min, and blood pressure is 150/85 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Cardiac examination shows a grade 3/6, high-pitched, blowing, diastolic murmur heard best over the right sternal border. The lungs are clear to auscultation. Femoral pulses are decreased bilaterally. An ECG shows sinus tachycardia and left ventricular hypertrophy. Which of the following is the most likely diagnosis?

A. Esophageal rupture
B. Pulmonary embolism
C. Aortic dissection (Correct Answer)
D. Papillary muscle rupture
E. Spontaneous pneumothorax

Explanation: ***Aortic dissection*** - The sudden onset of **severe, migrating anterior chest pain**, autonomic symptoms (sweating at rest), and **decreased bilateral femoral pulses** are highly characteristic of aortic dissection. - The presence of a new **diastolic murmur** (indicating aortic insufficiency due to dissection extending to the aortic valve), along with a history of **hypertension** and **smoking**, further supports this diagnosis. - **Decreased bilateral femoral pulses** suggest involvement of the descending aorta compromising flow to both lower extremities. *Esophageal rupture* - While esophageal rupture can cause **sudden, severe chest pain**, it typically presents with **odynophagia**, **vomiting**, and often **subcutaneous emphysema** or **Hamman's sign**, which are absent here. - It would not explain the **diastolic murmur** or the **bilateral decreased femoral pulses**. *Pulmonary embolism* - **Shortness of breath** and **chest pain** can occur with pulmonary embolism, but the pain is typically **pleuritic** rather than migrating. - It would not cause a **diastolic murmur** or **decreased peripheral pulses**. *Papillary muscle rupture* - Papillary muscle rupture is a complication of **myocardial infarction**, usually causing **acute severe mitral regurgitation** with a new **systolic murmur** and signs of **heart failure**. - The patient's presentation with migrating pain and a **diastolic murmur** is inconsistent with this diagnosis. *Spontaneous pneumothorax* - A spontaneous pneumothorax causes **sudden, sharp, pleuritic chest pain** and **dyspnea**, often accompanied by **decreased breath sounds** on the affected side. - It would not cause a **diastolic murmur** or **decreased femoral pulses**.

Question 692: A 55-year-old man presents to his primary care physician for a new patient appointment. The patient states that he feels well and has no concerns at this time. The patient has a past medical history of hypertension, an elevated fasting blood glucose, and is not currently taking any medications. His blood pressure is 177/118 mmHg, pulse is 90/min, respirations are 16/min, and oxygen saturation is 97% on room air. Physical exam is notable for an obese man with atrophy of his limbs and striae on his abdomen. Laboratory values are notable for a blood glucose of 175 mg/dL. Which of the following is the best next step in evaluation?

A. Hydrochlorothiazide
B. MRI of the head
C. Metformin
D. Weight loss
E. Dexamethasone suppression test (Correct Answer)

Explanation: ***Dexamethasone suppression test*** - The patient presents with **atrophy of the limbs** with concurrent **striae on the abdomen**, uncontrolled hypertension, and elevated blood glucose, which are all classic signs of **Cushing's syndrome**. - A **dexamethasone suppression test** is the best initial diagnostic step to confirm Cushing's syndrome by assessing the body's cortisol regulation. *Hydrochlorothiazide* - While the patient has **hypertension**, treating the symptom without addressing the underlying cause (Cushing's syndrome) would be insufficient and potentially delay proper diagnosis. - **Hydrochlorothiazide** is an antihypertensive, but without addressing the likely cortisol excess, blood pressure control will be challenging. *MRI of the head* - An **MRI of the head** (specifically the pituitary) would be considered after biochemical confirmation of Cushing's syndrome to localize a potential tumor, but it is not the initial diagnostic step. - Imaging is performed *after* biochemical tests indicate cortisol excess, to differentiate between pituitary, adrenal, or ectopic causes. *Metformin* - The patient has **elevated blood glucose**, but initiating an antidiabetic medication like **metformin** before evaluating for Cushing's syndrome would be treating a symptom without identifying the root cause. - Diabetes in this context is likely secondary to excess cortisol, so managing it effectively requires addressing the underlying endocrine disorder. *Weight loss* - While **weight loss** is generally beneficial for hypertension and diabetes, in the context of Cushing's syndrome with **limb atrophy** and **central obesity**, focusing solely on weight loss without addressing the hormonal imbalance would be ineffective. - The characteristic fat redistribution in Cushing's syndrome makes simple weight loss difficult and less impactful until cortisol levels are managed.

Question 693: A 61-year-old man presents to the emergency room with a painful, swollen left leg. He states that his symptoms began that morning after a long flight from Australia. He denies shortness of breath, chest pain, or cough. On review of systems, he notes that he has been constipated recently and had several episodes of bright red blood per rectum. He has not noticed any weight loss, fevers, or night sweats. He has a past medical history of a deep vein thrombosis 4 years ago during a hospitalization for community acquired pneumonia and was treated with warfarin for 3 months afterward. He also has chronic hepatitis C from previous intravenous drug use. The patient has a 30 pack-year smoking history and has never had a colonoscopy. His father is 84-years-old and has chronic kidney disease from diabetes, and his mother passed away from a massive pulmonary embolus when pregnant with his younger sister. In the emergency room, his temperature is 98.7°F (37.1°C), blood pressure is 142/85 mm/Hg, pulse is 79/min, and respirations are 14/min. On exam, he is in no acute distress. His left calf is larger in caliber than the right calf which is red and tender to palpation. Dorsiflexion of the foot worsens the pain. His abdomen is soft, nontender, and nondistended without hepatomegaly. The remainder of the physical exam is unremarkable. Labs are shown below: Hemoglobin: 13.0 g/dL Leukocyte count: 6,000/mm^3 Platelets: 160,000/mm^3 Aspartate aminotransferase: 15 U/L Alanine aminotransferase: 19 U/L Alkaline phosphatase: 81 IU/L Hepatitis C antibody: reactive Hepatitis C titer: 0 copies/mL Which of the following is the most likely cause of this patient’s condition?

A. Increased estrogen levels
B. Loss of antithrombin III in urine
C. Protein C deficiency
D. Resistance of factor V to inactivation by protein C (Correct Answer)
E. Malignancy

Explanation: ***Resistance of factor V to inactivation by protein C*** - This patient has **Factor V Leiden mutation**, the most common inherited thrombophilia (present in 5% of Caucasians) - **Key diagnostic clues**: Recurrent DVT (even if provoked events have lower thresholds in Factor V Leiden) and **strong family history** - mother with massive PE during pregnancy is highly suggestive, as pregnancy unmasks inherited thrombophilias - Factor V Leiden causes **resistance to activated protein C**, leading to prolonged clotting and increased VTE risk - While the rectal bleeding raises concern for malignancy, the **family history of thromboembolism** points to an inherited predisposition as the underlying cause *Malignancy* - Malignancy causes hypercoagulability through multiple mechanisms (tissue factor release, inflammatory cytokines, platelet activation) - The patient's **rectal bleeding, constipation, age 61, and lack of screening colonoscopy** are concerning for colorectal cancer - Malignancy is a strong consideration and warrants urgent colonoscopy - However, the **family history of massive PE in mother during pregnancy** more strongly suggests an inherited thrombophilia as the primary cause, though malignancy could be a coexisting/triggering factor *Increased estrogen levels* - Estrogen increases synthesis of clotting factors and decreases anticoagulant proteins, raising DVT risk - Seen with oral contraceptives, hormone replacement therapy, or pregnancy - This patient is a **61-year-old male**, making estrogen-related thrombosis extremely unlikely *Loss of antithrombin III in urine* - Occurs in **nephrotic syndrome** (proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia) - Loss of antithrombin III causes hypercoagulability - This patient has **no proteinuria, normal liver enzymes, no edema**, and no other features of nephrotic syndrome *Protein C deficiency* - Hereditary protein C deficiency is a rare thrombophilia causing recurrent VTE - While possible, **Factor V Leiden is 10-20 times more common** than protein C deficiency - The family history pattern (mother with PE in pregnancy) is more characteristic of Factor V Leiden

Question 694: A 32-year-old woman comes to the physician because of a 2-week history of involuntary loss of urine. She loses small amounts of urine in the absence of an urge to urinate and for no apparent reason. She also reports that she has an intermittent urinary stream. Two years ago, she was diagnosed with multiple sclerosis. Current medications include glatiramer acetate and a multivitamin. She works as a librarian. She has 2 children who attend middle school. Vital signs are within normal limits. The abdomen is soft and nontender. Pelvic examination shows no abnormalities. Neurologic examination shows a slight hypesthesia in the lower left arm and absent abdominal reflex, but otherwise no abnormalities. Her post-void residual urine volume is 131 mL. Bladder size is normal. Which of the following is the most likely cause of the patient's urinary incontinence?

A. Cognitive impairment
B. Vesicovaginal fistula
C. Bladder outlet obstruction
D. Detrusor sphincter dyssynergia (Correct Answer)
E. Impaired detrusor contractility

Explanation: ***Detrusor sphincter dyssynergia*** - This condition is characterized by **involuntary contraction of the external urethral sphincter** during bladder contraction, leading to an **intermittent urinary stream** and incomplete bladder emptying, often seen in neurological conditions like **multiple sclerosis**. - The **post-void residual urine volume of 131 mL** confirms incomplete bladder emptying, and the loss of small amounts of urine without urge suggests **overflow incontinence** due to chronic retention. *Cognitive impairment* - While cognitive impairment can cause urinary incontinence, typically it leads to **functional incontinence** where the patient is unable to recognize the need to urinate or is unable to reach the toilet in time. - The patient's presentation of an **intermittent urinary stream** and high post-void residual is not characteristic of incontinence solely due to cognitive issues. *Vesicovaginal fistula* - A vesicovaginal fistula involves an **abnormal connection between the bladder and vagina**, causing **continuous leakage of urine** from the vagina, often following childbirth or surgery. - The patient's symptoms of an **intermittent urinary stream** and neurological history are inconsistent with a fistula, and the pelvic exam was normal. *Bladder outlet obstruction* - Common causes include **benign prostatic hyperplasia** in men or **pelvic organ prolapse** in women, leading to difficulty emptying the bladder and symptoms like dribbling and straining. - While it can cause incomplete emptying and overflow, without any evidence of prolapse on pelvic exam or other obstructive factors, and given her **multiple sclerosis**, a neurological cause like DSD is more likely. *Impaired detrusor contractility* - This condition results in the bladder being **unable to effectively contract** to empty urine, leading to incomplete emptying and overflow incontinence. - While the patient has a high post-void residual volume, the presence of an **intermittent urinary stream** suggests that the detrusor *is* contracting, but facing resistance from a dyssynergic sphincter, rather than having impaired contractility itself.

Question 695: A 32-year-old African American woman comes to the physician because of fatigue and difficulty swallowing for 6 weeks. She also complains of painful discoloration in her fingers when exposed to cold weather. She has smoked one pack of cigarettes daily for 4 years. She appears younger than her stated age. Physical examination shows smooth, swollen fingers with small white calcifications on her fingertips bilaterally. This patient is at increased risk for which of the following complications?

A. Pulmonary hypertension (Correct Answer)
B. Chondrocalcinosis
C. Aortic aneurysm
D. Liver cirrhosis
E. Chronic obstructive pulmonary disease

Explanation: ***Pulmonary hypertension*** - The patient's symptoms (fatigue, dysphagia, Raynaud phenomenon, sclerodactyly with calcifications) are highly suggestive of **CREST syndrome**, a limited form of systemic sclerosis. - Pulmonary hypertension is a frequent and serious complication of systemic sclerosis, particularly in the limited cutaneous form (CREST syndrome), due to **vasculopathy** and **fibrosis** affecting pulmonary arteries. *Chondrocalcinosis* - This condition involves the deposition of **calcium pyrophosphate crystals** in cartilage, typically presenting as arthritis. - While calcifications are mentioned, they are described on fingertips (likely **calcinosis cutis**), not within joints, making chondrocalcinosis less likely in this context. *Aortic aneurysm* - Aortic aneurysms are more commonly associated with conditions like **atherosclerosis**, Marfan syndrome, or syphilis. - There is no direct link between systemic sclerosis (CREST syndrome) and an increased risk of aortic aneurysm. *Liver cirrhosis* - Liver cirrhosis is primarily caused by chronic liver damage from conditions like **hepatitis**, **alcohol abuse**, or non-alcoholic fatty liver disease. - While some autoimmune conditions can affect the liver, systemic sclerosis is not strongly associated with an increased risk of liver cirrhosis. *Chronic obstructive pulmonary disease* - COPD is characterized by persistent **airflow limitation** and is primarily caused by **smoking** and exposure to environmental pollutants. - While the patient smokes, the specific constellation of symptoms points to systemic sclerosis, which often involves **interstitial lung disease** rather than typical obstructive lung changes like COPD.

Question 696: A 19-year-old girl with a history of immune thrombocytopenic purpura (ITP), managed with systemic corticosteroids, presents with bruising, acne, and weight gain. Patient says that 3 months ago she gradually began to notice significant weight gain and facial and truncal acne. She says these symptoms progressively worsened until she discontinued her corticosteroid therapy 4 weeks ago. This week, she began to notice multiple bruises all over her body. Past medical history is significant for ITP, diagnosed 11 years ago, managed until recently with systemic corticosteroid therapy. The patient is afebrile and vital signs are within normal limits. On physical examination, there are multiple petechiae and superficial bruises on her torso and extremities bilaterally. There is moderate truncal obesity and as well as a mild posterior cervical adipose deposition. Multiple deep comedones are present on the face and upper torso. Which of the following is the best course of treatment in this patient?

A. Administration of intravenous immunoglobulin
B. Continuation of systemic corticosteroid therapy
C. Splenectomy (Correct Answer)
D. Transfusion of thrombocytes
E. Transplantation of stem cells

Explanation: ***Splenectomy*** - The patient has **chronic ITP** (11 years) with **steroid failure** due to intolerable side effects (Cushingoid features: truncal obesity, buffalo hump, acne) and now presents with **relapse** after discontinuation (petechiae, bruising). - **Splenectomy** is an established **second-line treatment** for chronic ITP when first-line therapies (corticosteroids, IVIG) fail or are not tolerated. It achieves durable remission in **60-70% of patients** by removing the primary site of platelet destruction. - In this patient who cannot tolerate long-term corticosteroids and needs definitive management, splenectomy is the most appropriate option among those listed. - **Note**: Modern practice also considers thrombopoietin receptor agonists (TPO-RAs like eltrombopag or romiplostim) as alternatives to splenectomy, but these are not among the answer choices. *Administration of intravenous immunoglobulin* - **IVIG** provides only **temporary elevation** of platelet counts (lasting days to weeks) and is primarily used for *acute severe bleeding* or to rapidly increase platelets before procedures. - While it could be used for short-term management of her current relapse, it does not address the need for **long-term definitive therapy** in a patient who has failed corticosteroids. - Not the best option when definitive treatment is needed. *Continuation of systemic corticosteroid therapy* - The patient has clear **corticosteroid toxicity** (Cushingoid features) and **discontinued therapy 4 weeks ago** specifically due to these intolerable side effects. - Continuing steroids would perpetuate weight gain, acne, metabolic complications, bone loss, and other serious adverse effects. - **Steroid-dependent ITP** requiring alternate therapy is an indication for second-line treatment. *Transfusion of thrombocytes* - **Platelet transfusions** are generally **ineffective in ITP** because transfused platelets are rapidly destroyed by the same autoimmune process targeting endogenous platelets. - Reserved only for **life-threatening hemorrhage** (e.g., intracranial bleeding), not for chronic management or mild mucocutaneous bleeding. - This patient has petechiae and superficial bruising but no evidence of severe bleeding. *Transplantation of stem cells* - **Hematopoietic stem cell transplantation** is an extremely high-risk procedure reserved for life-threatening **refractory hematologic malignancies** or severe aplastic anemia, not for chronic ITP. - ITP is an autoimmune disorder of platelet destruction, not a stem cell production problem. - This would be inappropriate and carries unacceptable morbidity/mortality risk for this condition.

Question 697: A 55-year-old man comes to the physician because of increasing shortness of breath for 1 month. Initially, he was able to climb the 3 flights of stairs to his apartment, but he now needs several breaks to catch his breath. He has no chest pain. He has rheumatic heart disease and type 2 diabetes mellitus. He emigrated from India about 25 years ago. The patient's current medications include carvedilol, torsemide, and insulin. He appears uncomfortable. His temperature is 37.3°C (99.1°F), pulse is 72/min and regular, respirations are 18/min, and blood pressure is 130/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Examination shows bilateral crackles at the lung bases. There is an opening snap followed by a low-pitched diastolic murmur at the fifth left intercostal space at the mid-clavicular line. An x-ray of the chest shows left atrial enlargement, straightening of the left cardiac border and increased vascular markings. Which of the following is the preferred intervention to improve this patient's symptoms?

A. Transcatheter aortic valve replacement
B. Tricuspid valve repair
C. Enalapril therapy
D. Percutaneous mitral balloon commissurotomy (Correct Answer)
E. Mitral valve replacement

Explanation: ***Percutaneous mitral balloon commissurotomy*** - The patient's symptoms (dyspnea, crackles, left atrial enlargement) and the characteristic "opening snap followed by a low-pitched diastolic murmur" at the apex (fifth left intercostal space at the mid-clavicular line) are highly indicative of **mitral stenosis**, likely due to his history of rheumatic heart disease. - Given the progressive symptoms and the classic auscultatory findings, **percutaneous mitral balloon commissurotomy** is the preferred intervention for symptomatic patients with isolated, severe mitral stenosis, especially when the valve anatomy is suitable (non-calcified, non-regurgitant). *Transcatheter aortic valve replacement* - **Transcatheter aortic valve replacement (TAVR)** is indicated for severe **aortic stenosis**, which is characterized by a systolic murmur, often radiating to the carotids, and symptoms like angina or syncope, not present here. - The patient's murmur is diastolic and apical, inconsistent with aortic stenosis. *Tricuspid valve repair* - **Tricuspid valve disease** typically presents with symptoms of right heart failure, such as peripheral edema, ascites, and jugular venous distension, which are not the primary complaints for this patient. - The murmur described is associated with the mitral valve, located in the left heart. *Enalapril therapy* - **Enalapril**, an ACE inhibitor, is often used in heart failure with reduced ejection fraction or hypertension, but it does not directly address the mechanical obstruction of a stenotic mitral valve. - While it can help manage heart failure symptoms, it is not the definitive intervention for symptomatic mitral stenosis. *Mitral valve replacement* - **Mitral valve replacement** is an option for severe mitral stenosis but is generally reserved for cases where **percutaneous mitral balloon commissurotomy** is contraindicated or has failed (e.g., highly calcified valve, significant regurgitation, atrial thrombus). - It is a more invasive surgical procedure compared to commissurotomy, making the latter the preferred *initial* intervention if feasible.

Question 698: A 54-year-old man comes to the physician because of excessive daytime sleepiness for 5 months. He wakes up frequently at night, and his wife says his snoring has become louder. He is 180 cm (5 ft 10 in) tall and weighs 104 kg (230 lb); his BMI is 33 kg/m2. His pulse is 80/min and his respiratory rate is 11/min. His jugular venous pressure is 7 cm H2O. He has 2+ pitting edema of the lower legs and ankles. Arterial blood gas analysis on room air shows a pH of 7.42 and a PCO2 of 41 mm Hg. An x-ray of the chest shows normal findings. Which of the following is the most likely underlying cause of this patient's condition?

A. Daytime alveolar hypoventilation
B. Decreased levels of hypocretin-1
C. Increased medullary ventilatory responsiveness
D. Impaired myocardial relaxation
E. Intermittent collapse of the oropharynx (Correct Answer)

Explanation: ***Intermittent collapse of the oropharynx*** - The patient's symptoms of **excessive daytime sleepiness**, frequent night awakenings, and **loud snoring** are classic signs of **obstructive sleep apnea (OSA)**. - OSA is characterized by the **intermittent collapse of the oropharynx** during sleep, leading to obstructed airflow. His obesity (BMI 33 kg/m2) is a significant risk factor for OSA. *Daytime alveolar hypoventilation* - This would typically present with **elevated PCO2** on arterial blood gas, indicating CO2 retention. The patient's PCO2 of 41 mm Hg is within the normal range, ruling out significant daytime alveolar hypoventilation. - While chronic severe OSA can eventually lead to obesity hypoventilation syndrome, the current ABG does not support this as the primary underlying cause. *Decreased levels of hypocretin-1* - **Decreased hypocretin-1** (also known as orexin) levels in the cerebrospinal fluid are a hallmark of **narcolepsy type 1**. - While narcolepsy causes excessive daytime sleepiness, it is not associated with loud snoring or night awakenings due to respiratory effort, which are prominent in this patient. *Increased medullary ventilatory responsiveness* - **Increased medullary ventilatory responsiveness** would lead to an enhanced drive to breathe, often resulting in **hypocapnia (low PCO2)**, especially in response to metabolic acidosis or hypoxemia. - This is contrary to the patient's normal PCO2 and clinical picture, which points towards an obstructive rather than a central ventilatory issue. *Impaired myocardial relaxation* - **Impaired myocardial relaxation** is a feature of **diastolic heart failure**, which could explain the elevated JVP and peripheral edema. - However, it does not explain the primary presenting symptoms of excessive daytime sleepiness and loud snoring, which point directly to a sleep-related breathing disorder rather than primarily a cardiac issue.

Question 699: A 53-year-old woman presents to a physician with a cough which she has had for the last 5 years. She mentions that her cough is worse in the morning and is associated with significant expectoration. There is no history of weight loss or constitutional symptoms like fever and malaise. Her past medical records show that she required hospitalization for breathing difficulty on 6 different occasions in the last 3 years. She also mentions that she was never completely free of her respiratory problems during the period between the exacerbations and that she has a cough with sputum most of the months for the last 3 years. She works in a cotton mill and is a non-smoker. Her mother and her maternal grandmother had asthma. Her temperature is 37.1°C (98.8°F), the pulse is 92/min, the blood pressure is 130/86 mm Hg, and her respiratory rate is 22/min. General examination shows obesity and mild cyanosis. Auscultation of her chest reveals bilateral coarse rhonchi. Her lung volumes on pulmonary function test are given below: Pre-bronchodilator Post-bronchodilator FEV1 58% 63% FVC 90% 92% FEV1/FVC 0.62 0.63 TLC 98% 98% The results are valid and repeatable as per standard criteria. Which of the following is the most likely diagnosis?

A. Idiopathic pulmonary fibrosis
B. Chronic bronchitis (Correct Answer)
C. Asthma
D. Extrinsic allergic alveolitis
E. Emphysema

Explanation: ***Chronic bronchitis*** - The patient presents with a chronic cough and sputum production for at least 3 months a year for 2 consecutive years, consistent with the definition of **chronic bronchitis**. - **Obstructive pattern** on PFT (FEV1/FVC < 0.70) with minimal reversibility, along with a history of recurrent exacerbations, supports this diagnosis. *Idiopathic pulmonary fibrosis* - Characterized by a **restrictive ventilatory defect** (reduced TLC) and often presents with progressive dyspnea and dry cough, which contradicts the patient's PFTs and productive cough. - Would show **pulmonary fibrosis** on imaging, not suggested by the patient's presentation. *Asthma* - Typically presents with **reversible airway obstruction** (significant improvement in FEV1 post-bronchodilator), which is not seen here (only 5% improvement). - Although the patient's mother and grandmother had asthma, her symptoms and PFTs do not align with active asthma exacerbations. *Extrinsic allergic alveolitis* - Usually involves **exposure to inhaled allergens** leading to inflammation of the alveoli, presenting with restrictive lung disease and often acute or subacute symptoms. - The patient's occupational exposure to cotton mill might suggest **byssinosis**, a type of occupational lung disease, but her PFTs and prolonged chronic cough are more consistent with bronchitis. *Emphysema* - Primarily defined by **destruction of alveolar walls** leading to air trapping and severe airflow obstruction, often associated with a history of smoking. - While it causes an obstructive pattern, the prominent chronic productive cough and minimal reversibility point more towards the airway inflammation of bronchitis rather than the parenchymal destruction of emphysema.

Question 700: A 27-year-old woman with a history of a "heart murmur since childhood" presents following a series of syncopal episodes over the past several months. She also complains of worsening fatigue over this time period, and notes that her lips have begun to take on a bluish tinge, for which she has been using a brighter shade of lipstick. You do a careful examination, and detect a right ventricular heave, clubbing of the fingers, and 2+ pitting edema bilaterally to the shins. Despite your patient insisting that every doctor she has ever seen has commented on her murmur, you do not hear one. Transthoracic echocardiography would most likely detect which of the following?

A. Mitral insufficiency
B. Aortic stenosis
C. Dynamic left ventricular outflow tract obstruction
D. Positive bubble study (Correct Answer)
E. Ventricular aneurysm

Explanation: ***Positive bubble study*** - The patient's symptoms, including **cyanosis** (**bluish tinge to the lips**), **clubbing**, and **right ventricular heave**, suggest **Eisenmenger syndrome**, a late complication of a **left-to-right shunt** that has reversed due to pulmonary hypertension. - A positive bubble study on echocardiography would confirm the presence of a **right-to-left shunt**, characteristic of Eisenmenger syndrome, by showing microbubbles crossing from the right to the left side of the heart. *Mitral insufficiency* - While mitral insufficiency can cause a murmur and heart failure symptoms, it does not typically lead to the **cyanosis** and **clubbing** described. - The absence of a murmur, despite a history of one, points away from a significant current insufficiency. *Aortic stenosis* - Aortic stenosis is characterized by an **ejection systolic murmur** that would likely be heard on examination, contradicting the scenario where no murmur is audible. - It usually presents with a different constellation of symptoms, such as angina, syncope, and heart failure, without the prominent cyanosis or clubbing seen here. *Dynamic left ventricular outflow tract obstruction* - This is characteristic of **hypertrophic obstructive cardiomyopathy (HOCM)**, which can cause exertional syncope. - However, HOCM does not typically lead to **cyanosis**, a **right ventricular heave**, or **clubbing**, which are strong indicators of a right-to-left shunt. *Ventricular aneurysm* - A ventricular aneurysm is a bulging of the ventricular wall, often a complication of a **myocardial infarction**, which is unlikely in a 27-year-old with a history of a "heart murmur since childhood." - It typically presents with symptoms related to heart failure, arrhythmias, or embolism, and would not explain the prominent **cyanosis** and **clubbing**.

Question 701: A 47-year-old man is brought to the emergency department by his wife 30 minutes after the onset of nausea, sweating, and palpitations. On the way to the hospital, he had an episode of non-bloody vomiting and intravenous fluid resuscitation has been started. He has no history of similar symptoms. For the past 2 weeks, he has been trying to lose weight and has adjusted his diet and activity level. He eats a low-carb diet and runs 3 times a week for exercise; he came home from a training session 3 hours ago. He was diagnosed with type 2 diabetes mellitus 2 years ago that is controlled with basal insulin and metformin. He appears anxious. His pulse is 105/min and blood pressure is 118/78 mm Hg. He is confused and oriented only to person. Examination shows diaphoresis and pallor. A fingerstick blood glucose concentration is 35 mg/dL. Shortly after, the patient loses consciousness and starts shaking. Which of the following is the most appropriate next step in management?

A. Administer intravenous dextrose (Correct Answer)
B. Administer intravenous phenoxybenzamine
C. Obtain an EEG
D. Administer intravenous lorazepam
E. Administer intramuscular glucagon

Explanation: ***Administer intravenous dextrose*** - The patient presents with severe **hypoglycemia** (fingerstick glucose 35 mg/dL) and associated neurological symptoms like confusion, disorientation, loss of consciousness, and seizures. **Intravenous dextrose** is the most rapid and effective treatment for severe hypoglycemia in a hospital setting. - Due to the rapid progression of symptoms, including loss of consciousness and shaking (suggesting a seizure), immediate administration of intravenous dextrose is critical to prevent further neurological damage. *Administer intravenous phenoxybenzamine* - **Phenoxybenzamine** is an alpha-blocker used to manage **pheochromocytoma**, a condition that can cause symptoms like palpitations, sweating, and hypertension but usually not severe hypoglycemia. - While pheochromocytoma can present with some similar symptoms, the patient's low blood glucose level clearly points to hypoglycemia as the primary acute issue, making phenoxybenzamine an inappropriate immediate treatment. *Obtain an EEG* - An **EEG (electroencephalogram)** is used to assess brain activity and diagnose seizure disorders or other neurological conditions. While the patient is seizing, the underlying cause is clearly identified as **hypoglycemia**. - Obtaining an EEG would delay critical treatment for hypoglycemia and is not the appropriate first step in a patient with an acutely reversible metabolic cause for seizures. *Administer intravenous lorazepam* - **Intravenous lorazepam** is a benzodiazepine used to treat acute seizures. While the patient is seizing, the cause of the seizure is severe hypoglycemia. - Treating the underlying hypoglycemia with dextrose will stop the seizure, making lorazepam unnecessary as the primary treatment unless the seizure persists after glucose correction. *Administer intramuscular glucagon* - **Intramuscular glucagon** is an appropriate treatment for severe hypoglycemia, particularly in an outpatient setting or when intravenous access is not immediately available. - However, in a hospital setting with established IV access, **intravenous dextrose** is the preferred and more rapid method to deliver glucose directly into the bloodstream for immediate effect.

Question 702: A 38-year-old male presents to his primary care physician complaining of increasing shortness of breath over the past 2 months. He reports experiencing an extended illness of several weeks as a child that required him to miss school. He is unsure but believes it involved a sore throat followed by a fever and joint pains. He does not recall seeing a physician or receiving treatment for this. Today, on physical examination, cardiac auscultation reveals an opening snap after the second heart sound followed by a diastolic murmur. A follow-up echocardiogram is conducted. Which of the following best explains the pathophysiology of this patient's condition?

A. Annular calcification
B. Congenital heart defect
C. Myocardial ischemia
D. Epitope homology (Correct Answer)
E. Atherosclerosis

Explanation: ***Epitope homology*** - The patient's history of a childhood illness involving a sore throat, fever, and joint pains strongly suggests **rheumatic fever**, which can lead to **rheumatic heart disease**. - **Epitope homology** refers to the molecular mimicry between streptococcal M protein antigens and self-antigens in cardiac tissue, leading to an autoimmune response that damages heart valves, primarily the **mitral valve**, causing **mitral stenosis** (opening snap and diastolic murmur). *Annular calcification* - **Annular calcification** primarily affects the mitral annulus in elderly patients and is often associated with age-related degenerative changes. - While it can cause mitral regurgitation or, less commonly, stenosis, it typically doesn't present with a history of childhood rheumatic fever. *Congenital heart defect* - **Congenital heart defects** are structural abnormalities present at birth, such as a bicuspid aortic valve, which can lead to murmurs. - While they can cause shortness of breath, the patient's history of a specific childhood illness followed by delayed cardiac symptoms is more consistent with an acquired condition like rheumatic heart disease. *Myocardial ischemia* - **Myocardial ischemia** is due to reduced blood flow to the heart muscle, most commonly from coronary artery disease, leading to symptoms like angina or shortness of breath. - It does not explain the audible **opening snap** or the specific **diastolic murmur** consistent with valvular stenosis, nor is it linked to a childhood illness involving a sore throat and joint pains. *Atherosclerosis* - **Atherosclerosis** is a systemic disease causing plaque buildup in arteries, leading to conditions like coronary artery disease or peripheral artery disease. - It is not the direct cause of valvular heart disease characterized by an **opening snap** and **diastolic murmur** in the context of a prior rheumatic fever episode.

Question 703: A 45-year-old woman presents with headaches. She says the headaches started about a month ago, and although initially, they were intermittent, over the past 2 weeks, they have progressively worsened. She describes the pain as severe, worse on the left than the right, and relieved somewhat by non-steroidal anti-inflammatory drugs (NSAIDs). The headaches are usually associated with nausea, vomiting, and photophobia. She denies any changes in vision, seizures, similar past symptoms, or focal neurologic deficits. Past medical history is significant for a posterior communicating artery aneurysm, status post-clipping 10 years ago. Her vital signs include: blood pressure 135/90 mm Hg, temperature 36.7°C (98.0°F), pulse 80/min, and respiratory rate 14/min. Her body mass index (BMI) is 36 kg/m2. On physical examination, the patient is alert and oriented. Her pupils are 3 mm on the right and mid-dilated on the left with subtle left-sided ptosis. Ophthalmic examination reveals a cup-to-disc ratio of 0.4 on the right and 0.5 on the left. The remainder of her cranial nerves are intact. She has 5/5 strength and 2+ reflexes in her upper extremities bilaterally and her left leg; her right leg has 3/5 strength with 1+ reflexes at the knee and ankle. The remainder of the physical examination is unremarkable. Which of the following findings in this patient most strongly suggests a further diagnostic workup?

A. Photophobia
B. Age of onset
C. Obesity
D. Left eye findings (Correct Answer)
E. Right-sided weakness

Explanation: ***Left eye findings*** - The combination of **left-sided mid-dilated pupil** and **subtle left-sided ptosis** points towards a **left oculomotor nerve (CN III) palsy**. This, in a patient with a history of a **posterior communicating artery aneurysm**, is a critical red flag for aneurysm re-rupture or expansion. - CN III palsy can cause progressive headaches and is a neurological emergency requiring urgent imaging to rule out pathologies like aneurysm expansion or hemorrhage. *Photophobia* - **Photophobia** is a common symptom associated with many types of headaches, including migraines, and by itself, does not strongly suggest a specific serious underlying pathology requiring immediate further workup. - While it contributes to the headache symptom complex, it lacks the specificity of the observed objective neurological signs. *Age of onset* - While the onset of new, severe headaches in a middle-aged adult warrants evaluation, the patient's age (45) for new-onset headaches is not as alarming as the objective neurological deficits present. - Headaches can develop at any age, and other features in this presentation are more indicative of an acute problem. *Obesity* - **Obesity** (BMI 36 kg/m2) is a risk factor for several conditions, including **idiopathic intracranial hypertension (pseudotumor cerebri)**, which can cause headaches. - However, obesity itself does not directly explain the acute and progressive nature of these headaches or the specific left eye findings. *Right-sided weakness* - The **right-sided weakness** (3/5 strength in the right leg with 1+ reflexes) is a lateralizing sign suggesting a central neurological lesion, likely in the contralateral brain. - While this finding is significant and requires investigation, the **left eye findings** (ptosis and dilated pupil) are more acutely concerning given the patient's history of a posterior communicating artery aneurysm, which directly impacts the third cranial nerve.

Question 704: A 52-year-old woman comes to the physician because of swelling of her legs for 2 months. She has noticed that her legs gradually swell up throughout the day. Two years ago, she underwent a coronary angioplasty. She has hypertension and coronary artery disease. She works as a waitress at a local diner. Her father died of liver cancer at the age of 61 years. She has smoked one pack of cigarettes daily for 31 years. She drinks one to two glasses of wine daily and occasionally more on weekends. Current medications include aspirin, metoprolol, and rosuvastatin. Vital signs are within normal limits. Examination shows 2+ pitting edema in the lower extremities. There are several dilated, tortuous veins over both calves. Multiple excoriation marks are noted over both ankles. Peripheral pulses are palpated bilaterally. The lungs are clear to auscultation. Cardiac examination shows no murmurs, gallops, or rubs. The abdomen is soft and nontender; there is no organomegaly. Which of the following is the most appropriate next step in management?

A. Sclerotherapy
B. CT scan of abdomen and pelvis
C. Compression stockings (Correct Answer)
D. Abdominal ultrasound
E. Adjust antihypertensive medication

Explanation: ***Compression stockings*** - The patient presents with **bilateral pitting edema**, **dilated, tortuous veins** (varicose veins), and symptoms that worsen throughout the day, which are classic signs of **chronic venous insufficiency (CVI)**. - Her occupation as a waitress (prolonged standing) is a significant risk factor for CVI. - **Compression stockings** are the first-line conservative treatment for CVI, helping to reduce edema and improve venous return. *Sclerotherapy* - **Sclerotherapy** is a procedure used to treat varicose veins by injecting a solution to close them. - While it can be an option for varicose veins, it is typically considered after conservative measures like compression stockings have been tried and found to be insufficient, or for cosmetic reasons. *CT scan of abdomen and pelvis* - A **CT scan of the abdomen and pelvis** would be used to investigate more serious causes of edema, such as malignancy with IVC compression or lymphatic obstruction. - Given the classic presentation of CVI with visible varicose veins, a CT scan is not the appropriate initial step. *Adjust antihypertensive medication* - The patient's vital signs are within normal limits, and her current medications (aspirin, metoprolol, rosuvastatin) are appropriate for her cardiac history. - Metoprolol (a beta-blocker) does not typically cause peripheral edema; dihydropyridine calcium channel blockers would be more likely to cause peripheral edema, but she is not on these medications. *Abdominal ultrasound* - An **abdominal ultrasound** could be used to evaluate for liver disease or ascites, but the patient has no signs of hepatic dysfunction (no jaundice, ascites, or hepatomegaly). - The prominent varicose veins and bilateral pitting edema that worsens with prolonged standing strongly point toward chronic venous insufficiency, making conservative management the appropriate first step.

Question 705: A 51-year-old woman comes to the physician because of worsening chest pain on exertion. She was diagnosed with coronary artery disease and hyperlipidemia 3 months ago. At the time of diagnosis, she was able to walk for 15 minutes on the treadmill until the onset of chest pain. Her endurance had improved temporarily after she began medical treatment and she was able to walk her dog for 30 minutes daily without experiencing chest pain. Her current medications include daily aspirin, metoprolol, atorvastatin, and isosorbide dinitrate four times daily. Her pulse is 55/min and blood pressure is 115/78 mm Hg. Treadmill walking test shows an onset of chest pain after 18 minutes. Which of the following is most likely to improve this patient’s symptoms?

A. Increase dose of daily metoprolol
B. Avoid isosorbide dinitrate at night (Correct Answer)
C. Add tadalafil to medication regimen
D. Decrease amount of aerobic exercise
E. Discontinue atorvastatin therapy

Explanation: ***Avoid isosorbide dinitrate at night*** - This patient's symptoms are worsening despite ongoing treatment, suggesting they may be developing **nitrate tolerance**. **Daily or frequent use of nitrates** (like isosorbide dinitrate four times daily) can lead to desensitization of the vascular smooth muscle cells. - To prevent or reverse nitrate tolerance, a **nitrate-free interval** of 8-12 hours is recommended, typically overnight, which allows for resensitization of the vascular endothelium. *Increase dose of daily metoprolol* - The patient's pulse is 55/min, which is already at the lower end of the target range for **beta-blockers** in stable angina (55-60 bpm). - Increasing the metoprolol dose further would likely cause **bradycardia** and could potentially worsen symptoms or cause side effects like fatigue. *Add tadalafil to medication regimen* - **Tadalafil** is a phosphodiesterase-5 inhibitor and is **contraindicated** in patients taking nitrates due to the risk of severe **hypotension**. - The patient is currently on isosorbide dinitrate, making combined use unsafe. *Decrease amount of aerobic exercise* - **Regular aerobic exercise** is an important component of cardiac rehabilitation and overall cardiovascular health for patients with coronary artery disease. - Decreasing exercise would go against established guidelines for managing CAD and could worsen her cardiovascular fitness. *Discontinue atorvastatin therapy* - **Atorvastatin** is a HMG-CoA reductase inhibitor essential for managing **hyperlipidemia** and **reducing cardiovascular risk** in patients with coronary artery disease. - Discontinuing it would increase her risk of adverse cardiovascular events and is not indicated.

Question 706: A 39-year-old woman comes to the physician because of a 5-month history of episodic retrosternal chest pain. She currently feels well. The pain is unrelated to exercise and does not radiate. The episodes typically last less than 15 minutes and lead to feelings of anxiety; resting relieves the pain. She has not had dyspnea or cough. She has hyperlipidemia treated with simvastatin. She does not smoke, drink alcohol, or use illicit drugs. Her temperature is 37°C (98.6°F), pulse is 104/min, respirations are 17/min, and blood pressure is 124/76 mm Hg. Cardiopulmonary examination shows no abnormalities. An ECG shows sinus tachycardia. Which of the following is the most appropriate next step in the evaluation of coronary artery disease in this patient?

A. Nuclear exercise stress test
B. No further testing needed
C. Troponin I measurement
D. Dobutamine stress echocardiography
E. Coronary CT angiogram (Correct Answer)

Explanation: ***Coronary CT angiogram*** - This patient has symptoms (non-exertional chest pain) raising suspicion for coronary artery disease (CAD), but her pre-test probability is low due to young age, female gender, and non-anginal features, making **coronary CT angiogram** an appropriate non-invasive first-line test. - CT angiogram offers high sensitivity for detecting **coronary atherosclerosis** and can rule out CAD in patients with low-to-intermediate pretest probability. *Nuclear exercise stress test* - This test is typically reserved for patients with a **higher pre-test probability of CAD** or those with equivocal initial findings, as it involves radiation exposure and is more resource-intensive. - The patient's chest pain is **unrelated to exercise**, making an exercise-based stress test less directly relevant as a first-line diagnostic. *No further testing needed* - While the patient's symptoms are atypical, her risk factor (hyperlipidemia) and recurrent retrosternal pain warrant further evaluation to **rule out CAD**, even with a low pre-test probability. - Dismissing symptoms without further testing could miss early or atypical presentations of CAD. *Troponin I measurement* - **Troponin I** is used to diagnose **acute myocardial infarction** and indicates active myocardial necrosis; it is not for evaluating chronic, episodic chest pain in a patient who currently feels well. - Her current well-being and the episodic nature of her pain make acute cardiac injury unlikely, and a normal troponin would not rule out underlying CAD. *Dobutamine stress echocardiography* - **Dobutamine stress echocardiography** is typically used for patients who cannot perform an exercise stress test (e.g., due to mobility issues) or when an exercise ECG is non-diagnostic. - Given the patient's ability to exert herself (implied by no known mobility issues) and a non-exertional pain pattern, a CT angiogram offers superior anatomical detail for initial investigation.

Question 707: A 61-year-old woman comes to her physician for a burning sensation and numbness in her right hand for 4 weeks. The burning sensation is worse at night and is sometimes relieved by shaking the wrist. In the past week, she has noticed an exacerbation of her symptoms. She has rheumatoid arthritis and type 2 diabetes mellitus. Her medications include insulin, methotrexate, and naproxen. Her vital signs are within normal limits. Examination shows swan neck deformities of the fingers on both hands and multiple subcutaneous nodules over bilateral olecranon processes. There is tingling and numbness over the right thumb, index finger, and middle finger when the wrist is actively flexed. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next best step in management?

A. Initiate sulfasalazine therapy
B. Volar splinting (Correct Answer)
C. Vitamin B6 supplementation
D. Initiate azathioprine therapy
E. Physiotherapy

Explanation: ***Volar splinting*** - The patient presents with classic symptoms of **carpal tunnel syndrome (CTS)**, including burning, numbness, and tingling in the distribution of the **median nerve** (thumb, index, and middle fingers), worse at night, and relieved by shaking the wrist (**flick sign**). - **Volar splinting** of the wrist in a neutral position is the first-line treatment for CTS as it reduces pressure on the median nerve, particularly at night. *Initiate sulfasalazine therapy* - **Sulfasalazine** is a **disease-modifying antirheumatic drug (DMARD)** used to treat rheumatoid arthritis, but it would not address the acute symptoms of carpal tunnel syndrome. - The patient is already on **methotrexate**, another DMARD, and there is no indication that her rheumatoid arthritis is poorly controlled in a way that would necessitate adding another DMARD for joint inflammation, separate from her neuropathic symptoms. *Vitamin B6 supplementation* - **Vitamin B6 (pyridoxine)** supplementation is sometimes considered for peripheral neuropathies, but there is no strong evidence for its efficacy in treating typical carpal tunnel syndrome. - While some studies have explored its use in specific cases, it is not a recommended first-line treatment for CTS and is not as effective as splinting. *Initiate azathioprine therapy* - **Azathioprine** is an **immunosuppressant** and DMARD used in the treatment of more severe rheumatoid arthritis or when other DMARDs are ineffective. - Similar to sulfasalazine, it would target systemic inflammation related to rheumatoid arthritis but would not directly treat the localized nerve compression causing carpal tunnel syndrome. *Physiotherapy* - While **physiotherapy** can be beneficial for strengthening and improving flexibility in the hand and wrist, it is generally considered a supportive therapy for carpal tunnel syndrome and is not typically the first-line management for acute symptoms. - **Volar splinting** is usually initiated first to stabilize the wrist and reduce nerve compression, with physiotherapy potentially added later as part of a comprehensive treatment plan or if splinting alone is insufficient.

Question 708: A 26-year-old man is brought to the emergency department due to right-sided facial and upper extremity weakness and aphasia. The patient was in his usual state of health until two hours prior to presentation, when he was eating breakfast with a friend and acutely developed the aforementioned symptoms. Medical history is unremarkable except for mild palpitations that occur during times of stress or when drinking coffee. Physical examination is consistent with the clinical presentation. Laboratory testing is unremarkable and a 12-lead electrocardiogram is normal. A non-contrast head CT and diffusion-weighted MRI shows no intracranial hemorrhage and an isolated superficial cerebral infarction. Transthoracic echocardiography with agitated saline mixed with air shows microbubbles in the left heart. There is a possible minor effusion surrounding the heart and the ejection fraction is within normal limits. Which of the following is most likely the cause of this patient's clinical presentation?

A. Aortic embolism
B. Amyloid deposition within vessels
C. Cardiac arrhythmia
D. Berry aneurysm rupture
E. Patent foramen ovale (Correct Answer)

Explanation: ***Patent foramen ovale*** - The presence of **microbubbles in the left heart** after agitated saline injection, combined with a **superficial cerebral infarction** in a young patient with an otherwise unremarkable medical history, is highly suggestive of a **paradoxical embolism** through a patent foramen ovale (PFO). - A PFO allows venous clots to bypass the pulmonary circulation and enter the systemic arterial circulation, leading to a stroke. *Aortic embolism* - While an aortic embolism can lead to stroke, there is no evidence provided (e.g., severe **aortic atherosclerosis**, valvular disease) to suggest an aortic source for the embolism. - The echocardiogram showing microbubbles passing from right to left heart points more strongly towards an intracardiac shunt. *Amyloid deposition within vessels* - **Cerebral amyloid angiopathy** typically affects older individuals and presents with **lobar hemorrhages** rather than isolated ischemic stroke. - Furthermore, there is no imaging or pathological evidence to suggest amyloid deposition. *Cardiac arrhythmia* - Although **cardiac arrhythmias** (e.g., **atrial fibrillation**) are a common cause of embolic stroke, the **normal 12-lead ECG** and the specific echocardiographic finding of microbubbles crossing the heart make an arrhythmia less likely to be the direct cause of this specific embolic event. - The mild palpitations are non-specific and are likely stress-induced. *Berry aneurysm rupture* - **Berry aneurysm rupture** causes a **subarachnoid hemorrhage**, which would be visible on non-contrast CT and would present with sudden, severe headache, not an isolated ischemic stroke. - The imaging showed no intracranial hemorrhage, ruling out this diagnosis.

Question 709: A 25-year-old female presents to a physician's office with complaints of having no energy for the last 2 weeks and sometimes feeling like staying home all day. She works for a technology start-up company and is attending graduate school part-time in the evening. She is very concerned about her health and tries to eat a balanced diet. She runs daily and takes yoga classes 3 times a week. She gets together with her friends every weekend and has continued to do so the last few weeks. Her schedule is quite hectic, and she is always on the go. There have been no changes in her sleep, appetite, or daily routine. She denies having flu-like symptoms, headaches, body aches, indigestion, weight loss, agitation, or restlessness. She admits to moderate drinking and marijuana use but has never smoked cigarettes. The medical history is unremarkable, and she takes no medications other than vitamin C for cold prevention. A friend suggested she take an herbal product containing ginseng and St. John's wort for her decreased energy levels. Her body mass index (BMI) is 22 kg/m2. The physical examination reveals no findings and lab testing shows the following: Sodium 138 mEq/L Potassium 3.9 mEq/L Chloride 101 mEq/L Thyroid stimulating hormone 3.5 μU/mL Hemoglobin (Hb%) 13.5 g/dL Mean corpuscular hemoglobin (MCH) 31 pg Mean corpuscular volume (MCV) 85 fL Leucocyte count 5000/mm3 Platelet count 250,000/mm3 The physician advises her to reduce the alcohol consumption and marijuana use. What else should she be advised?

A. She is likely over-exerted and taking the herbal supplements has no proven medical benefit. (Correct Answer)
B. She should increase her diet so that she has more energy to go about her day.
C. She should start with the herbal product and return if her energy level does not improve in 2 weeks.
D. She is taking excessive vitamin C and it is causing her low energy levels.
E. She should not take St. John's wort because of potential drug interactions with antidepressants.

Explanation: ***She is likely over-exerted and taking the herbal supplements has no proven medical benefit.*** - The patient's **hectic schedule**, combining full-time work, part-time graduate school, and regular intense exercise, strongly suggests **over-exertion** as the cause of her low energy. - While herbal remedies like ginseng and St. John's wort are often marketed for energy and mood, their efficacy for these specific complaints is **not scientifically proven**, and they can carry risks of side effects or interactions. *She should increase her diet so that she has more energy to go about her day.* - The patient reports eating a **balanced diet** and has a normal **BMI of 22 kg/m2**, making dietary insufficiency an unlikely cause of her fatigue. - Her routine and lack of weight changes suggest her caloric intake is likely **adequate** for her activity level. *She should start with the herbal product and return if her energy level does not improve in 2 weeks.* - Advising herbal products like St. John's wort is generally not recommended due to **unproven efficacy**, potential **drug interactions** (especially with other medications not mentioned but possible in the future), and **adverse effects**. - It is crucial to address the underlying cause (likely **over-exertion**) rather than suggesting unverified remedies. *She is taking excessive vitamin C and it is causing her low energy levels.* - There is **no evidence** to suggest that vitamin C intake, even in larger doses for cold prevention, causes **low energy levels** or fatigue. - Excessive vitamin C is primarily associated with **gastrointestinal upset** or kidney stones, not lethargy. *She should not take St. John's wort because of potential drug interactions with antidepressants.* - While St. John's wort does have significant interactions with antidepressants and many other medications due to its effect on the **CYP3A4 enzyme** and **P-glycoprotein**, the patient is not currently taking antidepressants. - Though an important consideration for future medication, this specific reason currently does not apply directly to her case as her immediate problem is likely over-exertion, and her current medication list is minimal.

Question 710: A 52-year-old woman presents to her primary care physician complaining of 3 weeks of persistent thirst despite consumption of increased quantities of water. She also admits that she has had increased frequency of urination during the same time period. A basic metabolic panel is performed which reveals mild hypernatremia and a normal glucose level. Urine electrolytes are then obtained which shows a very low urine osmolality that does not correct when a water deprivation test is performed. Blood tests reveal an undetectable level of antidiuretic hormone (ADH). Based on this information, what is the most likely cause of this patient's symptoms?

A. Diabetes mellitus
B. Central diabetes insipidus (Correct Answer)
C. Primary polydipsia
D. Surreptitious diuretic use
E. Nephrogenic diabetes insipidus

Explanation: ***Central diabetes insipidus*** - The patient presents with **polyuria**, **polydipsia**, **hypernatremia**, and a **low urine osmolality** that does not correct with a **water deprivation test**. - An **undetectable ADH level** confirms a defect in ADH production or release from the pituitary, which is characteristic of central diabetes insipidus. *Diabetes mellitus* - This condition is characterized by **hyperglycemia**, which is ruled out by the **normal glucose level** in the basic metabolic panel. - While it causes polyuria and polydipsia, the underlying mechanism is **osmotic diuresis due to glucose**, not a defect in ADH or renal response to ADH. *Primary polydipsia* - In primary polydipsia, patients consume excessive amounts of water, leading to **dilutional hyponatremia** rather than hypernatremia. - The **ADH levels would be appropriately suppressed** in a patient with primary polydipsia, not undetectable. *Surreptitious diuretic use* - Diuretic use would typically lead to **low blood pressure**, **electrolyte imbalances** (e.g., hypokalemia), and a **high urine sodium concentration**, none of which are explicitly mentioned here. - It would also not result in an **undetectable ADH level** in the absence of an underlying ADH deficiency. *Nephrogenic diabetes insipidus* - This condition involves the **kidneys' inability to respond to ADH**, leading to similar symptoms of polyuria and polydipsia with low urine osmolality. - However, in nephrogenic diabetes insipidus, the **ADH levels would be high or normal** as the pituitary is producing ADH, but the kidneys are not responding.

Question 711: A 20-year-old woman is brought to the emergency department because of severe muscle soreness, nausea, and darkened urine for 2 days. The patient is on the college track team and has been training intensively for an upcoming event. One month ago, she had a urinary tract infection and was treated with nitrofurantoin. She appears healthy. Her temperature is 37°C (98.6°F), pulse is 64/min, and blood pressure is 110/70 mm Hg. Cardiopulmonary examination shows no abnormalities. The abdomen is soft and non-tender. There is diffuse muscle tenderness over the arms, legs, and back. Laboratory studies show: Hemoglobin 12.8 g/dL Leukocyte count 7,000/mm3 Platelet count 265,000/mm3 Serum Creatine kinase 22,000 U/L Lactate dehydrogenase 380 U/L Urine Blood 3+ Protein 1+ RBC negative WBC 1–2/hpf This patient is at increased risk for which of the following complications?

A. Myocarditis
B. Metabolic alkalosis
C. Compartment syndrome
D. Acute kidney injury (Correct Answer)
E. Hemolytic anemia

Explanation: ***Acute kidney injury*** - The patient's elevated **creatine kinase (CK)** of 22,000 U/L, muscle soreness, and dark urine (positive for blood but negative for red blood cells) are all indicative of **rhabdomyolysis**. - **Rhabdomyolysis** releases large amounts of myoglobin, which is nephrotoxic and can precipitate in the renal tubules, leading to **acute tubular necrosis** and subsequent acute kidney injury. *Myocarditis* - While CK elevations can be seen in myocarditis, this patient's presentation is dominated by **skeletal muscle symptoms** and a history of intense exercise. - There are no specific cardiac symptoms or signs (e.g., chest pain, arrhythmias) to suggest myocardial involvement. *Metabolic alkalosis* - Rhabdomyolysis typically causes **metabolic acidosis** due to the release of cellular contents, including phosphate and sulfate. - There is no clinical or lab evidence (e.g., vomiting, diuretic use) to suggest metabolic alkalosis. *Compartment syndrome* - **Compartment syndrome** involves increased pressure within a muscle compartment, leading to pain, pallor, paresthesia, pulselessness, and paralysis. - While rhabdomyolysis can occasionally lead to severe swelling that causes compartment syndrome, the diffuse muscle tenderness and absence of focal limb findings make it less likely as the primary direct complication. *Hemolytic anemia* - Though the urine is positive for blood and negative for RBCs, this is characteristic of **myoglobinuria**, not hemoglobinuria, which would indicate hemolytic anemia. - The patient's **hemoglobin** is normal (12.8 g/dL), and there are no other signs of hemolysis (e.g., jaundice, reticulocytosis).

Question 712: Four days after undergoing a craniotomy and evacuation of a subdural hematoma, a 56-year-old man has severe pain and swelling of his right leg. He has chills and nausea. He has type 2 diabetes mellitus and chronic kidney disease, and was started on hemodialysis 2 years ago. Prior to admission, his medications were insulin, enalapril, atorvastatin, and sevelamer. His temperature is 38.3°C (101°F), pulse is 110/min, and blood pressure is 130/80 mm Hg. Examination shows a swollen, warm, and erythematous right calf. Dorsiflexion of the right foot causes severe pain in the right calf. The peripheral pulses are palpated bilaterally. Cardiopulmonary examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.1 g/dL Leukocyte count 11,800/mm3 Platelet count 230,000/mm3 Serum Glucose 87 mg/dL Creatinine 1.9 mg/dL Which of the following is the most appropriate next step in treatment?

A. Urokinase therapy
B. Iliac stenting
C. Warfarin therapy
D. Unfractionated heparin therapy (Correct Answer)
E. Inferior vena cava filter

Explanation: ***Unfractionated heparin therapy*** - The patient presents with classic symptoms of **deep vein thrombosis (DVT)**, including unilateral leg pain, swelling, warmth, erythema, and a positive Homan's sign (pain on dorsiflexion). The recent craniotomy places him at high risk for DVT. - **Unfractionated heparin is the anticoagulant of choice** for this patient due to TWO critical factors: 1. **Recent craniotomy (4 days ago)**: Requires a rapidly reversible anticoagulant in case of intracranial bleeding; UFH can be reversed with protamine sulfate 2. **Chronic kidney disease on hemodialysis**: Low molecular weight heparin (LMWH) is contraindicated in severe renal failure (CrCl <30 mL/min) as it is renally eliminated and increases bleeding risk. UFH is not renally cleared and can be monitored with aPTT. *Urokinase therapy* - **Urokinase is a thrombolytic agent** used to dissolve existing clots, primarily in cases of massive pulmonary embolism or severe DVT with limb-threatening ischemia (phlegmasia cerulea dolens). - Given the patient's **recent craniotomy and subdural hematoma evacuation**, thrombolytic therapy is **absolutely contraindicated** due to very high risk of intracranial hemorrhage. Recent neurosurgery is a contraindication for at least 2-4 weeks. *Iliac stenting* - **Iliac vein stenting** is a procedure typically used to treat chronic **iliac vein compression** (e.g., May-Thurner syndrome) or chronic post-thrombotic obstruction. - This is an **acute DVT presentation** (4 days post-op) with no indication of chronic iliac vein compression or obstruction. Stenting has no role in acute DVT management. *Warfarin therapy* - **Warfarin is an oral anticoagulant** used for long-term DVT treatment but has a **delayed onset of action** (requires 5-7 days to reach therapeutic INR). - It is **not suitable for acute initial treatment** of DVT, especially in a patient requiring rapid anticoagulation. Warfarin must be overlapped with parenteral anticoagulation (heparin) initially. - Additionally, warfarin dosing is complex in dialysis patients due to altered vitamin K metabolism. *Inferior vena cava filter* - An **IVC filter** is indicated for patients with DVT who have an **absolute contraindication to anticoagulation** (e.g., active bleeding, recent hemorrhagic stroke) or who develop recurrent thromboembolism despite adequate anticoagulation. - This patient **does not have a contraindication to anticoagulation**. While he had recent neurosurgery, unfractionated heparin is safe to use with careful monitoring and is rapidly reversible if needed. - IVC filters have significant complications (thrombosis, filter migration, IVC perforation) and should be avoided when anticoagulation is feasible.

Question 713: A 68-year-old man presents to the emergency department complaining of difficulty in breathing for the past 2 days. He has had recurrent episodes of bacterial pneumonia in the right lower lobe during the last 6 months. His last episode of pneumonia started 7 days ago for which he is being treated with antibiotics. He has a 35-pack-year smoking history. Past medical history is significant for hypertension for which he takes lisinopril. Physical examination reveals decreased breath sounds and dullness to percussion in the right lung base. Chest X-ray reveals a large right-sided pleural effusion, and chest CT scan shows a large mass near the hilum of the right lung. Cytologic examination of pleural fluid shows evidence of malignancy. Which of the following is the most likely diagnosis of this patient?

A. Small cell lung cancer
B. Non-small cell lung cancer (Correct Answer)
C. Metastatic lung disease
D. Pulmonary hamartoma
E. Mesothelioma

Explanation: ***Non-small cell lung cancer*** - The patient's **35-pack-year smoking history**, recurrent **right lower lobe pneumonia**, large **pleural effusion**, and a **hilar mass** with **malignant cells** in the pleural fluid are highly suggestive of **non-small cell lung cancer (NSCLC)**. - NSCLC is the most common type of lung cancer and often presents with features like **post-obstructive pneumonia** due to airway obstruction by the tumor, and **pleural effusions** indicating advanced disease. *Small cell lung cancer* - While associated with smoking and can present with hilar masses, **small cell lung cancer (SCLC)** typically has a more aggressive course with earlier onset of paraneoplastic syndromes and widespread metastases at diagnosis. - The presenting features in this case, particularly the recurrent pneumonia and large pleural effusion, are more commonly seen with NSCLC. *Metastatic lung disease* - Metastatic lung disease would imply cancer originating from another primary site, but the presence of a **large hilar mass** points to a lung primary. - While metastases can cause pleural effusions, the clinical picture strongly favors a **primary lung malignancy** in a heavy smoker. *Pulmonary hamartoma* - A **pulmonary hamartoma** is a benign tumor and would not cause a large pleural effusion with malignant cells or recurrent pneumonia due to airway obstruction. - They are typically asymptomatic and discovered incidentally. *Mesothelioma* - **Mesothelioma** is a rare cancer primarily associated with **asbestos exposure**, which is not mentioned in the patient's history. - It arises from the pleura and often presents with a diffuse pleural thickening rather than a distinct hilar mass.

Question 714: An 82-year-old man presents to the emergency department complaining of vision loss in his left eye. He states that it suddenly appeared as if a curtain was coming down over his left eye. It resolved after five minutes, and his vision has returned to normal. He has a history of coronary artery disease and type 2 diabetes. What is the most likely cause of this patient's presentation?

A. Cholesterol plaque embolization (Correct Answer)
B. Sclerosis and narrowing of retinal vessels
C. Deposition of retinal metabolism byproducts
D. Increased intraocular pressure due to a defect in the drainage of aqueous humor
E. Inflammation of the optic nerve

Explanation: ***Cholesterol plaque embolization*** - The sudden, transient vision loss described as a "**curtain coming down**" (amaurosis fugax) is highly suggestive of a **transient ischemic attack (TIA)** to the retina, often caused by **atheroemboli** from the carotid arteries. - The patient's history of **coronary artery disease** and **type 2 diabetes** increases his risk of atherosclerosis and subsequent embolization. *Sclerosis and narrowing of retinal vessels* - While **retinal vessel sclerosis** can occur in patients with diabetes and hypertension, it typically leads to **gradual and permanent vision changes**, not sudden, transient episodes. - **Chronic retinal ischemia**, rather than acute embolic events, is the usual manifestation of severe vascular narrowing. *Deposition of retinal metabolism byproducts* - The deposition of metabolic byproducts is characteristic of **macular degeneration**, which causes **progressive, central vision loss** and distortion, not episodic "curtain-like" vision loss. - This process is typically **slow and chronic**, differing from the acute, resolving symptoms presented. *Increased intraocular pressure due to a defect in the drainage of aqueous humor* - **Increased intraocular pressure** (glaucoma) leads to **gradual, peripheral vision loss** and can cause acute pain and blurry vision in angle-closure glaucoma, but not transient, curtain-like vision loss. - **Amaurosis fugax** is not a typical presentation for glaucoma. *Inflammation of the optic nerve* - **Optic neuritis** causes **acute vision loss** often accompanied by **pain with eye movement** and can be associated with demyelinating diseases. - However, the vision loss in optic neuritis is typically **sustained** rather than transient and resolving within minutes.

Question 715: A 30-year-old woman presents to the clinic for a 3-month history of painful hair loss. She was in her usual state of health until about 3 months ago when she started to develop some painfully itchy spots across her scalp. Since that time these spots have lost hair and scarred, with new spots continuing to form. On further questioning, she shares that, for the last couple of years, she has generally felt poorly, specifically noting intermittent fevers, muscle and joint pains, and fatigue. On physical exam, she has several erythematous and scaly plaques across her scalp. These areas have no hair growth, but some do demonstrate hyperpigmentation. Which of the following is the most likely diagnosis?

A. Trichotillomania
B. Secondary syphilis
C. Alopecia areata
D. Discoid lupus erythematosus (DLE) (Correct Answer)
E. Tinea capitis

Explanation: **Discoid lupus erythematosus (DLE)** - The patient's presentation with **painful, itchy spots** on the scalp that result in **scarred, hairless plaques** with **hyperpigmentation** is classic for DLE. - The systemic symptoms of **intermittent fevers, muscle/joint pains, and fatigue** suggest an underlying systemic autoimmune process, often seen in association with DLE, which can be part of Systemic Lupus Erythematosus (SLE) or occur in isolation. *Trichotillomania* - This is a psychiatric disorder characterized by **compulsive hair pulling**, leading to irregular patches of hair loss without inflammation or scarring. - The presence of **pain, itching, erythema, scaling, and scarring** in this patient is inconsistent with trichotillomania. *Secondary syphilis* - While secondary syphilis can cause hair loss (often described as "moth-eaten" alopecia) and systemic symptoms, it typically presents with a **diffuse maculopapular rash** on the trunk and extremities, including palms and soles, which is not described here. - The distinctive **scarring and hyperpigmentation** of the scalp lesions are also not typical of secondary syphilis. *Alopecia areata* - This condition presents with **sudden, non-scarring hair loss** in circular or oval patches, often in asymptomatic areas. - Unlike the current case, there is no significant inflammation, pain, itching, scaling, or scarring associated with alopecia areata. *Tinea capitis* - This fungal infection of the scalp typically causes **scaly, erythematous patches with broken hairs** (black dots) and can be itchy, but it usually does not lead to significant scarring or hyperpigmentation as prominently described. - While systemic symptoms can sometimes be present in severe cases, the constellation of symptoms including pronounced scarring and systemic complaints points away from a primary fungal infection.

Question 716: A 25-year-old woman is being evaluated due to complaint of fatigue and voiding pink urine. The laboratory results are as follows: Hb 6.7 Red blood cell count 3.0 x 1012/L Leukocyte count 5,000/mm3 Platelets 170 x 109/L Reticulocyte count 6% Hematocrit 32% The physician thinks that the patient is suffering from an acquired mutation in hematopoietic stem cells, which is confirmed by flow cytometry analysis that revealed these cells are CD 55 and CD 59 negative. However, the physician is interested in knowing the corrected reticulocyte count before starting the patient on eculizumab. What value does the physician find after calculating the corrected reticulocyte count?

A. 3.1%
B. 0.4%
C. 0.1%
D. 0.6%
E. 4.6% (Correct Answer)

Explanation: ***4.6%*** - The corrected reticulocyte count accounts for the degree of anemia by adjusting for the patient's hematocrit compared to normal. - **Formula: Corrected Retics% = Observed Retics% × (Patient's Hct / Normal Hct)** - Using normal Hct of 42% for women: 6% × (32/42) = 6% × 0.76 = **4.56% ≈ 4.6%** - This reflects the actual reticulocyte production capacity adjusted for the anemic state. *3.1%* - This value might result from using an incorrect normal hematocrit value in the calculation. - For example, using 6% × (32/60) would give approximately 3.2%, suggesting use of an inappropriately high reference value. *0.4%* - This value likely results from applying the **Reticulocyte Production Index (RPI)** formula, which includes a maturation factor correction: 6% × (32/42) × (1/2.5) = 1.82%, then with further error. - Such a low value from formula misapplication does not represent the standard corrected reticulocyte count requested. *0.1%* - This extremely low value would indicate **severe calculation error** or bone marrow failure, which contradicts the observed 6% reticulocyte count. - In PNH with hemolysis, reticulocyte production is typically increased, making this value implausible. *0.6%* - This incorrect value could result from mathematical errors in applying correction factors or using the wrong hematocrit values in the formula. - The standard corrected reticulocyte formula would not yield this value with the given parameters.

Question 717: A 70-year-old man with a recent above-the-knee amputation of the left lower extremity, due to wet gangrene secondary to refractory peripheral artery disease, presents with weakness and dizziness. He says that the symptoms began acutely 24 hours after surgery and have not improved. The amputation was complicated by substantial blood loss. He was placed on empiric antibiotic therapy with ciprofloxacin and clindamycin before the procedure, and blood and wound culture results are still pending. The medical history is significant for type 2 diabetes mellitus and hypertension. Current medications are metformin and lisinopril. The family history is significant for type 2 diabetes mellitus in both parents. Review of symptoms is significant for palpitations and a mild headache for the past 24 hours. His temperature is 38.2°C (100.8°F); blood pressure, 120/70 mm Hg (supine); pulse, 102/min; respiratory rate, 16/min; and oxygen saturation, 99% on room air. When standing, the blood pressure is 90/65 mm Hg and the pulse is 115/min. On physical examination, the patient appears pale and listless. The surgical amputation site does not show any signs of ongoing blood loss or infection. Laboratory tests and an ECG are pending. Which of the following is the next best step in management?

A. Administer IV fluids
B. Administer oral fludrocortisone
C. Administer IV norepinephrine
D. Administer oral midodrine
E. Administer IV fluids and withhold lisinopril (Correct Answer)

Explanation: ***Administer IV fluids and withhold lisinopril*** - The patient's **postural orthostatic hypotension** (blood pressure drop upon standing) and symptoms (weakness, dizziness, palpitations, pallor) following significant blood loss during surgery strongly suggest **hypovolemia**, which should be managed immediately with IV fluids. - **Lisinopril**, an ACE inhibitor, can exacerbate hypotension by blocking angiotensin II-mediated vasoconstriction and aldosterone secretion, so withholding it is crucial in this hypotensive patient. *Administer IV fluids* - While administration of IV fluids is a correct component of management for hypovolemia, it is incomplete without addressing potential medication-induced hypotension in this patient. - Simply administering IV fluids without withholding **lisinopril** may lead to suboptimal correction of the patient's hypotension. *Administer oral fludrocortisone* - **Fludrocortisone** is a mineralocorticoid used primarily for chronic orthostatic hypotension, such as in autonomic dysfunction, and would not be appropriate for acute, likely hypovolemia-induced hypotension in a postoperative setting. - Its effects are not immediate, and it does not address the acute fluid deficit or the potential exacerbating effect of **lisinopril**. *Administer IV norepinephrine* - **Norepinephrine** is a potent vasopressor used in distributive or cardiogenic shock, which is not indicated as the initial management for suspected hypovolemia. - Administering vasopressors in an unresuscitated hypovolemic patient can be dangerous, as it can worsen tissue perfusion by increasing systemic vascular resistance without adequate intravascular volume. *Administer oral midodrine* - **Midodrine** is an alpha-1 adrenergic agonist used for chronic orthostatic hypotension to increase peripheral vascular tone, similar to fludrocortisone. - It works slowly and is not indicated for the acute management of hypovolemic shock or postoperative hypotension.

Question 718: A 34-year-old man comes to the physician for a follow-up examination. He has a 3-month history of a nonproductive cough. He has been treated with diphenhydramine since his last visit 2 weeks ago, but his symptoms have persisted. He does not smoke. He drinks 3 beers on the weekends. He is 177 cm (5 ft 10 in) tall and weighs 100 kg (220.46 lbs); BMI is 35.1 kg/m2. His temperature is 37.1°C (98.8°F), pulse is 78/min, respirations are 14/min, and blood pressure is 130/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 97%. Physical examination and an x-ray of the chest show no abnormalities. Which of the following is the most appropriate next step in management?

A. Azithromycin therapy
B. Pulmonary function testing
C. CT scan of the chest
D. Omeprazole therapy (Correct Answer)
E. Oral corticosteroid therapy

Explanation: ***Omeprazole therapy*** - The patient's **obesity** (BMI 35.1), **nonproductive cough** lasting 3 months, and persistent symptoms despite antihistamines strongly suggest **gastroesophageal reflux disease (GERD)** as the cause. - **Proton pump inhibitors (PPIs)** like omeprazole are the first-line treatment for GERD. *Azithromycin therapy* - Azithromycin is an **antibiotic** used to treat bacterial infections. There is no evidence of infection (e.g., fever, abnormal chest X-ray, purulent sputum) in this patient. - Empiric antibiotic use for a nonproductive cough without signs of infection is generally inappropriate and can contribute to **antibiotic resistance**. *Pulmonary function testing* - Pulmonary function testing (PFTs) would be appropriate if there were concerns for **asthma**, **COPD**, or other intrinsic lung diseases, which are not suggested by the normal chest X-ray, oxygen saturation, and absence of wheezing or dyspnea. - The patient's lack of smoking history also makes COPD less likely. *CT scan of the chest* - A CT scan of the chest would be indicated for persistent cough if the **chest X-ray were abnormal** or if there were suspicion of a malignancy, interstitial lung disease, or bronchiectasis. - Given the normal chest X-ray and 3-month duration, a CT scan is not the initial next step, especially when there's a strong alternative diagnosis like GERD. *Oral corticosteroid therapy* - Oral corticosteroids are used to treat inflammatory conditions like asthma or COPD exacerbations. - There is no indication of airflow obstruction, allergic reaction, or significant inflammation based on the clinical presentation and normal chest X-ray, making corticosteroids inappropriate.

Question 719: A 32-year-old man is brought to the emergency department because of a 2-day history of confusion and rapidly progressive dyspnea. He has had a fever and chills for the past five days. Five years ago, he was diagnosed with hepatitis C. He has smoked two packs of cigarettes daily for 15 years and drinks one to two beers daily. He has a history of past intravenous heroin use. He appears pale, anxious, and in severe distress. His temperature is 39.3°C (102.7°F), respirations are 30/min, pulse is 59/min, and blood pressure is 80/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 75%. Examination shows multiple linear hemorrhages underneath the nails. There are nontender maculae on both palms and soles. Fine rales are heard bilaterally on auscultation of the chest. Cardiac examination shows an S3; a grade 3/6 high-pitched decrescendo early diastolic murmur is heard along the left sternal border and right second intercostal space. An x-ray of the chest shows a normal sized heart and pulmonary edema. An ECG shows P waves and QRS complexes that occur at regular intervals, but independently of each other. A transesophageal echocardiography (TEE) is most likely to show which of the following?

A. Eccentric hypertrophy of the left ventricle
B. Oscillating mobile mass on the tricuspid valve
C. A highly echogenic, thin, linear structure in the right atrium
D. Perivalvular thickening with an echolucent cavity (Correct Answer)
E. Anechoic space between pericardium and epicardium

Explanation: ***Perivalvular thickening with an echolucent cavity*** - The patient's history of **intravenous drug use**, fever, new murmur (aortic regurgitation), signs of systemic emboli (Janeway lesions/Osler nodes, confusion), and positive blood cultures (implied by the clinical picture) are highly suggestive of **infective endocarditis**. - Given the patient's presentation with septic shock and rapidly progressive dyspnea, this points to severe, likely acute, infective endocarditis with **perivalvular abscess formation** on the aortic valve, which would be seen as an echolucent cavity or thickening and destruction of perivalvular tissue. *Eccentric hypertrophy of the left ventricle* - This is typically associated with **chronic volume overload** states, such as chronic aortic regurgitation, not acute presentations of infective endocarditis. - While chronic aortic regurgitation can lead to eccentric hypertrophy, the acute and severe nature of this patient's illness with signs of infection makes it less likely to be the primary finding on TEE related to the current crisis. *Oscillating mobile mass on the tricuspid valve* - **Tricuspid valve endocarditis** is common in intravenous drug users due to direct inoculation into the right side of the heart. - However, the prominent **diastolic murmur** along the left sternal border and right second intercostal space, as well as pulmonary edema, indicate **left-sided heart involvement**, specifically the aortic valve, rather than isolated right-sided endocarditis. *A highly echogenic, thin, linear structure in the right atrium* - This description might fit a **catheter fragment** or other foreign body in the right atrium. - However, it does not explain the patient's severe symptoms, signs of valvular disease (new murmur), and systemic embolization. *Anechoic space between pericardium and epicardium* - This describes a **pericardial effusion**, which can be seen in endocarditis, especially with a perivalvular abscess extending into the pericardial space. - However, it is not the most specific or defining echocardiographic finding for a complicated aortic valve endocarditis with severe hemodynamic compromise and is less likely the primary TEE finding compared to direct visualization of the infection and its complications on the valve.

Question 720: A 55-year-old man presents to the physician with tiredness, lethargy, bone pain, and colicky right abdominal pain for 1 month. He has no comorbidities. He does not have any significant past medical history. His height is 176 cm (5 ft 7 in), weight is 88 kg (194 lb), and his BMI is 28.47 kg/m2. The physical examination is normal, except for mild right lumbar region tenderness. Laboratory studies show: Hemoglobin 13.5 g/dL Serum TSH 2.2 mU/L Serum calcium 12.3 mg/dL Serum phosphorus 1.1 mg/dL Serum sodium 136 mEq/L Serum potassium 3.5 mEq/L Serum creatinine 1.1 mg/dL Urine calcium Elevated An ultrasound of the abdomen reveals a single stone in the right ureter without hydroureteronephrosis. Clinically, no evidence of malignancy was observed. An X-ray of the long bones reveals diffuse osteopenia with subperiosteal bone resorption. The serum parathyroid hormone level is tested and it is grossly elevated. What is the most appropriate next step in his management?

A. Ultrasound of the neck only
B. CT scan of the neck
C. 99mTc sestamibi scan with ultrasound of the neck (Correct Answer)
D. Bone scan (DEXA)
E. Sestamibi scan only

Explanation: ***99mTc sestamibi scan with ultrasound of the neck*** - The patient presents with **hypercalcemia**, **hypophosphatemia**, elevated **PTH**, **nephrolithiasis**, and **osteopenia with subperiosteal bone resorption**. These are classic signs of **primary hyperparathyroidism**. - A **99mTc sestamibi scan** helps localize abnormally functioning parathyroid tissue (adenoma), while an **ultrasound of the neck** provides anatomical detail, guiding surgical planning for parathyroidectomy. *Ultrasound of the neck only* - While an ultrasound can identify some parathyroid adenomas, its sensitivity can be limited, especially for smaller or ectopically located glands. - It does not assess the functional activity or metabolic uptake, which is crucial for identifying the hyperfunctioning gland. *CT scan of the neck* - A CT scan can help identify parathyroid adenomas, particularly in cases where ultrasound is inconclusive, but it involves radiation exposure. - It is generally considered a second-line imaging modality for parathyroid localization after sestamibi scan and ultrasound, or in cases of ectopic adenomas. *Bone scan (DEXA)* - A **DEXA scan** measures **bone mineral density** and would confirm the severity of osteopenia or osteoporosis, which is expected in hyperparathyroidism. - However, it does not localize the source of the excess PTH, which is the immediate goal for surgical planning. *Sestamibi scan only* - A **sestamibi scan** is excellent for localizing hyperfunctioning parathyroid tissue but may lack precise anatomical resolution for surgical planning. - Combining it with an **ultrasound of the neck** provides both functional and anatomical information, optimizing surgical success.

Question 721: A 32-year-old man comes to the emergency room because of severe breathlessness for the past few hours. Over the course of a few years, he has been treated for asthma by several physicians, but his symptoms have continued to progress. He has never smoked. Both his father who died at the age of 40 years and his uncle (father's brother), died with chronic obstructive pulmonary disorder. His respiratory rate is 19/min and temperature is 37.0°C (98.6°F). On physical examination, the patient has significantly longer exhalation than inhalation. His expiratory time is longer than 6 seconds. Clubbing is present. Chest auscultation reveals bilateral crackles. Mild hepatomegaly is present. What is the most likely diagnosis?

A. Pulmonary edema
B. Asthma
C. Lung cancer
D. Pneumonia
E. α1-antitrypsin-deficiency (Correct Answer)

Explanation: ***α1-antitrypsin-deficiency*** - The combination of **progressive COPD-like symptoms** at a young age, a family history of early-onset COPD, **emphysema-like symptoms** (prolonged exhalation) without a smoking history, and **hepatomegaly** strongly suggests α1-antitrypsin deficiency. The presence of **clubbing** and **bilateral crackles** can also be present with severe lung disease in AAT deficiency. - **α1-antitrypsin (AAT)** is a protease inhibitor that protects the lungs from damage by neutrophil elastase; deficiency leads to unchecked tissue destruction, especially in the **lower lobes**, and can also cause liver disease due to protein accumulation. *Pulmonary edema* - Characterized by **shortness of breath**, **crackles**, and sometimes **clubbing** (in chronic cases), but does not explain the **prolonged exhalation**, **family history of early COPD**, or **hepatomegaly** in this context. - Typically associated with **cardiac dysfunction** or **fluid overload**, which are not indicated as primary issues here. *Asthma* - While asthma can cause **breathlessness** and **prolonged exhalation**, the **progressive nature** despite treatment, a **strong family history of early COPD**, **clubbing**, and **hepatomegaly** make asthma a less likely sole diagnosis. - Asthma is also usually episodic and responsive to bronchodilators, which is not described. *Lung cancer* - Lung cancer can cause **progressive breathlessness**, **clubbing**, and potentially **hepatomegaly** if there are liver metastases. - However, the patient's **young age**, **absence of smoking history**, and the **family history of early-onset COPD** are atypical for primary lung cancer as the underlying cause of this presentation. *Pneumonia* - Pneumonia would present with an **acute onset of symptoms**, often with **fever**, **cough**, and focal lung findings, which can include crackles and breathlessness. - It would not typically explain **progressive symptoms over years**, **prolonged exhalation**, **clubbing**, **hepatomegaly**, or the **family history of early COPD**.

Question 722: A 72-year-old man comes to the physician because of a 2-month history of intermittent retrosternal chest pain and tightness on exertion. He has type 2 diabetes mellitus, osteoarthritis of the right hip, and hypertension. Current medications include insulin, ibuprofen, enalapril, and hydrochlorothiazide. Vital signs are within normal limits. His troponin level is within the reference range. An ECG at rest shows a right bundle branch block and infrequent premature ventricular contractions. The patient's symptoms are reproduced during adenosine stress testing. Repeat ECG during stress testing shows new ST depression of > 1 mm in leads V2, V3, and V4. Which of the following is the most important underlying mechanism of this patient's ECG changes?

A. Diversion of blood flow from stenotic coronary arteries (Correct Answer)
B. Transient atrioventricular nodal blockade
C. Reduced left ventricular preload
D. Ruptured cholesterol plaque within a coronary vessel
E. Increased myocardial oxygen demand

Explanation: ***Diversion of blood flow from stenotic coronary arteries*** - The **adenosine stress test** induces **submaximal coronary vasodilation** in healthy vessels, diverting blood flow away from stenosed areas that are already maximally dilated, a phenomenon known as **coronary steal**. - This **relative hypoperfusion** in areas supplied by stenotic arteries leads to myocardial ischemia, manifested as **new ST depression** on the ECG due to **subendocardial oxygen supply-demand mismatch**. *Transient atrioventricular nodal blockade* - While adenosine can cause transient AV nodal blockade, leading to AV blocks, this would manifest as specific changes in **PR interval** or **QRS drop-out**, not ST segment depression indicative of ischemia. - The patient's symptoms and ECG changes point towards myocardial ischemia, not an AV conduction disturbance. *Reduced left ventricular preload* - Reduced preload can occur in certain cardiac conditions but is not the primary mechanism behind ST depression during an adenosine stress test. - ECG changes due to reduced preload are usually nonspecific, such as **sinus tachycardia** or **low voltage**, and do not typically cause new ST depression in specific leads. *Ruptured cholesterol plaque within a coronary vessel* - A ruptured plaque with subsequent **thrombus formation** would lead to **acute coronary syndrome (ACS)**, characterized by persistent chest pain, **elevated troponins**, and potentially **ST elevation** or new **pathologic Q waves** if complete occlusion occurs. - The patient's troponin level is normal, and his symptoms are intermittent and reproducible on stress testing, which is more consistent with **stable angina**. *Increased myocardial oxygen demand* - While increased myocardial oxygen demand is a component of angina pectoris, adenosine primarily causes **coronary vasodilation**, which can worsen ischemia in stenotic areas by diverting blood flow, rather than directly increasing myocardial oxygen demand itself. - **Dobutamine stress testing** would be the test that primarily increases myocardial oxygen demand.

Question 723: A 47-year-old woman with a long history of poorly controlled type 2 diabetes and recurrent urinary tract infections presents with complaints of fever, chills, and severe flank pain. On physical exam, she has left-sided costovertebral tenderness. Vitals include a temperature of 39.4°C (103.0°F), blood pressure of 125/84 mm Hg, and pulse of 84/min. She is currently taking metformin daily. Urine dipstick analysis is positive for leukocytes, nitrites, and blood. Laboratory studies show an elevated creatinine of 2.8 mg/dL (baseline 1.0 mg/dL). Urinalysis reveals fragments of tissue. What is the most likely diagnosis?

A. Acute cystitis
B. Acute glomerulonephritis
C. Acute tubular necrosis
D. Acute interstitial nephritis
E. Acute papillary necrosis (Correct Answer)

Explanation: ***Acute papillary necrosis*** - This patient's presentation with **fever, severe flank pain, costovertebral tenderness**, **elevated creatinine indicating acute kidney injury**, and **tissue fragments in urine** is classic for **acute papillary necrosis**. - Her **poorly controlled type 2 diabetes** and **recurrent UTIs** are major risk factors. Chronic hyperglycemia causes **renal medullary ischemia**, and recurrent infections further compromise blood supply to the renal papillae. - The **tissue fragments** represent sloughed papillae, a pathognomonic finding. The combination of **hematuria, acute kidney injury, and systemic symptoms** in a diabetic with recurrent infections strongly points to this diagnosis. - Other risk factors include analgesic abuse, sickle cell disease, and urinary tract obstruction. *Acute cystitis* - **Acute cystitis** presents with **dysuria, frequency, and urgency** but typically **without fever, systemic symptoms, or costovertebral tenderness**. - It does not cause **acute kidney injury** or **tissue fragments in urine**. - The severe presentation with AKI and CVA tenderness indicates upper urinary tract pathology. *Acute glomerulonephritis* - **Acute glomerulonephritis** presents with **hematuria, proteinuria, hypertension, and edema**, often following streptococcal infection. - It does not typically cause **fever, severe flank pain, or CVA tenderness**. - The presence of **nitrites** and **tissue fragments** points to bacterial infection with tissue necrosis, not glomerular inflammation. *Acute tubular necrosis* - **Acute tubular necrosis (ATN)** causes acute kidney injury but typically follows **ischemic insult** (hypotension, surgery) or **nephrotoxic exposure** (aminoglycosides, contrast). - ATN does not present with **fever, chills, severe flank pain, or tissue fragments in urine**. - Urinalysis in ATN shows muddy brown casts, not tissue fragments with nitrites. *Acute interstitial nephritis* - **Acute interstitial nephritis (AIN)** is typically a **drug-induced hypersensitivity reaction** presenting with **fever, rash, eosinophilia**, and AKI. - The classic triad is fever, rash, and eosinophilia, often occurring days to weeks after drug exposure. - **Nitrites** (indicating bacterial infection) and **tissue fragments** are not consistent with AIN, which shows sterile pyuria and white blood cell casts.

Question 724: A 17-year-old girl comes to the physician because of a sore throat, fevers, and fatigue for the past 3 weeks. Her temperature is 37.8°C (100°F), pulse is 97/min, and blood pressure is 90/60 mm Hg. Examination of the head and neck shows cervical lymphadenopathy, pharyngeal erythema, enlarged tonsils with exudates, and palatal petechiae. The spleen is palpated 2 cm below the left costal margin. Her leukocyte count is 14,100/mm3 with 54% lymphocytes (12% atypical lymphocytes). Results of a heterophile agglutination test are positive. This patient is at increased risk for which of the following conditions?

A. Mycotic aneurysm
B. Hodgkin lymphoma (Correct Answer)
C. Kaposi sarcoma
D. Hepatocellular carcinoma
E. Rheumatic fever

Explanation: ***Correct: Hodgkin lymphoma*** - **Epstein-Barr virus (EBV)**, the causative agent of infectious mononucleosis, is strongly associated with the development of **Hodgkin lymphoma** - Up to **30-50% of Hodgkin lymphoma cases** are linked to prior EBV infection, particularly the **mixed cellularity** and **lymphocyte-depleted** subtypes - EBV-positive Reed-Sternberg cells are found in these lymphoma subtypes *Incorrect: Mycotic aneurysm* - A mycotic aneurysm is an **infected aneurysm** typically caused by bacterial endocarditis or other systemic infections leading to arterial wall weakening - There is no direct association between infectious mononucleosis and the development of mycotic aneurysms *Incorrect: Kaposi sarcoma* - **Kaposi sarcoma** is caused by **Human Herpesvirus 8 (HHV-8)**, not EBV - Most commonly seen in immunocompromised individuals, such as those with HIV/AIDS - Not directly associated with Epstein-Barr virus infection *Incorrect: Hepatocellular carcinoma* - **Hepatocellular carcinoma** is primarily associated with chronic liver diseases, such as chronic **hepatitis B** or **hepatitis C** infection, **alcoholic liver disease**, and **nonalcoholic steatohepatitis (NASH)** - EBV is associated with **nasopharyngeal carcinoma** and **Burkitt lymphoma**, not hepatocellular carcinoma *Incorrect: Rheumatic fever* - **Rheumatic fever** is a delayed, non-suppurative complication of untreated **Group A Streptococcus (GAS)** pharyngitis - The patient's symptoms are consistent with **infectious mononucleosis** (positive heterophile agglutination test, atypical lymphocytes, persistent fatigue, splenomegaly), not GAS pharyngitis - Monospot test distinguishes EBV from bacterial pharyngitis

Question 725: A 50-year-old man presents to the emergency department with pain and swelling of his right leg for the past 2 days. Three days ago he collapsed on his leg after tripping on a rug. It was a hard fall and left him with bruising of his leg. Since then the pain and swelling of his leg have been gradually increasing. Past medical history is noncontributory. He lives a rather sedentary life and smokes two packs of cigarettes per day. The vital signs include heart rate 98/min, respiratory rate 15/min, temperature 37.8°C (100.1°F), and blood pressure 100/60 mm Hg. On physical examination, his right leg is visibly swollen up to the mid-calf with pitting edema and moderate erythema. Peripheral pulses in the right leg are weak and the leg is tender. Manipulation of the right leg is negative for Homan’s sign. What is the next best step in the management of this patient?

A. Send the patient to surgery for an emergency fasciotomy
B. Start intravenous heparin therapy immediately
C. Make a diagnosis of deep vein thrombosis based on history and physical
D. Perform a venous ultrasound (Correct Answer)
E. Perform intravenous venography within 24 hours

Explanation: ***Perform a venous ultrasound*** - The patient's presentation with acute unilateral leg swelling, pain, erythema, and weak peripheral pulses following trauma, along with **risk factors for venous thromboembolism (sedentary lifestyle, smoking)**, strongly suggests the possibility of a **deep vein thrombosis (DVT)**. - **Venous ultrasound** is the **most appropriate and preferred initial diagnostic test** for suspected DVT due to its **non-invasiveness, accessibility, and high sensitivity and specificity**. *Send the patient to surgery for an emergency fasciotomy* - **Fasciotomy** is indicated for **acute compartment syndrome**, which typically presents with severe pain out of proportion to injury, pain on passive stretch, paresthesia, and tense compartments. - While the patient has swelling and tenderness, the weak pulses are concerning, but the overall picture does not definitively point to compartment syndrome needing immediate fasciotomy without further diagnostic workup. *Start intravenous heparin therapy immediately* - Though DVT is suspected, **heparin therapy should not be initiated empirically without definitive diagnostic confirmation** due to the risk of bleeding complications. - A **venous ultrasound is crucial to confirm the diagnosis** before starting anticoagulation. *Make a diagnosis of deep vein thrombosis based on history and physical* - While the clinical picture is highly suggestive of DVT, **clinical diagnosis alone is not sufficiently accurate** to initiate potentially risky treatments like anticoagulation. - **Objective diagnostic testing (like ultrasound)** is essential to confirm the presence of a DVT. *Perform intravenous venography within 24 hours* - **Intravenous venography** is considered the **gold standard** for diagnosing DVT, but it is an **invasive procedure** with risks (e.g., contrast nephropathy, allergic reactions, radiation exposure). - It is **rarely used as a first-line diagnostic test** and is usually reserved for cases where ultrasound results are inconclusive or discordant with clinical suspicion.

Question 726: A 78-year-old man is brought to the emergency department because of difficulty speaking. The symptoms began abruptly one hour ago while he was having breakfast with his wife. He has hypertension, type 2 diabetes mellitus, and coronary artery disease. Current medications include pravastatin, lisinopril, metformin, and aspirin. His temperature is 37°C (98.6°F), pulse is 76/min, and blood pressure is 165/90 mm Hg. He is right-handed. The patient speaks in short, simple sentences, and has difficulty repeating sequences of words. He can follow simple instructions. Right facial droop is present. Muscle strength is 4/5 on the right side and 5/5 on the left, and there is a mild right-sided pronator drift. Which of the following is the most likely cause of the patient's symptoms?

A. Occlusion of the right penetrating arteries
B. Rupture of left posterior cerebral artery malformation
C. Occlusion of the right middle cerebral artery
D. Occlusion of the left middle cerebral artery (Correct Answer)
E. Occlusion of the right posterior inferior cerebellar artery

Explanation: ***Occlusion of the left middle cerebral artery*** - The patient exhibits **acute onset aphasia** (difficulty speaking, repeating word sequences, short sentences), right-sided **facial droop**, and **right-sided weakness** (pronator drift, 4/5 strength). This clinical presentation, affecting the dominant hemisphere (left in a right-handed person), points directly to **ischemia** in the territory supplied by the **left middle cerebral artery (MCA)**. - The patient's history of **hypertension, diabetes, and coronary artery disease** are significant risk factors for **atherosclerotic stroke**, making occlusion a highly likely etiology. *Occlusion of the right penetrating arteries* - Occlusion of penetrating arteries (causing a **lacunar stroke**) typically presents with **pure motor hemiparesis**, **pure sensory stroke**, or **ataxic hemiparesis**, without significant cortical signs like aphasia. - This patient's symptoms include prominent aphasia, which is a **cortical sign** and not characteristic of a lacunar stroke. *Rupture of left posterior cerebral artery malformation* - A rupture of a posterior cerebral artery (PCA) malformation would likely result in a **hemorrhagic stroke**, typically presenting with **sudden severe headache**, altered consciousness, and symptoms related to the PCA territory, such as **contralateral homonymous hemianopsia** and potentially **memory deficits** or **alexia without agraphia**. - This patient's symptoms (aphasia, focal weakness) and lack of headache are not typical for a PCA hemorrhage. *Occlusion of the right middle cerebral artery* - Occlusion of the **right middle cerebral artery** would cause symptoms affecting the **left side of the body**, such as **left hemiparesis, left facial droop**, and potentially **neglect** if the parietal lobe is involved. - The patient's symptoms are localized to the **right side of the body** and involve aphasia, indicating damage to the **left (dominant) hemisphere**. *Occlusion of the right posterior inferior cerebellar artery* - Occlusion of the **posterior inferior cerebellar artery (PICA)** causes **Lateral Medullary Syndrome (Wallenberg syndrome)**, characterized by **ipsilateral ataxia, nystagmus, dysphagia, dysarthria, Horner's syndrome, and contralateral loss of pain and temperature sensation**. - The patient's symptoms of aphasia, facial droop, and hemiparesis are not consistent with PICA territory ischemia.

Question 727: A 44-year-old male presents to his primary care physician with complaints of fatigue, muscle weakness, cramps, and increased urination over the past several weeks. His past medical history is significant only for hypertension, for which he was started on hydrochlorothiazide (HCTZ) 4 weeks ago. Vital signs at today's visit are as follows: T 37.2, HR 88, BP 129/80, RR 14, and SpO2 99%. Physical examination does not reveal any abnormal findings. Serologic studies are significant for a serum potassium level of 2.1 mEq/L (normal range 3.5-5.0 mEq/L). Lab-work from his last visit showed a basic metabolic panel and complete blood count results to all be within normal limits. Which of the following underlying diseases most likely contributed to the development of this patient's presenting condition?

A. Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)
B. Adrenal insufficiency
C. Cushing's disease
D. Hyperaldosteronism (Correct Answer)
E. Pituitary adenoma

Explanation: ***Correct: Hyperaldosteronism*** - This patient presents with **hypokalemia** (2.1 mEq/L), fatigue, muscle weakness, cramps, and increased urination, a constellation of symptoms highly suggestive of **primary hyperaldosteronism**. - While **hydrochlorothiazide (HCTZ)** can induce hypokalemia, the severity in this case (2.1 mEq/L) strongly suggests an underlying pathology compounded by the diuretic, given that his previous labs were normal. Hyperaldosteronism directly causes **potassium wasting** in the kidneys, and the diuretic exacerbates this effect. - The normal blood pressure control on HCTZ and the development of severe hypokalemia points to an underlying aldosterone excess being unmasked by the thiazide diuretic. *Incorrect: Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)* - SIADH is characterized by **euvolemic hyponatremia** due to excessive ADH secretion, leading to water retention and dilution of sodium. - It does not typically cause hypokalemia; instead, potassium levels are often normal or slightly reduced due to dilutional effects rather than direct renal wasting. *Incorrect: Adrenal insufficiency* - Adrenal insufficiency, such as Addison's disease, typically presents with **hyponatremia**, **hyperkalemia**, fatigue, and hypotension, which is contrary to this patient's presentation of hypokalemia and normal blood pressure. - It involves a deficiency in mineralocorticoids (like aldosterone) and glucocorticoids, leading to impaired sodium and water retention and reduced potassium excretion. *Incorrect: Cushing's disease* - Cushing's disease is characterized by excessive cortisol production, leading to symptoms like **central obesity**, **moon facies**, **buffalo hump**, and **hypertension**. While some patients may develop hypokalemia due to mineralocorticoid effects of very high cortisol, it's not the primary feature and other classic signs are absent in this case. - The presenting symptoms of severe hypokalemia, muscle weakness, and cramps without other typical Cushingoid features make this diagnosis less likely. *Incorrect: Pituitary adenoma* - Pituitary adenomas can cause various endocrine disorders depending on the hormones secreted (e.g., prolactinoma, acromegaly, or ACTH-secreting adenoma causing Cushing's disease). - A non-functioning pituitary adenoma does not directly cause hypokalemia or the specific constellation of symptoms seen here, and the patient lacks features of specific hormone-secreting adenomas.

Question 728: A 48-year-old male accountant presents to the family practice clinic for his first health check-up in years. He has no complaints, and as far as he is concerned, he is well. He does not have any known medical conditions. His blood pressure is 140/89 mm Hg and his heart rate is 89/min. Physical examination is otherwise unremarkable. What is the single best initial management for this patient?

A. Treat the patient with beta-blockers.
B. Try angiotensin-converting enzyme inhibitor.
C. Start trial of calcium channel blockers.
D. Return to the clinic for a repeat blood pressure reading and counseling on the importance of aerobic exercise. (Correct Answer)
E. The patient does not require any treatment.

Explanation: ***Return to the clinic for a repeat blood pressure reading and counseling on the importance of aerobic exercise.*** - The patient's blood pressure of **140/89 mm Hg** is considered **Stage 1 hypertension**. It is crucial to confirm sustained hypertension with **repeat measurements** over several weeks to avoid misdiagnosis and unnecessary medication. - Initial management for Stage 1 hypertension without other compelling indications typically involves **lifestyle modifications**, such as regular aerobic exercise, dietary changes, and weight management, before initiating pharmacotherapy. *Treat the patient with beta-blockers.* - **Beta-blockers** are generally not first-line agents for isolated hypertension unless there are specific indications such as **concomitant heart failure**, **post-myocardial infarction**, or **migraines**. - Without confirmed sustained hypertension and prior lifestyle interventions, initiating beta-blockers would be **premature**. *Try angiotensin-converting enzyme inhibitor.* - **ACE inhibitors** are effective first-line agents for hypertension, but only after proper diagnosis confirmation and a trial of **lifestyle modifications**. - Rushing to medication without confirming sustained hypertension and exploring non-pharmacological approaches is **not the recommended initial step**. *Start trial of calcium channel blockers.* - **Calcium channel blockers** are also effective antihypertensive agents, especially in older adults or those with **isolated systolic hypertension**. - However, similar to other pharmaceutical interventions, they should be considered **after confirming sustained hypertension** and attempting lifestyle changes. *The patient does not require any treatment.* - A blood pressure reading of **140/89 mm Hg** is elevated and indicates **Stage 1 hypertension**, which requires management. - While immediate medication might not be necessary, **monitoring and lifestyle interventions** are crucial to prevent progression to more severe hypertension and cardiovascular complications.

Question 729: A 73-year-old male presents to the ED with several days of fevers, cough productive of mucopurulent sputum, and pleuritic chest pain. He has not been to a doctor in 30 years because he “has never been sick”. His vital signs are: T 101F, HR 98, BP 100/55, RR 31. On physical exam he is confused and has decreased breath sounds and crackles on the lower left lobe. Gram positive diplococci are seen in the sputum. Which of the following is the most appropriate management for his pneumonia?

A. Azithromycin and outpatient follow-up
B. Levofloxacin and outpatient follow-up
C. Linezolid and inpatient admission
D. IV Penicillin G and inpatient admission (Correct Answer)
E. Oral Penicillin V and outpatient follow-up

Explanation: ***IV Penicillin G and inpatient admission*** - The patient exhibits features of **severe pneumonia** based on **CURB-65 criteria** (confusion, respiratory rate >30, diastolic BP ≤60, age >65), necessitating **inpatient admission**. - The presence of **Gram-positive diplococci** in sputum, along with the clinical presentation, strongly suggests **Streptococcus pneumoniae**, for which **Penicillin G** is an appropriate first-line treatment. *Azithromycin and outpatient follow-up* - This patient's **CURB-65 score** is high (at least 4: Confusion, RR >30, diastolic BP ≤60, Age >65), indicating a high mortality risk and requiring **inpatient management**, not outpatient follow-up. - While azithromycin is effective against atypical pathogens and can treat *S. pneumoniae*, the patient's severe presentation and sputum Gram stain indicating typical bacterial pneumonia require more aggressive initial therapy and hospitalization. *Levofloxacin and outpatient follow-up* - The patient's **clinical instability** (hypotension, tachypnea, confusion) and elevated CURB-65 score contraindicate **outpatient management**. - Although levofloxacin is a broad-spectrum fluoroquinolone that provides excellent coverage for *S. pneumoniae*, the severity of the patient's condition demands inpatient care and intravenous antibiotics. *Linezolid and inpatient admission* - **Linezolid** is typically reserved for **resistant Gram-positive infections** such as **MRSA pneumonia** or vancomycin-resistant enterococci (VRE), which are not indicated by the initial Gram stain showing typical Gram-positive diplococci consistent with *S. pneumoniae*. - While inpatient admission is appropriate, empiric use of linezolid for typical community-acquired pneumonia (CAP) due to *S. pneumoniae* is **unnecessarily broad-spectrum** and could contribute to antibiotic resistance. *Oral Penicillin V and outpatient follow-up* - This patient's **CURB-65 score** indicating severe pneumonia requires **inpatient hospitalization** and **intravenous antibiotics**, not outpatient management. - **Oral Penicillin V** is generally used for milder outpatient infections or as step-down therapy after initial IV treatment, and it would be insufficient for this severely ill patient.

Question 730: A 65-year-old man presents to the emergency department for shortness of breath. He was at home working on his car when he suddenly felt very short of breath, which failed to improve with rest. He states he was working with various chemicals and inhalants while trying to replace a broken piece in the engine. The patient was brought in by paramedics and is currently on 100% O2 via nasal cannula. The patient has a 52 pack-year smoking history and drinks 2 to 3 alcoholic drinks every night. He has a past medical history of asthma but admits to not having seen a physician since high school. His temperature is 98.2°F (36.8°C), blood pressure is 157/108 mmHg, pulse is 120/min, respirations are 29/min, and oxygen saturation is 77%. Physical exam demonstrates tachycardia with a systolic murmur heard best along the right upper sternal border. Breath sounds are diminished over the right upper lobe. Bilateral lower extremity pitting edema is noted. Which of the following best describes the most likely diagnosis?

A. Fe3+ hemoglobin in circulating red blood cells
B. Severe bronchoconstriction
C. Pulmonary edema secondary to decreased cardiac output
D. Ischemia of the myocardium
E. Rupture of an emphysematous bleb (Correct Answer)

Explanation: ***Rupture of an emphysematous bleb*** - The patient's significant **smoking history** (52 pack-years), acute onset of shortness of breath while straining (working on car), diminished breath sounds over the right upper lobe, and very low oxygen saturation of 77% strongly suggest a **spontaneous pneumothorax** likely due to a ruptured emphysematous bleb. - The history of asthma, while a confounder, does not explain the sudden, severe onset and unilateral diminished breath sounds in the context of extensive smoking. *Fe3+ hemoglobin in circulating red blood cells* - This describes **methemoglobinemia**, which can cause dyspnea and hypoxemia. However, it's typically associated with exposure to specific oxidizing agents (e.g., nitrates, certain local anesthetics), which are not explicitly mentioned as the chemicals the patient was using. - While it causes **cyanosis** and low oxygen saturation, the unilateral diminished breath sounds and acute onset with strain point away from this being the primary diagnosis. *Severe bronchoconstriction* - While the patient has a history of asthma, the **sudden, severe onset of shortness of breath**, very low oxygen saturation, and unilateral diminished breath sounds are not typical for an acute asthma exacerbation alone. - Asthma exacerbations usually involve **bilateral wheezing** and diffuse airway narrowing, not localized diminished breath sounds. *Pulmonary edema secondary to decreased cardiac output* - Pulmonary edema would typically present with **bilateral crackles** on examination and is commonly associated with left ventricular dysfunction or acute myocardial infarction, which is not clearly indicated. - The unilateral diminished breath sounds are inconsistent with a diffuse process like pulmonary edema. *Ischemia of the myocardium* - While the patient's age, smoking history, and hypertension put him at risk for cardiac events, the sudden onset of dyspnea, **unilateral diminished breath sounds**, and severe hypoxemia are more indicative of a pulmonary mechanical issue than acute myocardial ischemia. - Although angina can present as dyspnea, the physical exam findings of diminished breath sounds point to a primary lung pathology.

Question 731: A 68-year-old man is brought to the emergency department because of right-sided weakness for 2 hours. He has hypertension, dyslipidemia, and type 2 diabetes. Current medications include hydrochlorothiazide, metoprolol, amlodipine, pravastatin, and metformin. His pulse is 87/min and blood pressure is 164/98 mm Hg. Neurological examination shows right-sided weakness, facial droop, and hyperreflexia. Sensation is intact. Which of the following is the most likely cause of these findings?

A. Lipohyalinosis of penetrating vessels (Correct Answer)
B. Dissection of the vertebral artery
C. Stenosis of the internal carotid artery
D. Rupture of an intracranial aneurysm
E. Embolism from the left atrium

Explanation: ***Lipohyalinosis of penetrating vessels*** - This patient presents with an acute onset of **hemiparesis**, **facial droop**, and hyperreflexia, without cortical signs like cortical sensory loss or aphasia, which is characteristic of a **lacunar stroke**. - **Lipohyalinosis** is the most common cause of lacunar infarcts, resulting from chronic hypertension and diabetes affecting small penetrating arteries in the brain. *Dissection of the vertebral artery* - Vertebral artery dissection typically presents with **posterior circulation symptoms** such as vertigo, ataxia, brainstem dysfunction, and often includes severe headache or neck pain. - The presented symptoms of pure motor hemiparesis are more indicative of an anterior circulation event involving deeper structures. *Stenosis of the internal carotid artery* - Significant **internal carotid artery stenosis** typically causes larger territorial infarcts by reducing blood flow or via artery-to-artery embolism to the middle cerebral artery territory. - This would result in symptoms like **aphasia**, **cortical sensory deficits**, or **homonymous hemianopia**, which are not present here. *Rupture of an intracranial aneurysm* - A ruptured intracranial aneurysm usually causes a **subarachnoid hemorrhage**, leading to a sudden, severe headache ("thunderclap headache"), meningismus, and altered consciousness. - While focal neurological deficits can occur, the primary presentation is distinct from the patient's symptoms of a gradual onset of pure motor deficit. *Embolism from the left atrium* - An embolism from the left atrium (e.g., due to atrial fibrillation) typically causes a **cortical infarct** involving a larger vascular territory, such as the middle cerebral artery. - This would result in symptoms like **aphasia**, **neglect**, or **cortical sensory deficits**, which are absent in this presentation of pure motor hemiparesis.

Question 732: A 42-year-old woman comes to the physician because of 2 episodes of loss of consciousness over the past week. She recovered immediately and was not confused following the episodes. During the past 5 months, she has also had increased shortness of breath and palpitations. She has been unable to carry out her daily activities. She also reports some chest tightness that resolves with rest. She has no history of serious illness and takes no medications. She immigrated with her family from India 10 years ago. Her temperature is 37.3°C (99.1°F), pulse is 115/min and irregular, and blood pressure is 108/70 mm Hg. Examination shows jugular venous distention and pitting edema below the knees. Bilateral crackles are heard at the lung bases. Cardiac examination shows an accentuated and split S2. There is an opening snap followed by a low-pitched diastolic murmur in the fifth left intercostal space at the midclavicular line. An ECG shows atrial fibrillation and right axis deviation. Which of the following is the most likely underlying mechanism of these findings?

A. Increased left ventricular end diastolic pressure
B. Increased left to right shunting
C. Increased systemic arterial resistance
D. Increased left atrial pressure (Correct Answer)
E. Decreased left ventricular contractility

Explanation: ***Increased left atrial pressure*** - The patient's symptoms (dyspnea, palpitations, chest tightness, volume overload signs like JVD, edema, crackles) and cardiac findings (**accentuated S2, opening snap, diastolic murmur**) are highly suggestive of **mitral stenosis**. - **Mitral stenosis** causes obstruction of blood flow from the left atrium to the left ventricle, leading to a significant increase in **left atrial pressure** to maintain cardiac output, which can then cause atrial fibrillation and pulmonary hypertension. *Increased left ventricular end diastolic pressure* - This is typically seen in conditions like **aortic stenosis**, **aortic regurgitation**, or **decompensated heart failure** where the left ventricle is distended or failing. - The patient's presentation with an **opening snap** and **diastolic murmur** points away from primary left ventricular pathology causing elevated LVEDP, and more towards a valvular issue upstream. *Increased left to right shunting* - This typically occurs in **septal defects** (e.g., VSD, ASD, PDA) and would lead to symptoms of pulmonary hypertension and right heart strain, but the specific murmur and opening snap are not characteristic of a shunt. - While it can cause right ventricular hypertrophy and pulmonary hypertension, the classic auscultatory findings are distinct from those described here. *Increased systemic arterial resistance* - This is characteristic of **hypertension** or conditions causing systemic vasoconstriction, which primarily affect afterload on the left ventricle. - While it can lead to left ventricular hypertrophy over time, it does not explain the specific findings of an **opening snap** and **diastolic murmur**, or the symptoms of pulmonary congestion in this context. *Decreased left ventricular contractility* - This would lead to **systolic heart failure** with reduced ejection fraction, causing symptoms like fatigue and dyspnea, and often a **S3 gallop** with a systolic murmur if mitral regurgitation develops. - However, it does not explain the specific auscultatory findings of an **opening snap** and **diastolic murmur** that are pathognomonic for mitral stenosis.

Question 733: A 21-year-old woman comes to the physician because of a 1-day history of right leg pain. The pain is worse while walking and improves when resting. Eight months ago, she was diagnosed with a pulmonary embolism and was started on warfarin. Anticoagulant therapy was discontinued two months ago. Her mother had systemic lupus erythematosus. On examination, her right calf is diffusely erythematous, swollen, and tender. Cardiopulmonary examination shows no abnormalities. On duplex ultrasonography, the right popliteal vein is not compressible. Laboratory studies show an elevated serum level of D-dimer and insensitivity to activated protein C. Further evaluation of this patient is most likely to show which of the following?

A. Deficiency of protein C
B. Protein S deficiency
C. Elevated coagulation factor VIII levels
D. Mutation of coagulation factor V (Correct Answer)
E. Mutation of prothrombin

Explanation: ***Mutation of coagulation factor V*** - The patient's history of **recurrent DVT/PE** at a young age, family history of autoimmune disease (mother's SLE), and laboratory finding of **insensitivity to activated protein C** strongly point towards **Factor V Leiden mutation**. - This mutation makes **Factor V resistant to inactivation** by activated protein C, leading to a hypercoagulable state and increased risk of venous thromboembolism. *Deficiency of protein C* - While it also causes **insensitivity to activated protein C** and a hypercoagulable state, a true deficiency of protein C would lead to quantitative reduction, not primarily functional insensitivity. - Protein C deficiency can cause **severe thrombotic events**, but the given lab finding of "insensitivity to activated protein C" points more directly to a defect in Factor V. *Protein S deficiency* - **Protein S** acts as a cofactor for activated protein C, so its deficiency would also impair the anticoagulant pathway and could lead to thrombosis. - However, **Protein S deficiency** does not directly cause "insensitivity to activated protein C" as the primary defect; rather, it reduces the effectiveness of activated protein C. *Elevated coagulation factor VIII levels* - **High levels of Factor VIII** are a risk factor for VTE, but this condition would not lead to **insensitivity to activated protein C**. - While it contributes to a hypercoagulable state, it's a distinct mechanism not indicated by the specific lab finding mentioned. *Mutation of prothrombin* - **Prothrombin G20210A mutation** (mutation of prothrombin) leads to increased prothrombin levels and increased thrombin generation, predisposing to thrombosis. - However, this mutation would not result in **insensitivity to activated protein C**, which is the key laboratory finding in this patient.

Question 734: A 33-year-old woman comes to the physician because of a 6-month history of worsening shortness of breath and fatigue. Her paternal uncle had similar symptoms and died of respiratory failure at 45 years of age. The lungs are clear to auscultation. Pulmonary function testing shows an FVC of 84%, an FEV1/FVC ratio of 92%, and a normal diffusion capacity. An ECG shows a QRS axis greater than +90 degrees. Genetic analysis shows an inactivating mutation in the bone morphogenetic protein receptor type II (BMPR2) gene. Which of the following is the most likely cause of this patient's symptoms?

A. Thickening of the interventricular septum
B. Fibrosis of the pulmonary parenchyma
C. Chronic intravascular hemolysis
D. Elevated left atrial pressure
E. Elevated pulmonary arterial pressure (Correct Answer)

Explanation: ***Elevated pulmonary arterial pressure*** - The patient's symptoms (dyspnea, fatigue), family history of early respiratory failure, and the presence of an inactivating mutation in **BMPR2** are highly suggestive of **heritable pulmonary arterial hypertension (PAH)**. - **PAH** is characterized by elevated pressures in the pulmonary arteries, leading to right ventricular strain, which is reflected by the **ECG finding of a QRS axis greater than +90 degrees** (right axis deviation). - The **normal diffusion capacity** helps distinguish PAH from parenchymal lung diseases, and the **FEV1/FVC ratio of 92%** (elevated) with relatively preserved FVC is consistent with the restrictive physiology sometimes seen in PAH. *Thickening of the interventricular septum* - While septal thickening can occur in some cardiac conditions, it is not the primary cause of symptoms in the context of heritable PAH, nor is it directly indicated by the given pulmonary function tests or ECG. - **Hypertrophic cardiomyopathy** can cause septal thickening, but it typically presents with different cardiac pathologies and is not associated with BMPR2 mutations. *Fibrosis of the pulmonary parenchyma* - This would cause a **restrictive lung disease** with a **reduced FVC** and **reduced diffusion capacity** due to impaired gas exchange across thickened alveolar-capillary membranes. - The patient's **normal diffusion capacity** specifically rules out significant pulmonary fibrosis or other interstitial lung diseases. *Chronic intravascular hemolysis* - This condition would typically present with **anemia**, **jaundice**, **elevated LDH**, and possibly **splenomegaly**, none of which are mentioned. - It is not associated with the BMPR2 genetic mutation or the specific PFT and ECG findings in this case. *Elevated left atrial pressure* - Elevated left atrial pressure (e.g., due to **left-sided heart failure** or mitral stenosis) can cause pulmonary congestion and dyspnea, but would typically lead to **pulmonary edema** with crackles on auscultation and **reduced diffusion capacity** due to fluid in the alveoli. - The patient's clear lung auscultation and normal diffusion capacity make elevated left atrial pressure unlikely.

Question 735: A 33-year-old woman presents to her primary care physician for non-bloody nipple discharge. She states that it has been going on for the past month and that it sometimes soils her shirt. The patient drinks 2 to 3 alcoholic beverages per day and smokes 1 pack of cigarettes per day. She is currently seeking mental health treatment with an outpatient psychiatrist after a recent hospitalization for auditory hallucinations. Her psychiatrist prescribed her a medication that she can not recall. Otherwise, she complains of headaches that occur frequently. Her temperature is 98.6°F (37.0°C), blood pressure is 137/68 mmHg, pulse is 70/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for bilateral galactorrhea that can be expressed with palpation. Which of the following is the best next step in management?

A. Ultrasound and biopsy
B. Mammography
C. Serum prolactin level (Correct Answer)
D. CT scan of the head
E. Discontinuation of current psychiatric medications

Explanation: ***Serum prolactin level*** - The patient presents with **bilateral, non-bloody nipple discharge (galactorrhea)**, which is strongly suggestive of **hyperprolactinemia**. Given her psychiatric history and recent change in medication, a drug-induced cause (e.g., antipsychotics) is highly probable, making a serum prolactin level the most appropriate initial diagnostic step. - Elevated prolactin can be caused by various factors, including **prolactinomas**, **hypothyroidism**, and **medications** (especially antipsychotics that block dopamine D2 receptors), and measuring this level helps differentiate between these causes and guides further management. *Ultrasound and biopsy* - This approach is typically indicated for suspicious **breast masses** or **unilateral, bloody nipple discharge** to rule out malignancy. - The patient's symptoms are characteristic of galactorrhea, not a suspicious breast lesion requiring imaging and biopsy at this stage. *Mammography* - Mammography is primarily used for **breast cancer screening** or to investigate suspicious **breast lumps** or **bloody nipple discharge** in older women. - Given the patient's age (33) and the bilateral, non-bloody nature of the discharge, mammography is not the initial investigation of choice for galactorrhea. *CT scan of the head* - A CT scan of the head (or MRI) would be indicated if the **serum prolactin level is significantly elevated** and suggests a **pituitary adenoma** (prolactinoma), or if other neurological symptoms point to an intracranial pathology. - It is premature to order head imaging before confirming hyperprolactinemia, as the cause could be medication-related and not require imaging. *Discontinuation of current psychiatric medications* - While psychiatric medications, particularly **antipsychotics**, can cause hyperprolactinemia, discontinuing them should not be the *first* step without confirming the diagnosis and ruling out other serious causes. - Abrupt discontinuation of psychiatric medication can lead to relapse of mental health symptoms and is usually done under strict medical supervision after a clear diagnosis.

Question 736: A 25-year-old woman presents to her primary care physician with 3 weeks of palpitations and shortness of breath while exercising. She says that these symptoms have been limiting her ability to play recreational sports with her friends. Her past medical history is significant for pharyngitis treated with antibiotics and her family history reveals a grandfather who needed aortic valve replacements early due to an anatomic abnormality. She admits to illicit drug use in college, but says that she stopped using drugs 4 years ago. Physical exam reveals a clicking sound best heard at the apex. This sound occurs between S1 and S2 and is followed by a flow murmur. Which of the following is most likely associated with the cause of this patient's disorder?

A. Increased valvular dermatan sulfate (Correct Answer)
B. Intravenous drug abuse
C. Mutation in cardiac contractile proteins
D. Infection with Streptococcus pyogenes
E. Bicuspid aortic valve

Explanation: ***Increased valvular dermatan sulfate*** - The patient presents with classic signs of **mitral valve prolapse (MVP)**: a **mid-systolic click** followed by a **systolic murmur**. MVP is characterized by **myxomatous degeneration** of the mitral valve, leading to redundant and thickened leaflets. - This myxomatous degeneration is associated with an accumulation of **dermatan sulfate** and other proteoglycans within the valve tissue, leading to weakened collagen and elastic fibers. *Intravenous drug abuse* - While intravenous drug abuse can cause valvular disease, it typically leads to **infective endocarditis**, often affecting the **tricuspid valve** in the right heart. - This patient's signs and symptoms, particularly the mid-systolic click and the timing of the murmur, are not consistent with intravenous drug abuse-related endocarditis. *Mutation in cardiac contractile proteins* - Mutations in cardiac contractile proteins are characteristic of **hypertrophic cardiomyopathy (HCM)**, which presents with symptoms like shortness of breath and palpitations due to outflow tract obstruction. - However, HCM does not typically manifest with a **mid-systolic click** and a flow murmur originating from a prolapsing valve. *Infection with *Streptococcus pyogenes** - **Rheumatic fever**, caused by *Streptococcus pyogenes*, can lead to valvular damage, particularly to the **mitral valve (rheumatic mitral stenosis)**. However, this typically manifests as a **diastolic murmur** and is associated with a history of recurrent strep throat with inadequate treatment. - The patient's pharyngitis was treated with antibiotics, and the physical exam findings are not typical for chronic rheumatic heart disease. *Bicuspid aortic valve* - A **bicuspid aortic valve** is a congenital anomaly that can cause **aortic stenosis** or **aortic regurgitation**, leading to distinct murmurs (e.g., crescendo-decrescendo systolic ejection murmur for stenosis). - The patient's grandfather had an aortic valve abnormality, but her current findings of a **mid-systolic click** and a murmur after S1 point specifically to **mitral valve prolapse**, not bicuspid aortic valve disease.

Question 737: A 30-year-old African American woman comes to the physician because of fatigue and muscle weakness for the past 5 weeks. During this period, she has had recurrent headaches and palpitations. She has hypertension and major depressive disorder. She works as a nurse at a local hospital. She has smoked about 6–8 cigarettes daily for the past 10 years and drinks 1–2 glasses of wine on weekends. Current medications include enalapril, metoprolol, and fluoxetine. She is 168 cm (5 ft 6 in) tall and weighs 60 kg (132 lb); BMI is 21.3 kg/m2. Her temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 155/85 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no abnormalities. The abdomen is soft and nontender; bowel sounds are normal. Her skin is dry and there is no edema in the lower extremities. Laboratory studies show: Hemoglobin 13.3 g/dL Serum Na+ 146 mEq/L Cl- 105 mEq/L K+ 3.0 mEq/L HCO3- 30 mEq/L Urea nitrogen 10 mg/dL Glucose 95 mg/dL Creatinine 0.8 mg/dL Urine Blood negative Glucose negative Protein negative RBC 0–1/hpf WBC none Which of the following is the most likely diagnosis in this patient?

A. Cushing syndrome
B. Aldosteronoma (Correct Answer)
C. Laxative abuse
D. Pheochromocytoma
E. Renal artery stenosis

Explanation: ***Aldosteronoma*** - This patient presents with **hypertension**, **muscle weakness**, fatigue, **hypokalemia** (K+ 3.0 mEq/L), and **metabolic alkalosis** (HCO3- 30 mEq/L), which are classic signs of **primary hyperaldosteronism**. - **Aldosteronomas** are a common cause of primary hyperaldosteronism due to autonomous aldosterone production, leading to sodium retention, potassium excretion, and subsequent hypertension and hypokalemia. *Cushing syndrome* - While Cushing syndrome can cause hypertension and muscle weakness, it typically presents with features like **central obesity**, **moon facies**, **buffalo hump**, **striae**, and **hyperglycemia**, which are not described in this patient. - Although it can cause hypokalemia, the overall clinical picture is more suggestive of primary hyperaldosteronism given the constellation of symptoms. *Laxative abuse* - Laxative abuse can cause hypokalemia and metabolic alkalosis, but it typically presents with **diarrhea**, **abdominal pain**, and potentially features of **dehydration**, which are absent here. - Chronic laxative abuse would not typically be the primary cause of sustained hypertension in this context without other tell-tale signs. *Pheochromocytoma* - **Pheochromocytoma** causes episodic or sustained hypertension, often accompanied by **palpitations**, **headaches**, and **sweating** due to excessive catecholamine release. - However, it does not typically cause hypokalemia or metabolic alkalosis unless there is co-secretion of other hormones, making it less likely than aldosteronoma with the presented lab abnormalities. *Renal artery stenosis* - **Renal artery stenosis** can cause hypertension and sometimes hypokalemia due to increased renin secretion, leading to secondary hyperaldosteronism. - However, the primary cause would be renal ischemia, and the hyperaldosteronism would be reactive, whereas in this case, the hypokalemia and metabolic alkalosis strongly point towards autonomous aldosterone production.

Question 738: A 45-year-old man is rushed to the emergency department by his wife after complaining of sudden onset excruciating headache that started about an hour ago. On further questioning, the patient's wife gives a prior history of flank pain, hematuria, and hypertension in the patient, and she recalls that similar symptoms were present in his uncle. On examination, his GCS is 12/15. When his hip and knee are flexed, he resists subsequent extension of the knee. When the neck is passively flexed, there is severe neck stiffness and the patient's hips and knees flex involuntarily. During the examination, he lapses into unconsciousness. Which of the following mechanisms best explains what led to this patient's presentation?

A. Uremic encephalopathy from chronic renal disease
B. Meningeal irritation from a space occupying lesion
C. Increased wall tension within an aneurysm (Correct Answer)
D. Embolic occlusion of a cerebral vessel
E. Intracerebral hemorrhage due to vascular malformations

Explanation: ***Increased wall tension within an aneurysm*** - The sudden onset of an **excruciating headache** ("thunderclap headache") followed by rapid deterioration of consciousness (lapsing into unconsciousness) is highly suggestive of a **subarachnoid hemorrhage (SAH)**. - The patient's history of **flank pain, hematuria, hypertension**, and a **family history** of similar symptoms (uncle) point towards **autosomal dominant polycystic kidney disease (ADPKD)**, which is strongly associated with an increased risk of **cerebral aneurysms** and SAH. The neurological signs (**GCS 12/15**, resistance to knee extension with hip flexion (positive Kernig's sign: resistance to knee extension when hip is flexed), and flexion of hips and knees with neck flexion (positive Brudzinski's sign: active flexion of the neck causes involuntary flexion of hips and knees)) indicate **meningeal irritation** due to blood in the subarachnoid space and further support the diagnosis of SAH, likely from a ruptured aneurysm. *Uremic encephalopathy from chronic renal disease* - While the patient has signs suggestive of ADPKD, which can lead to chronic renal disease and uremic encephalopathy, the acute presentation of a **thunderclap headache** and rapid neurological decline is not typical of uremic encephalopathy, which usually has a more protracted and fluctuating course. - Uremic encephalopathy primarily results from the accumulation of **uremic toxins**, leading to altered mental status, asterixis, and seizures, but typically without the dramatic acute onset and meningeal signs seen here. *Meningeal irritation from a space occupying lesion* - Meningeal irritation can be caused by a space-occupying lesion if it bleeds or causes significant mass effect and inflammation, but the **sudden, excruciating headache** (thunderclap headache) followed by rapid neurological deterioration is not the primary presentation for most space-occupying lesions. - A space-occupying lesion would typically cause focal neurological deficits, seizures, or a more gradual onset of headache, rather than the abrupt, severe global headache and signs of meningeal irritation observed. *Embolic occlusion of a cerebral vessel* - **Embolic occlusion** typically causes an **ischemic stroke**, presenting with sudden focal neurological deficits such as hemiparesis, aphasia, or visual field loss, usually without severe headache as the primary symptom. - While a severe headache can occur in some ischemic strokes, it is not typically described as an "excruciating thunderclap" headache, and meningeal signs like Kernig's and Brudzinski's are absent unless there is hemorrhagic transformation. *Intracerebral hemorrhage due to vascular malformations* - Intracerebral hemorrhage (ICH) can cause a sudden severe headache and neurological deterioration, but it typically presents with **focal neurological deficits** corresponding to the area of hemorrhage. - While there may be some degree of meningeal irritation if the hemorrhage extends to the ventricles or subarachnoid space, the strong association with **ADPKD** and cerebral aneurysms makes SAH leading to meningeal irritation a more likely and specific explanation for this presentation.

Question 739: A 44-year-old woman presents to the outpatient clinic for the evaluation of amenorrhea which she noted roughly 4 months ago. Her monthly cycles up to that point were normal. Initially, she thought that it was related to early menopause; however, she has also noticed that she has a small amount of milk coming from her breasts as well. She denies any nausea, vomiting, or weight gain but has noticed that she has lost sight in the lateral fields of vision to the left and right. Her vital signs are unremarkable. Physical examination confirms bitemporal hemianopsia. What test is likely to reveal her diagnosis?

A. Serum estrogen and progesterone levels
B. Mammogram
C. Serum TSH and free T4
D. Urine pregnancy test
E. MRI brain (Correct Answer)

Explanation: ***MRI brain*** - The combination of **amenorrhea**, **galactorrhea** (milk production), and **bitemporal hemianopsia** is highly suggestive of a **pituitary adenoma**, particularly a **prolactinoma**. An MRI of the brain is the diagnostic imaging test of choice to visualize the pituitary gland and identify such a mass. - The **bitemporal hemianopsia** indicates compression of the **optic chiasm**, which is classically seen with suprasellar extension of a pituitary tumor. *Serum estrogen and progesterone levels* - While these levels might be abnormal in amenorrhea due to various causes, testing them would not directly identify the underlying cause, especially when there are clear signs of a mass effect on the optic chiasm. - This test is more appropriate for evaluating ovarian function or other hormonal imbalances not associated with mass effects. *Mammogram* - A mammogram is used to screen for or diagnose **breast cancer** and evaluate breast lumps. - Although the patient has galactorrhea, which is breast-related, the presence of amenorrhea and bitemporal hemianopsia points away from primary breast pathology as the root cause. *Serum TSH and free T4* - These tests evaluate **thyroid function**. While thyroid dysfunction can cause menstrual irregularities, it typically does not cause galactorrhea or bitemporal hemianopsia. - Hypothyroidism can cause menstrual irregularities and sometimes galactorrhea, but the bitemporal hemianopsia strongly points to a structural lesion. *Urine pregnancy test* - A pregnancy test is a routine initial step in evaluating amenorrhea in women of childbearing age to rule out pregnancy. - However, the additional symptoms of **galactorrhea** and **bitemporal hemianopsia** are not explained by pregnancy and strongly suggest a more serious underlying condition.

Question 740: A 47-year-old woman presents with blurry vision for the past 2 weeks. She says that symptoms onset gradually and have progressively worsened. She works as a secretary in a law firm, and now her vision is hampering her work. Past medical history is significant for psoriasis, diagnosed 7 years ago, managed with topical corticosteroids. Her blood pressure is 120/60 mm Hg, respiratory rate is 17/min, and pulse is 70/min. Her BMI is 28 kg/m2. Physical examination is unremarkable. Laboratory findings are significant for the following: RBC count 4.4 x 1012/L WBC count 5.0 x 109/L Hematocrit 44% Fasting plasma glucose 250 mg/dL Hemoglobin A1C 7.8% Which of the following would be the most likely cause of death in this patient?

A. Rhinocerebral mucormycosis
B. Coma
C. Peripheral neuropathy
D. Myocardial infarction (Correct Answer)
E. Renal failure

Explanation: ***Myocardial infarction*** - The patient's elevated **fasting plasma glucose** (250 mg/dL) and **HbA1C** (7.8%) indicate **uncontrolled diabetes mellitus**. Her **BMI of 28** kg/m2 points to **overweight/obesity**, another risk factor for cardiovascular disease. - **Cardiovascular disease**, including **myocardial infarction**, is the leading cause of death in patients with diabetes due to accelerated atherosclerosis. *Rhinocerebral mucormycosis* - This is an **opportunistic fungal infection** typically seen in severely immunocompromised patients, particularly those with uncontrolled diabetes and ketoacidosis. - While diabetes is a risk factor, the patient does not present with characteristic symptoms such as **facial pain**, **black nasal discharge**, or widespread immunosuppression. *Coma* - **Diabetic coma** can result from extreme hyperglycemia (**hyperosmolar hyperglycemic state**) or severe hypoglycemia. - While the patient has hyperglycemia, her blood pressure, respiratory rate, and pulse are stable, and the physical examination is unremarkable, suggesting she is not in immediate danger of diabetic coma. *Peripheral neuropathy* - **Diabetic peripheral neuropathy** is a common long-term complication of diabetes, causing symptoms like numbness, tingling, and pain, mainly in the extremities. - While likely present with long-standing uncontrolled diabetes, it is generally **not a direct cause of death** but rather contributes to morbidity and risk of secondary complications like foot ulcers and infections. *Renal failure* - **Diabetic nephropathy** is a major microvascular complication of diabetes leading to **chronic kidney disease** and potentially end-stage renal failure. - While possible in the long term, there are no specific direct indicators of severe or advanced renal failure in her current presentation such as elevated creatinine or signs of fluid overload; cardiovascular events pose a more immediate and common fatal risk in uncontrolled diabetes.

Question 741: A previously healthy 10-year-old boy is brought to the emergency department for the evaluation of one episode of vomiting and severe headache since this morning. His mother says he also had difficulty getting dressed on his own. He has not had any trauma. The patient appears nervous. His temperature is 37°C (98.6°F), pulse is 100/min, and blood pressure is 185/125 mm Hg. He is confused and oriented only to person. Ophthalmic examination shows bilateral optic disc swelling. There is an abdominal bruit that is best heard at the right costovertebral angle. A complete blood count is within normal limits. Which of the following is most likely to confirm the diagnosis?

A. Serum IGF-I level
B. Oral sodium loading test
C. Echocardiography
D. CT angiography (Correct Answer)
E. High-dose dexamethasone suppression test

Explanation: ***CT angiography*** - The patient presents with **malignant hypertension** (BP 185/125 mmHg, confusion, optic disc swelling) and an **abdominal bruit** especially at the **right costovertebral angle**, pointing strongly towards **renovascular hypertension** due to **renal artery stenosis**. - **CT angiography** is the most appropriate imaging modality to confirm **renal artery stenosis** by visualizing the renal arteries and identifying any narrowing. *Serum IGF-I level* - This test is used to screen for **growth hormone disorders** like **acromegaly** or **gigantism**, which are not indicated by the patient's symptoms. - The patient's presentation is focused on acute severe hypertension and neurological changes, rather than chronic growth disturbances. *Oral sodium loading test* - This test is used to confirm the diagnosis of **primary aldosteronism**, where **aldosterone levels** fail to suppress after a sodium load. - While primary aldosteronism can cause hypertension, it typically doesn't present with an **abdominal bruit** or the acute, severe neurological symptoms seen here. *Echocardiography* - **Echocardiography** assesses the heart's structure and function, which could show signs of **hypertensive heart disease** (e.g., left ventricular hypertrophy) due to long-standing uncontrolled hypertension. - However, it does not identify the underlying cause of the hypertension in this acute setting, especially when an **abdominal bruit** suggests a vascular origin. *High-dose dexamethasone suppression test* - This test is used to differentiate between **Cushing's disease** (pituitary ACTH-dependent) and other causes of **Cushing's syndrome** (e.g., ectopic ACTH production, adrenal tumor) due to excess cortisol. - The patient's symptoms are inconsistent with Cushing's syndrome, and the **abdominal bruit** points away from this diagnosis.

Question 742: A 26-year-old male professional soccer player is brought to the emergency department due to an episode of syncope during a game. He has felt increasing shortness of breath during the past 3 months. During the past week, he has been feeling chest pain upon exertion. He also tells the doctor that his brother had a sudden death a couple of years ago. His heart rate is 98/min, respiratory rate is 18/min, temperature is 36.5°C (97.7°F), and blood pressure is 110/72 mm Hg. On physical examination, there is a harsh crescendo-decrescendo systolic murmur immediately after S1; it is best heard at the left lower sternal border. There is also a holosystolic murmur at the apex that radiates to the axilla. When the Valsalva maneuver is performed, the murmur becomes louder. An ECG and an echocardiogram are performed, which confirm the diagnosis. What is the most likely cause of this patient's condition?

A. First-degree heart block
B. Aortic stenosis
C. Hypertrophic cardiomyopathy (Correct Answer)
D. Third-degree heart block
E. Cardiac tamponade

Explanation: ***Hypertrophic cardiomyopathy*** - The patient's history of **syncope**, exertional **chest pain**, and **shortness of breath** in a young athlete, combined with a family history of sudden death, are classic signs of hypertrophic cardiomyopathy (HCM). - The physical exam findings of a **harsh crescendo-decrescendo systolic murmur at the left lower sternal border** represent left ventricular outflow tract (LVOT) obstruction, the hallmark of obstructive HCM. - The **holosystolic murmur at the apex radiating to the axilla** represents mitral regurgitation due to systolic anterior motion (SAM) of the mitral valve, a common finding in HCM. - Both murmurs **increase with Valsalva maneuver** (due to decreased preload, exacerbating LVOT obstruction and worsening MR), which is highly characteristic of HCM. *First-degree heart block* - **First-degree heart block** is characterized by a prolonged PR interval on ECG and typically does not cause syncope, chest pain, or a murmur that changes with Valsalva. - It is generally asymptomatic and not associated with sudden cardiac death in the same manner as HCM. *Aortic stenosis* - While **aortic stenosis** also presents with a harsh systolic murmur and can cause syncope, it typically **decreases with Valsalva maneuver** (decreased preload reduces stroke volume and murmur intensity). - The murmur of aortic stenosis is typically heard best at the **right upper sternal border** and radiates to the carotid arteries, not the left lower sternal border. - Aortic stenosis would not cause the additional holosystolic murmur of mitral regurgitation seen in this patient. *Third-degree heart block* - **Third-degree heart block** (complete heart block) involves a complete dissociation between atrial and ventricular activity, leading to severe bradycardia and symptoms like syncope. - However, it does not typically produce the specific type of systolic murmurs described, nor does it fit the familial sudden death profile in the context of a young athlete's exertional symptoms. *Cardiac tamponade* - **Cardiac tamponade** is a medical emergency caused by fluid accumulation around the heart, leading to impaired ventricular filling. - Its classical signs include **hypotension, jugular venous distension, and muffled heart sounds (Beck's triad)**, none of which are described in this patient.

Question 743: A 39-year-old woman comes to the physician because of progressive pain and swelling of her wrists and hands for the past 2 months. Her hands are stiff in the morning; the stiffness decreases as she starts her chores. She also reports early-morning neck pain at rest for the past 3 weeks. She has no history of serious illness and takes no medications. Her sister has systemic lupus erythematosus. Vital signs are within normal limits. Examination shows bilateral swelling and tenderness of the wrists, second, third, and fourth metacarpophalangeal joints; range of motion is limited by pain. There is no vertebral tenderness. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. Laboratory studies show: Hemoglobin 12.8 g/dL Leukocyte count 9,800/mm3 Erythrocyte sedimentation rate 44 mm/h Serum Glucose 77 mg/dL Creatinine 1.1 mg/dL Total bilirubin 0.7 mg/dL Alkaline phosphatase 33 U/L AST 14 U/L ALT 13 U/L Rheumatoid factor positive Which of the following is the most appropriate next step in management?

A. Adalimumab
B. CT scan of the chest
C. Measurement of anti-CCP antibodies (Correct Answer)
D. X-ray of the cervical spine
E. Measurement of anti-Smith antibodies

Explanation: ***Measurement of anti-CCP antibodies*** - This patient presents with **classic rheumatoid arthritis (RA)**: symmetric polyarthritis affecting wrists and MCP joints, morning stiffness improving with activity, elevated ESR, and positive rheumatoid factor. - **Anti-CCP (anti-cyclic citrullinated peptide) antibodies** are highly specific for RA (~95% specificity) and should be measured to **confirm the diagnosis**. - Anti-CCP positivity helps with **prognostication** (associated with more aggressive disease and erosive changes) and guides early initiation of disease-modifying antirheumatic drugs (DMARDs) like methotrexate. - Early diagnosis and treatment of RA is crucial to prevent irreversible joint damage and disability. *Measurement of anti-Smith antibodies* - **Anti-Smith antibodies** are highly specific for **systemic lupus erythematosus (SLE)**, not RA. - This patient has **no clinical features of SLE** (no malar rash, photosensitivity, oral ulcers, serositis, renal involvement, or cytopenias). - Family history of SLE alone does not warrant testing when the clinical presentation clearly points to RA. - The neck pain is consistent with early RA involvement of cervical spine, not SLE. *Adalimumab* - **Adalimumab** is a TNF-alpha inhibitor used for RA, but it is **not first-line therapy**. - The diagnosis must first be confirmed, and conventional DMARDs (especially **methotrexate**) should be tried first. - Biologics like adalimumab are reserved for patients who fail conventional DMARDs or have severe disease at presentation. *CT scan of the chest* - There are **no respiratory symptoms** or abnormal cardiopulmonary findings on examination. - While RA can cause interstitial lung disease or pleural effusions, screening imaging is not indicated without clinical signs or symptoms. - The priority is confirming the diagnosis of RA. *X-ray of the cervical spine* - While the patient has neck pain, the **neurological examination is normal** and there is no vertebral tenderness. - Cervical spine involvement in RA (atlantoaxial subluxation) typically occurs in longstanding disease, not at presentation. - Imaging would be indicated if there were neurological deficits, severe pain, or mechanical symptoms suggesting instability.

Question 744: A 62-year-old man returns to his physician for a follow-up examination. During his last visit 1 month ago splenomegaly was detected. He has had night sweats for the past several months and has lost 5 kg (11 lb) unintentionally during this period. He has no history of a serious illness and takes no medications. The vital signs are within normal limits. The physical examination shows no abnormalities other than splenomegaly. The laboratory studies show the following: Hemoglobin 9 g/dL Mean corpuscular volume 95 μm3 Leukocyte count 12,000/mm3 Platelet count 260,000/mm3 Ultrasound shows a spleen size of 15 cm (5.9 in) and mild hepatomegaly. The peripheral blood smear shows teardrop-shaped and nucleated red blood cells (RBCs) and immature myeloid cells. The marrow is very difficult to aspirate but reveals hyperplasia of all 3 lineages. The tartrate-resistant acid phosphatase (TRAP) test is negative. Clonal marrow plasma cells are not seen. JAK-2 is positive. The cytogenetic analysis is negative for translocation between chromosomes 9 and 22. Which of the following is the most appropriate curative management in this patient?

A. Adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD)
B. Allogeneic bone marrow transplantation (Correct Answer)
C. Splenectomy
D. Splenic irradiation
E. Imatinib mesylate

Explanation: ***Allogeneic bone marrow transplantation*** - The patient's presentation with **splenomegaly**, night sweats, weight loss, anemia, **teardrop cells**, **nucleated RBCs**, **immature myeloid cells** in peripheral blood, **dry tap** on marrow aspiration, and **JAK2 positivity** is highly suggestive of **primary myelofibrosis**. - For younger patients with intermediate to high-risk primary myelofibrosis, allogeneic stem cell transplantation is the only potentially curative treatment. *Adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD)* - This is a chemotherapy regimen primarily used for the treatment of **Hodgkin lymphoma**. - It is not indicated for the management of primary myelofibrosis. *Splenectomy* - Splenectomy can be considered for patients with **severe, symptomatic splenomegaly** or refractory anemia/thrombocytopenia in myelofibrosis. - However, it is a **palliative measure** to alleviate symptoms, not a curative treatment for the underlying bone marrow disorder. *Splenic irradiation* - Splenic irradiation is used to reduce spleen size and relieve symptoms like pain or early satiety in patients with **myelofibrosis** who are not candidates for splenectomy. - It provides **symptomatic relief** but does not alter the disease course or offer a cure. *Imatinib mesylate* - Imatinib is a **tyrosine kinase inhibitor** primarily used to treat **chronic myelogenous leukemia (CML)**, specifically targeting the **BCR-ABL1 fusion gene**. - The patient's cytogenetic analysis was negative for translocation between chromosomes 9 and 22, ruling out CML, and Imatinib is not effective for JAK2-positive myelofibrosis.

Question 745: A 24-year-old previously healthy man comes to his physician because of dyspnea and hemoptysis for the past week. Examination shows inspiratory crackles at both lung bases. The remainder of the examination shows no abnormalities. His hemoglobin concentration is 14.2 g/dL, leukocyte count is 10,300/mm3, and platelet count is 205,000/mm3. Urine dipstick shows 2+ proteins. Urinalysis shows 80 RBC/hpf and 1–2 WBC/hpf. An x-ray of the chest shows pulmonary infiltrates. Further evaluation is most likely to show increased serum titers of which of the following?

A. Anti-PLA2R antibody
B. P-ANCA
C. Anti-GBM antibody (Correct Answer)
D. Immunoglobulin A
E. Anti-dsDNA antibody

Explanation: ***Anti-GBM antibody*** - The patient's presentation with **dyspnea**, **hemoptysis**, **pulmonary infiltrates**, **proteinuria**, and **hematuria** is highly suggestive of **Goodpasture syndrome**, a rapidly progressive glomerulonephritis with pulmonary hemorrhage. - Goodpasture syndrome is characterized by the presence of autoantibodies directed against the **collagen type IV** of the glomerular and alveolar basement membranes, specifically the **α3 chain of type IV collagen**. *Anti-PLA2R antibody* - **Anti-PLA2R antibodies** are associated with **membranous nephropathy**, a cause of nephrotic syndrome, which is not indicated by the patient's primary symptoms of dyspnea and hemoptysis, nor by the urinalysis showing significant hematuria. - While membranous nephropathy can cause proteinuria, it typically does not present with **pulmonary-renal syndrome** or significant hematuria (red blood cell casts are more indicative of glomerulonephritis). *P-ANCA* - **P-ANCA** (perinuclear anti-neutrophil cytoplasmic antibodies) are typically associated with **microscopic polyangiitis** or **eosinophilic granulomatosis with polyangiitis (Churg-Strauss)**, which can cause pulmonary-renal syndrome but usually present with systemic vasculitis symptoms like skin lesions or nerve involvement. - While microscopic polyangiitis can cause pulmonary hemorrhage and glomerulonephritis, the classic presentation of Goodpasture syndrome with its specific autoantibody profile is a more direct fit given the acute and severe pulmonary and renal symptoms. *Immunoglobulin A* - Increased serum **IgA** levels are characteristic of **IgA nephropathy (Berger's disease)** or **Henoch-Schönlein purpura**, which primarily cause glomerulonephritis. - These conditions do not typically cause severe **pulmonary hemorrhage** or the acute pulmonary-renal syndrome seen in this patient. *Anti-dsDNA antibody* - **Anti-dsDNA antibodies** are a hallmark of **systemic lupus erythematosus (SLE)**, which can affect multiple organ systems, including the kidneys (lupus nephritis) and lungs. - However, the acute and severe **pulmonary-renal syndrome** with hemoptysis and pulmonary infiltrates, without other systemic lupus symptoms, makes Goodpasture syndrome a more specific diagnosis in this context.

Question 746: A 42-year-old man presents to the clinic for a second evaluation of worsening blackened ulcers on the tips of his toes. His past medical history includes diabetes mellitus for which he takes metformin and his most recent HbA1c was 6.0, done 3 months ago. He also has hypertension for which he's prescribed amlodipine and chronic obstructive pulmonary disease (COPD) for which he uses an albuterol-ipratropium combination inhaler. He is also a chronic tobacco user with a 27-pack-year smoking history. He first noticed symptoms of a deep aching pain in his toes. Several months ago, he occasionally felt pain in his fingertips both at rest and with activity. Now he reports blackened skin at the tips of his fingers and toes. Evaluation shows: pulse of 82/min, blood pressure of 138/85 mm Hg, oral temperature 37.0°C (98.6°F). He is thin. Physical examination of his feet demonstrates the presence of 3, 0.5–0.8 cm, eschars over the tips of his bilateral second toes and right third toe. There is no surrounding erythema or exudate. Proprioception, vibratory sense, and monofilament examination are normal on both ventral aspects of his feet, but he lacks sensation over the eschars. Dorsal pedal pulses are diminished in both feet; the skin is shiny and hairless. Initial lab results include a C-reactive protein (CRP) level of 3.5 mg/dL, leukocytes of 6,000/mm3, erythrocyte sedimentation rate (ESR) of 34 mm/hr, and negative antinuclear antibodies. Which part of the patient's history is most directly associated with his current problem?

A. Diabetes mellitus
B. Hypertension
C. Autoimmune disorder
D. Chronic obstructive pulmonary disease
E. Tobacco smoking (Correct Answer)

Explanation: ***Tobacco smoking*** - The patient exhibits symptoms consistent with **Buerger's disease (thromboangiitis obliterans)**, which is strongly associated with **heavy tobacco use**. The blackened ulcers on the fingertips and toes ("blackened skin" and "eschars") are indicative of **ischemia** due to **vasculitis** of small and medium-sized arteries. - The "deep aching pain" in his toes and fingertips preceding the ulcers, along with diminished peripheral pulses and shiny, hairless skin, further supports a diagnosis of severe peripheral vascular disease primarily driven by smoking. *Diabetes mellitus* - While diabetes can cause **peripheral neuropathy** and **vascular disease**, this patient's **HbA1c of 6.0** indicates good glycemic control, making it less likely to be the primary cause of his extensive, severe ischemic ulcers. - The normal proprioception, vibratory sense, and monofilament examination (except over the eschars) suggest that **diabetic neuropathy** is not the direct cause of the current ischemic problem. *Hypertension* - Hypertension is a risk factor for **atherosclerosis** and cardiovascular disease, but it typically affects larger arteries and does not directly explain the specific pattern of **vasculitis** and **digital ischemia** seen in this patient (blackened fingertips and toes). - The patient's blood pressure is controlled with medication, and while it contributes to overall vascular risk, it's not as directly associated with the presented condition as tobacco use is. *Autoimmune disorder* - The negative antinuclear antibodies (ANA), near-normal ESR (34 mm/hr) and CRP (3.5 mg/dL) make a systemic **autoimmune disorder**, such as systemic lupus erythematosus or scleroderma, less likely to be the primary cause of his ulcers. - While some autoimmune conditions can cause vasculitis, the clinical picture, particularly the strong association with tobacco use and the distribution of lesions, points away from a primary autoimmune etiology. *Chronic obstructive pulmonary disease* - COPD is a **pulmonary condition** primarily affecting the lungs and is strongly associated with smoking, but it does not directly cause **peripheral ischemic ulcers** on the fingers and toes. - While COPD indicates the patient's long-standing smoking habit, it is the smoking itself, not the COPD directly, that causes the vascular pathology leading to the blackened ulcers.

Question 747: A 17-year-old girl is brought to the physician for a physical examination prior to participating in sports. She has no history of serious illness. She is on the school's cheerleading team and is preparing for an upcoming competition. Menarche was at 13 years of age, and her last menstrual period was 4 months ago. She is 167 cm (5 ft 6 in) tall and weighs 45 kg (99 lb); BMI is 16.1 kg/m2. Examination shows pale skin with thin, soft body hair. The patient is at increased risk for which of the following complications?

A. Shortened QT interval
B. Hyperkalemia
C. Fractures (Correct Answer)
D. Hyperthyroidism
E. Hyperphosphatemia

Explanation: ***Fractures*** - This patient presents with signs and symptoms highly suggestive of **anorexia nervosa**, including a **low BMI (16.1 kg/m2)**, **amenorrhea (last menstrual period 4 months ago)**, and physical findings like **pale skin** and **thin, soft body hair**. - **Estrogen deficiency** due to amenorrhea in anorexia nervosa leads to accelerated **bone loss** and **osteoporosis**, significantly increasing the risk of **pathological fractures**. *Shortened QT interval* - Anorexia nervosa is typically associated with **electrolyte imbalances** like **hypokalemia**, **hypomagnesemia**, and **hypophosphatemia**, which can lead to a **prolonged QT interval**, not a shortened one. - A shortened QT interval is rare and usually associated with **hypercalcemia** or genetic disorders. *Hyperkalemia* - Patients with anorexia nervosa often experience **hypokalemia** due to gastrointestinal losses (e.g., vomiting, laxative abuse) or diuretic use, which is commonly associated with eating disorders. - **Hyperkalemia** is less common unless there is kidney dysfunction, refeeding syndrome with rapid fluid shifts, or certain medications. *Hyperthyroidism* - Anorexia nervosa is more often associated with **euthyroid sick syndrome** or **hypothyroidism**, characterized by **low T3 levels** and normal or slightly low T4 and TSH. - **Hyperthyroidism** is an accelerated metabolic state, which is contrary to the reduced metabolic rate seen in severe malnutrition. *Hyperphosphatemia* - **Refeeding syndrome**, a potential complication of refeeding in severely malnourished patients like this one, is characterized by **hypophosphatemia** (not hyperphosphatemia), hypokalemia, and hypomagnesemia. - **Hypophosphatemia** occurs as glucose refeeding stimulates insulin release, leading to increased cellular uptake of phosphate.

Question 748: A 59-year-old man is brought to the emergency department by his wife for a 1-hour history of sudden behavior changes. They were having lunch together when, at 1:07 PM, he suddenly dropped his sandwich on the floor. Since then, he has been unable to use his right arm. She also reports that he is slurring his speech and dragging his right foot when he walks. Nothing like this has ever happened before. The vital signs include: pulse 95/min, blood pressure 160/90 mm Hg, and respiratory rate 14/min. The physical exam is notable for an irregularly irregular rhythm on cardiac auscultation. On neurological exam, he has a facial droop on the right half of his face but is able to elevate his eyebrows symmetrically. He has 0/5 strength in his right arm, 2/5 strength in his right leg, and reports numbness throughout the right side of his body. Angiography of the brain will most likely show a lesion in which of the following vessels?

A. Posterior cerebral artery
B. Internal carotid artery
C. Middle cerebral artery (Correct Answer)
D. Basilar artery
E. Anterior cerebral artery

Explanation: ***Middle cerebral artery*** - The patient's symptoms, including **right-sided weakness with arm > leg involvement** (0/5 arm, 2/5 leg), **facial droop** (lower face sparing the forehead), and **slurred speech (dysarthria/aphasia)**, are classic signs of an **MCA stroke**. - The **arm > leg pattern** is the key distinguishing feature of MCA territory infarction, as the MCA supplies the **lateral motor cortex** (which controls arm and face). - The finding of an **irregularly irregular rhythm** suggests **atrial fibrillation**, a common cause of **embolic stroke** to the MCA. *Posterior cerebral artery* - PCA strokes primarily affect the **occipital lobe** and **medial temporal lobe**, leading to **visual field defects** (e.g., homonymous hemianopsia) or memory deficits. - While it can cause sensory loss, it typically does not present with the **prominent motor deficits** and **facial droop** seen in this patient. *Internal carotid artery* - ICA occlusion can cause symptoms similar to MCA stroke, especially if the **MCA is a direct branch of the ICA**, or it can cause both MCA and ACA symptoms simultaneously. - However, the specific constellation of symptoms described (predominant motor and sensory deficits, speech issues) points more directly to the **MCA territory downstream**. *Basilar artery* - Basilar artery strokes affect the **brainstem** and often present with a combination of **cranial nerve palsies**, **ataxia**, bilateral weakness, **vertigo**, and sometimes **"locked-in" syndrome**. - The patient's symptoms are more consistent with a **hemispheric lesion**, not a brainstem lesion. *Anterior cerebral artery* - ACA strokes typically cause **contralateral leg > arm weakness** (opposite pattern from MCA), as the ACA supplies the **medial motor cortex**. - ACA strokes may also present with **behavioral changes** (e.g., abulia, apathy) due to involvement of the frontal lobe. - The patient's prominent **right arm weakness** and **facial droop** are not characteristic of an ACA stroke.

Question 749: A 58-year-old woman presents to the clinic with an abnormal sensation on the left side of her body that has been present for the past several months. At first, the area seemed numb and she recalls touching a hot stove and accidentally burning herself but not feeling the heat. Now she is suffering from a constant, uncomfortable burning pain on her left side for the past week. The pain gets worse when someone even lightly touches that side. She has recently immigrated and her past medical records are unavailable. Last month she had a stroke but she cannot recall any details from the event. She confirms a history of hypertension, type II diabetes mellitus, and bilateral knee pain. She also had cardiac surgery 20 years ago. She denies fever, mood changes, weight changes, and trauma to the head, neck, or limbs. Her blood pressure is 162/90 mm Hg, the heart rate is 82/min, and the respiratory rate is 15/min. Multiple old burn marks are visible on the left hand and forearm. Muscle strength is mildly reduced in the left upper and lower limbs. Hyperesthesia is noted in the left upper and lower limbs. Laboratory results are significant for: Hemoglobin 13.9 g/dL MCV 92 fL White blood cells 7,500/mm3 Platelets 278,000/mm3 Creatinine 1.3 U/L BUN 38 mg/dL TSH 2.5 uU/L Hemoglobin A1c 7.9% Vitamin B12 526 ng/L What is the most likely diagnosis?

A. Conversion disorder
B. Complex regional pain syndrome
C. Dejerine-Roussy syndrome (Correct Answer)
D. Medial medullary syndrome
E. Subacute combined degeneration of spinal cord

Explanation: ***Dejerine-Roussy syndrome*** - The patient's symptoms of **contralateral hemianesthesia**, followed by **dysesthesia**, **spontaneous burning pain**, and **allodynia/hyperalgesia**, developing after a stroke a month prior, are classic for **Dejerine-Roussy syndrome** (thalamic pain syndrome). The history of unnoticed burns and hyperesthesia supports this. - This syndrome is caused by a lesion in the **thalamus**, typically due to a stroke, which disrupts sensory pathways and leads to an abnormal processing of sensory information. *Conversion disorder* - Conversion disorder involves neurological symptoms that are **incompatible with recognized neurological or medical conditions** and are often associated with psychological stress. - The patient's symptoms are clearly attributable to a known neurological etiology (a recent stroke) and specific anatomical location (thalamus), ruling out conversion disorder. *Complex regional pain syndrome* - **Complex regional pain syndrome (CRPS)** is characterized by severe pain, swelling, and autonomic dysfunction, typically affecting a **single limb distal to an injury**, but not necessarily associated with a stroke to the brain. - While the patient has burning pain and hyperesthesia, the **hemibody distribution** and clear link to a prior stroke make CRPS less likely than a central lesion. *Medial medullary syndrome* - **Medial medullary syndrome** results from damage to the medial medulla and typically presents with **ipsilateral tongue weakness**, **contralateral hemiparesis**, and **contralateral loss of vibratory and proprioceptive sensation**, but not the prominent burning pain and allodynia described. - The patient's primary sensory complaints of burning pain and hyperesthesia across an entire hemibody are not characteristic of medial medullary syndrome. *Subacute combined degeneration of spinal cord* - **Subacute combined degeneration** is caused by **vitamin B12 deficiency** and affects the dorsal and lateral columns of the spinal cord, leading to **paresthesias**, weakness, gait ataxia, and impaired proprioception. - The patient's **vitamin B12 level is normal**, and the symptoms are acute-onset and unilateral, clearly linked to a stroke, not a progressive, symmetrical myelopathy.

Question 750: A 40-year-old man comes to the physician because of fatigue, increased sweating, and itching in his legs for the past 2 years. He has chronic bronchitis. He has smoked two packs of cigarettes daily for 24 years and drinks one to two beers every night. His only medication is a tiotropium bromide inhaler. His vital signs are within normal limits. He is 175 cm (5 ft 9 in) tall and weighs 116 kg (256 lb); BMI is 38 kg/m2. Physical examination shows facial flushing and bluish discoloration of the lips. Scattered expiratory wheezing and rhonchi are heard throughout both lung fields. Abdominal examination shows no abnormalities. Laboratory studies show: Erythrocyte count 6.9 million/mm3 Hemoglobin 20 g/dL Mean corpuscular volume 91 μm3 Leukocyte count 13,000/mm3 Platelet count 540,000/mm3 Serum Ferritin 8 ng/mL Iron 48 μg/dL Iron binding capacity 402 μg/dL (N: 251 - 406 μg/dL) Which of the following is the most appropriate next step in treatment?

A. Weight loss
B. Inhaled budesonide
C. Hydroxyurea
D. Allogeneic stem cell transplantation
E. Phlebotomy (Correct Answer)

Explanation: ***Phlebotomy*** - This patient has **secondary erythrocytosis** due to **chronic hypoxemia** from COPD (chronic bronchitis, 48 pack-year smoking history, cyanosis, wheezing). - Severe erythrocytosis (Hb 20 g/dL, Hct likely >60%) causes **hyperviscosity syndrome** manifesting as fatigue, headaches, and pruritus. - **Phlebotomy** is indicated when Hct >55% in secondary polycythemia to reduce thrombotic risk and improve symptoms related to hyperviscosity. - The goal is to reduce hematocrit to <55% while addressing the underlying hypoxemia with oxygen therapy and COPD optimization. - Iron deficiency (ferritin 8 ng/mL) may be present from prior phlebotomy or dietary causes; iron should NOT be supplemented as it would worsen erythrocytosis. *Weight loss* - While obesity (BMI 38) contributes to hypoventilation and worsens hypoxemia, weight loss is a long-term intervention that does not address the **acute hyperviscosity** and thrombotic risk. - Weight loss would be an appropriate adjunctive measure but not the most immediate next step. *Inhaled budesonide* - Inhaled corticosteroids are used for COPD patients with frequent exacerbations or asthma-COPD overlap. - This patient is already on appropriate bronchodilator therapy (tiotropium); adding corticosteroids does not address the primary issue of **severe erythrocytosis and hyperviscosity**. - Optimizing COPD therapy and oxygen supplementation would be more appropriate than adding inhaled steroids at this point. *Hydroxyurea* - Hydroxyurea is a cytoreductive agent used primarily in **polycythemia vera**, not secondary polycythemia. - This patient's erythrocytosis is driven by **hypoxia** (physiologic EPO response), not autonomous JAK2-driven proliferation. - Treating the underlying hypoxemia and using phlebotomy is more appropriate than cytoreductive therapy. *Allogeneic stem cell transplantation* - Stem cell transplantation is reserved for advanced myeloproliferative neoplasms or myelofibrosis with poor prognosis. - This is **secondary erythrocytosis**, not a malignant hematologic disorder, and does not warrant such aggressive treatment. - This option is completely inappropriate for this clinical scenario.

Question 751: A 32-year-old man presents to the physician for a check-up as part of his immigration application. On auscultation, there is a mild rumble heard at the cardiac apex preceded by an opening snap. His blood pressure is 132/76 and heart rate is 78/min. The patient suffers from occasional asthma attacks but has noticed that he becomes short of breath on exertion over the past 2 years. He is otherwise healthy. He does not recall if he had any serious infections during childhood, and there is no family history of congenital diseases. Which of the following could have been used to prevent the development of this condition?

A. Aspirin
B. Sulfasalazine
C. Indomethacin
D. Alprostadil
E. Penicillin (Correct Answer)

Explanation: ***Penicillin*** - The patient's symptoms (mild rumble at the cardiac apex, opening snap, dyspnea on exertion) are classic for **mitral stenosis**, most commonly caused by **rheumatic heart disease**. - **Penicillin** is used for the primary prevention of **streptococcal pharyngitis** (strep throat), which can lead to acute rheumatic fever and subsequent rheumatic heart disease if left untreated. *Aspirin* - **Aspirin** is an anti-inflammatory and anti-platelet agent, used to manage symptoms of acute rheumatic fever (arthralgia, fever) and prevent thrombus formation in conditions like atrial fibrillation complicating mitral stenosis, but it does not prevent the initial development of the valvular damage. - It would be used as a treatment *after* the initial infection and subsequent inflammation have occurred, not for primary prevention. *Sulfasalazine* - **Sulfasalazine** is an anti-inflammatory drug primarily used in the treatment of inflammatory bowel disease (Crohn's disease, ulcerative colitis) and rheumatoid arthritis. - It has no role in preventing bacterial infections like streptococcal pharyngitis or the development of rheumatic heart disease. *Indomethacin* - **Indomethacin** is a non-steroidal anti-inflammatory drug (NSAID) often used to treat conditions like gout, ankylosing spondylitis, and to close a patent ductus arteriosus in neonates. - It does not prevent bacterial infections or the development of rheumatic heart disease. *Alprostadil* - **Alprostadil** is a prostaglandin E1 analog used to maintain the patency of the ductus arteriosus in neonates with certain congenital heart defects prior to corrective surgery. - It has no relevance to the prevention of rheumatic heart disease.

Question 752: A 29-year-old nulliparous woman is found upon transthoracic echocardiography to have a dilated aorta and mitral valve prolapse. The patient has a history of joint pain, and physical examination reveals pectus excavatum and stretch marks on the skin. She does not take any medications and has no history of past drug use. The patient’s findings are most likely associated with which of the following underlying diagnoses?

A. Ehlers-Danlos syndrome
B. DiGeorge syndrome
C. Marfan syndrome (Correct Answer)
D. Friedrich’s ataxia
E. Turner syndrome

Explanation: ***Marfan syndrome*** - This patient's presentation with **dilated aorta**, **mitral valve prolapse**, **joint pain**, **pectus excavatum**, and **stretch marks** is highly characteristic of **Marfan syndrome**, an autosomal dominant connective tissue disorder affecting **fibrillin-1**. - **Fibrillin-1 deficiency** leads to defective elastic fibers, which explains the cardiovascular, musculoskeletal, and ocular manifestations. *Ehlers-Danlos syndrome* - While Ehlers-Danlos syndrome also affects connective tissue and can involve **joint hypermobility** and **skin stretch marks**, it is less typically associated with significant **aortic dilation** as the primary cardiovascular feature compared to Marfan syndrome. - The classic cardiovascular manifestation of Ehlers-Danlos syndrome, particularly type IV, is arterial rupture, not primarily aortic dilation or mitral valve prolapse (though these can occur). *DiGeorge syndrome* - DiGeorge syndrome is characterized by **congenital heart defects** (e.g., truncus arteriosus, tetralogy of Fallot), **hypocalcemia** due to parathyroid aplasia, and **T-cell immunodeficiency** due to thymic hypoplasia. - It does not typically present with the specific combination of aortic dilation, mitral valve prolapse, pectus excavatum, or joint pains seen in this patient. *Friedrich's ataxia* - Friedrich's ataxia is a **neurodegenerative disorder** characterized by progressive **gait ataxia**, dysarthria, and **cardiomyopathy** (typically hypertrophic). - It does not cause aortic dilation, mitral valve prolapse, pectus excavatum, or joint pain as its primary features. *Turner syndrome* - Turner syndrome (XO) primarily affects females and is characterized by **short stature**, **primary amenorrhea**, **webbed neck**, and specific cardiovascular defects like **bicuspid aortic valve** and **aortic coarctation**. - It is not typically associated with a dilated aorta, mitral valve prolapse, pectus excavatum, or joint pain in this combination.

Question 753: A 40-year-old man comes to the physician for the evaluation of episodic headaches for 5 months. The headaches involve both temples and are 4/10 in intensity. The patient has been taking acetaminophen, but the headaches did not subside. He has also had visual disturbances, including double vision. He has no nausea, temperature intolerance, or weight changes. The patient does not smoke. He drinks 2–3 beers on weekends. He appears pale. His temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure 125/80 mm Hg. Ophthalmologic examination shows impaired peripheral vision bilaterally. An MRI scan of the head with contrast shows a 16 × 11 × 9 mm intrasellar mass. Further evaluation is most likely to show which of the following findings?

A. Erectile dysfunction
B. Abdominal striae
C. Diffuse goiter
D. Galactorrhea (Correct Answer)
E. Coarse facial features

Explanation: ***Galactorrhea*** - The presence of an **intrasellar mass** causing **bitemporal headaches** and **impaired peripheral vision** (bitemporal hemianopsia) is highly suggestive of a **pituitary adenoma**, specifically a **prolactinoma** given the patient's age and general presentation. - **Galactorrhea** is a common symptom of a prolactinoma due to **hyperprolactinemia**, as elevated prolactin levels can stimulate breast milk production even in men. *Erectile dysfunction* - While **erectile dysfunction** can be associated with pituitary tumors, it is often due to hypogonadism secondary to compression of gonadotrophs or inhibition by high prolactin levels; however, **galactorrhea** is a more direct and specific manifestation of hyperprolactinemia. - Other causes of erectile dysfunction are more common and would need to be ruled out before attributing it solely to the pituitary mass. *Abdominal striae* - **Abdominal striae**, particularly purple striae, are characteristic of **Cushing's disease**, which is caused by an ACTH-secreting pituitary adenoma. - This patient's symptoms (headaches, visual disturbances) are more consistent with mass effect and hyperprolactinemia rather than excess cortisol. *Diffuse goiter* - A **diffuse goiter** indicates thyroid enlargement, typically associated with **thyroid disorders** such as Graves' disease or iodine deficiency. - While pituitary tumors can rarely affect thyroid function by compressing thyrotrophs, galactorrhea is a more direct and common manifestation of increased prolactin. *Coarse facial features* - **Coarse facial features** are a hallmark of **acromegaly**, caused by a growth hormone-secreting pituitary adenoma. - The patient's presentation does not include other signs of acromegaly such as enlarged hands, feet, or prognathism.

Question 754: A 24-year-old woman comes to the physician because of progressively worsening joint pain. She has had diffuse, aching pain in her knees, shoulders, and hands bilaterally for the past few months, but the pain has become much more severe in the past few weeks. She also reports night sweats and generalized malaise. On physical examination, radial and pedal pulses are weak. There are erythematous nodules over the legs that measure 3–5 cm. Laboratory studies show: Hematocrit 33.2% Hemoglobin 10.7 g/dL Leukocyte count 11,300/mm3 Platelet count 615,000/mm3 Erythrocyte sedimentation rate 94 mm/h Serum C-reactive protein 40 mg/dL (N=0.08–3.1) Which of the following is the most likely diagnosis?

A. Temporal arteritis
B. Polyarteritis nodosa
C. Takayasu arteritis (Correct Answer)
D. Microscopic polyangiitis
E. Thromboangiitis obliterans

Explanation: ***Takayasu arteritis*** - The patient's age (24-year-old woman), **diffuse joint pain**, night sweats, malaise, elevated inflammatory markers (ESR, CRP), and particularly the **weak radial and pedal pulses** suggest **large-vessel vasculitis**. - **Erythematous nodules** could represent a cutaneous manifestation of systemic inflammation or a secondary condition like **erythema nodosum**, which can be associated with inflammatory disorders. *Temporal arteritis* - This typically affects **older adults** (over 50 years old) and presents with symptoms like **headache**, **jaw claudication**, and **visual disturbances**. - While it is a large-vessel vasculitis with elevated inflammatory markers, the patient's young age and the specific systemic symptoms do not align with temporal arteritis. *Polyarteritis nodosa* - This is a **medium-vessel vasculitis** that often presents with **neurological symptoms**, abdominal pain, renal involvement, and sometimes **cutaneous nodules**. - However, **weak pulses** are not a characteristic feature of polyarteritis nodosa, as it does not primarily affect the large elastic arteries. *Microscopic polyangiitis* - This is a **small-vessel vasculitis** characterized by **glomerulonephritis**, pulmonary capillaritis, and often ANCA positivity. - It does not typically involve large artery occlusions causing weak pulses, and the joint pain is usually less prominent compared to the systemic vasculitic symptoms. *Thromboangiitis obliterans* - This is a **segmental inflammatory non-atherosclerotic occlusive disease** of small- and medium-sized arteries and veins, almost exclusively affecting **smokers**. - It presents with **ischemia** of the digits and extremities, but not the widespread systemic symptoms, diffuse joint pain, or large artery involvement leading to weak central pulses seen in this patient.

Question 755: A 55-year-old man presents to the physician with a cough which he has had for the last 5 years. He also mentions that he has been feeling breathless when playing any active sport for the last 1 year. He is a manager in a corporate company and has been a regular smoker for 10 years. He has visited multiple physicians and undergone multiple diagnostic evaluations, without permanent benefit. On physical examination his temperature is 37.0°C (98.6°F), the heart rate is 88/min, the blood pressure is 122/80 mm Hg, and the respiratory rate is 20/min. Inspection suggests a barrel chest and auscultation reveals the presence of bilateral end-expiratory wheezing and scattered rhonchi. He undergoes a detailed diagnostic evaluation which includes a complete blood count, chest radiogram, arterial blood gas analysis, and pulmonary function tests, all of which confirm a diagnosis of chronic obstructive lung disease. After analyzing all the clinical information and diagnostic workup, the physician differentiates between emphysema and chronic bronchitis based on a single clue. Which of the following is the most likely clue that helped the physician in making the differential diagnosis?

A. Decreased diffusion capacity of the lung for carbon monoxide (DLCO) (Correct Answer)
B. Increased hematocrit in hematologic evaluation
C. History of long-term exposure to cigarette smoke
D. Presence of chronic respiratory acidosis in arterial blood gas analysis
E. Flattened diaphragm on chest X-ray

Explanation: ***Decreased diffusion capacity of the lung for carbon monoxide (DLCO)*** - A **decreased DLCO** is characteristic of **emphysema** due to the destruction of alveolar-capillary membranes, which impairs gas exchange. - In contrast, **chronic bronchitis** primarily affects the airways and typically presents with a **normal or only slightly reduced DLCO**. *Increased hematocrit in hematologic evaluation* - **Increased hematocrit** (polycythemia) can occur in both emphysema and chronic bronchitis as a compensatory response to chronic hypoxemia, making it less specific for differentiation. - This finding reflects the body's attempt to increase oxygen-carrying capacity due to insufficient oxygen supply. *History of long-term exposure to cigarette smoke* - A **history of smoking** is a major risk factor for both **emphysema** and **chronic bronchitis**, so it does not help differentiate between the two conditions. - The patient's 10-year smoking history contributes to his overall COPD diagnosis but isn't specific to one subtype. *Presence of chronic respiratory acidosis in arterial blood gas analysis* - **Chronic respiratory acidosis** (elevated PaCO2 and compensated pH) often suggests significant hypoventilation, which is more typical in **chronic bronchitis** ("blue bloaters"). - While it can occur in severe emphysema, it is not the primary distinguishing factor and is more characteristic of the "bronchitic" phenotype. *Flattened diaphragm on chest X-ray* - A **flattened diaphragm** is an X-ray sign of **hyperinflation**, which is commonly seen in both moderate to severe emphysema and chronic bronchitis. - This finding indicates air trapping but does not specifically differentiate between the predominant pathological changes of emphysema versus chronic bronchitis.

Question 756: A 60-year-old man comes to the emergency department because of nausea, headache, and generalized fatigue for 2 days. He has not vomited. He was diagnosed with small cell lung cancer and liver metastases around 3 months ago and is currently receiving chemotherapy with cisplatin and etoposide. His last chemotherapy cycle ended one week ago. He has chronic obstructive lung disease and type 2 diabetes mellitus. Current medications include insulin and a salmeterol-fluticasone inhaler. He appears malnourished. He is oriented to time, place, and person. His temperature is 37.1°C (98.8°F), pulse is 87/min, respirations are 13/min, and blood pressure is 132/82 mm Hg. There is no edema. Examination shows decreased breath sounds over the left lung. Cardiac examination shows an S4. The abdomen is soft and nontender. Neurological examination shows no focal findings. Laboratory studies show: Hemoglobin 11.6 g/dL Leukocyte count 4,300/mm3 Platelet count 146,000/mm3 Serum Na+ 125 mEq/L Cl− 105 mEq/L K+ 4.5 mEq/L HCO3− 24 mEq/L Glucose 225 mg/dL Total bilirubin 1.1 mg/dL Alkaline phosphatase 80 U/L Aspartate aminotransferase (AST, GOT) 78 U/L Alanine aminotransferase (ALT, GPT) 90 U/L Further evaluation of this patient is likely to show which of the following sets of laboratory findings? (Serum osmolality / Urine osmolality / Urinary sodium excretion)

A. 255 mOsm/kg H2O / 45 mOsm/kg H2O / 12 mEq/L
B. 222 mOsm/kg H2O / 490 mOsm/kg H2O / 10 mEq/L
C. 310 mOsm/kg H2O / 420 mOsm/kg H2O / 16 mEq/L
D. 220 mOsm/kg H2O / 130 mOsm/kg H2O / 10 mEq/L
E. 269 mOsm/kg H2O / 269 mOsm/kg H2O / 82 mEq/L (Correct Answer)

Explanation: **B) Serum osmolality 269 mOsm/kg H2O, Urine osmolality 269 mOsm/kg H2O, Urinary sodium excretion 82 mEq/L** - The patient's **hyponatremia** (Na+ 125 mEq/L) in the context of small cell lung cancer (SCLC) and chemotherapy with cisplatin raises suspicion for **SIADH**. In SIADH, the kidneys continue to excrete sodium appropriately or even excessively, leading to relatively high urine sodium excretion and a less diluted urine than expected for the degree of hyponatremia. The serum osmolality is low, and the urine is inappropriately concentrated, often near-isotonic to plasma or even hypertonic. - With a serum sodium of 125 mEq/L, the calculated serum osmolality (2*Na + Glucose/18 + BUN/2.8) would be approximately 2*(125) + 225/18 + (BUN not provided, assume normal) ≈ 250 + 12.5 ≈ 262.5 mOsm/kg H2O. Since SIADH is characterized by the inability to excrete free water, urine osmolality tends to be relatively high (often >100 mOsm/kg H2O) and sometimes approaches serum osmolality, especially in severe cases, making "269 mOsm/kg H2O" plausible for both. Urinary sodium excretion is typically >30 mEq/L in SIADH. *A) Serum osmolality 220 mOsm/kg H2O, Urine osmolality 130 mOsm/kg H2O, Urinary sodium excretion 10 mEq/L* - A serum osmolality of 220 mOsm/kg H2O would be indicative of more profound hyponatremia than observed (Na+ 125 mEq/L), which would typically correspond to a serum sodium much lower than 125 mEq/L. - A urinary sodium excretion of 10 mEq/L is characteristic of conditions leading to **hypovolemic hyponatremia** (e.g., GI losses, diuretics where the body is attempting to conserve sodium), whereas SIADH is typically euvolemic with higher urinary sodium excretion. *C) Serum osmolality 255 mOsm/kg H2O, Urine osmolality 45 mOsm/kg H2O, Urinary sodium excretion 12 mEq/L* - While a serum osmolality of 255 mOsm/kg H2O is consistent with hyponatremia, a urine osmolality of 45 mOsm/kg H2O represents maximally dilute urine and would suggest **primary polydipsia** or advanced renal failure, not SIADH. - A urinary sodium excretion of 12 mEq/L is too low for SIADH, which features inappropriate sodium excretion despite hyponatremia. *D) Serum osmolality 222 mOsm/kg H2O, Urine osmolality 490 mOsm/kg H2O, Urinary sodium excretion 10 mEq/L* - A serum osmolality of 222 mOsm/kg H2O is too low for the given serum sodium of 125 mEq/L. - The combination of extremely low serum osmolality with a very concentrated urine (490 mOsm/kg H2O) and low urine sodium (10 mEq/L) would be highly unusual and not consistent with SIADH or other common causes of hyponatremia. *E) Serum osmolality 310 mOsm/kg H2O, Urine osmolality 420 mOsm/kg H2O, Urinary sodium excretion 16 mEq/L* - A serum osmolality of 310 mOsm/kg H2O is **hyperosmolar**, which contradicts the patient's hyponatremia (Na+ 125 mEq/L) and low calculated serum osmolality. - This option suggests a state of **dehydration** or hypernatremia, which is not supported by the clinical picture or laboratory findings.

Question 757: A 19-year-old Caucasian college student is home for the summer. Her parents note that she has lost quite a bit of weight. The daughter explains that the weight loss was unintentional. She also notes an increase in thirst, hunger, and urine output. Her parents decide to take her to their family physician, who suspects finding which of the following?

A. Elevated ketone levels (Correct Answer)
B. High T4 and T3 levels
C. Hypoglycemia
D. Hyperinsulinemia
E. Evidence of amyloid deposition in pancreatic islets

Explanation: ***Elevated ketone levels*** - The patient's symptoms of **unintentional weight loss**, polyphagia (increased hunger), polydipsia (increased thirst), and polyuria (increased urine output) are classic signs of **Type 1 Diabetes Mellitus** (T1DM). - In T1DM, the body cannot use glucose for energy due to insulin deficiency, leading to increased **fat metabolism** and the production of **ketones**, which serve as an alternative energy source. *High T4 and T3 levels* - Elevated levels of **thyroid hormones (T4 and T3)** are indicative of **hyperthyroidism**. - While hyperthyroidism can cause **weight loss**, it is typically associated with symptoms like **heat intolerance**, **tachycardia**, and **tremors**, which are not mentioned in this patient's presentation. *Hypoglycemia* - **Hypoglycemia** refers to dangerously low blood glucose levels and typically presents with symptoms such as **confusion**, **sweating**, **tremors**, and **palpitations**. - The patient's symptoms of significant weight loss, increased thirst, and increased hunger are characteristic of **hyperglycemia** (high blood glucose), not hypoglycemia. *Hyperinsulinemia* - **Hyperinsulinemia** refers to elevated insulin levels in the blood, often seen in the early stages of **Type 2 Diabetes Mellitus** as the body tries to compensate for insulin resistance, or in conditions like an **insulinoma**. - In Type 1 Diabetes, there is an **absolute deficiency of insulin**, meaning insulin levels would be low, not high. *Evidence of amyloid deposition in pancreatic islets* - **Amyloid deposition** in pancreatic islets primarily occurs in **Type 2 Diabetes Mellitus**, where it contributes to beta-cell dysfunction. - In **Type 1 Diabetes**, the pathophysiology involves autoimmune destruction of beta cells, leading to insulin deficiency, rather than amyloid deposition.

Question 758: A 14-year-old boy is brought to the physician for generalized fatigue and mild shortness of breath on exertion for 3 months. He has a history of recurrent patellar dislocations. He is at the 99th percentile for height and at the 30th percentile for weight. His temperature is 37°C (98.6°F), pulse is 99/min, and blood pressure is 140/50 mm Hg. Examination shows scoliosis, a protruding breast bone, thin extremities, and flat feet. Ocular examination shows upwards displacement of bilateral lenses. A grade 3/6 early diastolic murmur is heard along the left sternal border. Further evaluation of this patient is most likely to show which of the following?

A. Radio-femoral pulse delay
B. Paradoxical splitting of S2
C. Pulsus paradoxus
D. Water hammer pulse (Correct Answer)
E. Fixed splitting of S2

Explanation: ***Water hammer pulse*** - The patient's presentation with **tall stature**, **scoliosis**, **pectus carinatum** (protruding breast bone), **thin extremities**, **flat feet**, **recurrent patellar dislocations**, **ectopia lentis** (upwards lens displacement), and a **diastolic murmur** (suggesting aortic regurgitation) is highly consistent with **Marfan syndrome**. - **Aortic regurgitation (AR)**, a common cardiovascular complication of Marfan syndrome, causes a **water hammer pulse** (also known as a Corrigan's pulse) due to a rapid rise and fall in arterial pressure. *Radio-femoral pulse delay* - This finding is characteristic of **coarctation of the aorta**, a condition that typically presents with hypertension in the upper extremities and decreased pulses in the lower extremities. - While Marfan syndrome can have various cardiovascular manifestations, **coarctation of the aorta** is not a typical feature, and the described murmur is more indicative of **aortic regurgitation**. *Paradoxical splitting of S2* - This occurs when the **aortic valve closes after the pulmonary valve**, typically due to conditions like **left bundle branch block**, **aortic stenosis**, or **patent ductus arteriosus**. - This patient's symptoms and signs are more aligned with **Marfan syndrome** and its common cardiovascular complication, **aortic regurgitation**, rather than conditions causing paradoxical S2 splitting. *Pulsus paradoxus* - This refers to an **abnormally large decrease in systolic blood pressure during inspiration**, commonly seen in conditions like **cardiac tamponade**, **severe asthma**, or **constrictive pericarditis**. - It is not a characteristic finding in **Marfan syndrome** or its associated **aortic regurgitation**. *Fixed splitting of S2* - This is a hallmark sign of an **atrial septal defect (ASD)**, where the S2 sound is widely split and does not vary with respiration. - While Marfan syndrome can affect the heart, **ASD** is not a primary or common cardiovascular manifestation associated with the constellation of skeletal and ocular findings presented.

Question 759: A 40-year-old woman comes to the physician because of a small lump on the right side of her neck that she noticed while putting lotion on 1 week ago. She does not have any weight change, palpitations, or altered bowel habits. There is no family history of serious illness. Menses occur at regular 30-day intervals and lasts for 4 days. She appears well. Her temperature is 37°C (98.6° F), pulse is 88/min, and blood pressure is 116/74 mm Hg. Examination shows a small swelling on the right side of the neck that moves with swallowing. There is no lymphadenopathy. Ultrasound of the neck shows a 0.9-cm (0.35-in) right lobe thyroid mass with microcalcifications and irregular margins. Which of the following is the most appropriate next step in diagnosis?

A. Open biopsy
B. Fine-needle aspiration biopsy of the swelling (Correct Answer)
C. Thyroid-stimulating hormone level
D. CT of the neck
E. Thyroid scintigraphy

Explanation: ***Fine-needle aspiration biopsy of the swelling*** - The ultrasound shows **suspicious features** (microcalcifications and irregular margins) that are highly specific for **papillary thyroid carcinoma**. - According to **ATA guidelines**, FNA is indicated for nodules with high-risk ultrasound features, regardless of size or TSH level. - FNA is the **gold standard** for cytological diagnosis and can distinguish benign from malignant nodules with high accuracy. - In this case with clear suspicious features, **FNA should not be delayed** for other tests like TSH. *Thyroid-stimulating hormone level* - While TSH is part of the **initial workup** for thyroid nodules, it should not delay FNA when suspicious ultrasound features are already present. - The presence of microcalcifications and irregular margins makes a **"hot" (hyperfunctioning) nodule extremely unlikely**. - TSH can be checked concurrently but should not be the rate-limiting step before FNA. *CT of the neck* - Not the **initial diagnostic choice** for evaluating a thyroid nodule. - CT is reserved for assessing **extrathyroidal extension** and invasion after malignancy is suspected or confirmed on FNA. - It provides unnecessary **radiation exposure** when ultrasound has already characterized the nodule. *Open biopsy* - This is an **invasive surgical procedure** that is not the first step in diagnosing a thyroid nodule. - It is reserved for cases where FNA results are **nondiagnostic** after multiple attempts or when there is suspicion of lymphoma. *Thyroid scintigraphy* - Used to assess whether a nodule is **"hot" (hyperfunctioning) or "cold" (non-functioning)**. - Hot nodules are rarely malignant, but the suspicious ultrasound features in this case make a hot nodule **highly unlikely**. - Scintigraphy is **not indicated** when ultrasound already shows features suggestive of malignancy; FNA is the appropriate next step.

Question 760: A 77-year-old man is brought to his primary care physician by his daughter. She states that lately, his speech has been incoherent. It seemed to have started a few weeks ago and has been steadily worsening. He is otherwise well; however, she notes that she has had to start him on adult diapers. The patient has a past medical history of hypertension, hyperlipidemia, and type 2 diabetes mellitus. He has been smoking 1 pack of cigarettes per day for over 40 years. His temperature is 98.9°F (37.2°C), blood pressure is 167/108 mmHg, pulse is 83/min, respirations are 12/min, and oxygen saturation is 97% on room air. Physical exam reveals a confused elderly man who does not respond coherently to questions. Cardiac and pulmonary exam is within normal limits. Inspection of the patient's scalp reveals a healing laceration which the daughter claims occurred yesterday when he fell while walking. Gait testing is significant for the patient taking short steps with reduced cadence. Which of the following findings is most likely in this patient?

A. Dilated ventricles on MRI (Correct Answer)
B. Decreased dopamine synthesis in the substantia nigra on dopamine uptake scan
C. Severe atrophy of the cerebral cortex on MRI
D. White matter T2 hyperintensities of the cerebral cortex on MRI
E. Minor atrophy of the cerebral cortex on CT

Explanation: ***Dilated ventricles on MRI*** - The patient's symptoms of **incoherent speech**, **urinary incontinence**, and **gait disturbance (short steps, reduced cadence)**, developing over weeks in an elderly individual, are classic for **Normal Pressure Hydrocephalus (NPH)**. - **NPH** is characterized by **ventriculomegaly (dilated ventricles)** with normal intracranial pressure, which can be visualized on MRI. *Decreased dopamine synthesis in the substantia nigra on dopamine uptake scan* - This finding is characteristic of **Parkinson's disease**, which primarily presents with **bradykinesia, rigidity, tremor, and gait instability**. - While the patient has a gait disturbance, the prominent **incoherence and incontinence** over a short period are not typical for isolated Parkinson's disease. *Severe atrophy of the cerebral cortex on MRI* - **Severe cortical atrophy** is a hallmark of **Alzheimer's disease** and other neurodegenerative dementias. - Although dementia can cause incoherence, prominent **gait disturbance and incontinence** developing over weeks are less characteristic of early to moderate Alzheimer's, which typically progresses over years. *White matter T2 hyperintensities of the cerebral cortex on MRI* - **White matter hyperintensities** are often seen in **vascular dementia** or due to chronic small vessel ischemic disease. - While the patient has vascular risk factors, the triad of symptoms (gait, incontinence, cognitive decline) strongly points to NPH rather than solely vascular dementia. *Minor atrophy of the cerebral cortex on CT* - **Minor cortical atrophy** is a common finding in normal aging and is not specific enough to explain the rapid onset and specific triad of symptoms seen in this patient. - It would not account for the significant **ventricular enlargement** expected in NPH.

Question 761: A 56-year-old woman is brought to the emergency department by her husband because of slurred speech and left facial droop for the past 30 minutes. During this period, she has also had numbness on the left side of her face. She has never had such an episode before. She has hypertension, hypercholesterolemia, and type 2 diabetes mellitus. Her father died of lung cancer 1 week ago. The patient has smoked one pack of cigarettes daily for 30 years. She drinks one glass of wine daily. Her current medications include metformin, sitagliptin, enalapril, and atorvastatin. She is 168 cm (5 ft 6 in) tall and weighs 86 kg (190 lb); BMI is 30.5 kg/m2. She is oriented to time, place, and person. Her temperature is 37°C (98.7°F), pulse is 97/min, and blood pressure is 140/90 mm Hg. Examination shows drooping of the left side of the face. Her speech is clear. Examination shows full muscle strength. Deep tendon reflexes are 2+ bilaterally. A finger-nose test and her gait are normal. Cardiopulmonary examination shows a right-sided carotid bruit. A complete blood count and serum concentrations of creatinine, glucose, and electrolytes are within the reference ranges. An ECG shows left ventricular hypertrophy. A noncontrast CT scan of the brain shows no abnormalities. On the way back from the CT scan, her presenting symptoms resolve. Which of the following is the most likely diagnosis?

A. Partial seizure
B. Bell palsy
C. Conversion disorder
D. Transient ischemic attack (Correct Answer)
E. Multiple sclerosis

Explanation: ***Transient ischemic attack*** - The patient presents with **acute neurological deficits** (slurred speech, left facial droop, numbness) that **resolve spontaneously** within a short period (30 minutes), strongly suggesting a **transient ischemic attack (TIA)**. - Her significant risk factors for cerebrovascular disease, including **hypertension, hypercholesterolemia, type 2 diabetes mellitus, smoking**, and a **carotid bruit**, further support this diagnosis. *Partial seizure* - While seizures can cause focal neurological symptoms, they typically involve **stereotyped, repetitive movements or sensations**, and often have a **postictal state** that is not described here. - The patient's symptoms are more consistent with a **vascular event** given her risk profile and the nature of the transient deficit. *Bell palsy* - **Bell palsy** is an acute **peripheral facial nerve paralysis** affecting only the motor function of the face, leading to drooping that does **not resolve within minutes**. - It would not typically cause **slurred speech** or **numbness** (sensory deficits), as seen in this patient. *Conversion disorder* - **Conversion disorder** involves neurological symptoms that are inconsistent with known neurological conditions and often arise in response to psychological stress, which might be suggested by her father's recent death. - However, the patient's strong vascular risk factors and objective findings like a **carotid bruit** make a **physiological cause** (TIA) much more likely than a somatoform disorder. *Multiple sclerosis* - **Multiple sclerosis** is a **demyelinating disease** that causes neurological symptoms, but these are typically **episodic (relapsing-remitting)** and often involve **sensory, motor, visual, or balance problems** that **last days to weeks**, not minutes. - MS symptoms rarely resolve as quickly as described and are less common in this age group for a new presentation.

Question 762: A 71-year-old Caucasian male presents to your office with bloody diarrhea and epigastric pain that occurs 30 minutes after eating. He has lost 15 pounds in 1 month, which he attributes to fear that the pain will return following a meal. He has a history of hyperlipidemia and myocardial infarction. Physical exam and esophagogastroduodenoscopy are unremarkable. What is the most likely cause of this patient's pain?

A. Peptic ulcer disease
B. Amyloid deposition
C. Diverticulosis
D. Atherosclerosis (Correct Answer)
E. Crohn's disease

Explanation: ***Atherosclerosis*** - This patient's history of **hyperlipidemia** and **myocardial infarction** indicates generalized atherosclerosis, which can lead to **chronic mesenteric ischemia** (also known as "intestinal angina"). - The classic presentation includes **postprandial abdominal pain** (occurring 30-60 minutes after eating) due to increased oxygen demand by the intestines that cannot be met by stenotic mesenteric arteries, along with **weight loss** due to "food fear" (sitophobia). - The triad of postprandial pain, weight loss, and atherosclerotic risk factors is highly suggestive of this diagnosis. *Peptic ulcer disease* - While peptic ulcer disease can cause epigastric pain and bloody stools, it would be detected on **esophagogastroduodenoscopy (EGD)**, which was unremarkable in this patient. - Gastric ulcers typically cause pain shortly after eating, while duodenal ulcers cause pain 2-3 hours after eating and are relieved by food. - The normal EGD effectively rules out this diagnosis. *Amyloid deposition* - **Amyloidosis** can cause gastrointestinal symptoms like malabsorption and bleeding, but it is a rare systemic disorder that typically presents with other organ involvement (renal, cardiac, neurologic). - It does not typically cause the classic postprandial pain pattern seen with mesenteric ischemia. - The patient's strong atherosclerotic history points away from this diagnosis. *Diverticulosis* - **Diverticulosis** can cause painless bloody diarrhea (hematochezia), but it typically presents with **left lower quadrant pain** when complicated by diverticulitis, not epigastric pain. - The pain is not characteristically related to meals and does not cause the "food fear" behavior seen in mesenteric ischemia. *Crohn's disease* - **Crohn's disease** is an inflammatory bowel disease that can cause bloody diarrhea, abdominal pain, and weight loss. - However, the **postprandial epigastric pain occurring 30 minutes after eating** and the patient's strong history of **atherosclerotic disease** point more toward ischemic etiology rather than inflammatory bowel disease. - Crohn's typically affects younger patients and would show signs of chronic inflammation.

Question 763: A 24-year-old woman comes to the physician because of pain and swelling of her left leg over the past 24 hours. The pain is worse while walking and improves when resting. Seven months ago, she was diagnosed with a pulmonary embolism and was started on warfarin. Anticoagulant therapy was discontinued 1 month ago. Her sister has systemic lupus erythematosus. The patient does not smoke. She currently takes no medications. Her temperature is 37.8°C (100°F), pulse is 78/min, and blood pressure is 123/72 mm Hg. On physical examination, the left calf is diffusely erythematous, swollen, and tender. Dorsal flexion of the left foot elicits pain. Cardiopulmonary examination shows no abnormalities. On duplex ultrasonography, the left popliteal vein is not compressible. Laboratory studies show an elevated serum concentration of D-dimer and insensitivity to activated protein C. Further examination is most likely to show which of the following?

A. Deficiency of protein C
B. Mutation of prothrombin
C. Elevated levels of homocysteine
D. Antiphospholipid antibodies
E. Mutation of coagulation factor V (Correct Answer)

Explanation: ***Mutation of coagulation factor V*** - The patient presents with symptoms and signs of **deep vein thrombosis (DVT)**, recurrent as she had a previous pulmonary embolism, and an elevated D-dimer. - The specific finding of **insensitivity to activated protein C (APC)** is highly suggestive of a **Factor V Leiden mutation**, which is the most common inherited thrombophilia. *Deficiency of protein C* - A deficiency in **protein C** would lead to a hypercoagulable state due to reduced inactivation of factors Va and VIIIa. - However, while it would cause a predisposition to thrombosis, it would not directly manifest as **insensitivity to activated protein C (APC)** but rather as reduced levels of protein C activity. *Mutation of prothrombin* - A **prothrombin gene mutation (G20210A)** leads to elevated prothrombin levels, increasing clotting risk. - While it causes thrombosis, it does not explain the specific finding of **insensitivity to activated protein C**. *Elevated levels of homocysteine* - **Hyperhomocysteinemia** can result from genetic defects (e.g., MTHFR mutation) or nutritional deficiencies (e.g., B12, folate) and is a risk factor for thrombosis. - This condition does not directly cause **insensitivity to activated protein C** and would be reflected by elevated homocysteine levels, not an APC resistance assay. *Antiphospholipid antibodies* - **Antiphospholipid syndrome** is an acquired thrombophilia featuring antibodies (e.g., lupus anticoagulant, anticardiolipin) that cause thrombosis. The patient's sister has SLE, which is associated with antiphospholipid syndrome. - While it can cause recurrent thrombosis and may be suggested by her sister's SLE, it typically causes a **prolonged PTT** *in vitro* (due to lupus anticoagulant) and does not directly cause **insensitivity to activated protein C**; rather, it often involves a different mechanism of action on the clotting cascade.

Question 764: The rapid response team is called for a 74-year-old woman on an inpatient surgical floor for supraventricular tachycardia. The patient had surgery earlier in the day for operative management of a femur fracture. The patient has a history of hypertension, atherosclerosis, type 2 diabetes, and uterine cancer status post total abdominal hysterectomy 20 years prior. With carotid massage, valsalva maneuvers, and metoprolol, the patient breaks out of her supraventricular tachycardia. Thirty minutes later, the nurse notices a decline in the patient’s status. On exam, the patient has a temperature of 98.4°F (36.9°C), blood pressure of 102/74 mmHg, pulse of 86/min, and respirations are 14/min. The patient is now dysarthric with noticeable right upper extremity weakness of 2/5 in elbow flexion and extension. All other extremities demonstrate normal strength and sensation. Which of the following most likely contributed to this decline?

A. Long bone fracture
B. Diabetes
C. Hypertension
D. Malignancy
E. Atherosclerosis (Correct Answer)

Explanation: ***Atherosclerosis*** - The sudden onset of **right upper extremity weakness** and **dysarthria** after an episode of supraventricular tachycardia (SVT) strongly suggests an **ischemic stroke**. Atherosclerosis is the primary underlying condition that made this patient vulnerable to stroke. - **Carotid massage** in patients with **carotid atherosclerosis** carries a risk of **dislodging atherosclerotic plaques**, leading to embolic stroke. The temporal relationship between the carotid massage and the onset of focal neurological deficits 30 minutes later is highly suspicious for an atheroembolic event. - The patient's history of **hypertension** and **type 2 diabetes** are significant risk factors that accelerate the progression of atherosclerosis, increasing plaque burden and the likelihood of **atheroembolic events**. *Long bone fracture* - While a long bone fracture can lead to complications, such as **fat emboli**, these typically cause a triad of respiratory distress, neurological symptoms (altered mental status, not localized weakness), and a petechial rash. - The neurological symptoms of a fat embolism are usually more global and diffuse, unlike the focal deficits observed here (dysarthria, right upper extremity weakness). - Fat embolism syndrome typically develops **24-72 hours post-fracture**, not immediately after carotid massage. *Diabetes* - Diabetes is a significant risk factor for **atherosclerosis** and stroke, but it is not the direct cause of the acute neurological decline; rather, it contributes to the underlying vascular disease. - While diabetes can cause neurological complications like **neuropathy**, it does not typically present as acute focal weakness and dysarthria in this manner. *Hypertension* - Hypertension is a major modifiable risk factor for both **atherosclerosis** and **ischemic stroke**, contributing to vascular damage and plaque formation over time. - However, hypertension itself is not the immediate cause of the focal neurological deficits in this scenario; it primarily exacerbates the underlying atherosclerotic process that enables embolic events. *Malignancy* - Malignancy can increase the risk of prothrombotic states (**Trousseau's syndrome**) and lead to embolic events, potentially causing a stroke. - However, the patient's uterine cancer was treated 20 years prior, and there is no indication of active malignancy or a hypercoagulable state specifically linked to cancer in this acute presentation.

Question 765: A 38-year-old man with a history of hypertension presents to his primary care physician for a headache and abdominal pain. His symptoms began approximately 1 week ago and have progressively worsened. He describes his headache as pressure-like and is mildly responsive to ibuprofen. His abdominal pain is located in the bilateral flank area. His hypertension is poorly managed with lifestyle modification and chlorthalidone. He had 1 urinary tract infection that was treated with ciprofloxacin approximately 6 months ago. He has a home blood pressure monitor, where his average readings are 155/95 mmHg. Family history is significant for his father expiring secondary to a myocardial infarction and his history was complicated by refractory hypertension and end-stage renal disease. His vital signs are significant for a blood pressure of 158/100 mmHg. Physical examination is notable for bilateral flank masses. Laboratory testing is significant for a creatinine of 3.1 mg/dL. Urinalysis is remarkable for hematuria and proteinuria. Which of the following will this patient most likely be at risk for developing?

A. Migraine headache
B. Neuroendocrine pancreatic tumor
C. Lymphangioleiomyomatosis
D. Intracranial aneurysm (Correct Answer)
E. Epilepsy

Explanation: ***Intracranial aneurysm*** - This patient's presentation with **poorly controlled hypertension**, family history of **refractory hypertension and ESRD**, and bilateral **flank masses** strongly suggests **autosomal dominant polycystic kidney disease (ADPKD)**. - Patients with **ADPKD** have a significantly increased risk of developing **intracranial aneurysms**, which can rupture and cause subarachnoid hemorrhage, often presenting with a severe headache. *Migraine headache* - While headaches are a common symptom, the description of a **pressure-like headache** that is only mildly responsive to ibuprofen, combined with other systemic symptoms, is less typical for a migraine. - The presence of findings highly suggestive of ADPKD points to a more specific and severe cause for the headache in this context. *Neuroendocrine pancreatic tumor* - **Pancreatic cysts** can occur in ADPKD, but the development of **neuroendocrine pancreatic tumors** is not a characteristic or common complication of this genetic disorder. - The patient's symptoms are more consistent with renal manifestations and ADPKD-associated complications rather than a pancreatic tumor. *Lymphangioleiomyomatosis* - **Lymphangioleiomyomatosis (LAM)** is a rare lung disease characterized by abnormal smooth muscle cell proliferation, primarily affecting women. - It is often associated with **tuberous sclerosis complex (TSC)**, not ADPKD, and the patient's symptoms point to kidney disease rather than lung pathology. *Epilepsy* - Although **seizures** can occur in patients with **ADPKD** due to complications like uremia or intracerebral hemorrhage, **epilepsy** (a chronic neurological disorder characterized by recurrent unprovoked seizures) is not a direct or primary consequence of the disease itself. - The patient's current symptoms do not directly indicate a diagnosis of epilepsy.

Question 766: A 50-year-old female teacher presents to the clinic with complaints of discoloration of the skin around the right ankle accompanied by itching. She began noticing it a month ago and the pruritus worsened over time. She also has some pain and swelling of the region every night, especially on days when she teaches late into the evening. Her past medical history is significant for diabetes mellitus type 2, for which she takes metformin. She lives with her husband and takes oral contraceptive pills. On examination, the physician observes hyperpigmentation of the medial aspect of her right ankle. The skin is dry, scaly, and edematous along with some superficial varicosities. Dorsiflexion of the foot is extremely painful. Peripheral pulses are equally palpable on both lower limbs. There is a small 2 cm ulcer noted near the medial malleolus with thickened neighboring skin and indurated edges. Laboratory studies show D-dimer of 1,000 µg/L and HbA1c of 9%. Doppler ultrasound of the lower extremity reveals an intramural thrombus in the popliteal vein. Which of the following is the most likely diagnosis in this patient?

A. Basal cell carcinoma
B. Atopic dermatitis
C. Stasis dermatitis (Correct Answer)
D. Cellulitis
E. Diabetic foot

Explanation: ***Stasis dermatitis*** - The patient's presentation with **discoloration (hyperpigmentation)**, **itching (pruritus)**, **edema**, and a **venous ulcer** on the medial aspect of the ankle, along with **superficial varicosities** and a **popliteal vein thrombus**, are classic signs of **stasis dermatitis** due to **chronic venous insufficiency**. - Contributing factors like prolonged standing (teacher), **oral contraceptive use**, and diabetes (though less directly involved than venous issues for this specific diagnosis) increase the risk for venous stasis and associated dermatological changes. *Basal cell carcinoma* - Typically presents as a **pearly nodule** with **rolled borders** and **telangiectasias**, often on sun-exposed areas. - While an ulcer can occur, the widespread discoloration, edema, itching, and association with venous issues are not characteristic of basal cell carcinoma. *Atopic dermatitis* - Characterized by **eczematous lesions** (red, itchy, dry skin) often in flexural areas like the antecubital or popliteal fossae, with a history of allergies or asthma. - It does not present with hyperpigmentation, edema, or ulcers specifically associated with venous insufficiency. *Cellulitis* - Presents as an **acute bacterial infection** of the skin, characterized by **rapidly spreading redness**, **warmth**, **swelling**, and **pain**, often with fever and systemic symptoms. - While there is pain and swelling, the chronic nature, hyperpigmentation, itching, and presence of varicosities and a venous ulcer point away from an acute infection like cellulitis. *Diabetic foot* - Characterized by **neuropathy** (loss of sensation), **peripheral arterial disease**, and **infection**, leading to **puncture wounds** or **ischemic ulcers** often on pressure points of the foot. - While the patient has diabetes, the ulcer's location (medial malleolus), hyperpigmentation, edema, and clear evidence of venous thrombosis make **stasis dermatitis** a more fitting diagnosis than a typical diabetic foot ulcer.

Question 767: A 19-year-old female student presents to her physician for overall fatigue. She is having a hard time concentrating while studying and feeling tired most of the time. She also has had constipation for more than 3 weeks and rectal bleeding on occasions. She notices she is getting colder and often needs to wear warmer clothes than usual for the same weather. On examination, a small nodule around the size of 1cm is palpated in the left thyroid lobule; the gland is nontender. There is no lymphadenopathy. Her vital signs are: blood pressure is 118/75 mm Hg, respirations are 17/min, pulse is 87/min, and temperature is 36.1°C (97.0°F). Which of the following is the best next step in the management of this patient?

A. Combination T4 and T3 therapy
B. Radionuclide thyroid scan
C. Serum T3 levels
D. Thyroid ultrasound (Correct Answer)
E. Serum calcitonin levels

Explanation: ***Thyroid ultrasound*** - A **thyroid ultrasound** is the most appropriate initial imaging step when a **thyroid nodule** is palpable, and the patient also exhibits symptoms suggestive of **hypothyroidism** (fatigue, constipation, cold intolerance). - This imaging modality helps characterize the nodule's size, composition (solid vs. cystic), vascularity, and features suspicious for **malignancy**, guiding subsequent management. *Combination T4 and T3 therapy* - This therapy is used for treating **hypothyroidism** but should only be initiated after thyroid function is confirmed via blood tests, and the nature of the nodule is assessed. - Starting hormone replacement without further investigation of the nodule could mask or delay the diagnosis of a **thyroid malignancy**. *Radionuclide thyroid scan* - A **radionuclide thyroid scan** is primarily used to assess the functional status of a nodule (hot vs. cold), which is typically done after initial characterization by ultrasound and TSH level measurement. - It is not the first-line investigation for an incidentally found nodule, especially with symptoms suggesting possible hypothyroidism. *Serum T3 levels* - While thyroid function tests are necessary, **serum TSH** (Thyroid Stimulating Hormone) is the most sensitive initial test for evaluating thyroid function, not T3. - **Low T3 levels** might be seen in severe hypothyroidism, but TSH is usually the first to deviate and is a more reliable screening tool. *Serum calcitonin levels* - **Serum calcitonin** is a tumor marker for **medullary thyroid carcinoma (MTC)**. - While it can be measured when MTC is suspected, it is not a routine initial test for a palpable thyroid nodule and would typically be considered after other investigations suggest malignancy.

Question 768: A 36-year-old healthy man presents to his physician to discuss his concerns about developing heart disease. His father, grandfather, and older brother had heart problems, and he has become increasingly worried he might be at risk. He takes no medications and his past medical history is only significant for an appendectomy at 20 years ago. He is married happily with 2 young children and works as a hotel manager and exercises occasionally in the hotel gym. He drinks 3–5 alcoholic beverages per week but denies smoking and illicit drug use. Today his blood pressure is 146/96 mm Hg, pulse rate is 80/min, and respiratory rate is 16/min. He has a body mass index of 26.8 kg/m2. His physical examination is otherwise unremarkable. Laboratory tests show: Laboratory test Serum glucose (fasting) 88 mg/dL Serum electrolytes Sodium 142 mEq/L Potassium 3.9 mEq/L Chloride 101 mEq/L Serum creatinine 0.8 mg/dl Blood urea nitrogen 10 mg/dl Cholesterol, total 350 mg/dL HDL-cholesterol 40 mg/dL LDL-cholesterol 280 mg/dL Triglycerides 130 mg/dL Besides appropriate medications for his cholesterol and a follow-up for his hypertension, which of the following supplements is thought to provide a protective cardiovascular effect?

A. Folic acid (Correct Answer)
B. Thiamine
C. Vitamin K
D. Vitamin B12
E. Vitamin E

Explanation: ***Folic acid*** - Folic acid (Vitamin B9) is involved in the metabolism of **homocysteine**, and elevated homocysteine levels are associated with increased cardiovascular risk. - **Historically**, it was hypothesized that lowering homocysteine with folic acid would reduce cardiovascular events. - However, **large randomized controlled trials (HOPE-2, NORVIT, VISP) have failed to demonstrate cardiovascular benefit** from folic acid supplementation despite successfully lowering homocysteine levels. - Among the options listed, folic acid was the supplement most **historically thought** to provide cardiovascular protection, though current evidence does not support routine supplementation for this purpose. - **Current guidelines do NOT recommend** folic acid supplementation for cardiovascular disease prevention in the general population. *Thiamine* - **Thiamine** (Vitamin B1) is crucial for carbohydrate metabolism and nerve function. - Thiamine deficiency can lead to **beriberi** (including wet beriberi with cardiac manifestations), but supplementation in individuals without deficiency provides **no cardiovascular protection**. *Vitamin K* - **Vitamin K** is essential for blood clotting and bone metabolism, and may play a role in preventing vascular calcification. - However, there is **insufficient evidence** to recommend vitamin K supplementation for cardiovascular protection in clinical practice. *Vitamin B12* - **Vitamin B12** is important for nerve function, red blood cell formation, and homocysteine metabolism. - Like folic acid, B12 was studied for cardiovascular protection through homocysteine reduction, but **clinical trials failed to show benefit**. - Routine B12 supplementation for cardiovascular protection in individuals with normal B12 levels is **not recommended**. *Vitamin E* - **Vitamin E** is an antioxidant that was extensively studied for cardiovascular protection in the 1990s-2000s. - **Large clinical trials (HOPE, GISSI) conclusively showed NO cardiovascular benefit** from vitamin E supplementation, and some studies suggested potential harm at high doses. - Vitamin E supplementation for cardiovascular disease prevention is **not recommended**.

Question 769: In a routine medical examination, an otherwise healthy 12-year-old boy is noted to have tall stature with a wide arm span and slight scoliosis. Chest auscultation reveals a heart murmur. Transthoracic echocardiography shows an enlarged aortic root and aortic valve insufficiency. Mutations in fibrillin-1 gene are positive. Plasma homocysteine levels are not elevated. This patient is at high risk for which of the following complications?

A. Pheochromocytoma
B. Infertility
C. Aortic aneurysm (Correct Answer)
D. Thrombotic events
E. Arterial and visceral rupture

Explanation: ***Aortic aneurysm*** - The constellation of **tall stature**, **wide arm span**, **scoliosis**, an **enlarged aortic root**, and **aortic valve insufficiency** in the presence of **fibrillin-1 gene mutations** is characteristic of **Marfan syndrome**. - Patients with Marfan syndrome, due to defective **fibrillin-1**, are at high risk for **progressive aortic dilation** and subsequent **aortic aneurysm** formation or dissection. *Pheochromocytoma* - This condition is a tumor of the adrenal gland that secretes **catecholamines**, leading to symptoms like **hypertension**, sweating, and palpitations. - It is not directly associated with **Marfan syndrome** or the findings described in the patient. *Infertility* - While some genetic conditions can cause infertility, infertility is **not a typical complication** or characteristic feature of **Marfan syndrome**. - The described symptoms primarily relate to musculoskeletal and cardiovascular systems. *Thrombotic events* - Elevated plasma **homocysteine levels** are a risk factor for thrombotic events, which differentiates it from **Marfan syndrome**. - The patient's **normal homocysteine levels** rule out conditions like homocystinuria, which often presents with similar skeletal and ocular features but significant thrombotic risk. *Arterial and visceral rupture* - While **aortic dissection** (a type of arterial rupture) is a major complication of **Marfan syndrome**, the general term "arterial and visceral rupture" is more characteristic of **Ehlers-Danlos syndrome type IV** (vascular type). - Ehlers-Danlos syndrome type IV is caused by mutations in **collagen type III**, leading to fragile blood vessels and organs, which is distinct from the **fibrillin-1 defect** in Marfan syndrome.

Question 770: A 46-year-old man comes to the physician for routine physical examination. His blood pressure is 158/96 mm Hg. Physical examination shows no abnormalities. Serum studies show a potassium concentration of 3.1 mEq/L. His plasma aldosterone concentration (PAC) to plasma renin activity (PRA) ratio is 47 (N < 10). A saline infusion test fails to suppress aldosterone secretion. A CT scan of the abdomen shows bilateral adrenal gland abnormalities. Which of the following is the most appropriate next step in management?

A. Unilateral adrenalectomy
B. Eplerenone therapy (Correct Answer)
C. Propranolol therapy
D. Bilateral adrenalectomy
E. Amiloride therapy

Explanation: ***Eplerenone therapy*** - The patient presents with **hypertension**, **hypokalemia**, an elevated **PAC/PRA ratio** (47, normal < 10), and a failed saline suppression test, all consistent with **primary hyperaldosteronism**. - Given the **bilateral adrenal gland abnormalities** on CT scan, **bilateral adrenal hyperplasia (BAH)** is the most likely cause, for which medical management with a **mineralocorticoid receptor antagonist** like eplerenone or spironolactone is the preferred treatment. *Unilateral adrenalectomy* - This intervention is indicated for patients with **unilateral aldosterone-producing adenoma (Conn's syndrome)**, which is typically visualized as a solitary lesion on adrenal imaging. - The patient's CT scan indicates **bilateral adrenal abnormalities**, making unilateral adrenalectomy an inappropriate choice as the source of aldosterone overproduction is likely multifocal or generalized. *Propranolol therapy* - **Propranolol** is a non-selective **beta-blocker** primarily used to treat hypertension by reducing heart rate and cardiac output, and suppressing renin release. - It does not directly target the excessive aldosterone production or its effects in primary hyperaldosteronism, and thus would not adequately address the underlying pathology. *Bilateral adrenalectomy* - **Bilateral adrenalectomy** is an extreme measure reserved for cases of primary hyperaldosteronism due to **bilateral adrenal hyperplasia** that are refractory to medical therapy or in cases of **adrenocortical carcinoma**. - It results in lifelong requirement for **glucocorticoid and mineralocorticoid replacement**, making it a less desirable initial treatment compared to medical management. *Amiloride therapy* - **Amiloride** is a **potassium-sparing diuretic** that blocks epithelial sodium channels in the distal tubule and collecting duct. - While it can help correct hypokalemia and reduce blood pressure in primary hyperaldosteronism, it does not directly antagonize aldosterone's effects at the mineralocorticoid receptor and is generally less effective than eplerenone or spironolactone for long-term management of this condition.

Question 771: A 78-year-old man with advanced lung cancer with metastases to the brain is brought to the physician by his daughter, with whom he lives. The daughter reports that her father's condition has been slowly deteriorating over the past 2 months. His seizures have been poorly controlled despite maximal medical therapy. He has had progressive loss of mobility, a decrease in executive function, and worsening pain. The patient has Medicaid insurance. Current medications include high-dose corticosteroids and immediate-release opioid analgesics. The need for increased assistance has been distressing to the family, and they are concerned about the patient's overall comfort. The daughter asks the physician about her father's eligibility for hospice care. Which of the following responses from the physician about this model of care is most appropriate?

A. Your father cannot enter hospice care if there is a definitive cure for his disease.
B. Your father would have to be moved from home to a center that specializes in hospice care.
C. Your father is only eligible if his life expectancy is less than 6 months. (Correct Answer)
D. Your father's current medication regimen is incompatible with hospice care because of the risk of respiratory depression.
E. Hospice care is likely to hasten your father's death.

Explanation: ***Your father is only eligible if his life expectancy is less than 6 months.*** - This is the **primary criterion** for hospice eligibility under most insurance plans, including Medicaid. The patient's advanced lung cancer with brain metastases, uncontrolled seizures, and progressive decline suggest he may meet this criterion. - Hospice care focuses on **palliative management** for patients with a limited prognosis, emphasizing comfort and quality of life rather than curative treatment. *Your father cannot enter hospice care if there is a definitive cure for his disease.* - While true that hospice is for patients with **terminal illnesses** where curative treatment is no longer the focus, the statement implies a "definitive cure" is still an option, which is not the case for advanced metastatic lung cancer. - The patient's condition (advanced lung cancer with metastases, uncontrolled seizures, and significant functional decline) indicates that **curative treatments are no longer effective** or pursued. *Your father would have to be moved from home to a center that specializes in hospice care.* - **Most hospice care is provided in the patient's home**, or in long-term care facilities, allowing individuals to remain in a familiar environment. - While inpatient hospice facilities exist for complex symptom management, they are not a mandatory requirement for all hospice patients. *Your father's current medication regimen is incompatible with hospice care because of the risk of respiratory depression.* - Hospice care actively manages symptoms, including pain, and **opioids are a cornerstone of pain management** in terminal illness. The goal is comfort, not avoidance of effective medications. - The risk of respiratory depression is managed through careful titration and monitoring, and it does not preclude hospice admission, especially when pain is severe. *Hospice care is likely to hasten your father's death.* - Hospice care is focused on **comfort and quality of life** and does not intentionally hasten death. It provides **palliative care**, symptom management, and support for patients and families. - Studies have shown that hospice care can sometimes **prolong life** by improving symptom control and reducing hospitalizations, rather than shortening it.

Question 772: A 43-year-old man with a history of untreated HIV presents with fever, shortness of breath, and a nonproductive cough for the past week. Past medical history is significant for HIV diagnosed 10 years ago and never treated. His most recent CD4+ T cell count was 105/µL. Physical examination reveals bilateral crepitus over all lobes. No lymphadenopathy is present. A chest radiograph reveals bilateral infiltrates. Which of the following is the best treatment for this patient?

A. Amphotericin B
B. Highly active antiretroviral therapy (HAART)
C. Azithromycin
D. Trimethoprim-sulfamethoxazole (Correct Answer)
E. Ganciclovir

Explanation: ***Trimethoprim-sulfamethoxazole*** - The patient's presentation with **fever**, **shortness of breath**, **nonproductive cough**, **bilateral crepitus**, **bilateral infiltrates on chest X-ray**, and a **CD4+ T cell count of 105/µL** is highly suggestive of **Pneumocystis jirovecii pneumonia (PCP)**, which is best treated with **trimethoprim-sulfamethoxazole**. - This medication is the **first-line treatment** for PCP due to its efficacy against the organism. *Amphotericin B* - This is an **antifungal medication** primarily used to treat severe **systemic fungal infections** such as histoplasmosis or cryptococcosis. - While HIV patients are susceptible to fungal infections, the clinical presentation is more consistent with PCP, not a typical fungal pneumonia. *Highly active antiretroviral therapy (HAART)* - **HAART** is crucial for managing HIV infection by suppressing viral replication and improving immune function, but it is **not an immediate treatment for acute opportunistic infections** like PCP. - While it should be initiated once the acute infection is stable, the immediate priority is to treat the life-threatening pneumonia. *Azithromycin* - **Azithromycin** is an antibiotic typically used for bacterial infections, including some **atypical pneumonias** and for **PCP prophylaxis** in some cases, but it is not the primary treatment for active PCP. - It is also used as part of a regimen for **Mycobacterium avium complex (MAC) prophylaxis**, which presents differently. *Ganciclovir* - This is an **antiviral medication** primarily used to treat infections caused by **cytomegalovirus (CMV)**, which can cause retinitis, colitis, or pneumonitis in immunocompromised individuals. - The symptoms described are not characteristic of CMV pneumonitis, and ganciclovir would not be effective against PCP.

Question 773: A 55-year-old man is seen in the hospital for new onset shortness of breath. The patient was hospitalized 5 days ago after initially presenting with chest pain. He was found to have an ST-elevation myocardial infarction. He underwent percutaneous coronary intervention with stent placement with resolution of his chest pain. He states that he was doing well until yesterday when he developed dyspnea while walking around the hall and occasionally when getting out of bed to use the bathroom. His shortness of breath has since progressed, and he is now having trouble breathing even at rest. His medical history is also significant for type II diabetes mellitus and hypercholesterolemia. He takes aspirin, clopidogrel, metformin, and atorvastatin. His temperature is 97°F (36.1°C), blood pressure is 133/62, pulse is 90/min, respirations are 20/min, and oxygen saturation is 88% on room air. On physical examination, there is a holosystolic murmur that radiates to the axilla and an S3 heart sound. Coarse crackles are heard bilaterally. An electrocardiogram, a chest radiograph, and cardiac enzyme levels are pending. Which of the following is the most likely diagnosis?

A. Interventricular septum rupture
B. Thickened mitral valve leaflets
C. Dressler syndrome
D. Free wall rupture
E. Papillary muscle rupture (Correct Answer)

Explanation: **Papillary muscle rupture** - **Acute mitral regurgitation** due to papillary muscle rupture post-MI classically presents with new-onset **shortness of breath**, **crackles** (indicating pulmonary edema), an **S3 heart sound**, and a **holosystolic murmur** radiating to the axilla. - Rupture of the papillary muscle, often occurring 2-7 days post-MI, leads to severe mitral valve dysfunction and rapid **hemodynamic compromise**, accounting for the patient's rapidly worsening dyspnea and hypoxemia. *Interventricular septum rupture* - While a post-MI complication presenting with a **holosystolic murmur**, this murmur is typically best heard along the **left sternal border** and is associated with a palpable thrill, not radiating to the axilla. - Patients often develop **biventricular heart failure** and a step-up in oxygen saturation from the right atrium to the right ventricle, which is not suggested by the findings. *Thickened mitral valve leaflets* - **Mitral stenosis** due to thickened leaflets typically presents with a **diastolic murmur**, not a holosystolic murmur, and is often a chronic condition rather than an acute post-MI complication. - The patient's acute presentation within days of an MI makes a pre-existing chronic valvular issue less likely to be the primary cause of his acute decompensation. *Dressler syndrome* - This is a form of **post-cardiac injury syndrome** (pericarditis) that typically occurs weeks to months after an MI, not within days. - Symptoms include **pleuritic chest pain** and **fever**, along with a **pericardial friction rub**, which are not described in this patient. *Free wall rupture* - Free wall rupture is a catastrophic complication that typically leads to **cardiac tamponade** and **sudden death**, or rapid circulatory collapse with pulseless electrical activity. - The patient's presentation with progressive shortness of breath and a holosystolic murmur is not consistent with the acute, usually fatal, course of a free wall rupture.

Question 774: A 36-year-old right-handed man presents with complaints of difficulty writing for the past 6 months. He denies right-hand weakness, numbness, pain, and trauma. He can do most normal activities with his right hand, but whenever he holds a pen and starts to write, he experiences painful muscle spasms in his hand and arm. He is an account clerk by profession, and this problem causes him so much distress that he has started writing with his left hand. He is physically active. Sleep and appetite are normal. Past medical history is unremarkable. Physical examination is completely within normal limits with normal muscle tone, strength, and deep tendon reflexes. When he is asked to hold a pen and write, his hand becomes twisted with abnormal posturing while attempting to write. What is the next step in the management of this patient?

A. Selective serotonin reuptake inhibitor
B. Refer to the psychiatry clinic
C. Botulinum injection (Correct Answer)
D. Electroencephalogram
E. Wrist splint

Explanation: ***Botulinum injection*** - The patient's symptoms are highly suggestive of **Writer's cramp**, a form of **focal task-specific dystonia**, which is characterized by involuntary muscle spasms and abnormal posturing specifically during writing. - **Botulinum toxin injections** are the **first-line treatment** for focal dystonias, effectively relaxing the overactive muscles involved in the abnormal movements. *Selective serotonin reuptake inhibitor* - **SSRIs** are primarily used to treat **depression and anxiety disorders**, which are not the primary presenting symptoms in this patient. - While psychological stress can exacerbate dystonia, SSRIs do not directly address the underlying **motor control dysfunction** characteristic of writer's cramp. *Refer to the psychiatry clinic* - Although writer's cramp can cause significant distress and impact quality of life, the primary pathology is neurological, not psychiatric. - A referral to psychiatry would be appropriate if there were co-occurring mental health disorders that required specific treatment, but it is not the **next step** for the *motor symptoms*. *Electroencephalogram* - An **EEG** measures **electrical activity in the brain** and is primarily used to diagnose conditions like **seizures** or **encephalopathy**. - It would not provide diagnostic or therapeutic information for writer's cramp, which is a **movement disorder** rather than an epileptic condition. *Wrist splint* - A **wrist splint** provides **immobilization and support** for conditions like carpal tunnel syndrome, tenosynovitis, or wrist sprains. - It would not be effective for writer's cramp because the problem is with **involuntary muscle contractions** during a specific task, not simple joint instability or inflammation.

Question 775: A 33-year-old woman presents to a walk-in clinic for evaluation of some bumps around her eyes. The bumps are not itchy or painful. They have been getting larger since appearing last year. She has no other complaints. She has not sought out medical attention for the last 20 years due to lack of insurance coverage. Her medical history reveals no problems and she takes no medications. Her periods are regular. A review of systems reveals no other concerns. She does not drink, smoke, or use illicit drugs. Her vital signs show a heart rate of 86/min, respirations of 14/min, and blood pressure of 124/76 mm Hg. On examination, the rash is a series of small papules and plaques around her eyes. The rest of the examination is unremarkable. Which of the following initial blood tests are most appropriate at this time?

A. Fasting lipid profile alone (Correct Answer)
B. Thyroid stimulating hormone alone
C. Fasting blood glucose and lipid profile
D. Fasting blood glucose, lipid profile, and thyroid stimulating hormone
E. Fasting blood glucose alone

Explanation: ***Fasting lipid profile alone*** - The description of **papules and plaques around the eyes** strongly suggests **xanthelasma palpebrarum**, which is a cutaneous manifestation of **lipid disorders**. - A **fasting lipid profile** is the most appropriate initial test to evaluate for **hyperlipidemia**, which is often asymptomatic until complications arise. - Approximately **50% of patients with xanthelasma** have underlying dyslipidemia, making this the most direct and appropriate initial investigation. *Thyroid stimulating hormone alone* - While **hypothyroidism** can be associated with hyperlipidemia, the patient has no other symptoms or signs suggestive of thyroid dysfunction, making TSH alone less appropriate as the primary initial test for the presenting complaint. - Her **regular periods** and lack of other systemic complaints argue against significant thyroid pathology. *Fasting blood glucose and lipid profile* - Although **diabetes mellitus** (evaluated by fasting blood glucose) can be associated with dyslipidemia, there are no specific symptoms in this patient suggesting diabetes, such as **polyuria**, polydipsia, or unexplained weight changes. - Adding a **fasting blood glucose** test is not the most direct or necessary initial step for the evaluation of **xanthelasma**. *Fasting blood glucose, lipid profile, and thyroid stimulating hormone* - This option involves performing a wide array of tests without clear indications for all of them based on the presenting symptoms. - While these conditions can be related to metabolic health, the most direct and specific investigation for **xanthelasma** is the **lipid profile**. *Fasting blood glucose alone* - There are **no symptoms of diabetes** mentioned in the patient's history, such as frequent urination, increased thirst, or unexplained weight loss, making this test less relevant as the initial investigation for the described skin lesions. - The **papules and plaques around the eyes** are highly suggestive of a lipid metabolism issue, not primarily a glucose metabolism issue.

Question 776: A 45-year-old woman presents to the emergency department due to new-onset symptoms of asthma. She reports that the asthmatic attacks started a week ago. The past medical history includes gastroesophageal reflux disease and hepatitis B. On physical examination, the patient has bilateral foot drop as well as numbness and tingling sensation in all extremities. A complete blood count is relevant for eosinophilia of 9.1 × 10^9/L. Which of the markers below could explain all of the patient's current symptoms?

A. ESR
B. p-ANCA (Correct Answer)
C. HLA B-27
D. Anti-Ro/SSA
E. Anti-histone antibodies

Explanation: ***p-ANCA*** - The patient's presentation with new-onset **asthma**, **eosinophilia**, bilateral **foot drop** (suggesting mononeuritis multiplex), and neuropathic symptoms is highly indicative of **Eosinophilic Granulomatosis with Polyangiitis (EGPA)**, formerly known as Churg-Strauss syndrome. - Approximately 40-70% of patients with EGPA are **p-ANCA positive**, making it a key diagnostic marker. *ESR* - **Erythrocyte Sedimentation Rate (ESR)** is a non-specific marker of inflammation and would likely be elevated in EGPA as well as many other inflammatory conditions. - An elevated ESR alone does not explain the specific constellation of asthma, eosinophilia, and neuropathy. *HLA B-27* - **HLA-B27** is associated with spondyloarthropathies (e.g., ankylosing spondylitis, reactive arthritis) and acute anterior uveitis. - This marker is not related to the patient's symptoms of new-onset asthma, eosinophilia, and polyneuropathy. *Anti-Ro/SSA* - **Anti-Ro/SSA antibodies** are typically associated with Sjögren's syndrome and systemic lupus erythematosus (SLE). - These conditions do not commonly present with new-onset asthma, peripheral neuropathy (foot drop), and significant eosinophilia. *Anti-histone antibodies* - **Anti-histone antibodies** are primarily associated with drug-induced lupus erythematosus. - The clinical picture presented (asthma, eosinophilia, neuropathy) is not characteristic of drug-induced lupus.

Question 777: A 37-year-old woman presents to clinic for routine checkup. She has no complaints with the exception of occasional "shortness of breath." Her physical examination is unremarkable with the exception of a "snap"-like sound after S2, followed by a rumbling murmur. You notice that this murmur is heard best at the cardiac apex. A history of which of the following are you most likely to elicit upon further questioning of this patient?

A. Repeated episodes of streptococcal pharyngitis as a child (Correct Answer)
B. Hyperflexibility, vision problems, and pneumothorax
C. Systolic click auscultated on physical exam 10 years prior
D. Family history of aortic valve replacement at a young age
E. Cutaneous flushing, diarrhea, and bronchospasm

Explanation: **Repeated episodes of streptococcal pharyngitis as a child** - The described auscultation findings of a snap after S2 followed by a rumbling murmur loudest at the apex are classic for **mitral stenosis**. - The most common cause of acquired mitral stenosis is **rheumatic heart disease**, which develops after repeated episodes of **streptococcal pharyngitis**. *Hyperflexibility, vision problems, and pneumothorax* - These symptoms are characteristic of **Marfan syndrome**, which is associated with **mitral valve prolapse** or aortic root dilation and dissection, not mitral stenosis. - Marfan syndrome can cause mitral regurgitation, which presents as a holosystolic murmur, not a late diastolic rumbling murmur. *Systolic click auscultated on physical exam 10 years prior* - A systolic click is characteristic of **mitral valve prolapse**, which in its severe form can lead to mitral regurgitation, not mitral stenosis. - While mitral valve prolapse can sometimes progress, it typically does not evolve into the specific auscultatory findings of mitral stenosis. *Family history of aortic valve replacement at a young age* - A family history of early aortic valve replacement suggests a congenital **bicuspid aortic valve** or other inherited aortic valve disease. - This would manifest as an aortic murmur (e.g., aortic stenosis or regurgitation) and not the apical, diastolic murmur seen with mitral stenosis. *Cutaneous flushing, diarrhea, and bronchospasm* - These symptoms are classic for **carcinoid syndrome**, which can cause **tricuspid regurgitation** or **pulmonary stenosis** affecting the right side of the heart. - Carcinoid heart disease typically does not involve the mitral valve in its primary presentation.

Question 778: Twelve hours after undergoing a femoral artery embolectomy, an 84-year-old man is found unconscious on the floor by his hospital bed. He had received a patient-controlled analgesia pump after surgery. He underwent 2 coronary bypass surgeries, 2 and 6 years ago. He has coronary artery disease, hypertension, hypercholesterolemia, gastroesophageal reflux, and type 2 diabetes mellitus. His current medications include metoprolol, atorvastatin, lisinopril, sublingual nitrate, and insulin. He appears pale. His temperature is 36.1°C (97°F), pulse is 120/min, respirations are 24/min, and blood pressure 88/60 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 85%. The patient does not respond to commands and withdraws his extremities to pain. The pupils are constricted bilaterally. Examination shows cold, clammy skin and jugular venous distention. There is ecchymosis on the right temple and maxilla. There is a surgical incision over the right thigh that shows no erythema or discharge. Crackles are heard at both lung bases. A new grade 2/6 systolic murmur is heard at the apex. He is intubated and mechanically ventilated. Further evaluation of this patient is most likely to show which of the following?

A. Positive procalcitonin and interleukin-6 levels
B. Transudate within the pericardial layers
C. Improved mental status after naloxone administration
D. Pulsatile abdominal mass at the level of the umbilicus
E. A new left bundle branch block on an ECG (Correct Answer)

Explanation: ***A new left bundle branch block on an ECG*** - The patient exhibits classic signs of **acute myocardial infarction (AMI)**, including **hypotension**, **tachycardia**, **pulmonary edema** (crackles), new **systolic murmur** (mitral regurgitation due to papillary muscle dysfunction), and **unconsciousness** following a stressful event like surgery. A new left bundle branch block (LBBB) on ECG in this context is highly indicative of an ongoing AMI due to **ischemia**. - The patient has extensive cardiac risk factors (CAD, hypertension, hypercholesterolemia, diabetes, prior bypass surgeries) and recently underwent vascular surgery, increasing the risk of thrombotic events due to surgical stress and inflammatory response. *Positive procalcitonin and interleukin-6 levels* - **Procalcitonin** and **interleukin-6** are markers for **bacterial sepsis**. While the patient is unwell, there are no overt signs of infection like fever (temperature is low), and the clinical picture is more suggestive of cardiovascular collapse. - Though sepsis can cause hypotension and organ dysfunction, the presence of **jugular venous distention** and crackles points more towards **cardiogenic shock** with heart failure. *Transudate within the pericardial layers* - A **pericardial effusion** with transudate is consistent with **heart failure**, which this patient is experiencing. However, the acute presentation with circulatory collapse, new murmur, and neurological changes points more strongly to an acute ischemic event causing the heart failure. - While possible, it's a less specific finding than an ECG change like LBBB in the context of acute cardiac events and the patient's history. *Improved mental status after naloxone administration* - The patient-controlled analgesia (PCA) pump suggests the use of opioids, and **constricted pupils** and **unconsciousness** are signs of opioid overdose. However, the severe **hypotension**, **tachycardia**, **jugular venous distention**, **pulmonary crackles**, and **new systolic murmur** are not typical for isolated opioid overdose, which usually causes bradycardia and respiratory depression, but not usually heart failure signs. - While opioid toxicity should be considered and naloxone might be given empirically, it's unlikely to fully explain the entire clinical presentation, especially the signs of profound cardiogenic shock. *Pulsatile abdominal mass at the level of the umbilicus* - A **pulsatile abdominal mass** could indicate an **abdominal aortic aneurysm (AAA)** rupture. This would cause hypotension and shock, but typically presents with acute, severe abdominal or back pain, and a palpable mass, which is not described. - Ecchymosis on the temple and maxilla suggests a fall or head trauma, potentially secondary to a syncopal event from the underlying cardiovascular collapse, rather than a primary AAA rupture.

Question 779: A 46-year-old woman comes to the physician for a follow-up examination. She had a blood pressure recording of 148/94 mm Hg on her previous visit one week ago. Her home blood pressure log shows readings of 151/97 and 146/92 mm Hg in the past week. She has no history of serious illness and takes no medications. She is 160 cm (5 ft 3 in) tall and weighs 52 kg (115 lb); BMI is 20 kg/m2. Her pulse is 88/min and blood pressure is 150/96 mm Hg. Cardiopulmonary examination is unremarkable. Abdominal examination shows no abnormalities. The extremities are well perfused with strong peripheral pulses. Serum concentrations of electrolytes, creatinine, lipids, TSH, and fasting glucose are within the reference range. A urinalysis is within normal limits. Which of the following is the most appropriate next step in management?

A. Echocardiography
B. Renal ultrasonography
C. Polysomnography
D. Plasma renin activity
E. Electrocardiogram (Correct Answer)

Explanation: ***Electrocardiogram*** - An **electrocardiogram (ECG)** is essential for newly diagnosed hypertension to assess for **left ventricular hypertrophy (LVH)**, a common indicator of target-organ damage. - Early detection of **LVH** can guide treatment intensity and is associated with increased cardiovascular risk. *Echocardiography* - While echocardiography can provide a more detailed assessment of **cardiac structure** and function, it is generally considered a second-line investigation for **LVH** after ECG in uncomplicated hypertension. - ECG is a more cost-effective and readily available initial screening tool for **LVH**. *Renal ultrasonography* - **Renal ultrasonography** would be indicated if there were suspicious findings suggesting **renal artery stenosis**, such as refractory hypertension, an abdominal bruit, or unexplained decline in renal function. - Her normal **creatinine** and **urinalysis** do not suggest kidney disease as an etiology for her hypertension. *Polysomnography* - **Polysomnography** is used to diagnose **sleep apnea**, which can be a cause or exacerbating factor of hypertension. - The patient has no symptoms suggestive of **sleep apnea**, such as snoring, daytime somnolence, or witnessed apneic episodes. *Plasma renin activity* - **Plasma renin activity** is part of the workup for secondary hypertension, specifically to diagnose **primary hyperaldosteronism** or **renal artery stenosis**. - Given the patient's normal electrolytes and absence of other red flags, screening for these conditions is not indicated as a first step.

Question 780: An 11-year-old girl presents with a 1-day history of frothy brown urine. She has no significant medical history and takes no medications. She reports that several of her classmates have been sick, and she notes that she had a very sore throat with a fever approx. 2 weeks ago. Her blood pressure is 146/94 mm Hg, heart rate is 74/min, and respiratory rate is 14/min. Laboratory analysis reveals elevated serum creatinine, hematuria with RBC casts, and elevated urine protein without frank proteinuria. Physical examination reveals a healthy-looking girl with no abdominal or costovertebral angle tenderness. Which of the following is the most likely diagnosis?

A. Poststreptococcal glomerulonephritis (Correct Answer)
B. Membranoproliferative glomerulonephritis
C. Henoch-Schönlein purpura
D. Alport syndrome
E. Minimal change disease

Explanation: ***Poststreptococcal glomerulonephritis*** - The presentation of an 11-year-old girl with **frothy brown urine**, elevated blood pressure, hematuria with **RBC casts**, elevated serum creatinine, and a history of a **sore throat 2 weeks prior** is highly suggestive of **poststreptococcal glomerulonephritis (PSGN)**. - PSGN typically presents 1-3 weeks after a **Group A Streptococcus infection** of the pharynx or skin, characterized by glomerular inflammation and subsequent renal dysfunction. *Membranoproliferative glomerulonephritis* - This condition is characterized by **thickening of the glomerular basement membrane** and mesangial proliferation, often leading to a more chronic course. - While it can cause hematuria and proteinuria, the **acute onset following an infection** and the patient's specific age group make PSGN a more likely diagnosis. *Henoch-Schönlein purpura* - This is an **IgA vasculitis** characterized by a classic tetrad of symptoms: **palpable purpura**, arthralgia, abdominal pain, and renal disease. - The absence of **skin rash** or joint symptoms makes this diagnosis less likely, despite the presence of renal involvement (hematuria/proteinuria). *Alport syndrome* - Alport syndrome is a **hereditary nephropathy** characterized by progressive sensorineural hearing loss, ocular abnormalities, and end-stage renal disease due to mutations in collagen IV. - The acute, post-infectious presentation and absence of a family history or other systemic features make this an unlikely diagnosis. *Minimal change disease* - This condition is the most common cause of **nephrotic syndrome in children**, characterized by heavy proteinuria, hypoalbuminemia, edema, and hyperlipidemia. - While it presents with frothy urine (due to heavy proteinuria), it typically **does not cause significant hematuria, RBC casts, or hypertension** in the acute phase, and the primary issue is protein loss, not glomerular inflammation with RBC casts.

Question 781: A 46-year-old woman comes to the physician for a routine health examination. She was last seen by a physician 3 years ago. She has been healthy aside from occasional mild flank pain. Her only medication is a multivitamin. Her blood pressure is 154/90 mm Hg. Physical examination shows no abnormalities. Serum studies show: Sodium 141 mEq/L Potassium 3.7 mEq/L Calcium 11.3 mg/dL Phosphorus 2.3 mg/dL Urea nitrogen 15 mg/dL Creatinine 0.9 mg/dL Albumin 3.6 g/dL Subsequent serum studies show a repeat calcium of 11.2 mg/dL, parathyroid hormone concentration of 890 pg/mL, and 25-hydroxyvitamin D of 48 ng/mL (N = 25–80). Her 24-hour urine calcium excretion is elevated. An abdominal ultrasound shows several small calculi in bilateral kidneys. Further testing shows normal bone mineral density. Which of the following is the most appropriate next step in management?

A. Begin cinacalcet therapy
B. Order serum protein electrophoresis
C. Perform percutaneous nephrolithotomy
D. Begin hydrochlorothiazide therapy
E. Refer to surgery for parathyroidectomy (Correct Answer)

Explanation: ***Refer to surgery for parathyroidectomy*** * This patient presents with **hypercalcemia**, **elevated PTH**, and **normal vitamin D levels**, indicating **primary hyperparathyroidism**. The presence of **kidney stones** and **hypertension** (though mild) are common complications and indications for surgery. * Given her age (<50 years), symptomatic presentation (kidney stones, hypertension), and markedly elevated PTH, **parathyroidectomy** is the definitive treatment for primary hyperparathyroidism. *Begin cinacalcet therapy* * **Cinacalcet** is a calcimimetic that increases the sensitivity of the calcium-sensing receptor to extracellular calcium, thereby lowering PTH and calcium levels. * It is primarily used for **secondary hyperparathyroidism** in chronic kidney disease or for **inoperable primary hyperparathyroidism**, neither of which applies here. *Order serum protein electrophoresis* * **Serum protein electrophoresis** is used to diagnose conditions like **multiple myeloma**, which can cause hypercalcemia due to osteolytic lesions. * However, this patient's presentation with **elevated PTH** and normal albumin makes multiple myeloma less likely as the cause of her hypercalcemia. *Perform percutaneous nephrolithotomy* * **Percutaneous nephrolithotomy** is an invasive procedure used to remove large or complex kidney stones. * While the patient has kidney stones, addressing the **underlying cause (primary hyperparathyroidism)** through parathyroidectomy is the priority to prevent recurrence and other complications, rather than just treating the stones symptomatically. *Begin hydrochlorothiazide therapy* * **Hydrochlorothiazide** can be used to reduce urinary calcium excretion and prevent calcium stone formation in patients with idiopathic hypercalciuria. * However, in patients with **primary hyperparathyroidism**, thiazide diuretics can **worsen hypercalcemia** by increasing renal calcium reabsorption, making it contraindicated in this setting.

Question 782: Four days after being admitted to the intensive care unit for acute substernal chest pain and dyspnea, an 80-year-old man is evaluated for hypotension. Coronary angiography on admission showed an occlusion in the left anterior descending artery, and a drug-eluting stent was placed successfully. The patient has a history of hypertension and type 2 diabetes mellitus. Current medications include aspirin, clopidogrel, metoprolol, lisinopril, and atorvastatin. His temperature is 37.2 °C (99 °F), pulse is 112/min, respirations are 21/min, and blood pressure is 72/50 mm Hg. Cardiac examination shows a normal S1 and S2 and a new harsh, holosystolic murmur heard best at the left sternal border. There is jugular venous distention and a right parasternal heave. The lungs are clear to auscultation. Pitting edema extends up to the knees bilaterally. An ECG shows Q waves in the inferior leads. Which of the following is the most likely cause of this patient’s hypotension?

A. Post-infarction fibrinous pericarditis
B. Ascending aortic dissection rupture
C. Interventricular septum rupture (Correct Answer)
D. Left ventricular free wall rupture
E. Left ventricular aneurysm rupture

Explanation: ***Interventricular septum rupture*** - A **harsh, holosystolic murmur** heard best at the **left sternal border** 4 days after an **acute MI (LAD occlusion with stenting)** is highly suggestive of interventricular septum rupture. - VSR typically occurs **3-5 days post-MI** when myocardial necrosis weakens the septum, and can occur with both anterior and inferior infarctions. - The rupture creates a **left-to-right shunt**, leading to **hypotension** (decreased systemic cardiac output), **JVD** and **right parasternal heave** (RV volume overload), and biventricular failure. - The holosystolic murmur at the left sternal border with a palpable thrill is pathognomonic for VSR. *Post-infarction fibrinous pericarditis* - This would typically present with a **pericardial friction rub** and potentially pleuritic chest pain, not a holosystolic murmur. - While it can cause pericardial effusion and tamponade leading to hypotension, the specific murmur described points away from this diagnosis. *Ascending aortic dissection rupture* - This would present with **sudden, severe tearing chest pain** radiating to the back and often a new **aortic regurgitation murmur** (diastolic, not systolic). - The patient's presentation with a holosystolic murmur and recent MI points to a post-infarction mechanical complication. *Left ventricular free wall rupture* - This is catastrophic and typically presents with **sudden profound hypotension**, **electromechanical dissociation**, and rapid death. - Patients usually do not survive long enough for examination findings like a new murmur to develop; they present with acute tamponade and cardiovascular collapse. *Left ventricular aneurysm rupture* - A true LV aneurysm is a **late complication** (weeks to months post-MI), not occurring at day 4. - It would not typically cause a new, harsh holosystolic murmur indicative of an acute shunting process. - Aneurysm rupture would present similarly to free wall rupture with tamponade.

Question 783: A 73-year-old man with a 50-year history of type 2 diabetes and stage 3 chronic kidney disease presents to his primary care doctor for a scheduled follow-up and routine labs. He states that he has had no real change in his health except that he feels like he has had bouts of lightheadedness and almost passing out, which resolve with sitting down. The patient does not have a history of syncope or arrhythmia. On his labs, he is found to have a hemoglobin of 11.0 g/dL. His estimated glomerular filtration rate is determined to be 45 ml/min/1.73m^2. Testing of his stool is negative for blood. Additionally, a peripheral blood smear demonstrates normochromic cells. As a result, the patient is started on erythropoietin. Which of the following likely describes the anemia?

A. Macrocytic anemia with megaloblasts
B. Microcytic anemia
C. Macrocytic anemia without megaloblasts
D. Normocytic anemia with increased reticulocyte count
E. Normocytic anemia with decreased reticulocyte count (Correct Answer)

Explanation: ***Normocytic anemia with decreased reticulocyte count*** - Chronic kidney disease often leads to **anemia of chronic disease**, which is typically **normocytic and normochromic** due to impaired erythropoietin production by the kidneys. - A **decreased reticulocyte count** in this context indicates a blunted bone marrow response to the anemia, consistent with insufficient erythropoietin stimulation. *Macrocytic anemia with megaloblasts* - This is characteristic of **B12 or folate deficiency**, which would typically show **hypersegmented neutrophils** and megaloblasts on bone marrow smear, not specified here. - The patient's **normochromic cells** on peripheral smear make macrocytic anemia with megaloblasts less likely. *Microcytic anemia* - **Iron deficiency anemia** or **thalassemia** typically present as microcytic anemia, characterized by small, pale red blood cells. - The patient's **normochromic cells** on peripheral blood smear rule out microcytic anemia. *Macrocytic anemia without megaloblasts* - This can be seen in conditions like **alcoholism**, **liver disease**, or **hypothyroidism**, which are not indicated in this patient's presentation. - The patient's clinical picture and laboratory findings point more directly to a different underlying cause of anemia. *Normocytic anemia with increased reticulocyte count* - An **increased reticulocyte count** would suggest a responsive bone marrow trying to compensate for red blood cell loss or destruction, such as in **hemolytic anemia** or acute bleeding. - The patient's anemia is likely due to underproduction (as suggested by CKD and lack of bleeding), not increased destruction or loss.

Question 784: A 72-year-old man presents to the physician with severe lower back pain and fatigue for 3 months. The pain increases with activity. He has no history of a serious illness. He takes ibuprofen for pain relief. He does not smoke. The blood pressure is 105/65 mm Hg, the pulse is 86/min, the respirations are 16/min, and the temperature is 36.7℃ (98.1℉). The conjunctivae are pale. Palpation over the 1st lumbar vertebra shows tenderness. The heart, lung, and abdominal examination shows no abnormalities. No lymphadenopathy is palpated. The results of the laboratory studies show: Laboratory test Hemoglobin 9 g/dL Mean corpuscular volume 90 μm3 Leukocyte count 5,500/mm3 with a normal differential Platelet count 350,000/mm3 Serum Calcium 11.5 mg/dL Albumin 3.8 g/dL Urea nitrogen 54 mg/dL Creatinine 2.5 mg/dL Lumbosacral computed tomography (CT) scan shows a low-density lesion in the 1st lumbar vertebra and several similar lesions in the pelvic bones. Which of the following is the most likely diagnosis?

A. Waldenstrom’s macroglobulinemia
B. Multiple myeloma (Correct Answer)
C. Small-cell lung carcinoma
D. Secondary hyperparathyroidism
E. Metastatic prostatic cancer

Explanation: ***Multiple myeloma*** - The patient presents with classic symptoms and lab findings, including **anemia** (Hb 9 g/dL), **hypercalcemia** (11.5 mg/dL), **acute kidney injury** (creatinine 2.5 mg/dL, BUN 54 mg/dL), and **bone lesions** (low-density lesions in vertebrae and pelvic bones), collectively known as the **CRAB criteria**. - This constellation of findings is highly suggestive of multiple myeloma, a **plasma cell malignancy** that produces M-proteins, leading to organ damage and characteristic skeletal destruction. *Waldenstrom’s macroglobulinemia* - This condition is also a **B-cell lymphoma** characterized by IgM paraproteinemia, leading to hyperviscosity syndrome and lymphadenopathy. - However, it typically does not cause **lytic bone lesions** or **hypercalcemia**, which are prominent features in this case. *Small-cell lung carcinoma* - While it can metastasize to bone and cause paraneoplastic syndromes like SIADH (hyponatremia) or hypercalcemia (rarely), it does not typically present with widespread **radiolucent bone lesions** as described. - The patient has no history of smoking or respiratory symptoms, making this less likely. *Secondary hyperparathyroidism* - This condition is caused by **chronic kidney disease** leading to low calcium or vitamin D levels, resulting in elevated PTH. - It would present with **low or normal calcium** (not hypercalcemia) and elevated PTH levels, and bone lesions would be due to osteitis fibrosa cystica, which is distinct from the lytic lesions seen here. *Metastatic prostatic cancer* - Prostate cancer typically causes **osteoblastic (sclerotic) bone lesions**, appearing as increased density on imaging, rather than the low-density, **lytic lesions** described in the CT scan. - While it can cause back pain and bone metastases, the nature of the bone lesions is inconsistent with prostatic cancer.

Question 785: A 21-year-old woman presents with malaise, joint pains, and a rash that worsens with sun exposure. Examination reveals an erythematous facial rash with edema. Her complete blood count shows lymphocytopenia. In addition to the most likely diagnosis, which of the following disorders can also cause lymphocytopenia? I. HIV II. Autoimmune disorders III. Tuberculosis IV. Lymphoma V. Hypersplenism

A. I, II, IV, V (Correct Answer)
B. III, V
C. I, II, III
D. III, IV
E. I, III, V

Explanation: ***I, II, IV, V*** - The patient's symptoms (malar rash, photosensitivity, joint pains, malaise, lymphocytopenia) are highly suggestive of **Systemic Lupus Erythematosus (SLE)**, an **autoimmune disorder** (II). - **HIV (I)** directly destroys CD4+ T lymphocytes, causing profound lymphocytopenia. - **Autoimmune disorders (II)** like SLE, rheumatoid arthritis, and Sjögren's syndrome cause lymphocytopenia via antibody-mediated destruction. - **Lymphoma (IV)** causes lymphocytopenia through bone marrow infiltration, increased consumption, or sequestration. - **Hypersplenism (V)** causes sequestration and destruction of lymphocytes along with other blood cells. - While disseminated tuberculosis can occasionally cause lymphocytopenia, **chronic tuberculosis typically causes lymphocytosis**, making it a less reliable answer. *III, V* - This option is incomplete as it correctly identifies hypersplenism but omits HIV, autoimmune disorders, and lymphoma, which are more consistent causes of lymphocytopenia. - **Tuberculosis (III)** in its chronic form typically causes **lymphocytosis**, not lymphocytopenia, though severe disseminated disease may cause lymphocytopenia. *I, II, III* - While HIV and autoimmune disorders are correct, including **tuberculosis (III)** is problematic as chronic TB typically causes **lymphocytosis**, not lymphocytopenia. - This option omits lymphoma and hypersplenism, both important causes. *III, IV* - **Tuberculosis (III)** in chronic form typically causes **lymphocytosis** rather than lymphocytopenia, making it an unreliable choice. - Although **lymphoma (IV)** is correct, this option excludes HIV, autoimmune disorders, and hypersplenism. *I, III, V* - **HIV (I)** and **hypersplenism (V)** are valid causes, but **tuberculosis (III)** is inconsistent as chronic TB typically causes lymphocytosis. - This option incorrectly includes tuberculosis while omitting autoimmune disorders and lymphoma.

Question 786: A 62-year-old man is brought to the emergency department by his wife for high blood pressure readings at home. He is asymptomatic. He has a history of hypertension and hyperlipidemia for which he takes atenolol and atorvastatin, however, his wife reports that he recently ran out of atenolol and has not been able to refill it due to lack of health insurance. His temperature is 36.8°C (98.2°F), the pulse 65/min, the respiratory rate 22/min, and the blood pressure 201/139 mm Hg. He has no papilledema on fundoscopic examination. A CT scan shows no evidence of intracranial hemorrhage or ischemia. Of the following, what is the next best step?

A. Start or restart low-dose medication to reduce blood pressure gradually over the next 24–48 hours (Correct Answer)
B. Admit him to the ICU and start intravenous medication to reduce blood pressure by 25% in the first 4 hours
C. Start high-dose medication to bring his blood pressure to under 140/90 within 24 hours
D. Admit him to the ICU and start intravenous medication to reduce blood pressure by 10% in the first hour
E. Start or restart low-dose medication to reduce blood pressure rapidly over the next 24–48 hours

Explanation: ***Start or restart low-dose medication to reduce blood pressure gradually over the next 24–48 hours*** - This patient presents with **severe asymptomatic hypertension** (hypertensive urgency), indicated by a blood pressure of **201/139 mm Hg** without signs of **acute end-organ damage** (no papilledema, no focal neurological deficits). - The goal in hypertensive urgency is a gradual reduction in blood pressure over 24-48 hours using oral medications to prevent **hypoperfusion** of vital organs, especially given the rapid withdrawal of his **beta-blocker (atenolol)**. *Admit him to the ICU and start intravenous medication to reduce blood pressure by 25% in the first 4 hours* - This approach is reserved for **hypertensive emergencies**, where there is evidence of **acute end-organ damage** (e.g., papilledema, acute kidney injury, encephalopathy, myocardial ischemia). - The patient is **asymptomatic** with no signs of end-organ damage, making aggressive intravenous therapy inappropriate and potentially harmful due to the risk of **ischemia** from rapid BP reduction. *Start high-dose medication to bring his blood pressure to under 140/90 within 24 hours* - While target blood pressure is generally <140/90 mm Hg, aiming for such a rapid, specific reduction with high-dose medication in asymptomatic hypertension can cause **hypoperfusion** and potentially **cerebral ischemia**. - The goal for hypertensive urgency is a more modest and gradual reduction to about 160/100 mmHg over 24-48 hours, followed by a slower reduction to target levels. *Admit him to the ICU and start intravenous medication to reduce blood pressure by 10% in the first hour* - This is also an intervention typically considered for **hypertensive emergencies**, especially in specific scenarios like **aortic dissection** or **intracranial hemorrhage**, where rapid, controlled BP lowering is critical. - For **asymptomatic hypertension**, such a rapid reduction, even if less aggressive than 25%, is still too fast and carries risks without the immediate benefit of preventing acute organ damage. *Start or restart low-dose medication to reduce blood pressure rapidly over the next 24–48 hours* - While low-dose medication is appropriate, the term "rapidly" is concerning, as **rapid reductions** in blood pressure for asymptomatic hypertensive urgency can lead to **ischemia**, particularly in the brain, heart, or kidneys. - The reduction should be **gradual** to allow for autoregulation and avoid complications, distinguishing it from this option's emphasis on speed.

Question 787: A 65-year-old woman comes to clinic complaining of pain with chewing solid foods. She reports that she has been feeling unwell lately, with pains in her shoulders and hips, and she has lost five pounds in the past few months. Her vital signs are T 39C, RR 18 breaths/min, HR 95 bpm, BP 120/65 mmHg. When you ask her to stand from her chair to get on the exam table she moves stiffly but displays preserved proximal muscle strength. Another potential symptom or sign of this disease could be:

A. Blindness (Correct Answer)
B. Violaceous rash across the eyelids
C. Thickened, tight skin on the fingers
D. Hemoptysis
E. Easily sunburned on face and hands

Explanation: ***Blindness*** - This patient presents with symptoms highly suggestive of **giant cell arteritis (GCA)**, including **jaw claudication (pain with chewing)**, **proximal muscle pain (polymyalgia rheumatica-like symptoms)**, **low-grade fever**, and **weight loss**. - **Amaurosis fugax (transient monocular vision loss)** or **permanent blindness** due to **ischemic optic neuropathy** is a feared complication of untreated GCA, caused by inflammation of the **ophthalmic artery**. *Violaceous rash across the eyelids* - A **heliotrope rash** (violaceous discoloration of the eyelids) is characteristic of **dermatomyositis**, which is not supported by the patient's other symptoms. - While dermatomyositis can cause muscle weakness, it typically presents with **proximal muscle weakness** rather than the pain and stiffness described. *Thickened, tight skin on the fingers* - **Sclerodactyly (thickened, tight skin on the fingers)** is a hallmark of **scleroderma (systemic sclerosis)**, which is not indicated by the patient's symptoms. - Scleroderma often involves **Raynaud's phenomenon**, **esophageal dysmotility**, and **pulmonary fibrosis**. *Hemoptysis* - **Hemoptysis (coughing up blood)** is not a typical symptom of giant cell arteritis. - It could be a symptom of various respiratory or systemic conditions, such as **pulmonary embolism**, **bronchiectasis**, or **granulomatosis with polyangiitis (GPA)**, none of which fit the overall clinical picture. *Easily sunburned on face and hands* - **Photosensitivity** (being easily sunburned) is a common symptom of **systemic lupus erythematosus (SLE)**, which is not suggested by the patient's primary complaints. - SLE presents with a wide range of symptoms including **arthritis**, **malar rash**, and **nephritis**.

Question 788: A 48-year-old woman presents to her primary care physician with the complaints of persistent fatigue, dizziness, and weight loss for the past 3 months. She has hypothyroidism for 15 years and takes thyroxine replacement. Her blood pressure is 90/60 mm Hg in a supine position and 65/40 mm Hg while sitting, temperature is 36.8°C (98.2°F) and pulse is 75/min. On physical examination, there is a mild increase in thyroid size, with a rubbery consistency. Her skin shows diffuse hyperpigmentation, more pronounced in the oral mucosa and palmar creases. The morning serum cortisol test is found to be 3 µg/dL. Which of the following is the best next step in this case?

A. Serum adrenocorticotropic hormone (ACTH)
B. Plasma aldosterone
C. 21-hydroxylase antibodies
D. Adrenal imaging
E. Adrenocorticotropic hormone (ACTH) stimulation test (Correct Answer)

Explanation: ***Adrenocorticotropic hormone (ACTH) stimulation test*** - The patient's symptoms (fatigue, dizziness, weight loss, orthostatic hypotension, hyperpigmentation) and a very low morning cortisol level (3 µg/dL) are highly suggestive of **adrenal insufficiency**. - An **ACTH stimulation test** (cosyntropin test) is the gold standard for officially diagnosing adrenal insufficiency by measuring the adrenal glands' response to synthetic ACTH. *Serum adrenocorticotropic hormone (ACTH)* - While measuring **ACTH levels** is crucial to differentiate between primary and secondary adrenal insufficiency, it should be done after confirming adrenal insufficiency with an ACTH stimulation test. - A high ACTH level in conjunction with low cortisol confirms **primary adrenal insufficiency**, whereas a low ACTH indicates **secondary adrenal insufficiency**. *Plasma aldosterone* - **Aldosterone measurements** are useful in evaluating primary adrenal insufficiency, as it can be affected in this condition (leading to salt wasting). - However, the primary concern is cortisol deficiency, and confirming adrenal insufficiency takes precedence for immediate management and diagnosis. *21-hydroxylase antibodies* - **21-hydroxylase antibodies** are markers for **autoimmune adrenal insufficiency**, which is the most common cause of primary adrenal insufficiency. - While relevant for etiology, this test is performed after the diagnosis of adrenal insufficiency has been established by the ACTH stimulation test. *Adrenal imaging* - **Adrenal imaging** (e.g., CT or MRI) is typically performed to investigate the cause of adrenal insufficiency, especially after biochemical confirmation. - It helps in identifying adrenal masses, atrophy, or hemorrhage, but it is not the initial diagnostic step for functional assessment.

Question 789: A 51-year-old woman comes to the emergency department because of a 1-day history of severe pain in her left knee. To lose weight, she recently started jogging for 30 minutes a few times per week. She has type 2 diabetes mellitus and hypertension treated with metformin and chlorothiazide. Her sister has rheumatoid arthritis. She is sexually active with two partners and uses condoms inconsistently. On examination, her temperature is 38.5°C (101.3°F), pulse is 88/min, and blood pressure is 138/87 mm Hg. The left knee is swollen and tender to palpation with a significantly impaired range of motion. A 1.5-cm, painless ulcer is seen on the plantar surface of the left foot. Which of the following is most likely to help establish the diagnosis?

A. Measure HLA-B27
B. Perform MRI of the knee
C. Perform arthrocentesis (Correct Answer)
D. Perform ultrasonography of the knee
E. Measure rheumatoid factor

Explanation: ***Perform arthrocentesis*** - The patient presents with **acute monoarticular arthritis** (**swollen, tender, impaired range of motion** in one knee) with systemic signs of infection (fever). This clinical picture, especially in a patient with **diabetes** (a risk factor for infection) and a **foot ulcer** (potential source of infection), strongly indicates a **septic joint**. - **Arthrocentesis** (joint aspiration) is the **gold standard** for diagnosing septic arthritis, allowing for analysis of synovial fluid for cell count, differential, glucose, protein, gram stain, and culture to identify the causative organism. *Measure HLA-B27* - While **HLA-B27** is associated with seronegative spondyloarthropathies (e.g., ankylosing spondylitis, reactive arthritis), these conditions typically do not present with acute, severe monoarticular arthritis and fever in this manner, nor do they perfectly explain the foot ulcer as a source of infection. - Measuring HLA-B27 would not directly address the acute infectious process suspected in this patient. *Perform MRI of the knee* - An **MRI** can provide detailed imaging of joint structures, including effusions, cartilage damage, and osteomyelitis, but it is **not the primary diagnostic tool for identifying the cause of septic arthritis**. - While it might show signs consistent with inflammation, it **cannot identify the pathogen or confirm infection** in the same way fluid analysis can. *Perform ultrasonography of the knee* - **Ultrasonography** can confirm the presence of joint effusions (fluid in the joint) and guide aspiration, but it **cannot analyze the fluid itself** to determine the etiology of the effusion. - While useful for guiding arthrocentesis, it is not diagnostic on its own for septic arthritis. *Measure rheumatoid factor* - **Rheumatoid factor (RF)** is typically measured to aid in the diagnosis of **rheumatoid arthritis (RA)**, which usually presents as chronic, symmetrical polyarthritis, not acute monoarthritis with fever. - The sister having rheumatoid arthritis is a family history clue, but the patient's acute presentation is inconsistent with an initial RA flare. An elevated RF would not explain the patient's acute symptoms or the potential source of infection from the foot ulcer.

Question 790: A 43-year-old man comes to the physician for evaluation of a headache he has had for the last 6 months. The patient reports that nothing helps to relieve the headache and that it is more severe in the morning. Throughout the last 2 months, he has been unable to maintain an erection and states that his sexual desire is low. There is no personal or family history of serious illness. His temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 150/90 mm Hg. Examination shows an enlarged nose, forehead, and jaw and widened hands, fingers, and feet. His hands are sweaty. His serum glucose concentration is 260 mg/dL. Which of the following is the most appropriate next step in diagnosis?

A. Serum IGF-1 measurement (Correct Answer)
B. Basal prolactin measurement
C. MRI of the brain
D. 24-hour urine cortisol measurement
E. Oral glucose tolerance test

Explanation: ***Serum IGF-1 measurement*** - The patient's symptoms (enlarged nose, forehead, jaw, widened hands/feet, sweaty hands) are classic for **acromegaly**, which is caused by excess **growth hormone (GH)**. - **Insulin-like growth factor 1 (IGF-1)** levels are directly correlated with GH levels and are a reliable screening test for acromegaly, reflecting average GH secretion over time. *Basal prolactin measurement* - While a **pituitary adenoma** (which can cause acromegaly) can sometimes co-secrete **prolactin**, the primary clinical features here point to GH excess, not hyperprolactinemia. - Elevated prolactin typically causes **galactorrhea** and more pronounced hypogonadism, which are not the primary complaints. *MRI of the brain* - An **MRI of the brain** is the gold standard for visualizing a **pituitary adenoma** once acromegaly is biochemically confirmed. - However, it is not the initial *diagnostic step* to confirm acromegaly itself; hormonal assays are needed first. *24-hour urine cortisol measurement* - This test is used to diagnose **Cushing's syndrome**, which is characterized by symptoms like **central obesity, striae, and muscle weakness**, not the features of bony overgrowth seen here. - Although both can involve pituitary tumors, the symptoms described do not fit cortisol excess. *Oral glucose tolerance test* - An **oral glucose tolerance test (OGTT)**, with subsequent GH measurement, is considered the confirmatory diagnostic test for acromegaly. - Glucose normally suppresses GH, so a failure of GH suppression after glucose load confirms the diagnosis, but the **IGF-1 initial screen** is more appropriate due to its stability and convenience.

Question 791: A 43-year-old woman comes to the physician for a routine examination prior to starting a new job as a nurse. Over the past year, the patient has had mild shortness of breath and a cough productive of white sputum, particularly in the morning. She immigrated to the United States from South Africa with her parents 40 years ago. She received all appropriate immunizations during childhood, including the oral polio and BCG vaccine. She has smoked two packs of cigarettes daily for 30 years and drinks one glass of wine occasionally. Her only medication is a multivitamin. Her temperature is 36.5°C (97.7°F), pulse is 74/min, and blood pressure is 124/60 mm Hg. Bilateral wheezing is heard throughout both lung fields. A complete blood count and serum concentrations of electrolytes, urea nitrogen, and creatinine are within the reference range. Which of the following is the most appropriate next step to evaluate for tuberculosis in this patient?

A. X-ray of the chest
B. Sputum culture
C. Tuberculin skin test
D. PCR of the sputum
E. Interferon-gamma release assay (Correct Answer)

Explanation: ***Interferon-gamma release assay (IGRA)*** - This patient received a **BCG vaccine** in childhood, which can lead to a **false-positive tuberculin skin test (TST)**. An IGRA is preferred in individuals with a history of BCG vaccination because it is not affected by prior BCG vaccination. - The patient has risk factors for **latent tuberculosis infection (LTBI)**, including immigration from a region where tuberculosis is endemic (South Africa) and chronic respiratory symptoms, making screening for TB appropriate. *Tuberculin skin test (TST)* - While TST is a common screening tool for tuberculosis, a history of **BCG vaccination** (as in this patient) can cause a **false-positive result**, making interpretation difficult. - Due to the potential for false positives with BCG, an IGRA is generally recommended over TST for individuals with prior BCG vaccination. *X-ray of the chest* - A chest X-ray is useful for evaluating **active tuberculosis disease** and can show characteristic findings like **infiltrates, cavitations, or ghon complexes**. - However, it is **not the primary screening tool for latent TB infection** in an asymptomatic individual and would typically follow a positive screening test. *Sputum culture* - Sputum culture is the **gold standard for diagnosing active pulmonary tuberculosis**, as it confirms the presence of mycobacteria and allows for susceptibility testing. - It is not indicated as initial screening for **latent tuberculosis infection** in a patient with mild, non-specific symptoms and no clear signs of active disease. *PCR of the sputum* - **PCR of sputum** is a rapid diagnostic test for **active tuberculosis**, detecting mycobacterial DNA. - Similar to sputum culture, it is used to diagnose active disease, not to screen for **latent TB infection**, and would not be the initial step in this context.

Question 792: A 68-year-old male presents with several years of progressively worsening pain in his buttocks. Pain is characterized as dull, worse with exertion especially when ascending the stairs. He has a history of diabetes mellitus type II, obesity, coronary artery disease with prior myocardial infarction, and a 44 pack-year smoking history. Current medications include aspirin, atorvastatin, metoprolol, lisinopril, insulin, metformin, and varenicline. Upon further questioning, the patient's wife states that her husband has also recently developed impotence. His temperature is 99.5°F (37.5°C), pulse is 90/min, blood pressure is 150/90 mmHg, respirations are 12/min, and oxygen saturation is 96% on room air. Which of the following is the best initial step in management?

A. Ankle-brachial index (Correct Answer)
B. Pentoxifylline
C. Guided exercise therapy
D. Cilostazol
E. Angiography

Explanation: ***Ankle-brachial index*** - This patient's symptoms (buttock pain, worsening with exertion, impotence) along with multiple risk factors (diabetes, obesity, smoking, CAD) are highly suggestive of **peripheral artery disease (PAD)**, specifically **Leriche syndrome**. - The **ankle-brachial index (ABI)** is a non-invasive, inexpensive, and highly sensitive and specific diagnostic test for PAD, making it the best initial step for confirmation. *Pentoxifylline* - **Pentoxifylline** is a rheologic agent that can improve blood flow by reducing blood viscosity and enhancing red blood cell flexibility. - While it was previously used for claudication, it is **less effective** than cilostazol and generally **not considered a first-line treatment** for PAD. *Guided exercise therapy* - **Supervised exercise programs** are a cornerstone in the management of PAD symptoms and improve walking distance and quality of life. - However, performing a **diagnostic test like ABI** is crucial to confirm the diagnosis and determine the extent of PAD **before initiating treatment**. *Cilostazol* - **Cilostazol** is a phosphodiesterase inhibitor with antiplatelet and vasodilatory effects, proven to **improve walking distance** in patients with intermittent claudication. - While an effective treatment, it should be prescribed **after the diagnosis of PAD is confirmed** and after Lifestyle modifications (including exercise therapy) are considered. *Angiography* - **Angiography** (CT angiography, MR angiography, or conventional angiography) provides detailed imaging of arterial anatomy and is essential for **pre-procedural planning** of revascularization (e.g., stenting, bypass surgery). - It is a **more invasive and expensive test** that is typically performed **after the diagnosis of PAD is established** by ABI and conservative measures have been tried or when revascularization is being considered.

Question 793: A 60-year-old man comes to the emergency department because of a 2-day history of sharp chest pain and a nonproductive cough. The pain worsens with deep inspiration and improves when he leans forward. Three weeks ago, the patient was diagnosed with an ST-elevation myocardial infarction and underwent stent implantation of the right coronary artery. His temperature is 38.4°C (101.1°F) and blood pressure is 132/85 mm Hg. Cardiac auscultation shows a high-pitched scratching sound during expiration. An x-ray of the chest shows enlargement of the cardiac silhouette and a left-sided pleural effusion. Which of the following is the most likely underlying cause of this patient's current condition?

A. Occlusion of coronary artery stent
B. Immune response to cardiac antigens (Correct Answer)
C. Rupture of interventricular septum
D. Embolism to left pulmonary artery
E. Outpouching of ventricular wall

Explanation: ***Immune response to cardiac antigens*** - The patient's symptoms (chest pain worsening with inspiration and improving with leaning forward, fever, pericardial friction rub, enlarged cardiac silhouette, pleural effusion) occurring 3 weeks after an MI and stent implantation are classic for **Dressler's syndrome**, a **late post-myocardial infarction pericarditis**. - Dressler's syndrome is believed to be an **autoimmune reaction** involving antibodies targeting cardiac muscle cells that have been damaged during the MI. *Occlusion of coronary artery stent* - **Stent occlusion** would typically present with recurrent ischemic chest pain, often severe and oppressive, and potentially new ECG changes suggestive of ischemia or infarction, rather than pleuritic pain and pericardial signs. - While it's a serious complication, it doesn't explain the fever, pericardial friction rub, or pleural effusion seen in this patient. *Rupture of interventricular septum* - **Ventricular septal rupture** is a mechanical complication of MI that usually presents with sudden onset of a new, loud holosystolic murmur, hypotension, and signs of heart failure (e.g., dyspnea, pulmonary edema). - It would not typically cause the pleuritic chest pain, pericardial friction rub, or fever observed in this case. *Embolism to left pulmonary artery* - A **pulmonary embolism** typically causes sudden onset of dyspnea, pleuritic chest pain, and sometimes hemoptysis. While it can cause pleuritic chest pain, it wouldn't explain the pericardial friction rub, the typical positional relief of pain, or the enlarged cardiac silhouette. - The patient's presentation is more indicative of pericardial inflammation rather than pulmonary infarction. *Outpouching of ventricular wall* - An **outpouching of the ventricular wall**, known as a ventricular aneurysm, is a late complication of MI. It can cause heart failure, arrhythmias, or mural thrombus formation, but it is not typically associated with acute pleuritic chest pain, fever, or a pericardial friction rub. - An aneurysm might cause an enlarged cardiac silhouette but wouldn't explain the other acute inflammatory symptoms.

Question 794: A 36-year-old software professional consults a physician to discuss his concerns about small-vessel vasculitis as his mother and sister both have autoimmune small-vessel vasculitides. He has read about vasculitides and recently he came across an article which stated that an analgesic that he often uses for relief from a headache can cause small-vessel vasculitis. Due to his positive family history, he is especially concerned about his risk of developing small-vessel vasculitis. Which of the following clinical presentations is most likely to occur in this man?

A. Infarction of an internal organ
B. Aneurysm of an artery
C. Palpable purpura (Correct Answer)
D. Stroke
E. Absence of pulses in the upper extremity

Explanation: ***Correct: Palpable purpura*** - **Palpable purpura** is a classic manifestation of **small-vessel vasculitis** because inflammation and damage to small blood vessels lead to extravasation of red blood cells into the skin, forming palpable lesions. - The vasculitis discussed in the scenario is likely **drug-induced vasculitis**, often presenting as a **leukocytoclastic vasculitis** affecting small vessels in the skin, resulting in purpura. *Incorrect: Infarction of an internal organ* - **Infarction of internal organs** is more commonly associated with **medium or large-vessel vasculitides** due to the occlusion of larger arteries supplying these organs. - While small-vessel vasculitis can affect internal organs, **infarction** is less typical than skin manifestations. *Incorrect: Aneurysm of an artery* - **Aneurysm formation** is characteristic of **large and medium-vessel vasculitides**, such as **Kawasaki disease** or **polyarteritis nodosa**, which involve the structural weakening of arterial walls. - **Small-vessel vasculitides** primarily cause inflammation and necrosis of vessel walls, leading to purpura or hemorrhage, not routinely aneurysms. *Incorrect: Stroke* - **Stroke** can occur in vasculitis, but it is typically associated with **vasculitis affecting cerebral arteries** (often medium or large vessels) or conditions that cause emboli due to cardiac involvement (e.g., in Takayasu arteritis). - While small-vessel vasculitis can impact the central nervous system, **palpable purpura** is a more direct and common skin manifestation. *Incorrect: Absence of pulses in the upper extremity* - **Absence of pulses** in the upper extremities is a hallmark of **large-vessel vasculitis**, particularly **Takayasu arteritis**, where granulomatous inflammation leads to stenosis or occlusion of the aorta and its major branches. - This finding is inconsistent with **small-vessel vasculitis**, which does not typically affect major arterial blood flow in this manner.

Question 795: A 42-year-old man is brought to the emergency department because his neck was fixed in lateral flexion. For the past week, the patient has been complaining of low-grade fever, head pain, and neck pain. His partner has also noticed him behaving erratically. His family and personal medical history are not relevant. Upon admission, he is found with a body temperature of 38.6°C (101.5°F), and physical examination is unremarkable except for neck pain and fixed lateral flexion of the neck. He is confused, but there are no motor or sensory deficits. Deep tendon reflexes are accentuated. Magnetic resonance imaging of the brain shows leptomeningeal and gyral enhancement. Which of the following explains this patient’s condition?

A. Exposure to D2-antagonists
B. Trochlear nerve palsy
C. Viral infection
D. Genetic mutation
E. Acid-fast bacilli infection (Correct Answer)

Explanation: ***Acid-fast bacilli infection*** - The patient's presentation with **torticollis (fixed lateral flexion of the neck)**, low-grade fever, headache, altered mental status (**confusion**, erratic behavior), and **leptomeningeal and gyral enhancement** on MRI are highly suggestive of **tuberculous meningitis**. - **Accentuated deep tendon reflexes** can be seen in meningitis due to increased intracranial pressure or diffuse cerebral irritation. *Exposure to D2-antagonists* - **D2-antagonists**, such as antipsychotics, can cause **acute dystonic reactions**, including torticollis. - However, the presence of **fever, headache, confusion, and leptomeningeal enhancement** on MRI are not typical features of drug-induced dystonia. *Trochlear nerve palsy* - **Trochlear nerve (CN IV) palsy** typically causes **vertical diplopia** and compensatory **head tilt** to correct vision. - It does not cause fever, headache, altered mental status, or imaging findings of diffuse meningeal inflammation. *Viral infection* - While viral infections can cause meningitis or encephalitis with fever and headache, the specific presentation of **prominent torticollis** and **leptomeningeal and gyral enhancement** is more classic for tuberculous meningitis. - Furthermore, the clinical course and severity often differ. *Genetic mutation* - **Genetic mutations** are associated with various neurological disorders, but they are generally not linked to an **acute presentation** with fever, headache, altered mental status, and inflammatory MRI findings. - Conditions like hereditary dystonia typically have a different onset and progression.

Question 796: A 40-year-old Indian female is hospitalized with exertional dyspnea and lower extremity edema. The patient immigrated to the United States at age 15 and does not use tobacco, alcohol, or drugs. A mid-diastolic murmur is present and heard best at the apex. Which of the following symptoms would be most consistent with the rest of the patient’s presentation?

A. Asymmetric ventricular hypertrophy
B. Increased intracranial pressure
C. Hirsutism
D. Pulsus paradoxus
E. Hoarseness (Correct Answer)

Explanation: ***Hoarseness*** - This patient presents with symptoms suggestive of **mitral stenosis** (exertional dyspnea, edema, mid-diastolic apical murmur) likely due to a history of **rheumatic fever** prevalent in developing countries. - **Hoarseness (Ortner's syndrome)** can occur in severe mitral stenosis due to the dilated left atrium compressing the **left recurrent laryngeal nerve**. *Asymmetric ventricular hypertrophy* - This is a hallmark of **hypertrophic cardiomyopathy**, which typically presents with a harsh systolic murmur that increases with Valsalva, not a mid-diastolic murmur. - It involves hypertrophy of the interventricular septum, leading to outflow tract obstruction, which is inconsistent with the findings of mitral stenosis. *Increased intracranial pressure* - Symptoms like headache, papilledema, or altered mental status are associated with increased intracranial pressure, which has no direct link to mitral stenosis or the described cardiac symptoms. - While heart failure can lead to cerebral edema in extreme cases, it's not a primary or direct symptom of mitral stenosis itself. *Hirsutism* - Hirsutism is the excessive growth of dark, coarse hair in a male-like pattern in women, often due to **androgen excess** (e.g., PCOS). - This symptom is unrelated to the cardiovascular pathology suggested by the patient's presentation of exertional dyspnea, edema, and a mid-diastolic murmur. *Pulsus paradoxus* - This refers to an abnormally large decrease in **systolic blood pressure** during inspiration, most commonly seen in conditions like **cardiac tamponade**, severe asthma, or COPD. - It is not a characteristic finding of mitral stenosis; rather, a small pulse pressure can be seen due to reduced cardiac output.

Question 797: A 58-year-old man with an unknown previous medical history is found on the floor at home by his daughter. During the initial assessment, the patient has left-sided arm weakness and incomprehensible speech. The patient is admitted to the hospital where he is diagnosed with an ischemic stroke where his magnetic resonance image (MRI) scan showed diffusion restriction in the right middle cerebral artery (MCA) territory. Further evaluation reveals the patient had been on the floor for about 2 days before he was found by his daughter. At presentation to the hospital, the blood pressure is 161/88 mm Hg and the heart rate is 104/min and regular. His laboratory values at the time of admission are shown: BUN 40 mg/dL Creatinine 1.9 mg/dL Potassium 5.3 mEq/dL Sodium 155 mEq/dL Chloride 100 mEq/dL HCO3 24 mmol/L Hemoglobin 13.8 g/dL Hematocrit 40% Leukocytes 11,000/mL Platelets 300,000/µL Serum creatine kinase 40,000 U/L Which of the following is most indicated in this patient?

A. Forced diuresis with intravenous (IV) fluids (Correct Answer)
B. Stress echocardiography
C. Intravenous n-acetyl-cysteine
D. Transfusion of fresh frozen plasma (FFP)
E. Rhythm control with metoprolol

Explanation: ***Forced diuresis with intravenous (IV) fluids*** - The patient's **elevated serum creatine kinase (CK)** of 40,000 U/L, along with prolonged immobility ("on the floor for about 2 days"), severe dehydration (Na 155 mEq/dL, BUN 40 mg/dL, Cr 1.9 mg/dL), and hyperkalemia (K 5.3 mEq/dL), strongly suggests **rhabdomyolysis**. - **Aggressive intravenous fluids** are crucial to prevent and treat acute kidney injury (AKI) by flushing myoglobin from the renal tubules. **Forced diuresis** helps to maintain adequate urine output and dilute potential nephrotoxic substances. *Stress echocardiography* - This test is used to evaluate **coronary artery disease** or myocardial ischemia, which is not the immediate life-threatening concern in this patient. - While cardiac evaluation may be important later for stroke etiology, addressing the **rhabdomyolysis and AKI risk** is the highest immediate priority. *Intravenous n-acetyl-cysteine* - **N-acetylcysteine (NAC)** is primarily used to treat **acetaminophen overdose** or to prevent contrast-induced nephropathy. - It does not have a primary role in the management of **rhabdomyolysis** or associated acute kidney injury. *Transfusion of fresh frozen plasma (FFP)* - **Fresh frozen plasma (FFP)** is indicated for patients with **coagulopathies** and active bleeding or before invasive procedures, or for genetic coagulation factor deficiencies. - There is no evidence in the clinical presentation or lab values to suggest a coagulopathy requiring FFP transfusion. *Rhythm control with metoprolol* - Metoprolol is a beta-blocker used for **rate and rhythm control** in conditions like atrial fibrillation or tachycardia. - Although the patient has a heart rate of 104/min, this is likely secondary to dehydration and systemic stress, and restoring euvolemia is generally the primary intervention before considering specific rhythm control medications.

Question 798: A 33-year-old man presents to the emergency department with sudden onset right hand and right leg weakness. The patient was at home cleaning when his symptoms began. He also complains of diffuse and severe pain throughout his entire body which he states he has experienced before. The patient is an immigrant from South America, and his medical history is not known. His temperature is 98.9°F (37.2°C), blood pressure is 128/67 mmHg, pulse is 80/min, respirations are 16/min, and oxygen saturation is 99% on room air. CT of the head demonstrates no bleeding. Physical exam is notable for 2/5 strength in the patient's right arm and right leg. Which of the following is the best management in this patient?

A. Aspirin
B. Morphine and IV fluids
C. Heparin
D. Tissue plasminogen activator
E. Exchange transfusion (Correct Answer)

Explanation: ***Exchange transfusion*** - This patient presents with **acute stroke** (sudden right-sided weakness) in the setting of **sickle cell disease** (history of recurrent severe pain, South American origin where SCD is prevalent). - **Exchange transfusion** is the **definitive and urgent treatment** for acute stroke in sickle cell disease, aiming to rapidly reduce HbS to <30% and increase HbA levels. - This is a **neurological emergency** requiring immediate intervention to prevent further ischemic injury and improve outcomes. - Per ASH guidelines, exchange transfusion should be initiated as soon as possible for acute stroke in SCD patients. *Morphine and IV fluids* - While **pain management** and **hydration** are essential components of managing uncomplicated vaso-occlusive crisis, they are **insufficient** for acute stroke. - These are supportive measures but do not address the underlying pathophysiology of acute cerebral infarction in SCD. - In the context of acute stroke (a neurological emergency), more definitive intervention is required. *Tissue plasminogen activator* - **Thrombolytic therapy** is generally **contraindicated** in sickle cell-related stroke due to the different pathophysiology (small vessel occlusion, not large vessel thrombosis). - SCD patients have increased bleeding risk, making tPA potentially dangerous. - Exchange transfusion is the preferred intervention with better risk-benefit profile. *Heparin* - **Anticoagulation** is not indicated for acute stroke in sickle cell disease. - The mechanism is vaso-occlusion from sickled cells, not thromboembolism. - Could increase bleeding risk without addressing the underlying pathology. *Aspirin* - **Antiplatelet therapy** does not address the acute emergency of stroke in SCD. - While it may have a role in secondary prevention, it is not appropriate acute management. - The immediate priority is exchange transfusion to rapidly reduce sickling.

Question 799: A 74-year-old man returns to his physician to follow-up on laboratory studies obtained for anemia 2 weeks ago. He has no complaints. He has a 20-year history of hypertension and several years of knee osteoarthritis. He walks 2 miles a day. He does not smoke. He drinks alcohol moderately. He takes hydrochlorothiazide, losartan, and pain killers, including ibuprofen. The vital signs include: temperature 37.1°C (98.8°F), pulse 68/min, respiratory rate 12/min, and blood pressure 110/70 mm Hg. The physical examination shows no abnormalities. The laboratory studies show the following: Laboratory test Hemoglobin 10 g/dL Mean corpuscular volume 75 μm3 Leukocyte count 5,000/mm3 Platelet count 350,000/mm3 ESR 18 mm/hr Serum Ferritin 5 μg/L Iron 30 μg/L Total iron-binding capacity 500 μg/dL Calcium (Ca+) 9 mg/dL Albumin 4 g/dL Urea nitrogen 14 mg/dL Creatinine 0.9 mg/dL Monoclonal protein on serum electrophoresis is 12 g/L (non-IgM). Clonal bone marrow plasma cells comprise 4% of the total number of cells. Skeletal survey with magnetic resonance imaging reveals no pathologic findings. In addition to iron deficiency anemia, which of the following diagnosis is most appropriate to consider?

A. Symptomatic multiple myeloma
B. Monoclonal gammopathy of undetermined significance (Correct Answer)
C. Waldenstrom’s macroglobulinemia
D. Solitary plasmacytoma
E. Smoldering (asymptomatic) multiple myeloma

Explanation: ***Monoclonal gammopathy of undetermined significance (MGUS)*** - The presence of **monoclonal protein <30 g/L** (12 g/L, non-IgM), **clonal bone marrow plasma cells <10%** (4% in this case), and **absence of CRAB criteria** (hypercalcemia, renal insufficiency, anemia, bone lesions) are classic diagnostic criteria for MGUS. - The patient's **iron deficiency anemia** is unrelated to the plasma cell disorder and is likely secondary to chronic NSAID use (ibuprofen). - MGUS requires monitoring but no treatment. *Symptomatic multiple myeloma* - Requires the presence of **CRAB criteria** (hypercalcemia, renal insufficiency, anemia related to myeloma, bone lesions) or **myeloma-defining events**, which are absent in this patient. - Myeloma-related anemia is typically **normocytic/normochromic**, while this patient has **microcytic anemia due to iron deficiency**. *Waldenstrom's macroglobulinemia* - Characterized by **monoclonal IgM paraprotein** and lymphoplasmacytic lymphoma infiltration in the bone marrow. - The patient's monoclonal protein is specifically stated as **non-IgM**, ruling out Waldenstrom's macroglobulinemia. *Solitary plasmacytoma* - Involves a **single solitary lesion** of clonal plasma cells in bone or soft tissue, with otherwise normal bone marrow (<10% plasma cells) and no CRAB criteria. - The skeletal survey with MRI shows **no solitary lesion**, making this diagnosis inappropriate. *Smoldering (asymptomatic) multiple myeloma* - Defined by monoclonal protein **≥30 g/L** OR clonal bone marrow plasma cells **10-60%**, AND **absence of CRAB criteria or SLiM-CRAB criteria**. - This patient's monoclonal protein is only **12 g/L** and bone marrow plasma cells are **4%**, both below the diagnostic thresholds for smoldering myeloma.

Question 800: A 29-year-old woman comes to her primary care physician hoping she is pregnant. She reports that she had been taking oral contraceptive pills, but she stopped when she began trying to get pregnant about 7 months ago. Since then she has not had her period. She took a few home pregnancy tests that were negative, but she feels they could be wrong. She says she has gained 4 lbs in the past month, and her breasts feel full. Today, she expressed milk from her nipples. She complains of fatigue, which she attributes to stress at work, and headaches, to which she says “my sister told me she had headaches when she was pregnant.” She denies spotting or vaginal discharge. Her last menstrual period was at age 22, prior to starting oral contraceptive pills. Her medical and surgical history are non-significant. She has no history of sexually transmitted infections. She reports she and her husband are having intercourse 3-4 times a week. Her family history is significant for breast cancer in her mother and an aunt who died of ovarian cancer at 55. On physical examination, no breast masses are appreciated, but compression of the nipples produces whitish discharge bilaterally. A bimanual pelvic examination is normal. A urine pregnancy test is negative. Which of the following is the best initial step in management for this patient?

A. Magnetic resonance imaging of the head
B. Pelvic ultrasound
C. Serum follicle-stimulating hormone/luteinizing hormone ratio
D. Serum thyroid-stimulating hormone level (Correct Answer)
E. Mammogram

Explanation: ***Serum thyroid-stimulating hormone level*** - The patient presents with **amenorrhea**, **galactorrhea**, and non-specific symptoms like **fatigue** and **headaches**. These symptoms can be indicative of **hypothyroidism**, which can cause hyperprolactinemia and subsequently lead to galactorrhea and menstrual irregularities due to its impact on the hypothalamic-pituitary-gonadal axis. - **Thyroid-stimulating hormone (TSH)** is a crucial initial test as thyroid dysfunction is a common and treatable cause of these symptoms. *Magnetic resonance imaging of the head* - While **prolactinoma** causing hyperprolactinemia could lead to these symptoms and would eventually warrant an MRI, obtaining an MRI too early, before ruling out simpler and more common etiologies like hypothyroidism, is not the best initial step. - An MRI would be indicated if **prolactin levels are elevated** and other causes, such as hypothyroidism, have been ruled out. *Pelvic ultrasound* - A pelvic ultrasound is primarily used to evaluate the **uterus and ovaries** for structural abnormalities. - Given the patient's symptoms of **galactorrhea** and **amenorrhea** (without a positive pregnancy test), and the normal bimanual exam, a pelvic ultrasound is less likely to identify the primary cause compared to endocrine investigations. *Serum follicle-stimulating hormone/luteinizing hormone ratio* - This ratio is typically assessed in cases of **amenorrhea** to evaluate ovarian function or **polycystic ovary syndrome (PCOS)**. - While relevant for amenorrhea, it does not directly address the prominent symptom of **galactorrhea** which points more towards a pituitary or thyroid issue. *Mammogram* - A mammogram is a screening tool for **breast cancer**, and while the patient has a family history, her current symptoms are related to **milk production (galactorrhea)** and **menstrual irregularities**, not suspicious breast masses. - The physical exam showed no breast masses, and the discharge was bilateral and whitish, making breast cancer less likely as the primary cause of these specific symptoms.

Question 801: A 45-year-old woman presents to the office complaining of bilateral joint pain and stiffness in her hand joints for the past 3 months. She reports increasing difficulty holding a coffee cup or pen due to stiffness, especially in the morning. Over-the-counter ibuprofen partially relieves her symptoms. Past medical history is significant for dysthymia and gastroesophageal reflux disease. Vital signs are normal except for a low-grade fever. On examination, there is mild swelling and tenderness in the proximal interphalangeal and metacarpophalangeal joints and wrists. Nontender and non-pruritic nodules near the elbows are noted. Chest and abdominal examination are normal. X-rays of the hands reveal soft tissue swelling, joint space narrowing, and bony erosions. Her hematocrit is 32%, and her erythrocyte sedimentation rate is 40 mm/hr. This patient is at greatest risk for which of the following?

A. Obstructive pulmonary disease
B. Disease progression to distal interphalangeal joints
C. Sacroiliac joint inflammation
D. Osteitis deformans
E. Cardiovascular disease (Correct Answer)

Explanation: ***Cardiovascular disease*** - Patients with **rheumatoid arthritis (RA)**, suggested by the symptoms (bilateral hand joint pain, morning stiffness, swollen PIP/MCP joints, erosions, high ESR, subcutaneous nodules), have a significantly increased risk of **cardiovascular disease** due to systemic inflammation. - Chronic inflammation accelerates **atherosclerosis**, leading to a higher incidence of myocardial infarction, stroke, and heart failure in RA patients. *Obstructive pulmonary disease* - While RA can cause **interstitial lung disease** (ILD), which is restrictive, it is not a primary risk factor for **obstructive pulmonary disease** like COPD unless the patient has a history of smoking. - The presented symptoms do not directly point towards an obstructive lung process. *Disease progression to distal interphalangeal joints* - **Rheumatoid arthritis** typically spares the **distal interphalangeal (DIP) joints**, unlike **osteoarthritis** or **psoriatic arthritis**. - Involvement of the DIP joints would suggest a different underlying rheumatologic condition. *Sacroiliac joint inflammation* - **Sacroiliac joint inflammation** (sacroiliitis) is a hallmark feature of **spondyloarthropathies** (e.g., ankylosing spondylitis), which are distinct from rheumatoid arthritis. - RA primarily affects peripheral joints and typically does not involve the axial skeleton or sacroiliac joints. *Osteitis deformans* - **Osteitis deformans**, also known as **Paget's disease of bone**, is a chronic bone disorder characterized by abnormal bone remodeling. - It is not directly related to or a common complication of rheumatoid arthritis nor do the symptoms suggest this condition.

Question 802: A 42-year-old man presents to the emergency department with persistent cough. The patient states that for the past week he has been coughing. He also states that he has seen blood in his sputum and experienced shortness of breath. On review of systems, the patient endorses fever and chills as well as joint pain. His temperature is 102°F (38.9°C), blood pressure is 159/98 mmHg, pulse is 80/min, respirations are 14/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below. Hemoglobin: 12 g/dL Hematocrit: 36% Leukocyte count: 7,500/mm^3 with normal differential Platelet count: 107,000/mm^3 Serum: Na+: 138 mEq/L Cl-: 101 mEq/L K+: 4.2 mEq/L HCO3-: 24 mEq/L BUN: 32 mg/dL Glucose: 99 mg/dL Creatinine: 1.9 mg/dL Ca2+: 10.0 mg/dL AST: 11 U/L ALT: 10 U/L Urine: Color: Amber, cloudy Red blood cells: Positive Protein: Positive Which of the following is the best next step in management?

A. p-ANCA levels
B. Steroids
C. Azithromycin
D. Type IV collagen antibody levels (Correct Answer)
E. Renal biopsy

Explanation: ***Type IV collagen antibody levels*** - The patient presents with **pulmonary-renal syndrome**: hemoptysis, shortness of breath, elevated BUN/creatinine, hematuria, and proteinuria, which requires urgent evaluation for rapidly progressive glomerulonephritis (RPGN). - **Anti-GBM antibodies** (type IV collagen antibodies) are diagnostic for **Goodpasture syndrome** (anti-GBM disease), which can present as life-threatening pulmonary hemorrhage and RPGN. - While this patient has some **atypical features** for classic Goodpasture's (fever, arthralgias, thrombocytopenia suggest possible vasculitis), testing for **both anti-GBM and ANCA antibodies** is standard practice in pulmonary-renal syndrome. - Anti-GBM disease requires **urgent diagnosis and treatment** (plasmapheresis + immunosuppression) to prevent irreversible renal failure. *p-ANCA levels* - **p-ANCA** is associated with **microscopic polyangiitis** and other ANCA-associated vasculitides, which can also present with pulmonary-renal syndrome. - The constitutional symptoms (fever, arthralgias) and thrombocytopenia actually favor **ANCA-associated vasculitis** over Goodpasture's. - In clinical practice, **both anti-GBM and ANCA antibodies should be sent simultaneously** when evaluating pulmonary-renal syndrome, as they guide different treatment approaches. - This answer is reasonable but slightly less preferred in the context of this specific test question. *Steroids* - **Corticosteroids** are part of the treatment for both Goodpasture syndrome and ANCA-associated vasculitis. - However, initiating empiric treatment before obtaining **diagnostic serology** is not ideal, as the diagnosis directs specific therapy (e.g., plasmapheresis for anti-GBM disease). - In life-threatening presentations, steroids might be started empirically, but diagnostic testing should be done first or simultaneously. *Azithromycin* - **Azithromycin** is an antibiotic that would not address the underlying **autoimmune etiology** suggested by the pulmonary-renal syndrome. - While infection should be in the differential with fever, the constellation of hemoptysis, glomerulonephritis, and systemic symptoms points to autoimmune disease. *Renal biopsy* - **Renal biopsy** is the gold standard for definitive diagnosis and would show **linear IgG deposition** along the glomerular basement membrane in Goodpasture syndrome. - However, **serologic testing** (anti-GBM and ANCA antibodies) is **less invasive, faster, and highly specific**, making it the preferred initial diagnostic step. - Biopsy may be pursued if serology is negative or equivocal, or to assess degree of renal damage and guide prognosis.

Question 803: A 64-year-old woman presents to her primary care physician complaining of difficulty maintaining her balance while walking. Her husband comes along to the appointment with her, because he feels that she has not been acting herself at home lately. After further questioning him, it is noted that she has recently been voiding urine unintentionally at inappropriate times. If there is suspicion for an intracranial process, what would most likely be seen on MRI and what is the treatment?

A. Constricted ventricles; surgical resection
B. Dilated ventricles; ventricular shunt (Correct Answer)
C. Constricted ventricles; watch and wait
D. Dilated ventricles; surgical resection
E. Constricted ventricles; ventricular shunt

Explanation: **Dilated ventricles; ventricular shunt** - The patient's symptoms of **gait disturbance (difficulty maintaining balance)**, **cognitive decline (not acting herself)**, and **urinary incontinence** comprise the classic triad of **Normal Pressure Hydrocephalus (NPH)**. - NPH is characterized by **ventriculomegaly (dilated ventricles)** on imaging, despite normal cerebrospinal fluid (CSF) pressure, and is often treated with a **ventriculoperitoneal (VP) shunt** to drain excess CSF. *Constricted ventricles; surgical resection* - **Constricted ventricles** would indicate a reduction in ventricular size, which is not consistent with the clinical presentation of NPH or other conditions causing increased intracranial pressure leading to these symptoms. - **Surgical resection** is a treatment for tumors or other mass lesions, which would cause different symptom patterns and imaging findings; it is not a treatment for NPH. *Constricted ventricles; watch and wait* - As mentioned, **constricted ventricles** are not consistent with the clinical picture of NPH. - A **"watch and wait"** approach would be inappropriate for NPH, as symptoms are progressive and often treatable with shunting. *Dilated ventricles; surgical resection* - While **dilated ventricles** are characteristic of NPH, **surgical resection** is incorrect as it is not the treatment for this condition. - Surgical resection is primarily indicated for mass lesions and not for conditions involving CSF dynamics like NPH. *Constricted ventricles; ventricular shunt* - **Constricted ventricles** would rule out NPH, which is characterized by ventricular enlargement. - A **ventricular shunt** is used to drain CSF from dilated ventricles, so this treatment would be inappropriate for constricted ventricles.

Question 804: A 52-year-old woman presents with fatigue and pain of the proximal interphalangeal and metacarpophalangeal joints for the past 6 months. She also has knee and wrist pain that has been present for the past 2 months, with morning stiffness that improves over the course of the day. Physical examination is significant for subcutaneous nodules. Laboratory tests are significant for the following: Hemoglobin 12.5 g/dL Red blood cell count 4.9 x 106/µL White blood cell count 5,000/mm3 Platelet count 180,000/mm3 Coombs' test Negative C-reactive peptide (CRP) Elevated Erythrocyte sedimentation rate (ESR) Elevated Anti-cyclic citrullinated peptide antibody (anti-CCP antibody) Moderately positive Anti-nuclear antibody (ANA) Negative Rheumatoid factor (RF) Negative What is the most likely human leukocyte antigen (HLA) subtype associated with this disease?

A. HLA-B27
B. HLA-DR2
C. HLA-DQ2
D. HLA-DR4 (Correct Answer)
E. HLA-DR5

Explanation: ***HLA-DR4*** - The clinical presentation with **symmetrical polyarthritis** affecting small joints (PIP, MCP), morning stiffness, subcutaneous nodules, and elevated inflammatory markers (CRP, ESR) is highly suggestive of **rheumatoid arthritis (RA)**. - **HLA-DR4** is the **most strongly associated HLA subtype with rheumatoid arthritis**, particularly in populations of European descent, and often correlates with more severe disease. *HLA-B27* - **HLA-B27** is primarily associated with **seronegative spondyloarthropathies**, such as ankylosing spondylitis, reactive arthritis, and psoriatic arthritis, which have different clinical features than those presented. - The patient's symptoms (e.g., symmetrical small joint involvement, subcutaneous nodules) are inconsistent with the typical presentation of HLA-B27 associated diseases. *HLA-DR2* - **HLA-DR2** is associated with an increased risk of certain autoimmune diseases like **multiple sclerosis** and **narcolepsy**, but not primarily with rheumatoid arthritis. - While some HLA alleles can have weak associations, DR2 is not a significant genetic marker for RA. *HLA-DQ2* - **HLA-DQ2** is strongly associated with **celiac disease** and, to a lesser extent, type 1 diabetes. - There is no significant association between HLA-DQ2 and rheumatoid arthritis. *HLA-DR5* - **HLA-DR5** has been associated with certain autoimmune conditions such as **Hashimoto's thyroiditis** and some forms of uveitis. - It is not a primary genetic risk factor for rheumatoid arthritis, especially when compared to HLA-DR4.

Question 805: A 27-year-old woman presents to the emergency department for sudden, bilateral, painful loss of vision. She states that her symptoms started last night and have persisted until this morning. The patient has a past medical history of peripheral neuropathy which is currently treated with duloxetine and severe anxiety. Her temperature is 99.5°F (37.5°C), blood pressure is 100/60 mmHg, pulse is 100/min, respirations are 15/min, and oxygen saturation is 98% on room air. On physical exam, the patient demonstrates 4/5 strength in her upper and lower extremities with decreased sensation in her fingers bilaterally. Towards the end of the exam, the patient embarrassingly admits to having an episode of urinary incontinence the previous night. An MRI is obtained and is within normal limits. Which of the following represents the best next diagnostic step and its most likely result for this patient?

A. A lumbar puncture demonstrating oligoclonal bands (Correct Answer)
B. Urine toxicology panel demonstrating cocaine use
C. A repeat MRI 3 days later demonstrating periventricular lesions
D. A psychiatric evaluation revealing multiple acute life stressors
E. A high resolution CT demonstrating hyperdense lesions

Explanation: **A lumbar puncture demonstrating oligoclonal bands** - The patient's presentation with **sudden, bilateral, painful vision loss** (optic neuritis), **peripheral neuropathy**, **urinary incontinence**, and **fatigue** (implied by chronic anxiety and duloxetine use) is highly suggestive of **multiple sclerosis (MS)**. - A **normal initial MRI** does not rule out MS, especially if the lesions are small or in areas difficult to visualize initially. **Oligoclonal bands** in the CSF are a classic finding in MS, indicating intrathecal immunoglobulin production. *Urine toxicology panel demonstrating cocaine use* - While cocaine can cause various neurological symptoms, it typically wouldn't present with this specific constellation of **optic neuritis**, **peripheral neuropathy**, and **urinary incontinence**. - There are no direct indications in the patient's history or presentation (e.g., track marks, vasoconstriction) to strongly suspect cocaine use. *A repeat MRI 3 days later demonstrating periventricular lesions* - While a repeat MRI might eventually show lesions, especially considering the **dissemination in time and space** criteria for MS, waiting 3 days for MRI changes to appear isn't the *best next diagnostic step* given the acute symptoms. - A lumbar puncture can provide immediate biochemical evidence (oligoclonal bands) that would support an MS diagnosis even with no initial MRI findings, or equivocal MRI findings, which would lead to earlier treatment. *A psychiatric evaluation revealing multiple acute life stressors* - While the patient has a history of **severe anxiety** and takes duloxetine (an antidepressant), her symptoms (optic neuritis, neuropathy, incontinence) are **neurological deficits** that cannot be solely attributed to psychological factors. - While a psychiatric evaluation might be part of comprehensive care, it is not the *best next diagnostic step* to explain acute neurological symptoms. *A high resolution CT demonstrating hyperdense lesions* - **CT scans** are generally not the preferred imaging modality for early detection of MS lesions, as they are less sensitive than MRI for visualizing white matter plaques. - **Hyperdense lesions** on CT typically indicate hemorrhage or calcification, which is not consistent with the likely etiology of the patient's symptoms.

Question 806: A 70-year-old male patient comes into your office because of leg pain. The patient states that his calves have been hurting more and more over the last two months. The pain isn't present at rest, but the pain develops as the patient starts walking and exerting himself. He states that stopping to rest is the only thing that relieves the pain. Of note, the patient's medical history is significant for 30-pack-years of smoking, hypertension, hyperlipidemia, and a previous myocardial infarction status-post angioplasty and stent. On exam, the patient's lower legs (below knee) have glossy skin with loss of hair. The dorsalis pedis pulses are barely palpable bilaterally. Which of the following is the best initial therapy for this patient?

A. Cilostazol
B. Angioplasty and stenting
C. Clopidogrel
D. Arterial bypass surgery
E. Lifestyle modifications (Correct Answer)

Explanation: ***Lifestyle modifications*** - **Lifestyle modifications**, particularly **smoking cessation** and a supervised **exercise program**, are the cornerstone of initial therapy for **peripheral artery disease (PAD)**, especially in patients with intermittent claudication. - These interventions aim to improve collateral circulation, reduce cardiovascular risk, and improve exercise tolerance. *Cilostazol* - **Cilostazol** is a phosphodiesterase inhibitor used to treat **intermittent claudication** by improving blood flow and reducing symptoms. - However, it is typically reserved for patients whose symptoms do not improve with initial **lifestyle modifications**, making it a second-line therapy. *Angioplasty and stenting* - **Angioplasty and stenting** are **revascularization procedures** indicated for patients with more severe PAD or those whose claudication is refractory to conservative management and significantly impacts their quality of life. - They are not considered the best initial therapy, especially since the patient's symptoms, while bothersome, do not suggest immediate limb-threatening ischemia. *Clopidogrel* - **Clopidogrel** is an **antiplatelet medication** mainly used to reduce the risk of cardiovascular events (like MI or stroke) in patients with established **atherosclerotic disease**, including PAD. - While important for secondary prevention, it does not directly address the symptoms of intermittent claudication as effectively as exercise or cilostazol. *Arterial bypass surgery* - **Arterial bypass surgery** is a major **revascularization procedure** generally reserved for patients with **severe PAD**, critical limb ischemia (e.g., rest pain, non-healing ulcers, gangrene), or extensive arterial occlusions that are not amenable to less invasive interventions. - It carries significant risks and is not an appropriate initial treatment for this patient's presentation of intermittent claudication.

Question 807: A 62-year-old man presents to the emergency department with increased fatigue and changes in his vision. The patient states that for the past month he has felt abnormally tired, and today he noticed his vision was blurry. The patient also endorses increased sweating at night and new onset headaches. He states that he currently feels dizzy. The patient has a past medical history of diabetes and hypertension. His current medications include insulin, metformin, and lisinopril. His temperature is 99.5°F (37.5°C), blood pressure is 157/98 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Cardiopulmonary exam is within normal limits. HEENT exam reveals non-tender posterior and anterior chain lymphadenopathy. Abdominal exam reveals splenomegaly and hepatomegaly. There are large, non-tender palpable lymph nodes in the patient's inguinal region. Neurological exam is notable for decreased sensation in the patient's hands and feet. He also complains of a numb/tingling pain in his extremities that has been persistent during this time. Dermatologic exam is notable for multiple bruises on his upper and lower extremities. Which of the following is most likely to be abnormal in this patient?

A. Calcium
B. IgA and IgG
C. IgM (Correct Answer)
D. Natural killer cells
E. T-cells

Explanation: ***IgM*** - The patient's symptoms, including **fatigue**, **vision changes (blurry vision)**, **night sweats**, **headaches**, **dizziness**, **lymphadenopathy**, **hepatosplenomegaly**, **peripheral neuropathy** (decreased sensation, numb/tingling pain), and **easy bruising**, are highly suggestive of **Waldenström macroglobulinemia (WM)**. - WM is a **B-cell lymphoma** characterized by the overproduction of **monoclonal IgM paraprotein**, which can lead to **hyperviscosity syndrome** (causing vision changes, headaches, dizziness) and other systemic symptoms. *Calcium* - While hypercalcemia can be seen in some hematologic malignancies, it is **not a typical feature of Waldenström macroglobulinemia**. - **Multiple myeloma**, another plasma cell dyscrasia, is more commonly associated with hypercalcemia due to increased osteoclastic activity. *IgA and IgG* - **IgA and IgG myelomas** involve the overproduction of IgA and IgG antibodies, respectively, and present with different clinical features than described. - The constellation of symptoms in this patient, particularly the signs of hyperviscosity and a B-cell lymphoma affecting IgM production, does not align with these types of immunoglobulin abnormalities. *Natural killer cells* - Abnormalities in **natural killer (NK) cells** are typically associated with certain viral infections, autoimmune diseases, or specific NK cell lymphomas, which do not match the clinical picture. - While NK cells are part of the immune system, their primary role or dysfunction is not directly implicated in the presenting symptoms of Waldenström macroglobulinemia. *T-cells* - **T-cell lymphomas** involve the abnormal proliferation of T-lymphocytes and generally present with different clinical manifestations, such as skin lesions, lymphadenopathy, and organ infiltration. - The systemic symptoms, hyperviscosity, and specific organ involvement noted in this patient are more characteristic of a B-cell malignancy like Waldenström macroglobulinemia, not a primary T-cell disorder.

Question 808: A 27-year-old woman presents to your office complaining of difficulty swallowing, and she describes that "there is something in the back of her throat". Furthermore, she also feels an "achy" chest pain that has been getting progressively worse over the last few weeks. She denies having any fever, shortness of breath, cough, abdominal pain, heartburn, nausea, or vomiting. The patient has a history of wrist fracture as a child, migraines, and a recent diagnosis of myasthenia gravis. Which of the following is the most likely diagnosis?

A. Mediastinitis
B. Superior vena cava syndrome
C. Benign tumor of the thymus (Correct Answer)
D. Thyroglossal duct cyst
E. Anaplastic thyroid cancer

Explanation: ***Benign tumor of the thymus*** - The patient's history of **myasthenia gravis** is strongly associated with **thymic abnormalities**, including benign thymomas, which can cause symptoms like difficulty swallowing and chest pain by compressing surrounding structures. - The absence of fever, cough, or significant systemic symptoms makes infectious or more aggressive malignant processes less likely. *Mediastinitis* - This is an **inflammation of the mediastinum**, often accompanied by severe systemic symptoms such as **fever**, **chills**, and **profound malaise**, which are absent in this patient. - It usually follows chest trauma, surgery, or esophageal rupture and would present acutely with more severe, diffuse pain rather than localized esophageal symptoms. *Superior vena cava syndrome* - This syndrome is characterized by **venous congestion** of the head, neck, and upper extremities, leading to **facial swelling**, **dyspnea**, and possibly **distended neck veins**. - While it can cause chest discomfort, the primary symptoms presented (difficulty swallowing, foreign body sensation in the throat) are not typical of SVCS. *Thyroglossal duct cyst* - A thyroglossal duct cyst most commonly presents as a **midline neck mass** that moves with tongue protrusion. - Although it can cause dysphagia if very large, it does not typically cause chest pain or have a direct association with myasthenia gravis. *Anaplastic thyroid cancer* - This is a highly aggressive thyroid malignancy that usually presents with a **rapidly enlarging neck mass**, hoarseness, and significant airway obstruction. - It is typically seen in older individuals and would likely present with more acute and severe local compressive symptoms, including respiratory distress.

Question 809: A 67-year-old female presents to her primary care physician complaining of headaches in her left temple and scalp area, neck stiffness, occasional blurred vision, and pain in her jaw when chewing. The appropriate medical therapy is initiated, and a subsequent biopsy of the temporal artery reveals arteritis. Five months later, the patient returns to her physician with a complaint of weakness, leading to difficulty climbing stairs, rising from a chair, and combing her hair. The patient states that this weakness has worsened gradually over the last 2 months. She reports that her headaches, jaw pain, and visual disturbances have resolved. Physical examination is significant for 4/5 strength for both hip flexion/extension as well as shoulder flexion/extension/abduction. Initial laboratory work-up reveals ESR and creatine kinase levels within normal limits. Which of the following is the most likely diagnosis in this patient's current presentation?

A. Polymyalgia rheumatica
B. Mononeuritis multiplex
C. Polymyositis
D. Drug-induced myopathy (Correct Answer)
E. Dermatomyositis

Explanation: ***Drug-induced myopathy*** * **Glucocorticoid-induced myopathy** is a common consequence of long-term steroid therapy, often used in conditions like **giant cell arteritis**. * It typically presents with **proximal muscle weakness** (difficulty rising from a chair, climbing stairs, combing hair) and **normal creatine kinase (CK) levels**, differentiating it from inflammatory myopathies. *Polymyalgia rheumatica* * While often associated with **giant cell arteritis**, PMR primarily causes **pain and stiffness** in the shoulders, neck, and hips, rather than significant muscle weakness. * Patients with PMR exhibit **elevated ESR**, which is normal in this case. *Mononeuritis multiplex* * This condition involves **damage to two or more peripheral nerves**, typically presenting with **asymmetric weakness** and sensory deficits in specific nerve distributions. * It is not characterized by the **symmetrical proximal weakness** seen in this patient. *Polymyositis* * This is an **inflammatory myopathy** characterized by **proximal muscle weakness** and **elevated creatine kinase (CK) levels**. * The patient's **normal CK levels** and the history of steroid use make drug-induced myopathy more likely. *Dermatomyositis* * Similar to polymyositis, dermatomyositis is an **inflammatory myopathy** causing **proximal muscle weakness** and **elevated CK**. * It is distinguished by characteristic **skin rashes** (e.g., heliotrope rash, Gottron papules), which are absent in this patient.

Question 810: A 68-year-old male visits his primary care physician after an episode of syncope during a tennis match. He reports exertional dyspnea with mild substernal chest pain. On physical exam a systolic crescendo-decrescendo murmur is heard best at the right 2nd intercostal space. This murmur was not heard at the patient's last appointment six months ago. Which of the following would most support a diagnosis of aortic stenosis?

A. Asymmetric ventricular hypertrophy
B. Murmur radiates to axilla
C. Murmur radiates to carotid arteries bilaterally (Correct Answer)
D. Double pulsation of the carotid pulse
E. Presence of S3

Explanation: ***Murmur radiates to carotid arteries bilaterally*** - The **systolic crescendo-decrescendo murmur** heard best at the right 2nd intercostal space, along with radiation to the carotid arteries, is a classic finding in **aortic stenosis**. - This radiation pattern occurs because the turbulent blood flow through the narrowed aortic valve propagates into the great vessels of the neck. *Asymmetric ventricular hypertrophy* - **Asymmetric ventricular hypertrophy** (specifically of the interventricular septum) is characteristic of **hypertrophic obstructive cardiomyopathy (HOCM)**, not typically seen in aortic stenosis. - While left ventricular hypertrophy can occur in aortic stenosis due to chronic pressure overload, it is usually concentric and symmetrical, rather than asymmetric. *Murmur radiates to axilla* - A murmur radiating to the **axilla** is a hallmark feature of **mitral regurgitation**, due to the regurgitant jet targeting this area. - Aortic stenosis murmurs primarily radiate superiorly to the neck and sometimes to the apex, not the axilla. *Double pulsation of the carotid pulse* - A **double pulsation** (pulsus bisferiens) of the carotid pulse is often associated with **aortic regurgitation** complicating **hypertrophic cardiomyopathy** or **severe aortic stenosis** with significant regurgitation, resulting in a bifid pulse. - While it can be present, it is not as specific a diagnostic indicator for pure aortic stenosis as the typical radiation pattern of the murmur. *Presence of S3* - The presence of an **S3 gallop** typically indicates **left ventricular failure** due to volume overload, commonly seen in conditions like dilated cardiomyopathy or severe mitral/aortic regurgitation. - Although severe aortic stenosis can lead to heart failure, S3 is not a direct or specific finding for the *diagnosis* of aortic stenosis itself; it suggests a complication.

Question 811: A 43-year-old woman comes to the physician because of a 2-month history of chest pain. She describes the pain as intermittent and burning-like. She states that she has tried using proton pump inhibitors but has had no relief of her symptoms. She has had a 5-kg (11-lb) weight loss over the past 2 months. Her temperature is 36.7°C (98.1°F), pulse is 75/min, and blood pressure is 150/80 mm Hg. Examination shows tightness of the skin of the fingers; there are small nonhealing, nonpurulent ulcers over thickened skin on the fingertips. Fine inspiratory crackles are heard at both lung bases. There is mild tenderness to palpation of the epigastrium. Which of the following is most likely associated with her diagnosis?

A. Anti-Ro/SSA and anti-La/SSB antibodies
B. Anti-histone antibodies
C. Anti-topoisomerase antibodies (Correct Answer)
D. Anti-mitochondrial antibodies
E. c-ANCA

Explanation: ***Anti-topoisomerase antibodies*** - The patient's symptoms, including **skin tightening on fingers**, **non-healing fingertip ulcers**, and **inspiratory crackles (suggesting interstitial lung disease)**, are highly indicative of **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form. - **Anti-topoisomerase I (anti-Scl-70) antibodies** are strongly associated with **diffuse systemic sclerosis** and are often found in patients with significant organ involvement, including pulmonary fibrosis. *Anti-Ro/SSA and anti-La/SSB antibodies* - These antibodies are typically associated with **Sjogren's syndrome**, an autoimmune disorder primarily affecting exocrine glands. - While Sjogren's can present with dryness and joint pain, it does not typically cause **skin thickening**, **digital ulcers**, or the specific type of lung involvement seen here. *Anti-histone antibodies* - These are the hallmark antibodies for **drug-induced lupus**, which presents with symptoms similar to systemic lupus erythematosus (SLE) but resolves upon discontinuation of the causative drug. - The patient's symptoms are not consistent with lupus, and there is no mention of drug exposure. *Anti-mitochondrial antibodies* - These antibodies are highly specific for **primary biliary cholangitis (PBC)**, a chronic liver disease affecting the bile ducts. - While PBC can be associated with other autoimmune conditions, the primary symptoms presented in the patient (skin thickening, digital ulcers, pulmonary findings) are not characteristic of PBC. *c-ANCA* - **Cytoplasmic anti-neutrophil cytoplasmic antibodies (c-ANCA)** are primarily associated with **Granulomatosis with Polyangiitis (Wegener's)**, an autoimmune vasculitis affecting small- and medium-sized vessels. - This condition presents with upper and lower respiratory tract involvement and glomerulonephritis, which differs from the patient's presentation of skin thickening and specific lung findings.

Question 812: A 23-year-old man presents with increasing neck pain for several months that does not improve with nonsteroidal anti-inflammatory drugs. The patient says he has had neck pain ever since he was involved in a motor vehicle accident 10 months ago. For the last 2 weeks, he says he has also noticed weakness and numbness in his hands and has difficulty gripping objects. Physical examination reveals a thermal injury that he says he got while holding a hot cup of coffee a week ago when he could not feel the warmth of the coffee mug. Strength is 4/5 bilaterally during elbow flexion and extension and wrist extension. He also has exaggerated deep tendon reflexes bilaterally and decreased sensation symmetrically on the dorsal and ventral surface of both forearms and hands. Which of the following additional findings would you expect to find in this patient?

A. A cavitation in the cervical spinal cord (Correct Answer)
B. Bilateral carpal tunnel syndrome
C. Fusion of cervical vertebrae
D. Cervical spinal epidural abscess
E. Hypoplasia of the cerebellar vermis

Explanation: ***A cavitation in the cervical spinal cord*** - The patient's symptoms of **chronic neck pain**, **weakness and numbness in the hands**, **loss of pain and temperature sensation** (thermal injury from hot coffee), and **exaggerated deep tendon reflexes** ("upper motor neuron signs") are classic for **syringomyelia**, which involves a cavitation (syrinx) within the spinal cord. - The **motor vehicle accident (MVA) 10 months prior** could have led to a spinal cord injury, which is a common cause of secondary syringomyelia due to altered CSF flow. *Bilateral carpal tunnel syndrome* - While carpal tunnel syndrome causes **numbness and weakness in the hands**, it typically affects the **median nerve distribution** (thumb, index, middle, and radial half of ring finger) and does not explain the **thermal injury** due to loss of pain/temperature sensation or the **exaggerated deep tendon reflexes** (upper motor neuron signs). - Carpal tunnel syndrome primarily presents with **lower motor neuron signs** in the affected nerve distribution, not generalized hyperreflexia. *Fusion of cervical vertebrae* - **Cervical vertebral fusion** (e.g., Klippel-Feil syndrome) can cause neck pain and restricted range of motion but does not typically explain the acute onset of **sensory deficits (loss of pain/temperature)**, **weakness**, and **hyperreflexia** seen in this patient. - While some congenital fusions can predispose to spinal cord compression over time, the constellation of symptoms points more directly to a developing syrinx. *Cervical spinal epidural abscess* - An **epidural abscess** would likely present with more acute, severe, and rapidly progressive symptoms, including **fever**, **severe localized back/neck pain**, and signs of **infection**, none of which are mentioned here. - While it can cause neurological deficits, the subacute onset and specific sensory loss pattern are less typical for an abscess. *Hypoplasia of the cerebellar vermis* - **Cerebellar vermis hypoplasia** (e.g., Dandy-Walker malformation) primarily causes **ataxia**, **truncal instability**, and other **cerebellar signs**, often associated with hydrocephalus. - It does not explain the **localized cervical pain**, **hand weakness/numbness**, **thermal sensory loss**, and **upper motor neuron signs** in the limbs presented in this case.

Question 813: A 62-year-old woman presents to the office because she has noticed yellowish bumps and patches on her elbows and knees that seem to come and go. Recently she noticed the same yellow bumps on her eyelids. She is a new patient and reports that she is otherwise healthy but did not have insurance until recently so she has not been to the doctor in over 8 years. Past medical history is significant for occasional headaches that she treats with aspirin. She used to smoke a pack a day for the last 20 years but recently quit. Her father died of a heart attack at the age of 55 years and her mother had a stroke at 64 and lives in a nursing home. Her blood pressure is 135/87 mm Hg, the heart rate is 95/min, the respiratory rate is 12/min, and the temperature is 37.0°C (98.6°F). On physical exam, she has multiple tan-yellow, firm papules on her knees and elbows. The papules around her eyes are smaller and soft. You discuss the likely cause of the bumps and explain that you will need to order additional tests. What test should you perform?

A. Biopsy
B. Lipid panel (Correct Answer)
C. Celiac panel
D. PET scan
E. Erythrocyte sedimentation rate (ESR)

Explanation: ***Lipid panel*** - The yellowish bumps on elbows and knees (**tuberous/eruptive xanthomas**) and eyelids (**xanthelasma**) are pathognomonic for **dyslipidemia** (hypercholesterolemia or hypertriglyceridemia) - A **lipid panel** is the appropriate first-line test to measure total cholesterol, LDL, HDL, and triglycerides - Given her strong family history of premature cardiovascular disease (father died at 55 from MI), smoking history, and 8 years without medical care, screening for dyslipidemia is critical - Results will guide treatment decisions (statin therapy, lifestyle modifications) *Biopsy* - While biopsy could confirm lipid deposits histologically, it is unnecessarily invasive for classic xanthoma presentation - Reserved for atypical lesions when diagnosis is uncertain after initial blood work *Celiac panel* - Tests for celiac disease (anti-tissue transglutaminase antibodies) - No clinical indicators present (no diarrhea, malabsorption, weight loss, or GI symptoms) *PET scan* - Used primarily for cancer staging, neurological conditions, or cardiac viability assessment - Not indicated for evaluation of cutaneous lipid deposits - Expensive and exposes patient to unnecessary radiation *Erythrocyte sedimentation rate (ESR)* - Non-specific inflammatory marker for infections, autoimmune diseases, or malignancy - Patient's presentation is characteristic of metabolic/lipid disorder, not inflammatory disease - Would not provide diagnostic information for xanthomas

Question 814: A 55-year-old black male otherwise healthy presents for a yearly physical. No significant past medical history. Current medications are a multivitamin and rosuvastatin 20 mg orally daily. Vitals are temperature 37°C (98.6°F), blood pressure 155/75 mm Hg, pulse 95/min, respirations 16/min, and oxygen saturation 99% on room air. On physical examination, the patient is alert and cooperative. The cardiac exam is significant for a high-pitched diastolic murmur loudest at the left sternal border. Peripheral pulses are bounding and prominent followed by a quick collapse on palpation. Lungs are clear to auscultation. The abdomen is soft and nontender. Chest X-ray is normal. ECG is significant for left axis deviation and broad bifid P-waves in lead II. Transthoracic echocardiography shows a bicuspid aortic valve, severe aortic regurgitation, left atrial enlargement and left ventricular dilatation and hypertrophy. Left ventricular ejection fraction is 45%. Which of the following is the best course of treatment for this patient?

A. Outpatient management on nifedipine 45 mg orally daily
B. Reassurance and recommend long-term follow-up with outpatient cardiology for clinical surveillance with regular echocardiography
C. Outpatient management on enalapril 10 mg orally twice daily
D. Admit to hospital for aortic valve replacement (Correct Answer)
E. Administer dobutamine and nitroprusside

Explanation: ***Admit to hospital for aortic valve replacement*** - The patient presents with **severe aortic regurgitation** (AR) as evidenced by the high-pitched diastolic murmur, bounding peripheral pulses (Corrigan's pulse), and echocardiographic findings of **left atrial enlargement**, **left ventricular dilatation** and **hypertrophy**, and a **reduced left ventricular ejection fraction (LVEF) of 45%**. - Current guidelines recommend **aortic valve replacement (AVR)** for patients with severe AR who are symptomatic or have evidence of **LV dysfunction (LVEF < 50%)**, even if asymptomatic. *Outpatient management on nifedipine 45 mg orally daily* - **Nifedipine**, a dihydropyridine calcium channel blocker, is primarily used for **hypertension** and **angina**. - It is **not indicated** as a primary treatment for severe aortic regurgitation with LV dysfunction and would not address the underlying valve pathology. *Reassurance and recommend long-term follow-up with outpatient cardiology for clinical surveillance with regular echocardiography* - This approach is appropriate for **mild to moderate asymptomatic AR** with preserved LV function. - Given the patient's **severe AR** and **depressed LVEF (45%)**, active intervention with AVR is necessary, not just surveillance. *Outpatient management on enalapril 10 mg orally twice daily* - **Enalapril**, an ACE inhibitor, is beneficial for patients with **hypertension** and **heart failure with reduced ejection fraction**. - While it may help manage the patient's elevated blood pressure and provide afterload reduction, it does **not address the severe aortic regurgitation** and is not a substitute for valve replacement in this situation. *Administer dobutamine and nitroprusside* - **Dobutamine** is an inotropic agent used to increase cardiac contractility, typically in **acute decompensated heart failure** or **cardiogenic shock**. - **Nitroprusside** is a potent vasodilator used in **hypertensive emergencies** or to reduce afterload in acute heart failure; neither is a long-term solution for severe AR with chronic LV dysfunction requiring valve replacement.

Question 815: A 70-year-old man presented to the emergency department complaining of left-sided weakness for the past 5 hours. Past medical history is significant for a previous ischemic stroke involving the right posterior cerebral artery and left-sided homonymous hemianopia. He also has a history of type-II diabetes mellitus and hypertension. He takes an 81 mg aspirin, amlodipine, atorvastatin, and a vitamin supplement with calcium and vitamin D. A brain MRI reveals a small atrophic area of the left occipital lobe and a new acute infarct involving the territory of the right middle cerebral artery. Electrocardiogram (ECG) shows normal sinus rhythm. An echocardiogram reveals mild left ventricular hypertrophy with an ejection fraction of 55%. Doppler ultrasound of the carotid arteries reveals no significant narrowing. What is the next step in the management to prevent future risks of stroke?

A. Add dipyridamole (Correct Answer)
B. Add warfarin
C. Administer tPA
D. Increase aspirin to 325 mg
E. Stop aspirin and start warfarin

Explanation: ***Add dipyridamole*** - This patient has experienced a **recurrent ischemic stroke while on aspirin monotherapy**, indicating aspirin failure for secondary prevention. - **Dual antiplatelet therapy** with aspirin plus extended-release **dipyridamole** is a guideline-supported option for secondary prevention of non-cardioembolic ischemic stroke. - The **ESPS-2 and ESPRIT trials** demonstrated that aspirin-dipyridamole combination reduces recurrent stroke risk compared to aspirin alone. - **Note**: Current guidelines also support switching to clopidogrel or short-term dual therapy with aspirin-clopidogrel as alternative strategies, though clopidogrel is not offered as an option here. *Add warfarin* - **Warfarin** is an anticoagulant indicated for **cardioembolic stroke prevention**, particularly in patients with atrial fibrillation or other cardiac sources of embolism. - This patient has **normal sinus rhythm on ECG**, **no atrial fibrillation**, and a preserved ejection fraction (55%) with only mild LVH on echocardiogram. - The stroke mechanism appears to be **non-cardioembolic** (likely atherothrombotic or small vessel disease), making anticoagulation with warfarin inappropriate. *Administer tPA* - **Tissue plasminogen activator (tPA)** is an **acute thrombolytic therapy** for ischemic stroke, effective only within a narrow therapeutic window. - The standard window is **3-4.5 hours from symptom onset** in eligible patients. - This patient presented **5 hours after symptom onset**, placing him beyond the approved time window for tPA administration. *Increase aspirin to 325 mg* - There is **no evidence** that higher-dose aspirin (325 mg) is superior to low-dose aspirin (81 mg) for long-term secondary stroke prevention. - The **2021 AHA/ASA Guidelines** recommend aspirin doses of 50-325 mg daily, with lower doses (75-100 mg) preferred due to similar efficacy and better GI tolerability. - For patients with recurrent stroke on aspirin, **switching to or adding another antiplatelet agent** is more appropriate than simply increasing the aspirin dose. *Stop aspirin and start warfarin* - Switching to warfarin is **inappropriate** in this non-cardioembolic stroke context, as there is no identified cardiac source requiring anticoagulation. - This approach would **increase bleeding risk** without providing superior stroke prevention compared to appropriate antiplatelet therapy. - Warfarin is reserved for cardioembolic stroke prevention (e.g., atrial fibrillation, mechanical heart valves, left ventricular thrombus).

Question 816: A 45-year-old woman presents to the clinic for a routine examination. She has a chronic history of systemic lupus erythematosus, diagnosed at age 27. Medications include hydroxychloroquine and low-dose prednisone. She has had no recent flare-ups and is compliant with her medication. Anticardiolipin and anti-beta-2 glycoprotein-1 antibodies are negative, and she has had no history of thrombi or emboli. Physical examination is normal except for mild bilateral tenderness and swelling of the knees. Creatinine and GFR are normal. Which of the following is the next best step in management to monitor disease activity?

A. Anti-Smith antibody levels
B. Anti-dsDNA antibody levels (Correct Answer)
C. Urinalysis and renal biopsy
D. Reduce dosage and taper off hydroxychloroquine
E. Arthrocentesis and synovial fluid analysis

Explanation: ***Anti-dsDNA antibody levels*** - **Anti-dsDNA antibodies** correlate well with **disease activity** in SLE, especially with **lupus nephritis**, making them a useful marker for monitoring. - While her GFR is normal now, monitoring these antibodies can help detect early changes or increased risk of renal involvement. *Anti-Smith antibody levels* - **Anti-Smith antibodies** are highly specific for SLE but do not typically fluctuate with disease activity, so they are not useful for monitoring. - They are primarily used for diagnosis rather than follow-up. *Urinalysis and renal biopsy* - A **renal biopsy** is an invasive procedure and is not indicated at this time given her normal creatinine and GFR, and reported absence of recent flare-ups. - While **urinalysis** is important for monitoring, it is not the *next best step* to broadly assess systemic disease activity, and the question asks for monitoring disease activity, not just kidney function. *Reduce dosage and taper off hydroxychloroquine* - **Hydroxychloroquine** is a cornerstone of SLE management, even in quiescent disease, to prevent flares and organ damage. - Reducing its dosage without evidence of sustained remission or adverse effects is generally not recommended and could lead to a flare. *Arthrocentesis and synovial fluid analysis* - **Arthrocentesis** is a diagnostic procedure to identify the cause of joint effusion but is not a routine measure to monitor overall SLE disease activity. - Her mild knee tenderness and swelling could be part of her chronic SLE and does not automatically warrant an invasive joint procedure as the primary next step for overall disease monitoring.

Question 817: A 65-year-old man is brought to the emergency department by his wife because of progressive lethargy and confusion during the past 2 days. His wife reports that he has been complaining of nausea and increased urination for the past 5 days. He also developed a cough 1 week ago. He has a history of a cerebrovascular accident 3 years ago and was diagnosed with hypertension 10 years ago. Current medications include lisinopril and aspirin. His temperature is 38.5°C (101.3°F), pulse is 114/min, respirations are 15/min, and blood pressure is 108/75 mm Hg. He is somnolent and oriented only to person. Examination shows dry mucous membranes and decreased skin turgor. Crackles are heard at the left lung base. The remainder of the physical examination shows no abnormalities. Which of the following is the most appropriate next step in management?

A. Chest x-ray
B. Broad-spectrum antibiotics
C. Arterial blood gas analysis
D. Blood glucose measurement (Correct Answer)
E. Serum calcium measurement

Explanation: ***Blood glucose measurement*** - The patient's symptoms of **lethargy, confusion, nausea, increased urination, and dehydration** are highly suggestive of **hyperglycemia**, possibly diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS), especially in the setting of a recent infection (cough, fever). - Rapid determination of blood glucose levels is crucial for immediate diagnosis and initiation of appropriate treatment, which can be life-saving. *Chest x-ray* - While crackles at the lung base suggest **pneumonia**, a chest x-ray would confirm the diagnosis but is not the most immediate next step given the patient's severe neurological symptoms and signs of metabolic derangement. - Addressing the metabolic emergency (hyperglycemia) takes precedence for initial stabilization. *Broad-spectrum antibiotics* - The patient has signs of infection (cough, fever, crackles) and potential sepsis, making antibiotics important, but **uncontrolled hyperglycemia can mimic or worsen sepsis** and needs immediate attention. - Antibiotics should be considered after initial assessment and stabilization of immediate life threats, and often after obtaining cultures. *Arterial blood gas analysis* - An ABG would be useful to assess **acid-base status** in suspected DKA or lactic acidosis, but it is a more invasive and time-consuming test than a point-of-care blood glucose measurement. - Determining blood glucose will guide the urgency and interpretation of an ABG. *Serum calcium measurement* - While hypercalcemia can cause lethargy and confusion, the patient's symptoms of **polyuria** and **nausea** are also prominent in diabetic emergencies, and his past medical history does not strongly suggest hypercalcemia. - Blood glucose measurement is a more targeted and urgent test given the full constellation of symptoms.

Question 818: A 25-year-old female presents with recent muscle weakness, fatigue, and constipation. Physical examination reveals a bradycardic patient with cool, dry skin. Which of the following lab values would be most likely to be present with this patient's presentation?

A. Hypocalcemia
B. Elevated serum CK
C. Activating TSH-receptor immunoglobulins
D. Elevated serum calcitonin
E. Elevated serum TSH (Correct Answer)

Explanation: ***Elevated serum TSH*** - This patient presents with classic signs and symptoms of **primary hypothyroidism**: muscle weakness, fatigue, constipation, bradycardia, and cool, dry skin. - **Elevated TSH** is the hallmark laboratory finding in primary hypothyroidism, occurring in virtually all cases as the pituitary attempts to stimulate the underactive thyroid gland. - This is the **most likely** lab abnormality to be present and is the first-line diagnostic test for suspected hypothyroidism. *Elevated serum CK* - While **creatine kinase (CK)** can be elevated in hypothyroid myopathy due to muscle breakdown, this occurs in only 30-50% of hypothyroid patients. - It is a **secondary consequence** rather than a primary diagnostic finding, making it less likely to be present than elevated TSH. - CK elevation would not be the first test ordered in a patient with suspected hypothyroidism. *Activating TSH-receptor immunoglobulins* - These antibodies are characteristic of **Graves' disease**, which causes **hyperthyroidism**, not the hypothyroid symptoms presented. - The patient's **bradycardia**, **cool/dry skin**, and **constipation** are inconsistent with hyperthyroidism, which typically presents with tachycardia, warm/moist skin, and diarrhea. *Hypocalcemia* - While muscle weakness can occur with **hypocalcemia**, the constellation of findings including **fatigue**, **constipation**, **bradycardia**, and **cool, dry skin** do not point to a primary calcium disorder. - Hypocalcemia typically presents with perioral numbness, paresthesias, tetany, and positive Chvostek's/Trousseau's signs. *Elevated serum calcitonin* - An elevated **calcitonin** level is primarily associated with **medullary thyroid carcinoma**. - This condition does not explain the patient's constellation of symptoms, particularly the generalized hypothyroid signs and does not cause TSH-mediated thyroid dysfunction.

Question 819: A 65-year-old man comes to the physician because of fatigue and nausea for 1 week. Over the past six months, he has had to get up twice every night to urinate. Occasionally, he has had discomfort during urination. He has arterial hypertension. His father died of renal cell carcinoma. Current medications include ramipril. His temperature is 37.3°C (99.1°F), pulse is 88/min, and blood pressure is 124/78 mm Hg. The abdomen is soft and nontender. Cardiac and pulmonary examinations show no abnormalities. Rectal examination shows a symmetrically enlarged and smooth prostate. Serum studies show: Hemoglobin 14.9 g/dL Leukocyte count 7500/mm3 Platelet count 215,000/mm3 Serum Na+ 136 mEq/L Cl- 101 mEq/L K+ 4.9 mEq/L HCO3- 23 mEq/L Glucose 95 mg/dL Urea nitrogen 25 mg/dL Creatinine 1.9 mg/dL PSA 2.1 ng/mL (normal <4 ng/mL) Urine Blood negative Protein 1+ Glucose negative RBC casts negative Which of the following is the most appropriate next step in management?

A. Ureteral stenting
B. CT scan of the abdomen and pelvis
C. Renal ultrasonography (Correct Answer)
D. Four-glass test
E. Transrectal ultrasonography

Explanation: ***Renal ultrasonography*** - This patient presents with **fatigue**, **nausea**, and **nocturia**, along with elevated **creatinine** (1.9 mg/dL) and symptoms of lower urinary tract dysfunction (discomfort during urination, symmetrically enlarged prostate). These symptoms, particularly the elevated creatinine, suggest a possible **obstructive uropathy**. - Renal ultrasonography is the most appropriate initial imaging study to evaluate for **hydronephrosis**, which would confirm an obstructive process and help identify its level. This non-invasive test would also assess kidney size and cortical thickness. *Ureteral stenting* - Ureteral stenting is an **interventional procedure** to relieve ureteral obstruction. It is not a diagnostic step. - This procedure would be considered *after* an obstruction is confirmed and its cause is identified, not as the initial diagnostic step. *CT scan of the abdomen and pelvis* - A CT scan can provide more detailed anatomical information than an ultrasound but is generally reserved for situations where ultrasound is inconclusive or more detailed characterization of a mass or complex obstruction is required. - It involves **radiation exposure** and is typically not the first-line imaging modality for suspected urinary outflow obstruction due to its invasive nature. *Four-glass test* - The four-glass test is used to localize the site of **genitourinary infection** (urethritis, prostatitis, or cystitis) by analyzing urine and prostatic secretions. - While the patient has some urinary discomfort, his primary concern is **fatigue**, **nausea**, and **elevated creatinine**, which point towards renal dysfunction rather than a localized infection as the most immediate concern. *Transrectal ultrasonography* - **Transrectal ultrasonography (TRUS)** is primarily used to evaluate the prostate gland for conditions like prostate cancer or chronic prostatitis, and often guided biopsies. - While the patient has an enlarged prostate, his **PSA is normal** (2.1 ng/mL). The elevated creatinine and systemic symptoms indicate a need to assess the entire urinary tract for obstruction more broadly than just the prostate itself.

Question 820: A 33-year-old woman presents to the clinic complaining of a 9-month history of weight loss, fatigue, and a general sense of malaise. She additionally complains of an unusual sensation in her chest upon rapidly rising from a supine to a standing position. Current vitals include a temperature of 36.8°C (98.2°F), pulse of 72/min, blood pressure of 118/63 mm Hg, and a respiratory rate of 15/min. Her BMI is 21 kg/m2. Auscultation demonstrates an early-mid diastole low-pitched sound at the apex of the heart. A chest X-ray reveals a poorly demarcated abnormality in the heart and requires CT imaging for further analysis. What would most likely be seen on CT imaging?

A. Connection between the pulmonary artery and aorta
B. Fistula between the right and left atria
C. Normal cardiac imaging
D. Tumor within the right atrium
E. Tumor within the left atrium (Correct Answer)

Explanation: ***Tumor within the left atrium*** - The patient's symptoms of **weight loss, fatigue, malaise**, and **orthostatic symptoms** (unusual chest sensation upon rising) are classic for a **cardiac myxoma**, particularly one arising in the left atrium. - The auscultation finding of an **early-mid diastole low-pitched sound at the apex** (often called a "tumor plop") is highly suggestive of a left atrial myxoma prolapsing into the mitral valve orifice during diastole. *Tumor within the right atrium* - While cardiac myxomas can occur in the right atrium, left atrial myxomas are significantly more common (approximately 75% of cases). - A right atrial tumor would typically cause symptoms related to **right-sided heart failure** (e.g., peripheral edema, jugular venous distension) and would likely present with a different auscultatory finding, such as a right-sided "tumor plop" or tricuspid flow murmur. *Connection between the pulmonary artery and aorta* - This describes a **patent ductus arteriosus (PDA)**, a congenital heart defect. - A PDA typically presents with a **continuous "machinery-like" murmur** and symptoms like exertional dyspnea or failure to thrive, not the systemic symptoms or "tumor plop" described. *Fistula between the right and left atria* - This describes an **atrial septal defect (ASD)**. - ASDs typically cause a **fixed split S2** and can lead to right heart enlargement and pulmonary hypertension over time, but they do not cause a "tumor plop" or the constellation of systemic symptoms seen here. *Normal cardiac imaging* - Given the patient's clear symptoms, the suggestive auscultation finding, and an abnormal chest X-ray, it is highly unlikely that cardiac imaging would be normal. - The clinical picture strongly points to a structural cardiac abnormality, making normal imaging a very improbable finding.

Question 821: A 23-year-old woman presents to the emergency department with pain and frequent urination. She states she has felt uncomfortable with frequent small-volume urinary voids for the past 3 days, which have progressively worsened. The patient has no past medical history. She currently smokes 1 pack of cigarettes per day and engages in unprotected sex with 2 male partners. Her temperature is 103°F (39.4°C), blood pressure is 127/68 mmHg, pulse is 97/min, respirations are 17/min, and oxygen saturation is 98% on room air. Cardiac, pulmonary, and abdominal exams are within normal limits. There is tenderness upon palpation of the left costovertebral angle and the left flank. Urine is collected and a pregnancy test is negative. Which of the following is the best next step in management?

A. Ceftriaxone and hospital admission
B. Analgesics, encourage oral fluid intake, and discharge
C. Levofloxacin and outpatient follow-up (Correct Answer)
D. Abscess drainage and IV antibiotics
E. Nitrofurantoin

Explanation: ***Levofloxacin and outpatient follow-up*** - The patient presents with symptoms and signs consistent with **pyelonephritis**, including fever (103°F/39.4°C), flank pain (tenderness upon palpation of the left costovertebral angle and left flank), and urinary symptoms (frequent small-volume urinary voids). - Given her otherwise stable vitals, lack of severe comorbidities, and negative pregnancy test, **outpatient treatment with oral antibiotics** such as levofloxacin (a fluoroquinolone) is appropriate for uncomplicated pyelonephritis. *Ceftriaxone and hospital admission* - Uncomplicated pyelonephritis typically does not require hospital admission or intravenous antibiotics unless the patient is severely ill, unable to tolerate oral intake, or has complicating factors (e.g., pregnancy, urosepsis, underlying kidney disease). - While ceftriaxone is an effective antibiotic for pyelonephritis, it is typically used for initial parenteral treatment in hospitalized patients or those needing a single dose prior to oral agents. *Analgesics, encourage oral fluid intake, and discharge* - This approach is appropriate for mild, uncomplicated cystitis, not pyelonephritis, which is an upper urinary tract infection and carries a higher risk of systemic complications if not adequately treated with antibiotics. - Ignoring the infection and only managing symptoms would lead to worsening of the condition and potential complications. *Abscess drainage and IV antibiotics* - **Renal abscesses** are a potential complication of pyelonephritis but are not indicated by the initial presentation. This diagnosis typically requires imaging studies (e.g., CT scan) to confirm. - Abscess drainage would only be considered if an abscess were identified and contributing to treatment failure with antibiotics. *Nitrofurantoin* - Nitrofurantoin is primarily used for **uncomplicated cystitis** (bladder infection) as it achieves therapeutic concentrations in the bladder but not in the kidney tissue. - It is ineffective for pyelonephritis due to its poor penetration into renal parenchyma.

Question 822: A 47-year-old man with a history of diabetes mellitus presents for a primary care visit. His diabetes is well controlled on metformin, with fasting glucose concentrations between 110–150 mg/dl. His blood pressure on multiple office visits are between 115-130/75-85 mmHg. Today his temperature is 98°F (36.7 °C), blood pressure is 125/80 mmHg, pulse is 86/min, and respirations are 15/min. Labs are obtained with the following results: Hemoglobin A1c: 6.7% Glucose: 120 mg/dl Cholesterol (plasma): 190 mg/dL Urine albumin: 60mg/24hr Which of the following treatments is effective in slowing the progression of the most likely cause of this patient's abnormal albumin result?

A. No effective treatments
B. Aspirin
C. Metformin
D. Enalapril (Correct Answer)
E. Simvastatin

Explanation: ***Enalapril*** - The patient's urine albumin of **60 mg/24hr** indicates **microalbuminuria**, a sign of early **diabetic nephropathy**. Enalapril, an **ACE inhibitor**, is effective in slowing its progression by reducing intraglomerular pressure and proteinuria. - **ACE inhibitors** are first-line agents in diabetic patients with microalbuminuria due to their **renoprotective effects**, independent of blood pressure control. *No effective treatments* - This is incorrect as **ACE inhibitors** (like enalapril) and **ARBs** are well-established treatments for slowing the progression of diabetic nephropathy once microalbuminuria is present. - While complete reversal may not always occur, these medications significantly mitigate kidney damage and reduce the risk of progressing to **macroalbuminuria** and **end-stage renal disease**. *Aspirin* - **Aspirin** is used for primary or secondary prevention of **cardiovascular events**, but it does not directly treat or slow the progression of **diabetic nephropathy** or microalbuminuria. - Its role in diabetes is primarily related to its **antiplatelet effects** in patients at high cardiovascular risk. *Metformin* - **Metformin** is an **oral hypoglycemic** agent used to control **blood glucose levels** in type 2 diabetes. While good glycemic control is crucial for preventing diabetic complications, metformin itself does not directly treat or slow the progression of existing **diabetic nephropathy**. - Its primary action is to reduce **hepatic glucose production** and improve **insulin sensitivity**, thereby lowering blood sugar. *Simvastatin* - **Simvastatin** is a **lipid-lowering agent** (statin) used to manage **dyslipidemia** and reduce cardiovascular risk. It does not directly impact the progression of **diabetic nephropathy** or microalbuminuria. - While managing cholesterol is important for overall cardiovascular health in diabetic patients, it is not the primary treatment for **albuminuria**.

Question 823: A 45-year-old chronic smoker presents to the physician with a complaint of worsening left shoulder pain for several months which has become acutely worse the past 2 weeks and now radiates down his left arm. Physical examination reveals a palpable 2 x 1.5 cm supraclavicular lymph node along with decreased grip strength in his left hand. Examination of the face reveals partial ptosis of the left eyelid and miosis of the left eye. Laboratory testing shows the following values: Sodium (Na+) 135 mEq/L Potassium (K+) 3.6 mEq/L Chloride (Cl-) 100 mEq/L BUN 12 mg/dL Creatinine (Cr) 0.6 mg/dL Magnesium (Mg2+) 1.5 mg/dL Phosphate 3 mg/dL Calcium (Ca2+) 8.5 mg/dL An X-ray of the chest reveals a soft tissue mass at the apex of the left lung with possible involvement of the first rib. What is the most likely diagnosis?

A. Mesothelioma
B. Pancoast tumor (Correct Answer)
C. Pulmonary hamartoma
D. Subclavian aneurysm
E. Osteophyte

Explanation: **Pancoast tumor** - The patient presents with **shoulder pain**, **Horner's syndrome** (ptosis, miosis), **lymph node involvement**, **decreased grip strength** (due to brachial plexus involvement), and a **mass at the lung apex on X-ray**. These are classic signs of a Pancoast tumor, a type of **non-small cell lung cancer** often seen in **chronic smokers**. - The location of the tumor at the **lung apex** allows it to invade surrounding structures such as the **brachial plexus** (causing arm pain and weakness), adjacent ribs, vertebrae, and the **sympathetic chain** (leading to Horner's syndrome). *Mesothelioma* - **Mesothelioma** is a rare and aggressive cancer primarily associated with **asbestos exposure**, not typically presenting as an apical lung mass. - It usually affects the **pleura** and can cause shortness of breath and chest pain, but not specifically the constellation of symptoms observed here. *Pulmonary hamartoma* - A **pulmonary hamartoma** is a benign lung tumor that is typically **asymptomatic** and discovered incidentally. - It does not typically cause symptoms such as **Horner's syndrome**, **shoulder pain**, or **lymphadenopathy** as described in the patient's presentation. *Subclavian aneurysm* - A **subclavian aneurysm** could cause arm pain due to nerve compression or embolization, but it would not explain the **lung mass**, **Horner's syndrome**, or **supraclavicular lymph node** found in this patient. - It is a vascular abnormality, not a primary lung lesion. *Osteophyte* - An **osteophyte**, or bone spur, is a bony outgrowth typically associated with **osteoarthritis** and can cause pain due to nerve compression or joint impingement. - While it can cause arm pain, it does not explain the **lung mass**, **Horner's syndrome**, or **lymph node involvement** seen in this case.

Question 824: A 33-year-old Honduran woman presents to your clinic with shortness of breath. She reports that her symptoms have progressed over the past several months and are now impacting her quality of life because she cannot complete her usual exercise routine. She recalls "normal" childhood illnesses, including sore throats and fevers, but never required hospitalization. Vital signs are temperature 37 degrees Celsius, blood pressure 110/70 mm Hg, heart rate 109/min, respiratory rate 22/min, and oxygen saturation 98% on room air. Physical exam reveals a holosystolic, high-pitched, blowing murmur at the cardiac apex. One would expect that this murmur would also:

A. Also have a mid-systolic click loudest at S2
B. Increase with inspiration
C. Radiate to the neck
D. Have a characteristic machine-like sound
E. Increase with squatting or handgrip (Correct Answer)

Explanation: ***Increase with squatting or handgrip*** - The patient's symptoms (shortness of breath, history of repeated sore throats, and a **holosystolic, high-pitched, blowing murmur at the cardiac apex**) are highly suggestive of **mitral regurgitation**, likely due to **rheumatic heart disease**. - **Dynamic maneuvers** like **squatting** (increases preload and afterload) and **handgrip** (increases afterload) will **increase the intensity** of the murmur in mitral regurgitation as they increase left ventricular volume and pressure. *Also have a mid-systolic click loudest at S2* - A **mid-systolic click** followed by a late systolic murmur is characteristic of **mitral valve prolapse**, not typically severe mitral regurgitation. - The description of a **holosystolic murmur** at the apex does not fit the timing and quality of a mitral valve prolapse murmur. *Increase with inspiration* - Murmurs that typically **increase with inspiration** are those originating from the **right side of the heart**, such as tricuspid regurgitation. - A mitral regurgitation murmur, originating from the left side, is generally **unaffected or slightly decreased** by inspiration. *Radiate to the neck* - Murmurs that classically **radiate to the neck** are those of **aortic stenosis**, due to the turbulent flow ejecting into the carotid arteries. - Mitral regurgitation typically **radiates to the axilla** or left sternal border, not the neck. *Have a characteristic machine-like sound* - A **continuous, machinery-like murmur** is the classic description of a **patent ductus arteriosus (PDA)**. - This murmur is typically heard in congenital heart disease and is distinct from the holosystolic murmur of mitral regurgitation.

Question 825: A 32-year-old man comes to the emergency department because of worsening shortness of breath and a productive cough for 3 days. He sustained trauma to the right hemithorax during a fight 3 weeks ago. He had significant pain and mild shortness of breath following the incident but did not seek medical care. He does not smoke or drink alcohol. He is a construction worker. His temperature is 38.4°C (101.1°F), pulse is 95/min, respirations are 18/min, and blood pressure is 120/75 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Pulmonary examination shows decreased breath sounds over the right lower lung fields. CT scan of the chest shows fractures of the right 7th and 8th ribs, right pleural splitting and thickening, and a dense fluid collection in the pleural space. Which of the following is the most likely diagnosis?

A. Chylothorax
B. Mesothelioma
C. Lung abscess
D. Viral pleurisy
E. Pleural empyema (Correct Answer)

Explanation: ***Pleural empyema*** - The patient's history of **chest trauma** with **rib fractures** followed by a febrile illness, **productive cough**, and a **dense fluid collection with pleural thickening and splitting** on CT is highly suggestive of a pleural empyema. - Chest trauma can lead to the formation of a **hemothorax**, which, if not drained, can become infected and progress to an empyema. *Chylothorax* - Characterized by the accumulation of **lymph fluid** in the pleural space, typically caused by disruption of the **thoracic duct**. - While trauma can cause chylothorax, the presence of **fever**, **productive cough**, and a "dense" fluid collection (implying pus) makes empyema more likely. *Mesothelioma* - A rare and aggressive cancer associated with **asbestos exposure**, typically occurring decades after exposure. - Presents with chronic symptoms like chest pain, dyspnea, and weight loss, and usually involves a **nodular pleural thickening** rather than a dense fluid collection. *Lung abscess* - A localized area of **suppurative necrosis** within the lung parenchyma, often with a cavity containing pus. - While it can cause fever and productive cough, the CT findings describe a **pleural effusion** with thickening and splitting, indicating involvement of the pleural space, not exclusively the lung parenchyma. *Viral pleurisy* - Inflammation of the pleura due to a viral infection, causing **pleuritic chest pain** and sometimes a small, self-resolving effusion. - It would not typically present with a **dense fluid collection**, significant pleural thickening, or a purulent cough as described.

Question 826: A 23-year-old man comes to the emergency department for 2 days of severe headaches. The pain is most intense on his left forehead and eye. He had similar symptoms last summer. He has been taking indomethacin every 6 hours for the last 24 hours but has not had any relief. He has smoked 1 pack of cigarettes daily for the past 5 years. He works as an accountant and describes his work as very stressful. Physical examination shows drooping of the left eyelid, tearing of the left eye, and rhinorrhea. The left pupil is 2 mm and the right pupil is 4 mm. There is localized tenderness along the right supraspinatus muscle. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Giant cell arteritis
B. Medication overuse headache
C. Tension headache
D. Cluster headache (Correct Answer)
E. Trigeminal neuralgia

Explanation: ***Cluster headache*** - This patient presents with **recurrent, unilateral, severe headaches** localized to the forehead and eye, accompanied by **autonomic symptoms** (miosis of the left pupil, left eyelid drooping, tearing, rhinorrhea), which are classic features of cluster headache. - The episodic nature (similar symptoms last summer), lack of response to NSAIDs like indomethacin, and presentation in a young male (more common in men) further support this diagnosis. *Giant cell arteritis* - This typically affects **older individuals (usually >50 years old)** and is associated with systemic symptoms like jaw claudication, visual disturbances, and tenderness over the temporal artery. - The patient's age (23 years old) and absence of these specific symptoms make giant cell arteritis unlikely. *Medication overuse headache* - This condition arises from the **frequent and excessive use of acute headache medications** and presents as a chronic daily headache, often diffuse and lacking specific autonomic features. - While the patient has been taking indomethacin, his symptoms are episodic and highly characteristic of a primary headache disorder, not solely due to medication overuse. *Tension headache* - Tension headaches are typically described as a **bilateral, pressing, or tightening pain** of mild to moderate intensity, often without associated autonomic symptoms. - The unilateral, severe, piercing pain and prominent autonomic features in this case are inconsistent with a tension headache. *Trigeminal neuralgia* - This condition causes **brief, intense, shock-like pain episodes** in the distribution of one or more branches of the trigeminal nerve, often triggered by touch, chewing, or talking. - The patient's continuous severe headache with autonomic features is distinct from the lancinating pain of trigeminal neuralgia.

Question 827: A 22-year-old patient presents to the rural medicine clinic for a physical examination. She has a past medical history of major depressive disorder. The patient has a history of smoking 1 pack of cigarettes daily for 5 years. She states that she is not currently sexually active, but had sexual intercourse in the past. Her paternal grandfather died of a heart attack at the age of 60. She takes citalopram by mouth once every morning. The blood pressure is 110/70 mm Hg, the heart rate is 76/min, and the respiratory rate is 12/min. Her physical examination reveals a well-nourished, alert, and oriented female. While auscultating the heart, a 2/6 holosystolic murmur at the left upper sternal border is present. Which of the following would be the most appropriate next step for this patient?

A. Reassurance and follow up in 6 months
B. Observation and reassurance
C. Echocardiogram (Correct Answer)
D. Electrocardiogram
E. Referral to cardiology

Explanation: ***Echocardiogram*** - A **holosystolic murmur** at the **left upper sternal border** in a young patient warrants further investigation to rule out potential cardiac abnormalities that could lead to heart failure or pulmonary hypertension later in life. - An **echocardiogram** is the definitive diagnostic tool to visualize cardiac structures, assess valve function, and identify the cause of the murmur. *Reassurance and follow up in 6 months* - Reassurance alone is inappropriate as a systolic murmur, especially one described as 2/6, should be further evaluated to determine its etiology. - Delaying investigation could miss a significant cardiac condition that could worsen over time. *Observation and reassurance* - While some murmurs are benign, a **holosystolic murmur** is often indicative of a structural issue requiring definitive diagnosis rather than just observation. - This approach is insufficient given the potential for underlying pathology. *Electrocardiogram* - An **ECG** can detect electrical abnormalities, arrhythmias, or chamber enlargement but does not provide direct information about valve function or structural heart defects causing a murmur. - It is often a complementary test but not the primary diagnostic test for a murmur. *Referral to cardiology* - While a referral to cardiology may be necessary, especially if the echocardiogram reveals a significant issue, the immediate next step is to obtain diagnostic imaging to inform the cardiologist's assessment. - An **echocardiogram** is typically performed first or ordered by the primary care physician before a referral, depending on local practice and urgency.

Question 828: An x-ray of the chest shows an extensive consolidation within the right lower lobe consistent with lobar pneumonia. Sputum and blood cultures are sent to the laboratory for analysis, and empiric antibiotic treatment with intravenous cefotaxime is begun. Which of the following is most likely to have prevented this patient's pneumonia?

A. Rapid sequence induction
B. Prolonged bed rest
C. Smoking cessation
D. Perioperative antibiotic prophylaxis
E. Incentive spirometry (Correct Answer)

Explanation: ***Incentive spirometry*** - **Incentive spirometry** encourages deep breathing and helps prevent **atelectasis** and **pneumonia**, especially in postoperative or immobilized patients. - It improves **lung volume** and promotes the clearance of respiratory secretions. - This is the **most direct preventive measure** in the immediate perioperative or hospitalization period to reduce risk of hospital-acquired pneumonia. *Rapid sequence induction* - **Rapid sequence intubation** is a procedure used to quickly and safely secure the airway, reducing the risk of **aspiration** during intubation. - While it may prevent aspiration pneumonia specifically, it does not prevent lobar pneumonia from other causes and is not a prophylactic measure against general hospital-acquired pneumonia. *Prolonged bed rest* - **Prolonged bed rest** actually **increases** the risk of developing **pneumonia** and **atelectasis** due to reduced lung expansion and impaired clearance of secretions. - It leads to hypoventilation in dependent lung areas and can worsen respiratory function. *Smoking cessation* - While **smoking cessation** does help prevent pneumonia by improving mucociliary clearance and reducing susceptibility to respiratory infections, it is a **long-term preventive measure** rather than an immediate intervention. - In the context of **preventing postoperative or hospital-acquired pneumonia**, smoking cessation would need to occur well before hospitalization to have significant effect. - **Incentive spirometry** provides more immediate protection in the acute hospital setting. *Perioperative antibiotic prophylaxis* - **Perioperative antibiotic prophylaxis** is designed to prevent **surgical site infections**, not hospital-acquired pneumonia. - It targets specific bacteria associated with the surgical procedure and wound contamination, not general respiratory pathogens causing lobar pneumonia. - Routine antibiotic prophylaxis does not cover typical pneumonia pathogens unless specifically indicated.

Question 829: A 74-year-old African-American woman is brought to the emergency department by her home health aid. The patient was eating breakfast this morning when she suddenly was unable to lift her spoon with her right hand. She attempted to get up from the table, but her right leg felt weak. One hour later in the emergency department, her strength is 0/5 in the right upper and right lower extremities. Strength is normal in her left upper and lower extremities. Sensation is normal bilaterally. An emergency CT of the head does not show signs of hemorrhage. Subsequent brain MRI shows an infarct involving the internal capsule. Which of the following is true about her disease process?

A. The most common cause is embolism originating from the left atrium
B. IV thrombolysis cannot be used
C. The most important risk factors are ethnicity and sex
D. The most important risk factors are hypertension and diabetes (Correct Answer)
E. It is caused by ischemia to watershed areas

Explanation: ***The most important risk factors are hypertension and diabetes*** - The patient experienced a **lacunar stroke** due to damage to the **internal capsule**, which is typically caused by **small vessel disease**. - **Hypertension** and **diabetes** are the leading risk factors for **small vessel disease** and subsequent lacunar strokes. *The most common cause is embolism originating from the left atrium* - While **cardioembolic strokes** can occur, they more commonly affect larger cerebral arteries and result in cortical deficits, not typically isolated pure motor hemiparesis from internal capsule infarction. - The sudden onset of symptoms followed by isolated motor weakness without other cortical signs (like aphasia or neglect) makes a lacunar stroke more likely than an embolic stroke from the left atrium. *IV thrombolysis cannot be used* - **IV thrombolysis** (e.g., alteplase) can be used for **acute ischemic stroke** if administered within the appropriate time window (typically 4.5 hours from symptom onset) and if there are no contraindications. - The fact that the patient's symptoms started one hour prior to ED arrival means she would likely be within the window for potential thrombolysis, assuming no contraindications. *The most important risk factors are ethnicity and sex* - While race (African-American) and sex (female) can influence stroke risk, **modifiable risk factors** like **hypertension** and **diabetes** are much more significant and directly targetable for prevention and management in this context. - These demographic factors alone do not explain the pathophysiology of a lacunar stroke. *It is caused by ischemia to watershed areas* - **Watershed infarcts** occur in areas supplied by the most distal branches of two major arterial territories, often due to significant **hypoperfusion** (e.g., severe hypotension). - An infarct in the **internal capsule** suggests a small perforating artery occlusion, characteristic of a lacunar stroke, rather than a watershed infarct.

Question 830: A 68-year-old man is admitted to the intensive care unit after open abdominal aortic aneurysm repair. The patient has received 4 units of packed red blood cells during the surgery. During the first 24 hours following the procedure, he has only passed 200 mL of urine. He has congestive heart failure and hypertension. Current medications include atenolol, enalapril, and spironolactone. He appears ill. His temperature is 37.1°C (98.8°F), pulse is 110/min, respirations are 18/min, and blood pressure is 110/78 mm Hg. Examination shows dry mucous membranes and flat neck veins. The remainder of the examination shows no abnormalities. Laboratory studies show a serum creatinine level of 2.0 mg/dL and a BUN of 48 mg/dL. His serum creatinine and BUN on admission were 1.2 mg/dL and 18 mg/dL, respectively. Further evaluation of this patient is most likely to reveal which of the following findings?

A. Hematuria
B. Low urine sodium (Correct Answer)
C. Leukocyte casts
D. Decreased urine osmolarity
E. Proteinuria

Explanation: ***Low urine sodium*** - The patient's presentation with **oliguria** (200 mL urine in 24 hours), **acute kidney injury** (creatinine rise from 1.2 to 2.0 mg/dL, BUN from 18 to 48 mg/dL), and signs of **hypovolemia** (dry mucous membranes, flat neck veins, tachycardia, borderline hypotension) after major surgery and significant blood loss suggests **prerenal azotemia**. - In **prerenal azotemia**, the kidneys attempt to conserve sodium and water due to decreased renal perfusion, leading to a **low urine sodium concentration** (typically <20 mEq/L) and a low fractional excretion of sodium (FeNa <1%). *Hematuria* - **Hematuria** (blood in urine) is typically associated with intrinsic kidney diseases, urinary tract infections, kidney stones, or trauma, and is not a primary feature of prerenal azotemia. - While packed red blood cell transfusion occurred, this would not directly cause hematuria in the patient's own urine. *Leukocyte casts* - **Leukocyte casts** are indicative of **interstitial nephritis** or **pyelonephritis**, which are intrinsic kidney diseases characterized by inflammation and infection, respectively. - These findings are not consistent with the clinical picture of prerenal azotemia caused by hypoperfusion. *Decreased urine osmolarity* - In **prerenal azotemia**, the kidneys actively reabsorb water to compensate for hypovolemia, resulting in the production of **concentrated urine** with a **high urine osmolality** (typically >500 mOsm/kg). - **Decreased urine osmolarity** would suggest an inability to concentrate urine, which is seen in conditions like diabetes insipidus or severe intrinsic renal failure, not prerenal azotemia. *Proteinuria* - **Proteinuria** is characteristic of **glomerular damage** (e.g., glomerulonephritis) or sometimes tubular dysfunction, which are intrinsic kidney disorders. - While some minimal proteinuria can occur with any kidney injury, significant proteinuria is not a hallmark of prerenal azotemia caused by hypovolemia.

Question 831: A 15-year-old girl is hospitalized because of increased fatigue and weight loss over the past 2 months. The patient has no personal or family history of a serious illness. She takes no medications, currently. Her blood pressure is 175/74 mm Hg on the left arm and 90/45 on the right. The radial pulse is 84/min but weaker on the right side. The femoral blood pressure and pulses show no abnormalities. Temperature is 38.1℃ (100.6℉). The muscles over the right upper arm are slightly atrophic. The remainder of the examination reveals no abnormalities. Laboratory studies show the following results: Hemoglobin 10.4 g/dL Leukocyte count 5,000/mm3 Erythrocyte sedimentation rate 58 mm/h Magnetic resonance arteriography reveals irregularity, stenosis, and poststenotic dilation involving the proximal right subclavian artery. Prednisone is initiated with improvement of her symptoms. Which of the following is the most appropriate next step in the patient management?

A. Perform angioplasty of subclavian artery stenosis
B. Add cyclophosphamide for severe disease
C. Initiate antihypertensive therapy with ACE inhibitor
D. Monitor ESR and adjust prednisone dosage (Correct Answer)
E. Add methotrexate as steroid-sparing agent

Explanation: ***Monitor ESR and adjust prednisone dosage*** - The patient's presentation with **fatigue, weight loss, differential blood pressures, weak radial pulse**, elevated ESR, and subclavian artery stenosis is highly suggestive of **Takayasu arteritis**. - **Prednisone is the initial treatment** for Takayasu arteritis, and disease activity is monitored by clinical symptoms and inflammatory markers like **ESR**; thus, monitoring ESR and adjusting the dosage is appropriate. *Perform angioplasty of subclavian artery stenosis* - While there is **subclavian artery stenosis**, revascularization procedures like angioplasty are typically considered only **after 2-3 months of medical therapy** has failed to control inflammation and symptoms, or if there is critical ischemia. - Doing so acutely, while inflammation is still active, carries a **higher risk of restenosis** and complications. *Add cyclophosphamide for severe disease* - Cyclophosphamide is a strong immunosuppressant often reserved for **severe, refractory cases** or disease with critical organ involvement, or when patients fail to respond to less aggressive treatments. - The initial step is to optimize steroid therapy and assess response, as the patient has already shown some improvement with prednisone. *Initiate antihypertensive therapy with ACE inhibitor* - The elevated blood pressure is likely a consequence of the underlying **vasculitis affecting renal arteries** or aorta, or differential readings due to subclavian stenosis. - Addressing the underlying **inflammation with steroids is the primary treatment** for hypertension in Takayasu arteritis; adding antihypertensives might be considered later if hypertension persists despite inflammation control. *Add methotrexate as steroid-sparing agent* - **Methotrexate is a steroid-sparing agent** commonly used in Takayasu arteritis, particularly if patients cannot be tapered off steroids or experience significant side effects. - However, the immediate next step after initiating prednisone and seeing improvement is to **monitor disease activity** and adjust the prednisone dose before adding a second-line agent.

Question 832: A 37-year-old woman accompanied by her husband presents to the emergency department after loss of consciousness 30 minutes ago. The husband reports that she was sitting in a chair at home and began having sustained rhythmic contractions of all 4 extremities for approximately 1 minute. During transport via ambulance she appeared confused but arousable. Her husband reports she has no medical conditions, but for the past 2 months she has occasionally complained of episodes of sweating, palpitations, and anxiety. Her brother has epilepsy and her mother has type 1 diabetes mellitus. Laboratory studies obtained in the emergency department demonstrate the following: Serum: Na+: 136 mEq/L K+: 3.8 mEq/L Cl-: 100 mEq/L HCO3-: 19 mEq/L BUN: 16 mg/dL Creatinine: 0.9 mg/dL Glucose: 54 mg/dL C-peptide: Low Which of the following is the most likely diagnosis?

A. Beta cell tumor
B. Surreptitious insulin use (Correct Answer)
C. Diabetic ketoacidosis
D. Surreptitious sulfonylurea use
E. Alpha cell tumor

Explanation: ***Surreptitious insulin use*** - The patient presents with **hypoglycemia** (glucose 54 mg/dL) and symptoms consistent with **neuroglycopenia** (loss of consciousness, confusion, sustained rhythmic contractions similar to seizures). The **low C-peptide** in the presence of hypoglycemia strongly indicates exogenous insulin administration, as C-peptide is co-secreted with endogenous insulin. - The reported past episodes of **sweating, palpitations, and anxiety** are classic symptoms of **adrenergic response to hypoglycemia**, further supporting a diagnosis of recurrent hypoglycemic events. *Beta cell tumor* - A beta cell tumor (insulinoma) would also cause **hypoglycemia** (neuroglycopenia) and symptoms like sweating, palpitations, and anxiety. - However, an insulinoma would typically result in inappropriately **high C-peptide** levels during hypoglycemia, as the tumor produces both insulin and C-peptide endogenously. *Diabetic ketoacidosis* - **Diabetic ketoacidosis (DKA)** is characterized by **hyperglycemia**, **ketonemia**, and **metabolic acidosis**, which is the exact opposite of the patient's presentation of hypoglycemia. - While the patient's mother has type 1 diabetes, this patient does not exhibit any signs of DKA. *Surreptitious sulfonylurea use* - Sulfonylurea use would lead to **hypoglycemia** by stimulating insulin release from pancreatic beta cells. - This would result in **high C-peptide** levels during hypoglycemia, similar to an insulinoma, differentiating it from exogenous insulin use. *Alpha cell tumor* - **Alpha cell tumors (glucagonomas)** produce **excess glucagon**, which would lead to **hyperglycemia**, not hypoglycemia. - Symptoms typically associated with glucagonomas include necrolytic migratory erythema, diabetes, weight loss, and diarrhea, which are not present in this case.

Question 833: A 26-year-old man presents to his primary care physician complaining of impotence. He reports that he has a healthy, long-term relationship with a woman whom he hopes to marry, but he is embarrassed that he is unable to have an erection. Which of the following is the next best step?

A. Obtain a sperm sample
B. Prescribe sildenafil
C. Evaluate nocturnal tumescence (Correct Answer)
D. Duplex penile ultrasound
E. Prescribe vardenafil

Explanation: **Evaluate nocturnal tumescence** - Evaluating **nocturnal penile tumescence (NPT)** helps differentiate between **organic** and **psychogenic** erectile dysfunction (ED). - The presence of nocturnal erections indicates **intact physiological mechanisms**, suggesting a **psychogenic cause** of ED rather than a physical one. *Obtain a sperm sample* - A sperm sample is collected to assess **male fertility**, which is not the primary complaint or an immediate diagnostic step for erectile dysfunction. - **Erectile dysfunction** does not necessarily imply infertility, and a sperm sample would not help determine the cause of the inability to achieve an erection. *Prescribe sildenafil* - Prescribing a medication like **sildenafil** (a PDE5 inhibitor) without a proper diagnostic workup can mask the underlying cause of ED. - It is crucial to determine if the ED is **organic or psychogenic** first, as the treatment approach might differ significantly. *Duplex penile ultrasound* - A **duplex penile ultrasound** is used to assess **vascular flow** to the penis, but this invasive test is typically reserved for cases where an **organic cause is suspected** after initial evaluations, such as NPT. - It is not the initial best step, as it provides detailed information about vascular health but doesn't differentiate between organic and psychogenic causes as an initial screening. *Prescribe vardenafil* - Similar to sildenafil, **vardenafil** is a PDE5 inhibitor used to treat ED, but it should not be prescribed without first attempting to diagnose the underlying cause. - Providing symptomatic relief without understanding the etiology can delay appropriate management for potentially serious underlying conditions.

Question 834: A 75-year-old man comes to the physician because of a 4-month history of progressive shortness of breath and chest pressure with exertion. Cardiac examination shows a crescendo-decrescendo systolic murmur that is heard best in the second right intercostal space. Radial pulses are decreased and delayed bilaterally. Transesophageal echocardiography shows hypertrophy of the left ventricle and a thick, calcified aortic valve. The area of the left ventricular outflow tract is 30.6 mm2. Using continuous-wave Doppler measurements, the left ventricular outflow tract velocity is 1.0 m/s, and the peak aortic valve velocity is 3.0 m/s. Which of the following values most closely represents the area of the stenotic aortic valve?

A. 16.0 mm2
B. 23 mm2
C. 10.2 mm2 (Correct Answer)
D. 2.0 mm2
E. 6.2 mm2

Explanation: ***10.2 mm2*** - This value is calculated using the **continuity equation**, which states that the product of the area and velocity at one point in a tube must equal the product of the area and velocity at another point. The formula is: A1 × V1 = A2 × V2, where A1 is the **left ventricular outflow tract (LVOT) area**, V1 is the **LVOT velocity**, A2 is the **aortic valve area (AVA)**, and V2 is the **peak aortic valve velocity**. - Using the given values: 30.6 mm² × 1.0 m/s = A2 × 3.0 m/s. Solving for A2 gives A2 = (30.6 × 1.0) / 3.0 = **10.2 mm²** (approximately **0.1 cm²**). - A normal aortic valve area is generally > 2.0 cm² (200 mm²). Severe stenosis is defined as ≤ 1.0 cm² (100 mm²), and this calculated value of 0.1 cm² represents **critical aortic stenosis**, consistent with the patient's symptoms and physical examination findings. *16.0 mm2* - This value would be obtained if there was an error in calculation or if one of the velocity or area measurements was significantly different. It does not fit the continuity equation with the given parameters. - It suggests a higher aortic valve area than calculated, despite the clinical presentation and other measurements pointing towards critical stenosis. *23 mm2* - This value is significantly higher than the calculated aortic valve area and would suggest a less severe degree of stenosis than indicated by the patient's symptoms and other findings. - An error in applying the continuity equation or using incorrect values for velocity or area would lead to this result. *2.0 mm2* - This value indicates **extremely severe/critical aortic stenosis** beyond what is calculated. While the patient does have critical stenosis, the continuity equation with the provided data yields 10.2 mm², not 2.0 mm². - This would imply a much greater velocity ratio or different LVOT measurements than observed. *6.2 mm2* - While indicating very severe stenosis, this value is lower than what the continuity equation yields with the given data. - This result suggests a potential calculation error or misinterpretation of the provided velocities and areas.

Question 835: A 53-year-old woman comes to the physician because of progressive headache and fatigue for the past 2 months. One year ago, she was diagnosed with Cushing disease, which was ultimately treated with bilateral adrenalectomy. Current medications are hydrocortisone and fludrocortisone. Examination shows generalized hyperpigmentation of the skin and bitemporal visual field defects. Serum studies show an ACTH concentration of 1250 pg/mL (N = 20–100). Which of the following is the most appropriate next step in management?

A. Administer metyrapone
B. Administer bromocriptine
C. Reduce dosage of glucocorticoids
D. Resect small cell lung carcinoma
E. Perform radiotherapy of the pituitary (Correct Answer)

Explanation: ***Perform radiotherapy of the pituitary*** - The patient's symptoms (headache, fatigue, **hyperpigmentation**, bitemporal visual field defects), history of bilateral adrenalectomy for Cushing disease, and **very high ACTH level** (1250 pg/mL) are highly characteristic of **Nelson's syndrome**. This syndrome results from the unchecked growth of a pituitary adenoma after the removal of the adrenal glands, leading to an overproduction of ACTH. - **Radiotherapy of the pituitary** is a primary treatment for Nelson's syndrome, aiming to shrink the pituitary adenoma and reduce ACTH secretion, thereby alleviating symptoms and preventing further tumor growth or mass effect on the optic chiasm. *Administer metyrapone* - **Metyrapone** inhibits **11β-hydroxylase**, blocking cortisol synthesis in the adrenal glands. It is used to treat hypercortisolism (Cushing's syndrome) but is not appropriate here as the patient has undergone bilateral adrenalectomy and is already on replacement therapy. - This patient is experiencing a sequela of her adrenalectomy (Nelson's syndrome) characterized by ACTH overproduction, not excess cortisol. *Administer bromocriptine* - **Bromocriptine** is a **dopamine agonist** primarily used to treat **prolactinomas**. While some pituitary tumors may respond to dopamine agonists, it is not the standard or most effective treatment for ACTH-secreting pituitary adenomas causing Nelson's syndrome. - The clinical presentation points towards an ACTH-producing adenoma, not a prolactinoma, making bromocriptine an inappropriate first-line treatment. *Reduce dosage of glucocorticoids* - The patient is taking hydrocortisone and fludrocortisone as **adrenal hormone replacement therapy** after bilateral adrenalectomy. Reducing this dosage would lead to **adrenal insufficiency**, which could be life-threatening. - The current problem is excessive ACTH from a growing pituitary tumor, not iatrogenic hypercortisolism from replacement therapy. *Resect small cell lung carcinoma* - While **small cell lung carcinoma** can cause **ectopic ACTH syndrome**, leading to hyperpigmentation and elevated ACTH, the patient's history of **Cushing disease treated with bilateral adrenalectomy** and the development of bitemporal hemianopsia strongly point to a pituitary-derived issue (Nelson's syndrome). - The bitemporal visual field defect is a classic sign of a **pituitary mass compressing the optic chiasm**, which is inconsistent with an ectopic source of ACTH.

Question 836: Six days after being admitted to the hospital for a cholecystectomy, a 56-year-old woman has high-grade fevers, chills, malaise, and generalized weakness. She has been hospitalized twice in the last year for acute cholecystitis. She had a molar extraction around 2 weeks ago. Her last colonoscopy was 8 months ago and showed a benign polyp that was removed. She has mitral valve prolapse, hypertension, rheumatoid arthritis, and hypothyroidism. Current medications include metformin, rituximab, levothyroxine, and enalapril. Her temperature is 38.3°C (101°F), pulse is 112/min, and blood pressure is 138/90 mm Hg. Examination shows painless macules over her palms and soles and linear hemorrhages under her nail beds. The lungs are clear to auscultation. There is a grade 3/6 systolic murmur heard best at the apex. Blood is drawn and she is started on intravenous antibiotic therapy. Two sets of blood cultures grow coagulase-negative staphylococci. An echocardiography shows a large oscillating vegetation on the mitral valve and moderate mitral regurgitation. Which of the following is the strongest predisposing factor for this patient's condition?

A. Recent dental procedure
B. Colonic polyp
C. Immunosuppression
D. Predamaged heart valve
E. Infected peripheral venous catheter (Correct Answer)

Explanation: ***Infected peripheral venous catheter*** - The patient has **coagulase-negative Staphylococci** (e.g., *Staphylococcus epidermidis*) growing in blood cultures and a **mitral valve vegetation**. This organism is a common cause of **catheter-related bloodstream infections** and **prosthetic valve endocarditis**. - Given her recent hospitalization for cholecystectomy, it's highly probable she had an **intravenous catheter** inserted, which could have been the source of infection, leading to infective endocarditis. *Recent dental procedure* - Dental procedures can cause **transient bacteremia** and are a risk factor for endocarditis, typically involving **viridans group streptococci**, not coagulase-negative staphylococci. - The molar extraction occurred two weeks ago, and while still plausible, the current organism points to a different source. *Colonic polyp* - Colon polyps and malignancy are associated with ***Streptococcus gallolyticus* (formerly *bovis*) endocarditis**, which is not the organism isolated here. - The polyp was benign and removed, reducing its likelihood as a direct source of infection. *Immunosuppression* - The patient is on **rituximab** for rheumatoid arthritis, which causes B-cell depletion and **immunosuppression**, increasing susceptibility to various infections, including endocarditis. - While immunosuppression is a risk factor for infection in general, it doesn't specifically predispose to coagulase-negative *Staphylococcus* endocarditis more than a direct portal of entry like a catheter. *Predamaged heart valve* - **Mitral valve prolapse** is a known risk factor for infective endocarditis due to turbulent flow and damage to the valve leaflets, providing a nidus for bacterial adherence. - However, the specific organism, **coagulase-negative Staphylococci**, strongly suggests a healthcare-associated or catheter-related source as a more direct predisposing factor over a pre-existing valve condition.

Question 837: A 35-year-old male is brought to the emergency room after he was found to have a blood pressure of 180/100 mm Hg during a routine health check-up with his family physician. Past medical history is insignificant and both of his parents are healthy. He currently does not take any medication. The patient's blood pressure normalizes before the emergency department physician can evaluate him. During the physical examination, his blood pressure is 148/80 mm Hg, heart rate is 65/min, temperature is 36.8°C (98.2°F), and respirations are 14/min. He has a round face, centripetal obesity, and striae on the skin with atrophy over the abdomen and thighs. On visual field examination, he is found to have loss of vision in the lateral visual fields bilaterally. You order a low dose dexamethasone suppression test, which is positive, and you proceed to measure ACTH and obtain a high-dose dexamethasone suppression test. If this is a pituitary gland disorder, which of the following lab abnormalities is most likely present in this patient?

A. Before test: ACTH low, after test: cortisol elevation
B. Before test: ACTH high, after test: aldosterone suppression
C. Before test: ACTH high, after test: cortisol suppression (Correct Answer)
D. Before test: ACTH low, after test: aldosterone normalizes
E. Before test: ACTH high, after test: cortisol elevation

Explanation: ***Before test: ACTH high, after test: cortisol suppression*** - A diagnosis of **Cushing's disease** (pituitary ACTH overproduction) is supported by **high ACTH** levels before the high-dose dexamethasone suppression test. - **Cortisol suppression** after a high-dose dexamethasone test helps differentiate Cushing's disease from ectopic ACTH production or adrenal tumors, as pituitary adenomas retain some sensitivity to feedback inhibition. *Before test: ACTH low, after test: cortisol elevation* - **Low ACTH** levels would indicate an adrenal etiology of Cushing's syndrome (e.g., adrenal adenoma), not a pituitary disorder. - **Cortisol elevation** after the high-dose test would suggest an ectopic ACTH-producing tumor or adrenal tumor, as these are typically resistant to suppression. *Before test: ACTH high, after test: aldosterone suppression* - While ACTH may be high in Cushing's disease, the high-dose dexamethasone test primarily evaluates **cortisol suppression**, not aldosterone. - Aldosterone levels are primarily regulated by the **renin-angiotensin-aldosterone system**, and its suppression is not a direct diagnostic feature of Cushing's disease in this context. *Before test: ACTH low, after test: aldosterone normalizes* - **Low ACTH** contradicts a pituitary origin, pointing towards an adrenal cause where adrenal cortisol overproduction suppresses ACTH. - Normalization of aldosterone is not the expected or primary diagnostic outcome of a high-dose dexamethasone suppression test for Cushing's syndrome. *Before test: ACTH high, after test: cortisol elevation* - Although ACTH would be high before the test in a pituitary disorder, **cortisol elevation** *after* the high-dose dexamethasone test would indicate resistance to suppression. - Resistance to suppression with high ACTH usually points towards **ectopic ACTH production** (e.g., from small cell lung cancer), not a pituitary adenoma.

Question 838: A 23-year-old man comes to the physician with a 1-week history of sharp, substernal chest pain that is worse with inspiration and relieved with leaning forward. He has also had nausea and myalgias. His father has coronary artery disease. His temperature is 37.3°C (99.1°F), pulse is 110/min, and blood pressure is 130/84 mm Hg. Cardiac examination shows a high-pitched rubbing sound between S1 and S2 that is best heard at the left sternal border. An ECG shows depressed PR interval and diffuse ST elevations. What is the most likely diagnosis?

A. Dressler syndrome
B. Acute pericarditis (Correct Answer)
C. Mycobacterium tuberculosis infection
D. Systemic lupus erythematosus
E. Acute myocardial infarction

Explanation: ***Acute pericarditis*** - The patient's **sharp, substernal chest pain** that is **worse with inspiration** and **relieved by leaning forward** is a classic presentation of acute pericarditis. - The **pericardial friction rub** on cardiac examination and **diffuse ST elevations** with a **depressed PR interval** on ECG are highly characteristic findings. *Dressler syndrome* - Dressler syndrome is a **late complication of myocardial infarction or cardiac surgery**, typically occurring weeks to months afterward. - This patient's symptoms developed over a week and are not preceded by such events. *Mycobacterium tuberculosis infection* - While *Mycobacterium tuberculosis* can cause pericarditis, it typically presents as **chronic constrictive pericarditis** with effusions and more systemic symptoms like significant fever and night sweats. - The acute onset and classic ECG findings are less consistent with tuberculous pericarditis. *Systemic lupus erythematosus* - SLE can cause pericarditis, but it's usually part of a **multi-system inflammatory picture** with other classic SLE symptoms (e.g., malar rash, arthralgias, renal involvement). - There are no other features to suggest SLE in this case, and the isolated, acute presentation points more directly to infectious or idiopathic pericarditis. *Acute myocardial infarction* - While an MI causes chest pain and ST elevations, the pain is usually described as **crushing or heavy**, not typically pleuritic or relieved by leaning forward. - **PR depression** is not seen in MI, and the ST elevations are usually localized to specific arterial territories, not diffuse.

Question 839: A 67-year-old man comes to the physician because of difficulty walking for 2 months. He has been falling to his left side when he walks more than a few feet. His speech has also changed in the past few months, and he now pauses between each syllable. He has never had similar symptoms before. He has hypertension and cirrhosis as a result of alcoholic liver disease. He does not smoke and he no longer drinks alcohol. His current medications include lisinopril and hydrochlorothiazide daily. His vital signs are within normal limits. Physical examination shows discrete scleral icterus and jaundice. There is ascites and gynecomastia present. Neurological examination shows nystagmus with fast beats toward the left. He has dysmetria and tremor when performing left-sided finger-nose-finger testing, and dysdiadochokinesia with rapid alternating movements. He has a wide-based gait and a pronator drift of the left arm. He has full range of motion in his arms and legs without rigidity. He has full muscle strength, and sensation to light touch is intact. Further evaluation is most likely to show which of the following?

A. Increased number of trinucleotide CAG repeats
B. Periventricular plaques
C. Left-sided posterior capsular infarct
D. Left-sided cerebellar tumor (Correct Answer)
E. Decreased serum thiamine levels

Explanation: ***Left-sided cerebellar tumor*** - The patient presents with classic signs of **cerebellar dysfunction**, including **ataxia** (difficulty walking, falling to the left), **dysarthria** (speech pauses, known as **scanning speech**), **nystagmus**, **dysmetria**, **dysdiadochokinesia**, and a **wide-based gait**. - The symptoms are predominantly left-sided (**left pronator drift, falling to the left, left-sided dysmetria and dysdiadochokinesia, nystagmus with fast beats toward the left**), localizing the lesion to the left cerebellum. Given the progressive nature and the patient's age, a **tumor** is a likely etiology. *Increased number of trinucleotide CAG repeats* - This is characteristic of **Huntington's disease**, which typically presents with **chorea**, psychiatric symptoms, and cognitive decline, not primarily cerebellar signs. - While some cerebellar symptoms can occur, the prominent and specific cerebellar findings described are not the hallmark presentation of Huntington's. *Periventricular plaques* - **Periventricular plaques** are characteristic lesions of **multiple sclerosis (MS)**. - MS usually presents in younger adults and often has a relapsing-remitting course; the patient's age and the specific constellation of symptoms are less typical for MS. *Left-sided posterior capsular infarct* - A **posterior capsular infarct** would primarily cause **contralateral motor and sensory deficits**, such as hemiparesis or hemianesthesia. - It would not typically explain the extensive cerebellar signs like **dysmetria**, **dysdiadochokinesia**, **nystagmus**, and **scanning speech**. *Decreased serum thiamine levels* - **Thiamine deficiency** can lead to **Wernicke-Korsakoff syndrome**, characterized by **ataxia**, **ophthalmoplegia**, and **confusion**. - While ataxia is present, the specific combination of left-sided cerebellar signs, scanning speech, and nystagmus with fast beats toward one side points more strongly to a focal cerebellar lesion rather than a diffuse metabolic encephalopathy, especially given the history of chronic alcohol use but recent sobriety.

Question 840: A 56-year-old man comes to the physician because of chest pain and shortness of breath for 3 days. The pain is present at rest and worsens with deep inspiration. His temperature is 37.2°C (99°F), pulse is 102/min, respirations are 23/min, and blood pressure is 135/88 mm Hg. Examination shows decreased breath sounds at the left lower lobe. Laboratory studies show: Hematocrit 42% Leukocyte count 6,500/μL Serum Fasting glucose 90 mg/dL Lactate dehydrogenase 75 U/L Total protein 7.2 g/dL An x-ray of the chest shows a small left-sided pleural effusion but no other abnormalities. A diagnostic thoracentesis is performed and 100 mL of bloody fluid are aspirated from the left pleural space. Pleural fluid analysis shows a lactate dehydrogenase of 65 U/L and a total protein of 5.1 g/dL. Pleural fluid cytology shows normal cell morphology. Further evaluation of this patient is most likely to show a history of which of the following?

A. Infliximab use
B. Oropharyngeal dysphagia
C. Asbestos exposure (Correct Answer)
D. Congestive heart failure
E. Prolonged immobilization

Explanation: ***Asbestos exposure*** - This patient has a **bloody exudative pleural effusion** (meets Light's criteria with pleural protein/serum protein ratio of 0.71 and pleural LDH/serum LDH ratio of 0.87) with **normal initial cytology**. - The combination of bloody effusion, exudative characteristics, and pleuritic chest pain raises concern for **malignant mesothelioma**, which is strongly associated with **asbestos exposure** (often 20-40 years after exposure). - While the presentation is relatively acute (3 days of symptoms), mesothelioma patients often notice symptoms acutely even though the disease has been developing insidiously. Normal cytology on first thoracentesis does not exclude malignancy—**repeat sampling, immunohistochemistry, or thoracoscopic biopsy** may be needed. - Further workup would likely include detailed occupational/environmental history focusing on asbestos exposure. *Prolonged immobilization* - This is a major risk factor for **pulmonary embolism (PE)**, which can present with pleuritic chest pain, dyspnea, tachycardia, and bloody pleural effusion. - PE is an important differential, especially given the acute 3-day presentation and vital sign abnormalities (tachycardia, tachypnea). - However, PE-related effusions are typically **small and exudative**, and the question context (emphasizing the bloody exudative nature and workup direction) suggests a focus on identifying underlying malignancy risk factors rather than acute thrombotic causes. *Congestive heart failure* - CHF causes **transudative pleural effusions** due to increased hydrostatic pressure, characterized by pleural fluid protein <3 g/dL, protein ratio <0.5, and LDH ratio <0.6. - This patient's effusion is **exudative** (protein 5.1 g/dL with ratio 0.71, LDH ratio 0.87), ruling out CHF as the primary cause. - Additionally, CHF effusions are typically **non-bloody** and bilateral. *Infliximab use* - TNF-alpha inhibitors like infliximab can cause **drug-induced lupus** with serositis and pleural effusions. - However, these effusions are typically **non-bloody**, accompanied by other lupus manifestations (fever, arthritis, rash, positive ANA), and occur in the context of chronic inflammatory disease treatment. - The bloody nature and isolated presentation make this unlikely. *Oropharyngeal dysphagia* - Suggests risk for **aspiration pneumonia** with possible parapneumonic effusion. - Parapneumonic effusions can be exudative but are usually associated with **fever, infiltrate on chest X-ray, and elevated WBC count**—none of which are present. - Bloody effusions are uncommon with aspiration, and there are no clinical clues suggesting aspiration (no cough, choking, or recurrent pneumonias).

Question 841: A 27-year-old man comes to the physician because of a 4-month history of unintentional weight gain, fatigue, and decreased sexual desire. There is no personal or family history of serious illness. His blood pressure is 149/88 mm Hg. Physical examination shows central obesity and abdominal striae. He has a prominent soft tissue bulge at the dorsum of his neck. Laboratory studies show a 24-hour urinary free cortisol of 200 μg (N < 50) and a morning serum ACTH of 1 pg/mL (N = 7–50). Which of the following tests is most likely to confirm the underlying etiology of this patient's symptoms?

A. Abdominal CT (Correct Answer)
B. Chest CT
C. ACTH stimulation test
D. Brain MRI
E. CRH stimulation test

Explanation: ***Abdominal CT*** - The clinical picture of **weight gain**, **fatigue**, decreased sexual desire, **hypertension**, **central obesity**, **abdominal striae**, and a **dorsocervical fat pad ("buffalo hump")** is highly suggestive of **Cushing's syndrome**. - The laboratory results, specifically the **elevated 24-hour urinary free cortisol** and the **very low morning serum ACTH (1 pg/mL)**, indicate **ACTH-independent Cushing's syndrome**, most commonly caused by an **adrenal adenoma** (autonomous cortisol production). An abdominal CT would be used to visualize the adrenal glands and identify such a tumor. *Chest CT* - A chest CT would be indicated if there was suspicion for **ectopic ACTH production** (e.g., small cell lung carcinoma), but this is ruled out by the **low ACTH level**. - Ectopic ACTH production would lead to **high ACTH levels**, which is contrary to this patient's findings. *ACTH stimulation test* - The **ACTH stimulation test (Cosyntropin test)** is used to evaluate **adrenal insufficiency**, not Cushing's syndrome. - In Cushing's syndrome, the adrenal glands are already overproducing cortisol, so further stimulation would not be informative for diagnosis or etiology. *Brain MRI* - A brain MRI would be performed if **Cushing's disease** (pituitary adenoma secreting ACTH) was suspected. - However, the patient's **very low ACTH level** contradicts Cushing's disease, which would cause an **elevated or inappropriately normal ACTH** level. *CRH stimulation test* - The **CRH stimulation test** is used to distinguish between **Cushing's disease** and **ectopic ACTH production** or **adrenal tumors**. - Given the patient's **low ACTH level**, an adrenal tumor (ACTH-independent Cushing's) is the most likely cause, making this test less relevant for confirming the underlying etiology in this specific case.

Question 842: An overweight 57-year-old woman comes to her primary care physician for a routine checkup. She has no current complaints and takes no medications. Her mother and brother have type 2 diabetes mellitus and hypertension. Vital signs show a blood pressure of 145/95 mmHg, temperature of 37°C (98.6°F), and a pulse of 85/minute. Her lab results are shown: Fasting blood glucose 158 mg/dL HbA1c 8.6% Low-density lipoprotein 210 mg/dL High-density lipoprotein 27 mg/dL Triglycerides 300 mg/dL Which of the following tests is recommended for this patient?

A. Monofilament test after 5 years, then yearly follow-up
B. Digital fundus photography after 5 years, then yearly follow-up
C. Digital fundus photography now, then yearly follow-up (Correct Answer)
D. Fasting lipid profile every 5 years
E. Albumin-to-creatinine ratio after 5 years, then yearly follow-up

Explanation: ***Digital fundus photography now, then yearly follow-up*** - This patient has newly diagnosed **Type 2 Diabetes Mellitus**, as indicated by a fasting blood glucose of 158 mg/dL and an HbA1c of 8.6%. According to guidelines, all patients with newly diagnosed **Type 2 DM** should undergo a comprehensive dilated eye examination (or fundus photography) at the time of diagnosis. - This is crucial for early detection of **diabetic retinopathy**, which can be asymptomatic in its early stages but can lead to irreversible vision loss if not managed. *Monofilament test after 5 years, then yearly follow-up* - The **monofilament test** is used to screen for **diabetic neuropathy**, which typically develops over several years in patients with diabetes. - For Type 2 DM, screening with monofilament testing should begin **at the time of diagnosis**, not after 5 years. The 5-year delay is appropriate for Type 1 DM patients. - This option is incorrect because it delays initial screening inappropriately for a Type 2 DM patient. *Digital fundus photography after 5 years, then yearly follow-up* - This timing is generally recommended for **Type 1 Diabetes Mellitus**, where retinopathy typically develops after several years of disease. - For **Type 2 Diabetes Mellitus**, retinopathy can be present at the time of diagnosis due to an often prolonged asymptomatic period, so immediate screening is recommended. *Fasting lipid profile every 5 years* - This patient has significant dyslipidemia (LDL 210 mg/dL, HDL 27 mg/dL, Triglycerides 300 mg/dL) at the time of diagnosis of diabetes. - Patients with diabetes are at higher risk for cardiovascular disease, necessitating more frequent monitoring and management of lipids, typically yearly or as needed based on treatment response, not every 5 years. *Albumin-to-creatinine ratio after 5 years, then yearly follow-up* - The **albumin-to-creatinine ratio** screens for **diabetic nephropathy**, which, like retinopathy, can be present at the time of diagnosis for Type 2 DM. - The recommended practice is to screen for microalbuminuria starting **at diagnosis for Type 2 DM** (or five years after diagnosis for Type 1 DM), then yearly thereafter. - This option is incorrect because it inappropriately delays initial screening by 5 years for a Type 2 DM patient.

Question 843: A 35-year-old patient presents to the emergency department with sudden onset severe headache and dizziness following a motor vehicle accident. After initial assessment, the patient is sent for an urgent CT scan of the head. CT scan reveals a mild hypodensity in the left cerebellum. What is the most likely etiology/cause?

A. Lacunar infarction
B. Cardiac emboli
C. Arterial blood leakage
D. Carotid stenosis
E. Arterial dissection (Correct Answer)

Explanation: ***Arterial dissection*** - The patient's presentation with **sudden onset severe headache** and dizziness following a **motor vehicle accident (MVA)** is highly suggestive of arterial dissection, particularly of the vertebral arteries, which supply the cerebellum. - Trauma from an MVA can cause tears in the arterial walls, leading to dissection and subsequent **stroke** or **transient ischemic attack (TIA)** symptoms related to the affected vessel. *Lacunar infarction* - **Lacunar infarcts** typically result from occlusion of small penetrating arteries and are often associated with **chronic hypertension** and diabetes, which are not mentioned here. - Their symptoms are usually focal and can include pure motor stroke, pure sensory stroke, or ataxic hemiparesis, which is not the primary presentation. *Cardiac emboli* - While cardiac emboli can cause cerebellar stroke, the **sudden onset headache** and history of **MVA** make arterial dissection a more likely cause. - A cardiac source would typically be suspected in patients with **atrial fibrillation** or other cardiac conditions predisposing to clot formation. *Arterial blood leakage* - This term is vague and does not represent a specific cerebrovascular event. While dissection involves a tear in the arterial wall, the consequence is often **ischemia** or **infarction**, not just "leakage" as a primary diagnosis described by CT hypodensity. - Hypodensity on CT typically indicates an **ischemic stroke** (infarction), not active blood leakage. *Carotid stenosis* - **Carotid stenosis** primarily affects the anterior circulation of the brain, leading to symptoms like **amaurosis fugax**, hemiparesis, or aphasia, which are not consistent with a cerebellar stroke. - While it can cause embolic strokes, it would not typically cause a direct cerebellar infarct in the absence of other symptoms.

Question 844: A 67-year-old woman is brought to the emergency department by her caretakers for a change in behavior. The patient lives in a nursing home and was noted to have abnormal behavior, urinary incontinence, and trouble walking. The patient has been admitted to the hospital before for what seems to be negligence from her caretakers. Laboratory values are ordered as seen below. Serum: Na+: 120 mEq/L Cl-: 98 mEq/L K+: 4.3 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.2 mg/dL Urinalysis is notable for bacteruria without pyuria or nitrates. Physical exam is notable for a confused woman who is unable to answer questions appropriately. She states she has no pain or symptoms and is not sure why she is here. She thinks the year is 1982. Which of the following complications could be seen with treatment of this patient?

A. Osmotic demyelination (Correct Answer)
B. Diarrhea and flora destruction
C. Autoimmune pontine demyelination
D. Central nervous system infection
E. Cerebral edema

Explanation: ***Osmotic demyelination*** - This patient presents with **severe hyponatremia (Na+ 120 mEq/L)**, likely chronic given her baseline dementia and nursing home status, requiring cautious correction. - Rapid correction of chronic hyponatremia can lead to **osmotic demyelination syndrome (ODS)**, also known as central pontine myelinolysis, a devastating neurological complication. *Diarrhea and flora destruction* - While antibiotic treatment for a **urinary tract infection (UTI)** can cause diarrhea and disrupt gut flora, this is a common side effect of antibiotics in general, not a specific complication tied to the severe hyponatremia or its correction. - The primary concern with hyponatremia treatment is neurological damage, not gastrointestinal upset. *Autoimmune pontine demyelination* - **Autoimmune pontine demyelination** is not a recognized complication of hyponatremia assessment or treatment. - Osmotic demyelination syndrome is iatrogenic, caused by overly rapid correction of a chronic electrolyte imbalance. *Central nervous system infection* - Although the patient has **bacteriuria without pyuria or nitrates**, suggesting colonization rather than an active UTI, an untreated UTI could theoretically spread to the CNS. - However, CNS infection is not a direct complication of *treatment* for hyponatremia; rather, it would be a complication of an untreated or severe infection. *Cerebral edema* - **Cerebral edema** is a complication of *acute hyponatremia* if not treated, as water shifts into brain cells due to the osmotic gradient. - In a chronic setting, the brain has usually adapted to the low sodium; rapid *correction* of hyponatremia causes water to move *out* of brain cells, leading to demyelination, not edema.

Question 845: A 77-year-old male presents to the emergency department because of shortness of breath and chest discomfort. The patient states his ability to withstand activity has steadily declined, and most recently he has been unable to climb more than one flight of stairs without having to stop to catch his breath. On physical exam, the patient has a harsh crescendo-decrescendo systolic murmur heard over the right sternal border, with radiation to his carotids. Which of the following additional findings are most likely in this patient?

A. A constant, machine-like murmur heard between the scapulae
B. A wide and fixed split S2
C. A high-pitched, blowing, holosystolic murmur
D. A diastolic murmur heard at the cardiac apex
E. A paradoxically split S2 (Correct Answer)

Explanation: ***A paradoxically split S2*** - The patient's symptoms (shortness of breath, chest discomfort, decreased exercise tolerance) and physical exam findings (harsh **crescendo-decrescendo systolic murmur** over the right sternal border radiating to the carotids) are classic for **aortic stenosis**. - In severe aortic stenosis, the **aortic valve closes late**, causing a paradoxical split S2 where P2 precedes A2 upon inspiration. *A constant, machine-like murmur heard between the scapulae* - This description is characteristic of a **patent ductus arteriosus (PDA)**, which typically presents in infancy or early childhood and is associated with a continuous murmur. - The patient's age and specific murmur characteristics (crescendo-decrescendo systolic) do not align with PDA. *A wide and fixed split S2* - A fixed and wide split S2 is a hallmark of an **atrial septal defect (ASD)**, where the S2 split does not change with respiration. - This finding is unrelated to the pathophysiology of aortic stenosis. *A high-pitched, blowing, holosystolic murmur* - This type of murmur is characteristic of **mitral regurgitation** or **tricuspid regurgitation**. - These conditions present differently on physical exam and often have distinct symptom profiles compared to aortic stenosis. *A diastolic murmur heard at the cardiac apex* - A diastolic murmur heard at the cardiac apex primarily suggests **mitral stenosis** or **tricuspid stenosis**. - **Aortic stenosis** is a systolic event, and while it can sometimes be associated with other murmurs, this specific finding is not a primary or most likely additional finding.

Question 846: A 74-year-old right-handed woman was referred to the hospital due to concerns of a stroke. In the emergency department, the initial vital signs included blood pressure of 159/98 mm Hg, heart rate of 88/min, and respiratory rate of 20/min. She exhibited paucity of speech and apathy to her condition, although she complied with her physical examination. The initial neurologic evaluation included the following results: Awake, alert, and oriented to person, place, and time No visual field deficits Right-sided gaze deviation with full range of motion with doll’s head maneuver No facial asymmetry Grossly intact hearing No tongue deviation, equal palatal elevation, and good guttural sound production Absent pronator or lower extremity drift Decreased sensation to light touch on the right leg Normal appreciation of light touch, pressure, and pain Normal proprioception and kinesthesia Manual muscle testing: 5+ right and left upper extremities 5+ right hip, thigh, leg, and foot 3+ left hip and thigh 2+ left leg and foot A head computed tomography (CT) scan and a head magnetic resonance imaging (MRI) confirmed areas of ischemia. Which artery is the most likely site of occlusion?

A. Superior division of the right middle cerebral artery
B. Right anterior cerebral artery (Correct Answer)
C. Right middle cerebral artery stem (M1)
D. Inferior division of the left middle cerebral artery
E. Inferior division of the right middle cerebral artery

Explanation: ***Right anterior cerebral artery*** - The patient's symptoms, including **left leg weakness** (3+ at hip/thigh, 2+ at leg/foot), **right gaze deviation**, and **apathy with paucity of speech**, are characteristic of a **right anterior cerebral artery (ACA) stroke**. The ACA supplies the motor and sensory cortices responsible for the contralateral leg and also the frontal lobe areas involved in executive function and motivation. - **Urinary incontinence** is also a common feature of ACA strokes, though not explicitly mentioned here, the other symptoms strongly point to this localization. *Superior division of the right middle cerebral artery* - Occlusion of the superior division of the **right middle cerebral artery (MCA)** would typically cause **contralateral hemiparesis and hemisensory loss affecting the face and arm more than the leg**. - As the patient is right-handed, a right MCA stroke would present with left-sided weakness, but the **leg involvement would be less pronounced** than what is seen here, and could also present with **gaze preference towards the right**, but speech would be spared. *Right middle cerebral artery stem (M1)* - A complete occlusion of the **right MCA stem (M1)** would result in a **dense contralateral hemiplegia** (face, arm, and leg equally affected), **contralateral hemianesthesia**, and a **homonymous hemianopia with gaze deviation to the right**. - While gaze deviation to the right is present, the **predominant leg weakness** with sparing of the arm and face makes a complete M1 occlusion less likely. *Inferior division of the left middle cerebral artery* - Occlusion of the **inferior division of the left MCA** in a right-handed individual would lead to **Wernicke's aphasia** (fluent but nonsensical speech) and a right lower quadrantanopia, with less prominent motor deficits. - The patient presents with **paucity of speech, not aphasia**, and left-sided motor deficits, not right. *Inferior division of the right middle cerebral artery* - An infarction in the **inferior division of the right MCA** would typically cause **left homonymous hemianopia or quadrantanopia** and potentially **left hemineglect**, with less significant motor or sensory deficits, unless the posterior limb of the internal capsule is also affected. - The patient's primary symptoms of **leg weakness** and speech changes are not typical for an inferior division right MCA stroke.

Question 847: A 34-year-old woman presents with fatigue, depressed mood, weight gain, and constipation. She gradually developed these symptoms over the past 6 months. She is G2P2 with the last pregnancy 9 months ago. She had a complicated delivery with significant blood loss requiring blood transfusions. She used to have a regular 28-day cycle but notes that recently it became irregular with duration lasting up to 40 days, more pain, and greater blood loss. She does not report any chronic conditions, and she is not on any medications. She is a current smoker with a 10-pack-year history. Her blood pressure is 130/80 mm Hg, heart rate is 54/min, respiratory rate is 11/min, and temperature is 35.8°C (96.4°F). Her skin is dry and pale with a fine scaling over the forearms and shins. There is a mild, non-pitting edema of the lower legs. Her lungs are clear to auscultation. Cardiac auscultation does not reveal any pathological sounds or murmurs although S1 and S2 are dulled at all points of auscultation. The abdomen is mildly distended and nontender on palpation. Neurological examination is significant for decreased deep tendon reflexes. Her blood tests show the following results: Erythrocytes count 3.4 million/mm3 Hb 12.2 mg/dL MCV 90 μm3 Reticulocyte count 0.3% Leukocyte count 5,600/mm3 Serum vitamin B12 210 ng/mL T4 total 1.01 μg/dL T4 free 0.6 ng/dL TSH 0.2 μIU/mL Which of the following lab values should be used to monitor treatment in this patient?

A. Free T4 (Correct Answer)
B. Vitamin B12
C. TSH
D. MCV
E. Total T3

Explanation: ***Free T4*** - This patient presents with **Sheehan syndrome**, which is a cause of **central hypothyroidism**. In central hypothyroidism, the **pituitary gland** fails to produce adequate TSH, leading to decreased T4 production by the thyroid gland. - In cases of central hypothyroidism, **free T4** is the most reliable lab value to monitor treatment because TSH levels may not accurately reflect thyroid status due to pituitary dysfunction. *Vitamin B12* - Although the patient's vitamin B12 levels are on the lower end of the normal range, the clinical picture is not primarily consistent with **vitamin B12 deficiency**, and it is not the primary marker for monitoring this patient's underlying condition. - While vitamin B12 deficiency can cause fatigue and neurological symptoms, the constellation of symptoms (bradycardia, hypothermia, dry skin, constipation, and menstrual irregularities) points more strongly to **hypothyroidism**. *TSH* - In **primary hypothyroidism**, TSH is elevated and is the primary parameter for monitoring treatment. However, in **central hypothyroidism** (as seen in Sheehan syndrome), TSH levels may be inappropriately low or normal even when thyroid hormone levels are deficient. - Therefore, using **TSH** alone to monitor central hypothyroidism can be misleading as it does not accurately reflect the peripheral thyroid hormone status. *MCV* - The patient's **MCV (Mean Corpuscular Volume)** is normal, indicating that she does not have **macrocytic anemia**, which can be associated with hypothyroidism or vitamin B12 deficiency. - While anemia can be a feature of hypothyroidism, MCV itself is not a direct marker for monitoring thyroid hormone treatment. *Total T3* - **Total T3** levels can be affected by **protein binding** and are generally less reliable than free T4 in assessing thyroid function, especially in the presence of confounding factors. - **Free T4** is a direct measure of metabolically active thyroid hormone and is therefore a more accurate indicator for monitoring treatment in central hypothyroidism.

Question 848: A 38-year-old woman presents with worsening fatigue and difficulty talking for the last few hours. Past medical history is significant for type 2 diabetes mellitus, managed with metformin and insulin. Additional current medications are a pill to ''calm her nerves'' that she takes when she has to perform live on stage for work. On physical examination, the patient is lethargic, easily confused, and has difficulty responding to questions or commands. There is also significant diaphoresis of the face and trunk present. Which of the following is the most likely etiology of this patient’s current symptoms?

A. Diabetic ketoacidosis
B. Hyperosmolar nonketotic coma
C. Medication overdose
D. Hypoglycemia (Correct Answer)
E. Benzodiazepine intoxication

Explanation: ***Hypoglycemia*** - The patient's symptoms of **worsening fatigue, difficulty talking, lethargy, confusion, and diaphoresis** are classic signs of **hypoglycemia**. - Her history of **type 2 diabetes mellitus** treated with **insulin** further supports this, as insulin can cause blood glucose levels to drop too low. *Diabetic ketoacidosis* - While diabetic ketoacidosis (DKA) can cause **lethargy and confusion**, it typically presents with **ketonuria, metabolic acidosis**, and often **polydipsia/polyuria**. - **Diaphoresis** is not a common symptom of DKA; instead, patients are often dehydrated. *Hyperosmolar nonketotic coma* - Hyperosmolar nonketotic coma (HONK) is characterized by **severe hyperglycemia, dehydration, and altered mental status** without significant ketosis. - While some symptoms like **lethargy and confusion** overlap, **diaphoresis** is not typical, and patients often present with profound dehydration. *Medication overdose* - Although the patient takes a "calming pill," the combination of symptoms and medical history points more strongly to a metabolic cause. - A **medication overdose** would need more specific information about the drug and dosage to confirm, and the diaphoresis coupled with altered mental status fits hypoglycemia more precisely. *Benzodiazepine intoxication* - Benzodiazepine intoxication can cause **sedation, confusion, and slurred speech**, which can mimic some of the patient's symptoms. - However, **significant diaphoresis** is not a typical hallmark of benzodiazepine intoxication, and the patient's diabetic history provides a more direct explanation.

Question 849: A 67-year-old woman comes to the clinic complaining of progressive fatigue over the past 4 months. She noticed that she is feeling increasingly short of breath after walking the same distance from the bus stop to her home. She denies chest pain, syncope, lower extremity edema, or a cough. She denies difficulty breathing while sitting comfortably, but she has increased dyspnea upon walking or other mildly strenuous activity. Her past medical history includes mild osteoporosis and occasional gastric reflux disease. She takes oral omeprazole as needed and a daily baby aspirin. The patient is a retired accountant and denies smoking history, but she does admit to 1 small glass of red wine daily for the past 5 years. Her diet consists of a Mediterranean diet that includes fruits, vegetables, and fish. She states that she has been very healthy previously, and managed her own health without a physician for the past 20 years. On physical examination, she has a blood pressure of 128/72 mm Hg, a pulse of 87/min, and an oxygen saturation of 94% on room air. HEENT examination demonstrates mild conjunctival pallor. Lung and abdominal examinations are within normal limits. Heart examination reveals a 2/6 systolic murmur at the right upper sternal border. The following laboratory values are obtained: Hematocrit 29% Hemoglobin 9.8 g/dL Mean red blood cell volume 78 fL Platelets 240,000/mm3 White blood cells 6,000/mm3 What is the most likely reticulocyte range for this patient?

A. >7%
B. < 1% (Correct Answer)
C. >5%
D. > 1.5%
E. 0%

Explanation: ***< 1%*** - This patient presents with **microcytic anemia** (MCV 78 fL, Hgb 9.8 mg/dL) and symptoms of iron deficiency. A **low reticulocyte count** (< 1%) indicates the bone marrow is not adequately responding to the anemia, which is characteristic of iron deficiency due to chronic blood loss or malabsorption. - The conjunctival pallor, systolic murmur, and chronic omeprazole use (which can impair iron absorption) further support the diagnosis of iron deficiency anemia. *>7%* - A reticulocyte count > 7% would suggest a **robust bone marrow response** to anemia, typically seen in conditions like **hemolytic anemia** or **acute blood loss** where the body is actively trying to replace lost red blood cells. - This patient's clinical picture and microcytic anemia do not align with a highly regenerative bone marrow response. *>5%* - Similar to >7%, a reticulocyte count > 5% indicates a **significant regenerative anemia**, implying a rapid production of new red blood cells. - This is inconsistent with the patient's **iron deficiency anemia**, where iron availability limits erythropoiesis and thus reticulocyte production. *> 1.5%* - A reticulocyte count > 1.5% (or > 2-3% as an absolute count) generally indicates a **mild to moderate regenerative anemia**. - While it's slightly higher than what would be expected in uncompensated iron deficiency, it's still lower than what would be seen in highly regenerative anemias and higher than expected given the evidence of impaired erythropoiesis due to iron lack. *0%* - A reticulocyte count of 0% would indicate **complete cessation of red blood cell production** by the bone marrow, as seen in severe **aplastic anemia** or pure red cell aplasia. - While the patient's anemia is chronic and likely due to iron deficiency, there is no evidence of complete bone marrow failure.

Question 850: A 20-year-old female with type I diabetes mellitus presents to the emergency department with altered mental status. Her friend said that she has been out late either studying for upcoming tests or attending prayer group meetings. As far as the friend can recollect, the patient appeared to be in her usual state of health until only two days ago, when she was prescribed trimethoprim-sulfamethoxazole for a urinary tract infection. The patient complained that the medication was making her feel nauseous and bloated. The patient also relies on glargine and lispro for glycemic control. Her temperature is 100.5°F (38.1°C), blood pressure is 95/55 mmHg, pulse is 130/min, and respirations are 30/min. Her pupils are equal and reactive to light bilaterally. The remainder of the physical exam is unremarkable. Her basic metabolic panel is displayed below: Serum: Na+: 116 mEq/L Cl-: 90 mEq/L K+: 5.0 mEq/L HCO3-: 2 mEq/L BUN: 50 mg/dL Glucose: 1,200 mg/dL Creatinine: 1.5 mg/dL Which of the following is true regarding this patient's presentation?

A. Azotemia independently contributes to the patient's encephalopathy
B. Hyperglycemia to this magnitude supports hyperglycemic hyperosmolar nonketotic syndrome
C. Hypochloremia to this magnitude supports a pure anion-gap metabolic acidosis
D. Hyponatremia is independently associated with a poor prognosis
E. Hyperkalemia is independent of the patient's total body potassium stores (Correct Answer)

Explanation: ***Hyperkalemia is independent of the patient's total body potassium stores*** - In **diabetic ketoacidosis (DKA)**, intracellular potassium shifts extracellularly due to **acidemia** and **insulin deficiency**, leading to **normal or elevated serum potassium** despite depleted total body potassium stores. - The patient's presentation with **DKA** (hyperglycemia, acidosis, altered mental status) coupled with a normal serum potassium level in the setting of significant fluid loss suggests a substantial deficit in total body potassium. *Azotemia independently contributes to the patient's encephalopathy* - While the patient has **elevated BUN and creatinine**, indicating **azotemia**, the primary cause of her altered mental status is likely **diabetic ketoacidosis (DKA)** with severe **hyperglycemia** and **acidosis**, leading to an **osmolar shift** and brain edema. - Although severe azotemia can cause encephalopathy, in this context, the profound metabolic derangements of DKA are the more prominent contributors to her altered mental status. *Hyperglycemia to this magnitude supports hyperglycemic hyperosmolar nonketotic syndrome* - Although the glucose level is very high (1200 mg/dL), the presence of **severe metabolic acidosis** (HCO3- 2 mEq/L) is characteristic of **diabetic ketoacidosis (DKA)**, not hyperglycemic hyperosmolar nonketotic syndrome (HHNS). - **HHNS** is typically characterized by extreme hyperglycemia, hyperosmolarity, and dehydration, but with **minimal or no ketosis or acidosis**. *Hypochloremia to this magnitude supports a pure anion-gap metabolic acidosis* - The patient has a **high anion-gap metabolic acidosis** (calculated anion gap = Na+ - (Cl- + HCO3-) = 116 - (90 + 2) = 24), which is characteristic of DKA. - The **hypochloremia** is secondary to the profound dehydration and is often a response to the acidosis, but the primary acidosis is high anion-gap, not pure non-anion gap (hyperchloremic) acidosis. *Hyponatremia is independently associated with a poor prognosis* - The **hyponatremia** in this patient is largely **pseudohyponatremia** due to severe hyperglycemia, which draws water out of cells and dilutes serum sodium. - While severe hyponatremia can indicate a poor prognosis in other contexts, in DKA, it often reflects the severity of hyperglycemia and dehydration, and corrects with resolution of hyperglycemia and fluid resuscitation; it is not an independent prognostic factor in this setting.

Question 851: A 36-year-old man presents to his physician with an acute burning retrosternal sensation with radiation to his jaw. This sensation began 20 minutes ago when the patient was exercising at the gym. It does not change with position or with a cough. The patient’s vital signs include: blood pressure is 140/90 mm Hg, heart rate is 84/min, respiratory rate is 14/min, and temperature is 36.6℃ (97.9℉). Physical examination is only remarkable for paleness and perspiration. The patient is given sublingual nitroglycerin, the blood is drawn for an express troponin test, and an ECG is going to be performed. At the moment of performing ECG, the patient’s symptoms are gone. ECG shows increased R amplitude in I, II V3-V6, and ST depression measuring for 0.5 mm in the same leads. The express test for troponin is negative. Which of the following tests would be reasonable to perform next to confirm a diagnosis in this patient?

A. Echocardiography
B. Chest radiography
C. CT angiography
D. Blood test for CPK-MB
E. Exercise stress testing (Correct Answer)

Explanation: ***Exercise stress testing*** - The patient's symptoms (chest pain radiating to the jaw, exacerbated by exercise, relieved by nitroglycerin) are highly suggestive of **angina**, despite the negative troponin and transient ECG changes. - An **exercise stress test** is appropriate to evaluate for inducible ischemia, as it can reproduce symptoms and ECG changes under controlled conditions, helping to confirm a diagnosis of **coronary artery disease**. *Echocardiography* - While echocardiography can assess **cardiac function** and wall motion abnormalities, it primarily evaluates structural heart disease and myocardial function. - It would not sufficiently confirm or rule out **exercise-induced ischemia** in a patient with resolved symptoms and normal initial workup for acute coronary syndrome. *Chest radiography* - **Chest radiography** provides images of the lungs, heart silhouette, and thoracic cage, primarily used to rule out pulmonary causes of chest pain or major structural abnormalities. - It is not a diagnostic tool for **coronary artery disease** or exercise-induced angina. *CT angiography* - **CT angiography** is excellent for visualizing coronary arteries and detecting stenoses, but it involves radiation exposure and contrast. - It is often reserved for patients with intermediate to high pre-test probability of CAD or when stress tests are inconclusive or contraindicated, not as a primary next step given the clinical picture and resolved symptoms. *Blood test for CPK-MB* - **Creatine phosphokinase-MB (CPK-MB)** is an older marker for myocardial damage, largely replaced by troponin due to its higher specificity and sensitivity. - Since the **troponin test was negative**, further testing with a less sensitive marker like CPK-MB would not provide additional diagnostic value for acute myocardial injury.

Question 852: A 46-year-old woman complains of chronic cough for the past 3 weeks. She was recently diagnosed with hypertension and placed on an angiotensin receptor blocker therapy (ARBs). Chest X-ray shows large nodular densities bilaterally. Bronchial biopsy showed granulomatous inflammation of the pulmonary artery. Lab investigations showed a positive cANCA with a serum creatinine of 3.6 mg/dL. Urine analysis shows RBC casts and hematuria. Which is the most likely cause of this presentation?

A. Granulomatosis with polyangiitis (Correct Answer)
B. Hypertensive medication
C. Churg-Strauss syndrome
D. Polyarteritis nodosa
E. Microscopic polyangiitis

Explanation: ***Granulomatosis with polyangiitis*** - The combination of **chronic cough** with **bilateral nodular densities** on chest X-ray, **granulomatous inflammation** on lung biopsy, a **positive c-ANCA**, and rapidly progressive glomerulonephritis (elevated creatinine, RBC casts, hematuria) is highly characteristic of **Granulomatosis with polyangiitis (GPA)**. - GPA is a small-vessel vasculitis that typically affects the **upper and lower respiratory tracts** and the **kidneys**. *Hypertensive medication* - While ACE inhibitors can cause a dry cough, **angiotensin receptor blockers (ARBs)**, which the patient is on, are typically not associated with cough. - ARBs do not cause lung nodules, granulomatous inflammation, positive c-ANCA, or rapidly progressive glomerulonephritis. *Churg-Strauss syndrome* - **Churg-Strauss syndrome (Eosinophilic granulomatosis with polyangiitis)** characteristically presents with **asthma**, **eosinophilia**, and **allergic rhinitis**, which are not mentioned in this patient's presentation. - Although it can cause lung involvement and vasculitis, the absence of prominent eosinophilia and allergic symptoms makes it less likely, and it is typically associated with p-ANCA, not c-ANCA. *Microscopic polyangiitis* - **Microscopic polyangiitis (MPA)** also causes necrotizing glomerulonephritis and pulmonary capillaritis, often with **p-ANCA positivity**. - However, MPA typically lacks the **granulomatous inflammation** and **large nodular densities** seen in GPA. *Polyarteritis nodosa* - **Polyarteritis nodosa (PAN)** is a medium-vessel vasculitis that generally spares the **pulmonary circulation** and glomerulonephritis, distinguishing it from this case. - PAN is typically **ANCA-negative** and does not involve granulomatous inflammation.

Question 853: A 67-year-old man presents to your office with a chief complaint of constipation and many other perturbing minor medical concerns. He reports tiring easily, which he attributes to old age and years of persistent pain in his back and ribs. A complete blood count shows low hemoglobin and elevated serum creatinine. A peripheral blood smear shows stacks of red blood cells among other findings, and serum electropheresis reveals an abnormal concentration of protein resulting in a spike. Which of the following additional findings would you expect to see in this patient?

A. Bence-Jones proteins in the urine (Correct Answer)
B. Smudge cells on peripheral smear
C. Early satiety and splenomegaly
D. No additional findings - normal aging explains symptoms
E. An elevated PSA and a nodular prostate

Explanation: ***Bence-Jones proteins in the urine*** - The constellation of symptoms (fatigue, bone pain, constipation, anemia, elevated creatinine, **rouleaux formation** on peripheral smear, and **monoclonal spike** on serum electrophoresis) is highly suggestive of **multiple myeloma**. - **Bence-Jones proteins** (monoclonal light chains) are often excreted in the urine in multiple myeloma due to overproduction by malignant plasma cells. *Smudge cells on peripheral smear* - **Smudge cells** are characteristic of **chronic lymphocytic leukemia (CLL)**, a different hematologic malignancy that does not typically present with a monoclonal protein spike or extensive bone pain. - While CLL can cause fatigue and anemia, it typically involves lymphadenopathy and does not present with the specific bone and kidney involvement seen here. *Early satiety and splenomegaly* - **Early satiety** and **splenomegaly** are common findings in **myeloproliferative neoplasms** (e.g., chronic myeloid leukemia, myelofibrosis) or lymphomas. - These conditions do not present with a prominent **monoclonal protein spike** or the type of bone pain and renal dysfunction seen in this patient. *No additional findings - normal aging explains symptoms* - While some symptoms like fatigue and constipation can be associated with aging, the presence of **anemia**, **elevated creatinine**, **rouleaux formation**, and a **monoclonal protein spike** are **pathologic findings** that cannot be attributed to normal aging. - These findings strongly indicate an underlying disease process requiring further investigation. *An elevated PSA and a nodular prostate* - These findings are indicative of **benign prostatic hyperplasia (BPH)** or **prostate cancer**, conditions of the prostate gland. - While possible in an older male, they do not explain the systemic symptoms of bone pain, anemia, renal dysfunction, rouleaux formation, or the monoclonal protein spike, which point to a distinct hematologic malignancy.

Question 854: A 55-year-old woman presents to a primary care clinic for a physical evaluation. She works as a software engineer, travels frequently, is married with 2 kids, and drinks alcohol occasionally. She does not exercise regularly. She currently does not take any medications except for occasional ibuprofen or acetaminophen. She is currently undergoing menopause. Her initial vital signs reveal that her blood pressure is 140/95 mmHg and heart rate is 75/min. She weighs 65 kg (143 lb) and is 160 cm (63 in) tall. Her physical exam is unremarkable. A repeat measurement of her blood pressure is the same as before. Among various laboratory tests for hypertension evaluation, the physician requests fasting glucose and hemoglobin A1c levels. Which of the following is the greatest risk factor for type 2 diabetes mellitus?

A. Menopause
B. Occupation
C. Age
D. Body mass index (Correct Answer)
E. Hypertension

Explanation: ***Body mass index*** - The patient's **BMI** is 25.4 kg/m², which falls into the **overweight** category (BMI 25-29.9 kg/m²). **Obesity** (BMI ≥ 30 kg/m²) and overweight status are significant and modifiable risk factors for **insulin resistance** and type 2 diabetes mellitus. - Excess body fat, particularly **visceral fat**, leads to increased free fatty acid release and inflammation, impairing insulin signaling in target tissues. *Menopause* - While menopause can lead to changes in **body fat distribution** and increase the risk of metabolic syndrome components, it is not as strong a direct risk factor for type 2 diabetes as BMI. - The hormonal shifts during menopause may contribute to **insulin resistance** but do not independently confer as high a risk as overweight or obesity. *Occupation* - The patient's occupation as a **software engineer** and frequent travel may contribute to a sedentary lifestyle, which is an indirect risk factor for obesity and diabetes. However, occupation itself is not a direct or primary biological risk factor. - A sedentary lifestyle decreases **metabolic demand** and can lead to weight gain if not balanced with regular physical activity. *Age* - **Advancing age** is a known risk factor for type 2 diabetes due to a gradual decline in pancreatic beta-cell function and increased insulin resistance over time. - While the patient's age (55) is a risk factor, her elevated **BMI** represents a more immediate and modifiable risk for developing the disease. *Hypertension* - **Hypertension** is often a comorbidity of type 2 diabetes and part of the **metabolic syndrome**, but it is generally considered a consequence or co-existing condition rather than the primary risk factor for the development of diabetes itself. - Both hypertension and type 2 diabetes share common pathophysiological mechanisms such as **insulin resistance** and inflammation.

Question 855: A 65-year-old man comes to the physician because of a 10-day history of episodic retrosternal pain, shortness of breath, and palpitations. The episodes occur when he climbs stairs or tries to walk briskly on his treadmill. The symptoms resolve when he stops walking. The previous evening he felt dizzy and weak during such an episode. He also reports that he had a cold 2 weeks ago. He was diagnosed with type 2 diabetes mellitus four years ago but is otherwise healthy. His only medication is glyburide. He appears well. His pulse is 62/min and is weak, respirations are 20/min, and blood pressure is 134/90 mmHg. Cardiovascular examination shows a late systolic ejection murmur that is best heard in the second right intercostal space. The lungs are clear to auscultation. Which of the following mechanisms is the most likely cause of this patient's current condition?

A. Catecholamine-induced transient regional systolic dysfunction
B. Lymphocytic infiltration of the myocardium
C. Increased release of endogenous insulin
D. Increased left ventricular oxygen demand (Correct Answer)
E. Critical transmural hypoperfusion of the myocardium

Explanation: ***Increased left ventricular oxygen demand*** - The patient's symptoms (retrosternal pain, shortness of breath, palpitations, dizziness, weakness) occurring with exertion and resolving with rest are classic for **angina pectoris**, especially in the presence of risk factors like **type 2 diabetes**. - The late systolic ejection murmur points to an outflow obstruction, likely **aortic stenosis**, which significantly increases the **workload on the left ventricle** and its oxygen demand, leading to ischemia during exertion. *Catecholamine-induced transient regional systolic dysfunction* - While **catecholamines** can induce transient dysfunction (e.g., **Takotsubo cardiomyopathy**), this usually presents acutely in response to severe emotional or physical stress and is not typically associated with a chronic, exertional pattern or an existing murmur. - This mechanism does not explain the exertional nature of the symptoms, which points more directly to **ischemia** due to increased demand. *Lymphocytic infiltration of the myocardium* - **Lymphocytic infiltration** is characteristic of **myocarditis**, which typically presents with **acute heart failure symptoms**, arrhythmias, or chest pain, often following a viral infection. - While the patient had a cold, the exertional nature of his symptoms and the presence of a **systolic murmur** are not consistent with myocarditis as the primary cause of his current condition. *Increased release of endogenous insulin* - Glyburide increases **insulin secretion**, but increased insulin release itself does not directly cause anginal symptoms, shortness of breath, or palpitations. - While **hypoglycemia** (a side effect of glyburide) can cause dizziness and weakness, it would not explain the retrosternal pain or the exertional pattern resolving with rest, or the systolic murmur. *Critical transmural hypoperfusion of the myocardium* - **Critical transmural hypoperfusion** usually refers to severe, sustained reduction in blood flow, often due to significant **coronary artery disease (CAD)** or **vasospasm**, leading to **myocardial infarction** or unstable angina. - While this patient likely has underlying CAD given his diabetes, the episodic, exertional nature of his symptoms, resolving with rest, is more characteristic of stable angina due to an imbalance between increased demand and fixed supply, rather than critical, sustained hypoperfusion.

Question 856: A 68-year-old man is brought to the emergency department because of progressive weakness of his lower extremities and urinary incontinence for the past 2 weeks. Over the past 2 months, he has had increasing back pain. His temperature is 37.1°C (98.8°F), pulse is 88/min, and blood pressure is 106/60 mm Hg. Examination shows an ataxic gait. Muscle strength is decreased in bilateral lower extremities. Sensation to pain, temperature, and position sense is absent in the buttocks, perineum, and lower extremities. Ankle clonus is present. Digital rectal examination is unremarkable. An x-ray of the spine shows multiple sclerotic lesions in the thoracic and lumbar vertebrae. Further evaluation of this patient is most likely to show which of the following?

A. Bence Jones protein in the urine
B. Irregular, asymmetric mole
C. Left testicular mass
D. Elevated prostate-specific antigen (Correct Answer)
E. Enlarged left thyroid lobe

Explanation: ***Elevated prostate-specific antigen (Correct)*** - The patient's symptoms of **progressive lower extremity weakness**, **urinary incontinence**, **back pain**, and neurological deficits (**ataxic gait**, decreased strength, sensory loss in a saddle distribution, ankle clonus) suggest **spinal cord compression**. - **Sclerotic lesions** on spine X-ray in an older man, particularly when associated with spinal cord compression symptoms, are highly indicative of **metastatic prostate cancer**. Prostate cancer commonly metastasizes to bone and often causes sclerotic bone lesions. *Bence Jones protein in the urine (Incorrect)* - **Bence Jones proteins** are commonly found in the urine of patients with **multiple myeloma**. - Multiple myeloma typically causes **lytic bone lesions**, not sclerotic lesions, and is characterized by systemic symptoms like hypercalcemia and renal failure. *Irregular, asymmetric mole (Incorrect)* - An **irregular, asymmetric mole** is characteristic of **malignant melanoma**. - While melanoma can metastasize to bone, it more commonly causes **lytic bone lesions** rather than sclerotic lesions, and spinal cord compression from melanoma metastases is less common than from prostate cancer. *Left testicular mass (Incorrect)* - A **left testicular mass** would suggest **testicular cancer**, which can metastasize to bone. - However, testicular cancer is more common in younger men, and its bone metastases are typically **lytic**, not sclerotic. *Enlarged left thyroid lobe (Incorrect)* - An **enlarged left thyroid lobe** could indicate **thyroid cancer**. - Although thyroid cancer can metastasize to bone and cause pain, it typically causes **lytic lesions** and is less commonly associated with the specific neurological deficits described alongside sclerotic lesions in this age group.

Question 857: A 47-year-old woman presents to her primary care physician for a wellness checkup. The patient states that she currently feels well and has no complaints. She has failed multiple times at attempting to quit smoking and has a 40 pack-year smoking history. She drinks 4 alcoholic beverages every night. The patient is currently taking a multivitamin and vitamin D supplements. She has also attempted to eat more salmon given that she has heard of its health benefits. Physical exam is notable for back stiffness on mobility testing. The patient states that she frequently has back pain when sitting. Laboratory values are obtained as seen below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 4.3 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 1.1 mg/dL Ca2+: 12.2 mg/dL PTH: 75 pg/mL (normal 10 - 65 pg/mL) Urine: Color: Yellow pH: 7.0 Blood: 1+ Protein: Negative Nitrite: Positive Bacteria: Positive Ca2+: Low Benzodiazepines: Positive Which of the following is the best explanation for this patient’s electrolyte abnormalities?

A. Renal cell carcinoma
B. Familial hypocalciuric hypercalcemia (Correct Answer)
C. Hyperparathyroidism
D. Multiple myeloma
E. Hypervitaminosis D

Explanation: ***Familial hypocalciuric hypercalcemia*** - This condition presents with **mildly elevated calcium** and **inappropriately normal or mildly elevated PTH**, alongside **low urine calcium excretion**. - The patient's serum calcium of 12.2 mg/dL, PTH of 75 pg/mL (normal 10-65 pg/mL), and low urine calcium are classic findings for **FHH**. *Renal cell carcinoma* - While renal cell carcinoma can cause **hypercalcemia through PTH-related peptide (PTHrP) secretion**, this typically results in **low PTH levels**, which is not seen here. - PTHrP-mediated hypercalcemia often leads to **increased urinary calcium excretion**, contrasting with the low urine calcium observed in this patient. *Hyperparathyroidism* - **Primary hyperparathyroidism** would cause **elevated PTH** and **hypercalcemia** with **increased urinary calcium excretion**, unlike the low urinary calcium in this patient. - While **secondary hyperparathyroidism** can lead to elevated PTH, it is usually associated with **hypocalcemia** or normal calcium, not hypercalcemia. *Multiple myeloma* - **Multiple myeloma** causes hypercalcemia through **bone destruction** by plasma cells, typically presenting with **suppressed PTH levels**. - This condition is also associated with a **monoclonal protein spike** and **renal insufficiency**, which are not indicated by the provided lab values. *Hypervitaminosis D* - **Excessive vitamin D intake** leads to hypercalcemia by increasing intestinal calcium absorption and bone resorption, which would typically cause **suppressed PTH levels**. - The patient reports taking vitamin D supplements, but her PTH is elevated and urine calcium low, pointing away from vitamin D toxicity as the primary cause.

Question 858: An 82-year-old man—a retired physics professor—presents with progressive difficulty walking. He has bilateral knee osteoarthritis and has used a walker for the past several years. For the past 6 months, he has experienced problems walking and maintaining balance and has been wheelchair-bound. He has fallen several times, hitting his head a few times but never losing consciousness. He complains of occasional difficulty remembering names and phone numbers, but his memory is otherwise fine. He also complains of occasional incontinence. Physical examination reveals a slow wide-based gait with small steps and intermittent hesitation. He scores 22 out of 30 on the Mini-Mental State Examination (MMSE). A brain MRI demonstrates dilated ventricles with high periventricular fluid-attenuated inversion recovery (FLAIR) signal. A large-volume lumbar puncture improves his gait. Which of the following is the most likely risk factor for the development of this condition?

A. Alzheimer’s disease
B. Diabetes mellitus
C. Epilepsy
D. Subarachnoid hemorrhage (Correct Answer)
E. Hypertension

Explanation: ***Subarachnoid hemorrhage*** - This patient presents with classic **normal pressure hydrocephalus (NPH)**: gait disturbance, mild dementia (MMSE 22/30), and urinary incontinence (the "wet, wacky, and wobbly" triad). - **Subarachnoid hemorrhage (SAH)** is the most well-established risk factor for **secondary NPH**, as blood products in the subarachnoid space impair CSF reabsorption at the arachnoid granulations. - The patient's history of **multiple falls with head trauma** raises suspicion for possible prior SAH events, which could have been subclinical or unrecognized. - Secondary NPH (from SAH, meningitis, head trauma, or neurosurgery) is more common than idiopathic NPH. *Hypertension* - While hypertension is a risk factor for **vascular dementia** and cerebral small vessel disease, it is **not an established risk factor for NPH**. - Hypertension contributes to microvascular disease but does not directly impair CSF absorption mechanisms that lead to NPH. *Alzheimer's disease* - Alzheimer's disease is a **differential diagnosis** for NPH, not a risk factor. - Alzheimer's typically presents with prominent **early memory loss** as the primary symptom, whereas NPH characteristically presents with **gait disturbance first**. - Brain imaging in Alzheimer's shows **cortical atrophy**, not the ventricular dilation with periventricular hyperintensity seen in NPH. *Diabetes mellitus* - Diabetes causes **microvascular disease** and increases stroke risk but is not a recognized risk factor for NPH. - It does not affect CSF dynamics or arachnoid granulation function in a way that would predispose to hydrocephalus. *Epilepsy* - Epilepsy is characterized by **recurrent seizures** and has no established relationship to NPH development. - While some neurological conditions can cause both seizures and hydrocephalus, epilepsy itself does not cause impaired CSF absorption.

Question 859: A 15-year-old girl presents with four days of malaise, painful joints, nodular swelling over her elbows, low-grade fever, and a rash on her chest and left shoulder. Two weeks ago, she complained of a sore throat that gradually improved but was not worked up. She was seen for a follow-up approximately one week later. At this visit her cardiac exam was notable for a late diastolic murmur heard best at the apex in the left lateral decubitus position with no radiation. Which of the following is the best step in the management of this patient?

A. Aortic valve replacement
B. Mitral valve repair
C. Reassurance that this is a benign murmur and send home
D. Penicillin therapy (Correct Answer)
E. NSAIDS for symptomatic relief

Explanation: ***Penicillin therapy*** - This patient presents with symptoms highly suggestive of **acute rheumatic fever (ARF)** following an untreated streptococcal pharyngitis (sore throat). The **Jones criteria** are met with **polyarthritis**, **subcutaneous nodules**, **erythema marginatum (rash)**, and the development of **rheumatic carditis** indicated by the new murmur. - **Penicillin therapy** is crucial to eradicate any remaining Group A Streptococcus (GAS) and prevent further progression of the disease and recurrent episodes, which can lead to more severe cardiac damage. *Aortic valve replacement* - **Aortic valve replacement** is a surgical intervention used for severe **aortic valve disease**. Although rheumatic heart disease can eventually affect the aortic valve, the patient is currently in the acute phase of ARF, and the murmur described (late diastolic at the apex) is more consistent with **mitral stenosis or mitral insufficiency**, not typically severe aortic valve disease requiring immediate replacement. *Mitral valve repair* - **Mitral valve repair** is also a surgical procedure indicated for significant **mitral valve dysfunction**. - While rheumatic carditis can lead to mitral valve damage, it is premature to consider surgical intervention at the onset of ARF, especially given that the immediate goal is to treat the underlying infection and inflammation. *Reassurance that this is a benign murmur and send home* - This is an inappropriate step as the patient presents with multiple signs and symptoms indicative of a serious inflammatory condition (**acute rheumatic fever**). - The new cardiac murmur, coupled with the other clinical findings, clearly suggests **rheumatic carditis**, which is a significant and potentially damaging manifestation of ARF, requiring urgent medical attention. *NSAIDS for symptomatic relief* - **NSAIDs (non-steroidal anti-inflammatory drugs)** can be used for **symptomatic relief** of arthralgia and fever in ARF. - However, NSAIDs do not address the underlying streptococcal infection or prevent further cardiac damage, making them an adjunct therapy rather than the primary best step in management.

Question 860: A 16-year-old boy comes to the physician with a 4-day history of sore throat and mild fever. He is on the varsity soccer team at his high school, but has been unable to go to practice for the last few days because he has been very tired and is easily exhausted. He has no history of serious illness and takes no medications. His mother has type 2 diabetes mellitus. He appears weak and lethargic. His temperature is 38.7°C (101.7°F), pulse is 84/min, and blood pressure is 116/78 mm Hg. Examination shows enlarged, erythematous, and exudative tonsils; posterior cervical lymphadenopathy is present. Abdominal examination shows no abnormalities. His hemoglobin concentration is 14.5 g/dL and leukocyte count is 11,200/mm3 with 48% lymphocytes. A heterophile antibody test is positive. In addition to supportive therapy, which of the following is the most appropriate next step in management?

A. Oral corticosteroid therapy
B. Oral amoxicillin therapy
C. Intravenous foscarnet therapy
D. Intravenous acyclovir therapy
E. Write a medical note excusing the patient from soccer activities (Correct Answer)

Explanation: ***Write a medical note excusing the patient from soccer activities*** - The patient's symptoms (sore throat, fatigue, fever), physical findings (exudative tonsils, posterior cervical lymphadenopathy), and **positive heterophile antibody test** are classic for **infectious mononucleosis (IM) caused by Epstein-Barr virus (EBV)**. - While supportive care is key, a critical management step for IM, especially in athletes, is to advise against strenuous physical activity, particularly contact sports, for at least 3-4 weeks due to the risk of **splenic rupture**. - The patient should be restricted from all athletic activities until splenomegaly resolves and adequate recovery time has passed. *Oral corticosteroid therapy* - **Corticosteroids** are generally reserved for severe complications of mononucleosis, such as **airway obstruction** due to massive tonsillar hypertrophy, **severe thrombocytopenia**, or **hemolytic anemia**. - There is no indication for routine corticosteroid use in this patient with moderate symptoms. *Oral amoxicillin therapy* - **Amoxicillin** is an antibiotic and is not effective against viral infections like infectious mononucleosis. - Furthermore, administration of **amoxicillin** or **ampicillin** in patients with EBV infection frequently leads to a characteristic **maculopapular rash**, which can be easily mistaken for an allergic reaction. *Intravenous foscarnet therapy* - **Foscarnet** is an antiviral medication used primarily for **cytomegalovirus (CMV)** infections, particularly in immunocompromised individuals, and for acyclovir-resistant herpes simplex virus (HSV). - It is not indicated for the treatment of typical infectious mononucleosis caused by EBV. *Intravenous acyclovir therapy* - **Acyclovir** is an antiviral drug primarily used to treat **herpes simplex virus (HSV)** and **varicella-zoster virus (VZV)** infections. - While EBV is a herpesvirus, acyclovir has **limited clinical efficacy** in treating acute infectious mononucleosis and is not routinely recommended.

Question 861: A 36-year-old man presents to his physician with the complaint of bilateral lower back pain. The pain is 5/10, constant, aching, aggravated by bending forward and lying supine, and is alleviated by resting in a neutral position. The pain appeared 3 days ago after the patient overstrained at the gym. He does not report changes in sensation or limb weakness. The patient works as a business analyst. The patient’s weight is 88 kg (194 lb), and the height is 186 cm (6 ft 1 in). The vital signs are within normal limits. The neurological examination shows equally normal lower limb reflexes, and preserved muscle tone and power. The paravertebral palpation of the lumbar region increases the pain. Which of the following non-pharmacological interventions is the most appropriate in the presented case?

A. Electromyographic biofeedback
B. Maintaining usual activity as tolerated (Correct Answer)
C. Therapeutic ultrasonography
D. Bed rest for 3 days
E. Manual traction

Explanation: ***Maintaining usual activity as tolerated*** - This patient presents with acute, **non-radicular low back pain** without neurological deficits, likely due to **musculoskeletal strain** from overstraining at the gym. For such cases, current guidelines recommend maintaining activity as tolerated. - Early mobilization and avoiding prolonged rest help prevent deconditioning and promote faster recovery, as it also prevents the transition from acute to chronic pain. *Electromyographic biofeedback* - This intervention is typically used for **chronic pain conditions**, muscle re-education, or specific neuromuscular disorders. - It is not a primary recommended non-pharmacological treatment for acute, uncomplicated lower back pain and is usually not used in the initial phase of injury. *Therapeutic ultrasonography* - The evidence for the effectiveness of therapeutic ultrasonography in treating **acute low back pain** is limited and inconsistent. - It is not considered a first-line treatment for acute musculoskeletal strain and is often reserved for specific conditions or as an adjunct therapy. *Bed rest for 3 days* - Prolonged bed rest (more than 1-2 days) is **not recommended** for acute low back pain. - It can lead to **deconditioning**, increased stiffness, and actually *delay* recovery, potentially contributing to chronic pain. *Manual traction* - **Manual traction** has limited evidence of effectiveness for acute low back pain and is generally not recommended as a routine treatment. - It may be considered for specific conditions like **radiculopathy** with signs of nerve compression, which this patient does not have.

Question 862: A 68-year-old man comes to the physician for a routine health maintenance examination. His wife has noticed that his left eye looks smaller than his right eye. He has had left shoulder and arm pain for 3 months. He has hypertension and coronary artery disease. Current medications include enalapril, metoprolol, aspirin, and atorvastatin. His medical history is significant for gonorrhea, for which he was treated in his 30's. He has smoked two packs of cigarettes daily for 35 years. He does not drink alcohol. His temperature is 37°C (98.6°F), pulse is 71/min, and blood pressure is 126/84 mm Hg. The pupils are unequal; when measured in dim light, the left pupil is 3 mm and the right pupil is 5 mm. There is drooping of the left eyelid. The remainder of the examination shows no abnormalities. Application of apraclonidine drops in both eyes results in a left pupil size of 5 mm and a right pupil size of 4 mm. Which of the following is the most appropriate next step in management?

A. Erythrocyte sedimentation rate
B. CT scan of the chest (Correct Answer)
C. Applanation tonometry
D. Anti-acetylcholine receptor antibodies
E. Rapid plasma reagin

Explanation: ***CT scan of the chest*** - The patient presents with **Horner's syndrome** (miosis, ptosis, and anhidrosis - though anhidrosis isn't explicitly mentioned, miosis and ptosis are clearly present) - The combination of Horner's syndrome, **70 pack-year smoking history**, and **shoulder/arm pain** is highly suspicious for a **Pancoast tumor** (superior sulcus tumor) compressing the sympathetic chain - The **apraclonidine test** confirms **postganglionic Horner's syndrome** (reversal of anisocoria), consistent with a compressive lesion - **CT scan of the chest** is the most appropriate next step to evaluate for an apical lung mass *Erythrocyte sedimentation rate* - ESR is a non-specific inflammatory marker that would not directly diagnose the underlying cause of Horner's syndrome - While it may be elevated in malignancies or inflammatory conditions, it doesn't provide the specific anatomical information needed to identify a Pancoast tumor *Applanation tonometry* - This test measures intraocular pressure and is used to screen for glaucoma - Not relevant to the evaluation of Horner's syndrome or the patient's other concerning symptoms *Anti-acetylcholine receptor antibodies* - These antibodies are used to diagnose **myasthenia gravis**, an autoimmune neuromuscular disorder - Myasthenia gravis can cause ptosis and fatigable muscle weakness, but it does **not** cause miosis or anisocoria - The positive apraclonidine test confirms this is Horner's syndrome, not myasthenia gravis *Rapid plasma reagin* - RPR is a screening test for syphilis - While the patient has a history of gonorrhea (different STI), there are no current symptoms suggestive of syphilis - Neurosyphilis would not explain the specific pattern of postganglionic Horner's syndrome or the shoulder pain in this smoking patient

Question 863: A 30-year-old African American man comes to the doctor's office for an annual checkup. He feels healthy and his only concern is an occasional headache after work. Past medical history is significant for an appendectomy 10 years ago and a fractured arm playing football in high school. His mother has type 2 diabetes mellitus, while his father and grandfather both have hypertension. He does not drink alcohol, smoke cigarettes, or use drugs. His vital signs include: pulse 78/min and regular, respiratory rate 16/min, and temperature 36.8°C (98.2°F). Physical examination reveals an overweight African American man 167 cm (5 ft 6 in) tall and weighing 80 kg (176 lb) with a protuberant belly. BMI is 28.7 kg/m2. The remainder of the examination is unremarkable. During his last 2 visits, his blood pressure readings have been 140/86 mm Hg and 136/82 mm Hg. Today his blood pressure is 136/86 mm Hg and his laboratory tests show: Serum Glucose (fasting) 90.0 mg/dL Serum Electrolytes: Sodium 142.0 mEq/L Potassium 3.9 mEq/L Chloride 101.0 mEq/L Serum Creatinine 0.8 mg/dL Blood urea nitrogen 9.0 mg/dL Urinalysis: Glucose Negative Ketones Negative Leukocytes Negative Nitrite Negative RBCs Negative Casts Negative Which of the following is the next best step in the management of this patient?

A. Start him on hydrochlorothiazide.
B. Recommend weight loss, more exercise, and a salt-restricted diet. (Correct Answer)
C. Start him on lisinopril.
D. Order a glycosylated hemoglobin test (HbA1c).
E. Start him on hydrochlorothiazide and lisinopril together.

Explanation: ***Recommend weight loss, more exercise, and a salt-restricted diet.*** - The patient's blood pressure readings over three visits (140/86, 136/82, and 136/86 mm Hg) indicate **hypertension**, with the first reading meeting criteria for **Stage 2 hypertension** (systolic ≥140 mm Hg) and subsequent readings in the **Stage 1 range** (130-139/80-89 mm Hg). - However, this patient is young (30 years old) with **no evidence of end-organ damage** and likely has a **low 10-year ASCVD risk** (<10%), making him appropriate for initial management with **lifestyle modifications alone**. - **Lifestyle modifications** are the cornerstone of initial hypertension management and include: weight loss (BMI 28.7 with central obesity), regular physical activity, dietary changes (DASH diet with salt restriction <2.3g sodium/day), and limiting alcohol. - Per **2017 ACC/AHA guidelines**, for patients with Stage 1 hypertension and low CV risk, or those with borderline readings like this patient, lifestyle modification should be attempted first with reassessment in 3-6 months before initiating pharmacotherapy. *Start him on hydrochlorothiazide.* - While **thiazide diuretics** are first-line pharmacotherapy for hypertension and particularly effective in African American patients, medication is typically initiated when: (1) blood pressure is consistently ≥140/90 mm Hg **and** patient has high CV risk (≥10% ASCVD risk), or (2) lifestyle modifications fail after 3-6 months. - This patient has not yet attempted lifestyle modifications and likely has low CV risk given his young age and absence of other cardiovascular risk factors beyond family history and overweight status. - Starting medication immediately without counseling on lifestyle changes would bypass a critical and potentially effective intervention. *Start him on lisinopril.* - **ACE inhibitors** like lisinopril are first-line agents for hypertension, particularly beneficial in patients with compelling indications such as diabetes, chronic kidney disease, heart failure, or post-MI—none of which this patient currently has. - As with thiazide diuretics, initiation of an ACE inhibitor would typically follow an unsuccessful trial of **lifestyle modification** in a young, low-risk patient with borderline hypertension. *Order a glycosylated hemoglobin test (HbA1c).* - While the patient has a family history of diabetes and is overweight, his **fasting glucose is 90 mg/dL**, which is completely normal (<100 mg/dL). - An HbA1c test would be indicated if fasting glucose was ≥100 mg/dL (impaired fasting glucose) or if there were clinical signs of diabetes, which are not present. - Although diabetes screening may be reasonable given his risk factors, addressing his **confirmed hypertension** is the more pressing clinical priority at this visit. *Start him on hydrochlorothiazide and lisinopril together.* - **Combination therapy** with two antihypertensive agents is typically reserved for patients with **Stage 2 hypertension (≥140/90 mm Hg) with high CV risk** or those who do not achieve blood pressure targets with monotherapy plus lifestyle modifications. - Initiating two medications simultaneously in a young patient who has not attempted lifestyle changes is an overly aggressive approach that increases the risk of side effects and cost without clear benefit.

Question 864: A 72-year-old woman is brought to the emergency department by her daughter because of left-sided weakness for 1 hour. She does not have headache or blurring of vision. She has hypertension, hypercholesterolemia, type 2 diabetes, and coronary artery disease. She has smoked one half-pack of cigarettes daily for 45 years. Her medications include atorvastatin, amlodipine, metformin, and aspirin. Her temperature is 37°C (98.6°F), pulse is 92/min, and blood pressure is 168/90 mm Hg. Examination shows a left facial droop. Muscle strength is decreased on the left side. Deep tendon reflexes are 3+ on the left. Sensation to pinprick, light touch, and vibration as well as two-point discrimination are normal. Which of the following is the most likely cause of these findings?

A. Lipohyalinosis of lenticulostriate arteries (Correct Answer)
B. Rupture of an intracranial aneurysm
C. Dissection of the vertebral artery
D. Embolism from the left atrium
E. Atherosclerosis of the internal carotid artery

Explanation: ***Lipohyalinosis of lenticulostriate arteries*** - This patient presents with a **pure motor deficit** (left-sided weakness and facial droop) without sensory changes, a classic presentation for a **lacunar stroke**. - **Lipohyalinosis** affects small, penetrating arteries like the lenticulostriate arteries, often caused by chronic **hypertension** and **diabetes**, both present in this patient. *Rupture of an intracranial aneurysm* - An aneurysm rupture typically causes a **subarachnoid hemorrhage**, presenting with a sudden, severe **thunderclap headache**, meningismus, and altered mental status, which are absent here. - While it can cause neurological deficits, the pure motor presentation without headache is less characteristic of an acute rupture. *Dissection of the vertebral artery* - Vertebral artery dissection often presents with **posterior circulation symptoms** such as vertigo, ataxia, diplopia, and neck pain, none of which are described. - While it can lead to stroke, the isolated motor deficit without other brainstem signs makes it less likely. *Embolism from the left atrium* - Cerebral embolism usually results in a **cortical stroke** with a broader range of symptoms including aphasia, neglect, or sensory deficits in addition to motor weakness, depending on the affected large vessel territory. - While the patient has risk factors for atrial fibrillation (CAD, hypertension), the isolated motor deficit is more typical of a small vessel occlusion. *Atherosclerosis of the internal carotid artery* - Severe carotid atherosclerosis can cause strokes due to **artery-to-artery embolism** or hemodynamically significant stenosis, typically affecting larger cerebral arteries leading to cortical signs. - Symptoms often include **amaurosis fugax** or broader neurological deficits localized to the anterior circulation, which differ from the pure motor lacunar syndrome seen here.

Question 865: A 69-year-old man is brought to the emergency department for severe tearing lower back pain for 12 hours. The pain radiates to the flank and he describes it as 8 out of 10 in intensity. He has nausea and has vomited several times. He has no fever, diarrhea, or urinary symptoms. When he stands up suddenly, he becomes light-headed and has to steady himself for approximately 1 to 2 minutes before he is able to walk. He has hypertension and hyperlipidemia. Two years ago, he had a myocardial infarction and underwent coronary artery bypass grafting of his right coronary artery. He has smoked one and a half packs of cigarettes daily for 40 years and drinks 1 to 2 beers daily. His current medications include chlorthalidone, atorvastatin, lisinopril, and aspirin. He appears acutely ill. His temperature is 37.2°C (98.9°F), pulse is 130/min and regular, respirations are 35/min, and blood pressure is 80/55 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 85%. Examination shows a pulsatile mass in the abdomen. Intravenous fluids and high-flow oxygen are started. Thirty minutes later, the patient dies. Which of the following was the strongest predisposing factor for the condition leading to this patient's death?

A. Hyperlipidemia
B. Smoking (Correct Answer)
C. Male sex
D. Hypertension
E. Advanced age

Explanation: ***Smoking*** - **Smoking** is the strongest predisposing factor for **abdominal aortic aneurysms (AAAs)**, which is the most likely cause of this patient's death due to rupture. It significantly accelerates **atherosclerosis** and causes **degeneration of the arterial wall**. - Smokers have a **four to five times higher risk** of developing an AAA compared to non-smokers, and the risk increases with the duration and intensity of smoking. *Hyperlipidemia* - While **hyperlipidemia** contributes to **atherosclerosis** and is a risk factor for cardiovascular disease, its direct association with AAA formation is less significant than smoking. - **Statins** (like atorvastatin, which the patient is taking) are used to manage hyperlipidemia and can slow the progression of atherosclerosis, but they do not reverse the underlying damage. *Male sex* - **Male sex** is a risk factor for AAAs, with men being **4 to 5 times more likely** to develop them compared to women. - However, compared to smoking, which causes significant biochemical and structural changes in the arterial wall, being male is a less modifiable and less potent individual risk factor. *Hypertension* - **Hypertension** is a risk factor for AAA development and rupture, as **elevated blood pressure** places increased stress on the arterial wall. - While important, its influence on AAA formation is generally considered secondary to the direct damaging effects of smoking on arterial wall integrity. *Advanced age* - **Advanced age** is a significant risk factor for AAAs because the arterial walls naturally **weaken and stiffen** over time due to degenerative changes. - Although age is a strong association, modifiable risk factors like smoking contribute more to the *initiation and progression* of AAA pathology than age alone.

Question 866: A 19-year-old woman comes to the physician for a routine health maintenance examination. She appears well. Her vital signs are within normal limits. Cardiac auscultation shows a mid-systolic click and a grade 3/6, late-systolic, crescendo murmur that is best heard at the cardiac apex in the left lateral recumbent position. After the patient stands up suddenly, the click is heard during early systole and the intensity of the murmur increases. Which of the following is the most likely underlying cause of this patient's examination findings?

A. Congenital interventricular communication
B. Myxomatous degeneration (Correct Answer)
C. Dystrophic valvular calcification
D. Congenital valvular fusion
E. Myosin heavy chain defect

Explanation: ***Myxomatous degeneration*** - The classic auscultation findings of a **mid-systolic click** followed by a **late-systolic crescendo murmur** heard best at the apex are characteristic of **mitral valve prolapse (MVP)**. - The change in timing of the click to early systole and increased murmur intensity upon standing are due to decreased left ventricular volume, which accentuates MVP by causing the mitral valve leaflets to prolapse earlier and more severely. These findings are the result of **myxomatous degeneration** of the mitral valve leaflets. *Congenital interventricular communication* - This condition (e.g., **ventricular septal defect**) typically presents with a **holosystolic murmur** best heard at the lower left sternal border and is usually detected earlier in life. - It would not cause a mid-systolic click or a late-systolic crescendo murmur that changes with position in this manner. *Dystrophic valvular calcification* - **Dystrophic calcification** is a common cause of **aortic stenosis** in older individuals and is not typically associated with mitral valve prolapse in a young patient. - Aortic stenosis produces a **crescendo-decrescendo systolic murmur** loudest at the right upper sternal border, often radiating to the carotids, without a mid-systolic click. *Congenital valvular fusion* - **Congenital valvular fusion** usually leads to **stenosis** (e.g., congenital aortic stenosis or bicuspid aortic valve) or **regurgitation**, depending on the valve involved. - While it can cause murmurs, it does not typically present with the specific mid-systolic click and late-systolic crescendo murmur characteristic of mitral valve prolapse, especially with its dynamic changes. *Myosin heavy chain defect* - A **myosin heavy chain defect** is a common genetic cause of **hypertrophic cardiomyopathy (HCM)**. - HCM typically produces a **crescendo-decrescendo systolic murmur** that increases with Valsalva maneuver (due to decreased preload) and decreases with squatting (due to increased preload and afterload), but it does not feature a mid-systolic click.

Question 867: A 30-year-old woman is brought to the clinic at her husband's insistence for sleep disturbances. Most nights of the week she repeatedly gets out of bed to pace around their apartment before returning to bed. The woman says that while she's lying in bed, she becomes overwhelmed by a "creepy-crawly" feeling in her legs that she can only relieve by getting out of bed. Past medical history is noncontributory and physical exam is unremarkable. Which of the following laboratory studies is most likely abnormal in this patient?

A. Hemoglobin A1c
B. Nerve conduction studies
C. Liver function tests
D. Lumbar puncture
E. Complete blood count (Correct Answer)

Explanation: ***Complete blood count*** - The patient's symptoms are highly suggestive of **restless legs syndrome (RLS)**, characterized by an irresistible urge to move the legs, often accompanied by uncomfortable sensations that worsen at rest and improve with movement, and are worse in the evening or night [1]. - **Iron deficiency** is a common and treatable secondary cause of RLS [2]. While **serum ferritin** is the most specific test for iron stores (and should be checked in all RLS patients), a **complete blood count (CBC)** is the most appropriate initial screening test among the given options. - CBC may reveal **microcytic anemia** (low MCV, low hemoglobin) suggesting iron deficiency [3], though iron deficiency can exist without anemia. In clinical practice, CBC abnormalities would prompt further iron studies including ferritin, serum iron, TIBC, and transferrin saturation. *Hemoglobin A1c* - While **diabetes mellitus** can be associated with peripheral neuropathy causing leg discomfort, diabetic neuropathy typically presents with different symptoms: numbness, tingling, or burning pain in a stocking-glove distribution. - Diabetic neuropathy symptoms are **not relieved by movement** in the characteristic way seen in RLS, and symptoms don't specifically worsen at rest or in the evening. *Nerve conduction studies* - These studies evaluate peripheral nerve function and can detect neuropathy or nerve damage. - While secondary RLS can occasionally be associated with peripheral neuropathy, the classic presentation described here suggests **primary RLS** or iron deficiency-related RLS, neither of which would show abnormal nerve conduction studies [1]. - Nerve conduction studies would only be considered if there were additional neurological findings suggesting neuropathy. *Liver function tests* - **Chronic liver disease** can occasionally be associated with RLS, but this is uncommon and there are no clinical indicators of liver dysfunction in this patient (no jaundice, no ascites, no hepatomegaly, unremarkable physical exam). - LFTs are not part of the routine workup for RLS. *Lumbar puncture* - A **lumbar puncture** analyzes cerebrospinal fluid and is used to diagnose CNS infections, inflammatory conditions, or demyelinating diseases. - RLS is a movement disorder related to dopaminergic dysfunction and iron metabolism, not a CNS inflammatory or infectious process. Lumbar puncture has no role in RLS diagnosis and would not show abnormalities.

Question 868: A 70-year-old male with a 10-year history of COPD visits his pulmonologist for a checkup. Physical examination reveals cyanosis, digital clubbing, and bilateral lung wheezes are heard upon auscultation. The patient has a cough productive of thick yellow sputum. Which of the following findings is most likely present in this patient?

A. Increased pH of the arterial blood
B. Decreased arterial carbon dioxide content
C. Increased pulmonary arterial resistance (Correct Answer)
D. Increased right ventricle compliance
E. Increased cerebral vascular resistance

Explanation: ***Increased pulmonary arterial resistance*** - Chronic **hypoxia** due to advanced COPD (cyanosis, digital clubbing) leads to widespread **pulmonary vasoconstriction**. - This persistent vasoconstriction increases **pulmonary arterial resistance**, eventually causing **pulmonary hypertension** and **cor pulmonale**. *Increased pH of the arterial blood* - Patients with severe COPD and chronic respiratory insufficiency typically develop **respiratory acidosis** due to CO2 retention, causing a decreased or normal-low pH, not an increased pH. - An increased pH (alkalosis) would suggest hyperventilation or metabolic conditions not indicated by the symptoms of advanced COPD. *Decreased arterial carbon dioxide content* - COPD, especially with features like cyanosis and productive cough, often leads to **impaired gas exchange** and **CO2 retention**, resulting in an **increased arterial carbon dioxide content (hypercapnia)**, not a decrease. - A decreased CO2 content would typically be seen in hyperventilation. *Increased right ventricle compliance* - Chronic pulmonary hypertension, a common complication of severe COPD, puts increased pressure on the right ventricle, leading to **hypertrophy** and eventually **dilation** and **decreased compliance** (stiffening), not increased compliance. - Increased compliance would imply a more easily distensible ventricle, which is not characteristic of cor pulmonale. *Increased cerebral vascular resistance* - **Hypercapnia** (increased arterial CO2), common in severe COPD, causes **cerebral vasodilation** to increase blood flow to the brain, leading to **decreased cerebral vascular resistance**, not increased. - Increased cerebral vascular resistance is typically seen in conditions like severe vasoconstriction or edema.

Question 869: A 57-year-old woman is admitted to the intensive care unit for management of shock. Her pulse is feeble and blood pressure is 86/45 mm Hg. The patient undergoes pulmonary artery catheterization which shows an elevated pulmonary capillary wedge pressure and increased systemic vascular resistance. Which of the following additional findings is most likely in this patient?

A. Bronchospasm due to excessive histamine release
B. Mottled skin due to release of endotoxins
C. Bradycardia due to neurologic dysfunction
D. Cold skin due to loss of intravascular fluid volume
E. Confusion due to decreased stroke volume (Correct Answer)

Explanation: ***Confusion due to decreased stroke volume*** - The presented symptoms (low BP, elevated PCWP, increased SVR) indicate **cardiogenic shock**, where the heart's pumping ability is impaired, leading to reduced cardiac output and **decreased stroke volume**. - **Decreased stroke volume** directly results in reduced perfusion to vital organs, including the brain, which manifests as **confusion** due to cerebral hypoperfusion. *Bronchospasm due to excessive histamine release* - **Bronchospasm** is not directly indicated by the hemodynamic profile of cardiogenic shock; it is more characteristic of **anaphylactic shock**. - While some inflammatory mediators can be released in shock, widespread **histamine release** leading to bronchospasm is not a primary feature of cardiogenic shock. *Mottled skin due to release of endotoxins* - **Mottled skin** can occur in various shock states due to poor peripheral perfusion but is often more prominent in **septic shock** where **endotoxins** play a significant role. - The hemodynamic profile (elevated PCWP, increased SVR) is inconsistent with typical **septic shock**, which usually presents with low SVR and normal or low PCWP. *Bradycardia due to neurologic dysfunction* - **Bradycardia** is generally not a primary compensatory mechanism in shock; the body usually attempts to increase heart rate to maintain cardiac output. - While severe neurologic dysfunction can cause bradycardia, in shock, **tachycardia** is a more common compensatory response unless there are specific pre-existing conditions or severe terminal stages. *Cold skin due to loss of intravascular fluid volume* - **Cold skin** is indeed common in cardiogenic shock due to increased SVR and vasoconstriction, however, the primary problem is a failing heart pump, not **loss of intravascular fluid volume**. - **Loss of intravascular fluid volume** would indicate hypovolemic shock, which is characterized by a low PCWP (due to decreased preload) unlike the elevated PCWP seen in this patient.

Question 870: A 72-year-old man presents to the emergency department with severe respiratory distress. He was diagnosed with metastatic pancreatic cancer 6 months ago and underwent 2 rounds of chemotherapy. He says that he has had a cough and flu-like symptoms for the past week. During the interview, he is having progressive difficulty answering questions and suddenly becomes obtunded with decreased motor reflexes. His temperature is 38.8°C (102.0°F), blood pressure is 90/60 mm Hg, pulse is 94/min, and respirations are 22/min. Pulse oximetry is 82% on room air. The patient’s medical record contains an advanced directive stating that he would like all interventions except for cardiopulmonary resuscitation. Which of the following is the most appropriate next step in management?

A. Administer intravenous antibiotics and draw blood for testing.
B. Intubate and administer intravenous antibiotics. (Correct Answer)
C. Intubate only.
D. Observe and monitor vital signs for improvement.
E. Administer intravenous fluids.

Explanation: ***Intubate and administer intravenous antibiotics.*** - The patient presents with **severe respiratory distress**, **hypoxia (82% SpO2)**, **fever**, **hypotension**, and **altered mental status**, indicating **septic shock** with **respiratory failure**. **Intubation** is necessary to secure the airway and provide ventilatory support given his rapidly deteriorating respiratory status and obtundation. - Given the signs of severe infection (fever, flu-like symptoms, sepsis), **empiric intravenous antibiotics** are crucial to treat the suspected underlying infection, likely pneumonia given the respiratory symptoms. The advanced directive specifically excludes CPR but allows "all interventions," which would include intubation and antibiotics. *Administer intravenous antibiotics and draw blood for testing.* - While immediate **intravenous antibiotics** and **blood tests** are appropriate for sepsis, this option does not address the patient's **acute respiratory failure** and **obtundation**, which require immediate airway management. - Delaying intubation could lead to further respiratory compromise, cardiorespiratory arrest, or irreversible organ damage. *Intubate only.* - This option correctly identifies the need for **intubation** due to acute respiratory failure and altered mental status. - However, it fails to address the underlying severe infection and septic shock, which requires immediate **antibiotic administration** to improve outcomes. *Observe and monitor vital signs for improvement.* - This patient is in **severe respiratory distress** and **septic shock** with rapidly deteriorating vital signs and altered mental status. **Observation** alone would be inappropriate and could lead to rapid clinical decline and death. - Immediate aggressive intervention is required to stabilize the patient. *Administer intravenous fluids.* - **Intravenous fluids** are necessary to manage **septic shock** and hypotension, but they are not the most immediate or comprehensive next step given the patient's **acute respiratory failure** and need for airway management. - This option solely addresses circulation and neglects the critical respiratory and infectious components.

Question 871: A 74-year-old man is brought from a nursing home to the emergency room for progressive confusion. The patient has a history of stroke 3 years ago, which rendered him wheelchair-bound. He was recently started on clozapine for schizoaffective disorder. Vital signs reveal a temperature of 38.7°C (101.66°F), a blood pressure of 100/72 mm Hg, and a pulse of 105/minute. On physical examination, he is disoriented to place and time. Initial lab work-up results are shown: Serum glucose: 945 mg/dL Serum sodium: 120 mEq/L Serum urea: 58 mg/dL Serum creatinine: 2.2 mg/dL Serum osmolality: 338 mOsm/kg Serum beta-hydroxybutyrate: negative Urinalysis reveals: numerous white blood cells and trace ketones Which of the following manifestations is more likely to be present in this patient?

A. Nausea or vomiting
B. Abdominal pain
C. Rapid deep breathing
D. Fruity odor of the breath
E. Seizures (Correct Answer)

Explanation: ***Seizures*** - The patient exhibits features of **Hyperosmolar Hyperglycemic State (HHS)**, including severe hyperglycemia (>600 mg/dL), elevated serum osmolality (>320 mOsm/kg), and significant dehydration, all of which increase the risk of neurological complications like **seizures**. - **Hyponatremia** (120 mEq/L) also contributes to cerebral edema and neurological dysfunction, further increasing the risk of seizures in HHS. *Nausea or vomiting* - While non-specific, **nausea and vomiting** are **less common** and less prominent in HHS compared to Diabetic Ketoacidosis (DKA). - The absence of significant ketonemia (negative serum beta-hydroxybutyrate) makes DKA less likely, where these gastrointestinal symptoms are more typical. *Abdominal pain* - **Abdominal pain** is a more characteristic symptom of **Diabetic Ketoacidosis (DKA)**, often associated with severe acidosis. - In HHS, abdominal pain is generally **infrequent** unless an underlying precipitating event, such as an acute abdomen or pancreatitis, is present. *Rapid deep breathing* - **Rapid deep breathing (Kussmaul respirations)** is a compensatory mechanism for **metabolic acidosis**, typically seen in DKA due to severe ketoacid production. - In HHS, there is usually **no significant metabolic acidosis** (due to minimal ketonemia), so Kussmaul respirations are not expected. *Fruity odor of the breath* - A **fruity odor of the breath** is indicative of **ketone body production**, specifically acetone, which is a hallmark of DKA. - The patient's **negative serum beta-hydroxybutyrate** and trace ketones in the urine (likely due to starvation or catabolism from illness) rule out significant ketosis, making this manifestation unlikely.

Question 872: A 58-year-old woman is followed in the nephrology clinic for longstanding chronic kidney disease (CKD) secondary to uncontrolled hypertension. Her glomerular filtration rate (GFR) continues to decline, and she is approaching initiation of hemodialysis. Plans are made to obtain vascular access at the appropriate time, and the patient undergoes the requisite screening to be enrolled as an end stage renal disease (ESRD) patient. Among patients on chronic hemodialysis, which of the following is the most common cause of death?

A. Cardiovascular disease (Correct Answer)
B. Infection
C. Stroke
D. Hyperkalemia
E. Cancer

Explanation: ***Cardiovascular disease*** - **Cardiovascular disease** is the leading cause of mortality in patients with **end-stage renal disease (ESRD)**, accounting for approximately 50% of all deaths. - This is due to a high prevalence of traditional risk factors (e.g., hypertension, diabetes) compounded by ESRD-specific factors like **uremic toxins**, volume overload, and inflammation, which accelerate atherosclerosis and cause cardiac remodeling. *Infection* - While **infection** is a significant cause of mortality in dialysis patients, it is the second leading cause, behind cardiovascular disease. - Dialysis patients are immunocompromised and frequently exposed to invasive procedures, increasing their risk for various infections, particularly access-related infections. *Stroke* - **Stroke** is a serious complication in ESRD patients due to accelerated atherosclerosis and hypertension, but it is not the most common cause of death. - While the risk of stroke is elevated in this population, it contributes to a smaller proportion of overall mortality compared to cardiac events. *Hyperkalemia* - Although **hyperkalemia** can be acutely life-threatening in ESRD patients due to its effects on cardiac rhythm, it is usually managed effectively with dialysis and medication. - Fatal hyperkalemia is relatively rare as a primary cause of death due to vigilant monitoring and timely intervention in patients on chronic hemodialysis. *Cancer* - Patients with ESRD have an increased risk of developing certain **cancers**, and cancer can be a cause of death. - However, cancer-related mortality is less common than deaths from cardiovascular disease or infection in the dialysis population.

Question 873: A 67-year-old man presents to his primary care physician for a wellness checkup. The patient states he has been doing well and currently has no concerns. The patient's daughter states that she feels he is abnormally fatigued and has complained of light-headedness whenever he gardens. He also admits that he fainted once. The patient has a past medical history of type II diabetes, hypertension, and constipation. He recently had a "throat cold" that he recovered from with rest and fluids. His temperature is 98.9°F (37.2°C), blood pressure is 167/98 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 99% on room air. Physical exam reveals a systolic murmur heard best along the right upper sternal border. An ECG is performed and demonstrates no signs of ST elevation. Cardiac troponins are negative. Which of the following is the most likely diagnosis?

A. Outflow tract obstruction
B. Calcification of valve leaflets (Correct Answer)
C. Incompetent valve
D. Autoimmune valve destruction
E. Bicuspid valve

Explanation: ***Calcification of valve leaflets*** - The patient's age (67 years old), symptoms (fatigue, light-headedness, syncope with exertion), and the presence of a **systolic murmur heard best along the right upper sternal border** are classic signs of **aortic stenosis**. - In elderly patients, **degenerative calcification** of the aortic valve leaflets is the most common cause of aortic stenosis. *Outflow tract obstruction* - While aortic stenosis is a form of outflow tract obstruction, this option is too general. - **Calcification of valve leaflets** is the specific pathological mechanism leading to the obstruction in this patient's age group. *Incompetent valve* - An incompetent valve (regurgitation) typically causes a **diastolic murmur** or a holosystolic regurgitant murmur, not the systolic ejection murmur described. - The symptoms of an incompetent valve can differ, often including signs of volume overload rather than exertional syncope directly caused by reduced forward flow. *Autoimmune valve destruction* - **Rheumatic fever** can cause valve damage, but this is less common in developed countries in a 67-year-old with this specific presentation. - Autoimmune causes are usually associated with specific rheumatic diseases or serological markers, none of which are mentioned. *Bicuspid valve* - A **bicuspid aortic valve** is a congenital anomaly that can lead to aortic stenosis, often presenting at a younger age (40s-60s) but can manifest later due to accelerated calcification. - While it's a possibility, in a 67-year-old without prior history, **degenerative calcification** of a trileaflet valve is statistically more likely.

Question 874: A 25-year-old man presents to the emergency department for a fever and abdominal pain. The patient states that his pain has been worsening over the past week in the setting of a fever. He has a past medical history of IV drug abuse and multiple admissions for septic shock. His temperature is 102°F (38.9°C), blood pressure is 94/54 mmHg, pulse is 133/min, respirations are 22/min, and oxygen saturation is 100% on room air. Physical exam is notable for a murmur over the left upper sternal border. Abdominal exam reveals left upper quadrant tenderness. Laboratory values are ordered as seen below. Hemoglobin: 15 g/dL Hematocrit: 44% Leukocyte count: 16,700/mm^3 Platelet count: 299,000/mm^3 Which of the following is the most likely diagnosis?

A. Hepatic abscess
B. Splenic abscess (Correct Answer)
C. Mesenteric ischemia
D. Appendicitis
E. Diverticulitis

Explanation: ***Splenic abscess*** - The patient's history of **IV drug abuse**, recurrent septic shock, and a new murmur strongly suggest **infective endocarditis**, which can lead to septic emboli. - **Left upper quadrant tenderness**, fever, and leukocytosis in this context are highly indicative of a **splenic abscess** resulting from a septic embolus traveling to the spleen. *Hepatic abscess* - While possible in IV drug users, **hepatic abscesses** typically present with right upper quadrant pain and may be associated with biliary tract disease or portal vein bacteremia. - The focused left upper quadrant tenderness and characteristic murmur are less consistent with a primary hepatic abscess. *Mesenteric ischemia* - This condition involves severe abdominal pain out of proportion to exam findings, often with risk factors like atrial fibrillation or atherosclerosis, and is unlikely to present with a focus on the left upper quadrant with a new murmur indicating endocarditis. - Elevated **lactate** and significant gastrointestinal symptoms like bloody stools are typically seen but are not mentioned here. *Appendicitis* - Characterized by **periumbilical pain migrating to the right lower quadrant**, rebound tenderness, and guarding, which is inconsistent with the patient's presentation of left upper quadrant pain. - While it causes fever and leukocytosis, the location of pain and the new murmur point away from appendicitis. *Diverticulitis* - Most commonly presents with **left lower quadrant pain** and fever, predominantly in older individuals. - The patient's left upper quadrant pain and high-risk factors for endocarditis make diverticulitis a less likely diagnosis.

Question 875: A 40-year-old woman comes to the physician for a 2-month history of chest pain and heartburn after meals. The patient reports that the pain is worse at night and especially when lying down. She has a history of Raynaud's disease treated with nifedipine. There is no family history of serious illness. She emigrated to the US from Nigeria 5 years ago. She does not smoke or drink alcohol. Vital signs are within normal limits. Cardiopulmonary examination shows no abnormalities. Thickening and hardening of the skin is seen on the hands and face. There are several firm, white nodules on the elbows and fingertips. Further evaluation of this patient is most likely to show which of the following findings?

A. Anti-RNA polymerase III antibodies
B. Anti-U1 RNP antibodies
C. Anti-Scl-70 antibodies
D. Anticentromere antibodies (Correct Answer)
E. Anti-dsDNA antibodies

Explanation: ***Anticentromere antibodies*** - The patient presents with symptoms consistent with **limited cutaneous systemic sclerosis (lcSSc)**, including Raynaud's phenomenon, heartburn, skin thickening confined to the face and hands, and calcinosis (firm, white nodules). **Anticentromere antibodies** are highly specific for lcSSc. - **Calcinosis**, **Raynaud's phenomenon**, **esophageal dysmotility**, **sclerodactyly**, and **telangiectasias** (CREST syndrome) are hallmarks of lcSSc, and anticentromere antibodies are found in 50-90% of these patients. *Anti-RNA polymerase III antibodies* - These antibodies are strongly associated with **diffuse cutaneous systemic sclerosis (dcSSc)**, which typically involves widespread skin thickening on the trunk and proximal extremities. - They are also linked to a higher risk of **scleroderma renal crisis** and **malignancy**, neither of which are suggested by the patient's current presentation. *Anti-U1 RNP antibodies* - These antibodies are characteristic of **mixed connective tissue disease (MCTD)**, an overlap syndrome with features of systemic lupus erythematosus, scleroderma, and polymyositis. - While MCTD can include Raynaud's and esophageal dysfunction, the prominence of skin thickening and calcinosis more strongly points towards scleroderma. *Anti-Scl-70 antibodies* - Also known as **anti-topoisomerase I antibodies**, these are primarily associated with **diffuse cutaneous systemic sclerosis (dcSSc)**. - Patients with anti-Scl-70 antibodies tend to have more severe internal organ involvement, particularly **interstitial lung disease**, which is not the prominent feature in this case. *Anti-dsDNA antibodies* - These antibodies are highly specific for **systemic lupus erythematosus (SLE)** and are often associated with lupus nephritis. - The patient's symptoms of prominent skin thickening, Raynaud's, and calcinosis are not typical for SLE as the primary diagnosis.

Question 876: A 65-year-old woman presents with progressive gait difficulty, neck pain, and bladder incontinence. She also complains of urinary urgency. Past medical history is significant for uncontrolled diabetes mellitus with a previous hemoglobin A1c of 10.8%. Physical examination reveals slightly increased muscle tone in all limbs with brisk tendon reflexes. Sensory examination reveals a decrease of all sensations in a stocking and glove distribution. Her gait is significantly impaired. She walks slowly with small steps and has difficulty turning while walking. She scores 23 out of 30 on a mini-mental state examination (MMSE). A brain MRI reveals dilated ventricles with a callosal angle of 60 degrees and mild cortical atrophy. What is the most appropriate next step in the management of this patient?

A. Donepezil
B. Acetazolamide
C. Ventriculoperitoneal shunt
D. Large-volume lumbar tap (Correct Answer)
E. Levodopa

Explanation: **Large-volume lumbar tap** - The symptoms (gait difficulty, urinary incontinence, cognitive decline) in the setting of **hydrocephalus** with a **callosal angle of 60 degrees** are highly suggestive of **Normal Pressure Hydrocephalus (NPH)**. A large-volume lumbar tap is both diagnostic and therapeutic in NPH, as it can temporarily improve symptoms and predict responsiveness to shunting. - The absence of significant cortical atrophy despite dilated ventricles further supports NPH, as does the improvement in balance and gait after CSF removal. *Ventriculoperitoneal shunt* - While a **ventriculoperitoneal shunt** is the definitive treatment for NPH, it is typically performed only after a positive response to a **lumbar tap trial**. This trial helps to confirm the diagnosis and identify patients who are most likely to benefit from the shunt. - Proceeding directly to shunting without a diagnostic tap could lead to unnecessary surgery in patients who may not benefit or whose symptoms are due to other conditions. *Donepezil* - **Donepezil** is an **acetylcholinesterase inhibitor** used in the treatment of **Alzheimer's disease** and other dementias. While cognitive decline is present, the constellation of symptoms (gait disturbance, incontinence, and hydrocephalus) points away from primary Alzheimer's. - It would not address the underlying pathophysiology of NPH and is unlikely to improve the gait or incontinence. *Acetazolamide* - **Acetazolamide** is a **carbonic anhydrase inhibitor** that can reduce **cerebrospinal fluid (CSF) production**. It is sometimes used to manage hydrocephalus in specific circumstances (e.g., communicating hydrocephalus in infants or idiopathic intracranial hypertension). - However, it is generally not considered effective for NPH, where the issue is impaired CSF absorption rather than overproduction. It also carries side effects that might not be suitable for an elderly patient. *Levodopa* - **Levodopa** is a **dopamine precursor** used in the treatment of **Parkinson's disease** to manage motor symptoms like bradykinesia, rigidity, and tremor. While the patient has gait difficulty, the presence of incontinence, cognitive decline, and hydrocephalus points away from Parkinson's disease. - The gait disturbance in NPH is often described as "magnetic gait" or "gait apraxia," which differs from the shuffling gait of Parkinson's and would not respond to levodopa.

Question 877: A 24-year-old man is running a marathon (42.2 km) on a hot summer day and collapses about halfway through the run. Emergency personnel are called and find him having a seizure. As the seizure subsides, the runner exhibits confusion, dry lips and decreased skin turgor. On the way to the emergency department, he denies taking medication or having a history of seizures. He reports that he drank water, but he admits that it was probably not enough. Which of the following would be the next best step in the management of this patient?

A. 0.9% NaCl (Correct Answer)
B. Relcovaptan
C. Furosemide
D. Indapamide
E. 3% NaCl

Explanation: ***0.9% NaCl*** - The patient presents with signs of **volume depletion** (dry lips, decreased skin turgor) and **exercise-associated collapse with seizure**. - While the seizure raises concern for **exercise-associated hyponatremia (EAH)**, **initial management** requires stabilization with **isotonic saline (0.9% NaCl)** for volume resuscitation. - Without laboratory confirmation of sodium levels, **isotonic saline is the safest initial choice** as it provides volume support without risking rapid sodium shifts. - If severe hyponatremia is later confirmed with labs, treatment can be escalated to hypertonic saline with careful monitoring. *3% NaCl* - **Hypertonic saline (3% NaCl)** is indicated for **severe, symptomatic hyponatremia** with neurological manifestations (seizures, altered mental status). - While this patient has a seizure suggesting possible severe hyponatremia, **hypertonic saline should only be administered after laboratory confirmation** of serum sodium levels. - Administering 3% NaCl without labs risks **overcorrection** and **osmotic demyelination syndrome** if the diagnosis is incorrect or correction is too rapid. - Initial stabilization with isotonic saline is safer until sodium levels are known. *Relcovaptan* - Relcovaptan is a **vasopressin V2 receptor antagonist** used for treating **chronic hyponatremia** (e.g., SIADH, heart failure). - It is **not appropriate for acute emergency management** of suspected exercise-associated hyponatremia with active seizures. - The patient requires immediate fluid resuscitation and stabilization, not oral chronic therapy. *Furosemide* - **Furosemide** is a loop diuretic that promotes excretion of water and electrolytes, which would **worsen hypovolemia**. - It is **contraindicated** in a patient presenting with signs of volume depletion and potential heatstroke. *Indapamide* - **Indapamide** is a thiazide-like diuretic that would promote further diuresis and **exacerbate dehydration**. - Thiazide diuretics can also cause hyponatremia, making this particularly inappropriate in this clinical context.

Question 878: A 55-year-old man comes to the physician because of weight loss and increased urinary frequency for the past month. He has also noticed blood in the urine, usually towards the end of voiding. He emigrated to the U.S. from Kenya 5 years ago. He has smoked one pack of cigarettes daily for 35 years. Physical examination shows a palpable liver edge and splenomegaly. Laboratory studies show a hemoglobin concentration of 9.5 mg/dL and a urine dipstick is strongly positive for blood. A CT scan of the abdomen shows bladder wall thickening and fibrosis. A biopsy specimen of the bladder shows squamous cell carcinoma. Which of the following additional findings is most likely in this patient?

A. Peripheral nonpitting edema
B. Elevated mean pulmonary artery pressure
C. Dilation of right and left ventricles
D. Atrophy of the retina with sclerosing keratitis
E. Calcified cysts in the liver (Correct Answer)

Explanation: ***Calcified cysts in the liver*** - The patient's history of emigration from **Kenya**, **hematuria**, and **squamous cell carcinoma of the bladder** strongly suggest **Schistosoma haematobium** infection (urogenital schistosomiasis). - The **hepatosplenomegaly** and palpable liver edge indicate concurrent **hepatosplenic schistosomiasis**, most commonly caused by **Schistosoma mansoni**, which is endemic in the same regions as S. haematobium. - **Calcified hepatic granulomas** (appearing as calcified cysts) are characteristic findings of chronic S. mansoni infection, resulting from granulomatous reactions around trapped parasite eggs in the liver. - Co-infection with both species is common in endemic areas of Africa. *Peripheral nonpitting edema* - While advanced liver disease from schistosomiasis can cause **portal hypertension** and hypoalbuminemia leading to edema, this typically presents as **pitting edema**, not nonpitting. - Nonpitting edema suggests lymphedema or myxedema, which are not characteristic manifestations of schistosomiasis. *Elevated mean pulmonary artery pressure* - **Pulmonary hypertension** can occur in chronic hepatosplenic schistosomiasis when parasite eggs embolize to pulmonary vessels or due to portopulmonary hypertension. - However, this is a less common complication compared to the hepatic calcifications, which are nearly universal in chronic hepatosplenic disease. *Dilation of right and left ventricles* - **Biventricular dilation** suggests dilated cardiomyopathy or severe chronic heart failure. - While severe pulmonary hypertension from schistosomiasis could cause **right ventricular dilation**, biventricular involvement is not a typical manifestation. - Hepatic calcifications are far more common and directly related to the hepatosplenic findings in this patient. *Atrophy of the retina with sclerosing keratitis* - These **ocular manifestations** are not associated with schistosomiasis. - Sclerosing keratitis is typically seen in onchocerciasis (river blindness) or other conditions, not schistosomal infections.

Question 879: A 40-year-old woman presents with a ‘tingling’ feeling in the toes of both feet that started 5 days ago. She says that the feeling varies in intensity but has been there ever since she recovered from a stomach flu last week. Over the last 2 days, the tingling sensation has started to spread up her legs. She also reports feeling weak in the legs for the past 2 days. Her past medical history is unremarkable, and she currently takes no medications. Which of the following diagnostic tests would most likely be abnormal in this patient?

A. Noncontrast CT of the head
B. Serum hemoglobin concentration
C. Nerve conduction studies (Correct Answer)
D. Serum calcium concentration
E. Transthoracic echocardiography

Explanation: ***Nerve conduction studies*** - The patient's ascending **motor weakness** and **sensory paresthesias** following a gastrointestinal infection are classic symptoms of **Guillain-Barré Syndrome (GBS)**, which is characterized by **demyelination** of peripheral nerves. - **Nerve conduction studies** would reveal **markedly slowed conduction velocities**, **conduction block**, and **prolonged distal latencies**, indicating the demyelinating neuropathy characteristic of GBS. *Noncontrast CT of the head* - This test is primarily used to evaluate **acute neurological deficits** suggestive of stroke, hemorrhage, or mass lesions within the brain. - The patient's symptoms are consistent with a **peripheral neuropathy** and do not suggest a central nervous system pathology. *Serum hemoglobin concentration* - This measures the concentration of **hemoglobin in the blood** and is used to diagnose **anemia**. - While anemia can cause fatigue, it does not typically cause the **ascending paralysis** and **paresthesias** described, nor is it directly related to a recent stomach flu in this manner. *Serum calcium concentration* - This measures the level of **calcium in the blood**, which is important for muscle and nerve function. - While extreme imbalances can cause neurological symptoms, there is no direct indication or typical association between the patient's symptoms and a primary calcium disorder. *Transthoracic echocardiography* - This imaging test evaluates the **structure and function of the heart**. - The patient's symptoms are neurological and do not suggest a primary cardiac etiology or complication that would warrant an echocardiogram.

Question 880: A 53-year-old woman comes to the physician because of a 3-year history of increasing weakness of her extremities and neck pain that is worse on coughing or sneezing. She first noticed weakness of her right upper extremity 3 years ago, which progressed to her right lower extremity 2 years ago, her left lower extremity 1 year ago, and her left upper extremity 6 months ago. She has had difficulty swallowing and speaking for the past 5 months. Vital signs are within normal limits. Examination shows an ataxic gait. Speech is dysarthritic. Muscular examination shows spasticity and muscle strength is decreased in all extremities. There is bilateral atrophy of the sternocleidomastoid and trapezius muscles. Deep tendon reflexes are 4+ bilaterally. Plantar response shows an extensor response bilaterally. Sensation is decreased below the C5 dermatome bilaterally. Which of the following is the most likely cause of this patient's symptoms?

A. Cerebral glioblastoma multiforme
B. Foramen magnum meningioma (Correct Answer)
C. Cerebellar astrocytoma
D. Amyotrophic lateral sclerosis
E. Multiple sclerosis

Explanation: ***Foramen magnum meningioma*** - Progressive **quadriparesis** in a **descending or ascending pattern**, associated with **neck pain exacerbated by coughing/sneezing**, suggests compression at the **craniocervical junction**. - **Spasticity**, **hyperreflexia**, **bilateral extensor plantar responses**, and **sensory loss below C5** are classic signs of **upper motor neuron dysfunction** and **spinal cord compression** at this level. *Cerebral glioblastoma multiforme* - This typically presents with **focal neurological deficits**, **seizures**, or **symptoms of increased intracranial pressure**, rarely with progressive quadparesis and sensory level as seen. - While it causes **upper motor neuron signs**, extensive spinal cord involvement and a clear sensory level are not characteristic. *Cerebellar astrocytoma* - Primarily causes **ataxia**, **dysmetria**, and other **cerebellar signs**, but does not explain the widespread spastic quadriparesis, clear sensory level, or bulbar symptoms. - Neck pain worsened by coughing or sneezing and prominent upper motor neuron signs are not typical for this tumor. *Amyotrophic lateral sclerosis* - This disease affects both **upper and lower motor neurons** but typically spares sensation. - The presence of **sensory loss below C5** and prominent **neck pain** makes ALS less likely. *Multiple sclerosis* - Characterized by **disseminated lesions in time and space**, often with relapsing-remitting symptoms and prominent sensory complaints, but a clear, progressive sensory level and severe neck pain are atypical. - While it can cause **spasticity** and **ataxia**, the progressive, compressive pattern of symptoms and consistent sensory level point away from MS.

Question 881: A 40-year-old woman comes to the emergency department because of difficulty walking for the past 4 hours. She first noticed her symptoms after getting up this morning and her foot dragging while walking. She feels tired. She has a history of chronic sinusitis. Six months ago, she was diagnosed with asthma. Current medications include an albuterol inhaler and inhaled corticosteroids. Her temperature is 38.9°C (102°F), pulse is 80/min, and her blood pressure is 140/90 mm Hg. Auscultation of her lungs shows diffuse wheezing over bilateral lung fields. Physical examination shows tender subcutaneous nodules on the extensor surfaces of the elbows. There are palpable, non-blanching erythematous lesions on both shins. Dorsiflexion of the right foot is impaired. Sensation to pinprick, light touch, and vibration is decreased over the ulnar aspect of the left forearm. Laboratory studies show: Hemoglobin 11.3 g/dL Leukocyte count 24,500 Segmented neutrophils 48% Eosinophils 29% Lymphocytes 19% Monocytes 4% Platelet count 290,000/mm3 Serum Urea nitrogen 32 mg/dL Creatinine 1.85 mg/dL Urine Blood 2+ Protein 3+ Which of the following is the most likely diagnosis in this patient?

A. Granulomatosis with polyangiitis
B. Excessive glucocorticoid use
C. Goodpasture syndrome
D. Henoch-Schönlein purpura
E. Eosinophilic granulomatosis with polyangiitis (Correct Answer)

Explanation: ***Eosinophilic granulomatosis with polyangiitis (EGPA)*** - This patient presents with a classic triad: **asthma**, **eosinophilia** (29%), and **multisystem vasculitis** as evidenced by mononeuropathy, skin lesions (nodules and palpable purpura), and kidney involvement. - The history of chronic sinusitis, new-onset foot drop (mononeuropathy), **palpable purpura**, and elevated creatinine with proteinuria strongly point towards EGPA. *Granulomatosis with polyangiitis (GPA)* - While GPA can cause sinusitis, kidney disease, and neuropathy, it typically presents with **neutrophilic inflammation** and **c-ANCA** positivity, not prominent eosinophilia or severe asthma. - Granulomatosis with polyangiitis typically involves the **upper and lower respiratory tracts** and kidneys but lacks the pronounced eosinophilia and severe asthma seen here. *Excessive glucocorticoid use* - This condition is associated with Cushingoid features, **osteoporosis**, and immunosuppression, none of which fully explain the patient's acute neurological deficits, eosinophilia, or vasculitic manifestations. - Although the patient has asthma, her symptoms are not consistent with the side effects of inhaled corticosteroids or chronic systemic glucocorticoid use. *Goodpasture syndrome* - Goodpasture syndrome is characterized by **recurrent pulmonary hemorrhage** and rapidly progressive **glomerulonephritis** due to anti-GBM antibodies. - It does not explain the prominent eosinophilia, asthma, or the presence of subcutaneous nodules and palpable purpura. *Henoch-Schönlein purpura (HSP)* - HSP typically presents in children with **palpable purpura** on the buttocks and lower extremities, **arthralgias**, abdominal pain, and **IgA nephropathy**. - It does not involve significant eosinophilia, severe asthma, or mononeuropathy as seen in this adult patient.

Question 882: A 67-year-old woman presents with her husband because of left leg pain and swelling of 3 days' duration. She has a history of type 2 diabetes mellitus and recent hospitalization for congestive heart failure exacerbation. On physical examination, the left calf is 4 cm greater in circumference than the right. Pitting edema is present on the left leg and there are superficial dilated veins. Venous duplex ultrasound shows an inability to fully compress the lumen of the profunda femoris vein. Which of the following is the most likely diagnosis?

A. Erythema nodosum
B. Deep venous thrombosis (Correct Answer)
C. Lymphangitis
D. Superficial venous thrombophlebitis
E. Ruptured popliteal cyst

Explanation: ***Deep venous thrombosis*** - The patient presents with **unilateral left leg pain and swelling**, a 4 cm difference in calf circumference, **pitting edema**, and dilated superficial veins, all classic signs of **deep venous thrombosis (DVT)**. - The **venous duplex ultrasound** findings of an inability to fully compress the lumen of the **profunda femoris vein** are diagnostic for DVT, confirming the presence of a thrombus within a deep vein. *Erythema nodosum* - This condition presents as **tender, red nodules** typically on the shins, usually associated with systemic diseases, infections, or drugs, and does not involve significant leg swelling or venous occlusion. - It is a **panniculitis**, an inflammation of subcutaneous fat, and would not lead to diagnostic findings of non-compressible deep veins on ultrasound. *Lymphangitis* - Characterized by **red streaks** tracking along lymphatic pathways, **fever**, and painful swollen lymph nodes, often due to a bacterial infection, which are not described in this patient’s presentation. - While it can cause some swelling, it does not typically produce the extensive pitting edema, calf circumference discrepancy, or deep venous compromise seen in DVT. *Superficial venous thrombophlebitis* - Involves inflammation and thrombosis of a **superficial vein**, presenting as a **tender, palpable cord** along the course of the vein, often with associated skin redness. - It usually causes localized discomfort and swelling and does not typically lead to significant, diffuse leg swelling from deep vein obstruction or an inability to compress a deep vein on ultrasound. *Ruptured popliteal cyst* - Presents with sudden onset of **calf pain and swelling**, often mimicking DVT, but is typically associated with a history of **arthritis** and often involves **ecchymosis** around the malleolus (crescent sign). - While it can cause swelling, it would not result in a non-compressible deep vein on venous duplex ultrasound.

Question 883: A 16-year-old woman presents to the emergency department for evaluation of acute vomiting and abdominal pain. Onset was roughly 3 hours ago while she was sleeping. She has no known past medical history. Her family history is positive for hypothyroidism and diabetes mellitus in her maternal grandmother. On examination, she is found to have fruity breath and poor skin turgor. She appears fatigued and her consciousness is slightly altered. Laboratory results show a blood glucose level of 691 mg/dL, sodium of 125 mg/dL, and elevated serum ketones. Of the following, which is the next best step in patient management?

A. Administer IV fluids and insulin (Correct Answer)
B. Initiate basal-bolus insulin regimen
C. Initiate insulin glargine 10 units at bedtime only
D. Initiate oral antidiabetic medications
E. Initiate insulin aspart at mealtimes only

Explanation: ***Administer IV fluids and insulin*** - The patient presents with **fruity breath**, **altered consciousness**, **hyperglycemia (691 mg/dL)**, **hyponatremia**, and **elevated serum ketones**, which are classic signs of **diabetic ketoacidosis (DKA)**. - The immediate management for DKA involves aggressive **intravenous fluid resuscitation** to correct dehydration and hypovolemia, followed by a continuous **intravenous insulin infusion** to lower blood glucose and suppress ketogenesis. *Initiate basal-bolus insulin regimen* - A **basal-bolus insulin regimen** is appropriate for long-term management of diabetes but is not the immediate treatment for acute DKA, which requires continuous intravenous insulin. - This approach does not address the severe dehydration and electrolyte imbalances seen in DKA, which need urgent fluid replacement. *Initiate insulin glargine 10 units at bedtime only* - **Insulin glargine** is a long-acting insulin used for basal insulin coverage, typically in the chronic management of diabetes. - This dose is insufficient to manage acute DKA, and it also fails to address the critical need for fluid resuscitation. *Initiate oral antidiabetic medications* - **Oral antidiabetic medications** are suitable for individuals with type 2 diabetes or milder forms of insulin resistance, not for acute DKA. - They are ineffective in severe hyperglycemia and metabolic acidosis characteristic of DKA, and do not address dehydration. *Initiate insulin aspart at mealtimes only* - **Insulin aspart** is a rapid-acting insulin used to cover mealtime glucose excursions. - Administering it only at mealtimes is inadequate for acute DKA, which requires continuous insulin infusion and aggressive fluid management.

Question 884: A 13-year-old boy is brought to the physician because of bleeding from his lips earlier that day. He has a history of recurrent nosebleeds since childhood. His father has a similar history of recurrent nosebleeds. He is at the 60th percentile for height and weight. Examination shows multiple, small dilated capillaries over the lips, nose, and fingers. The remainder of the examination shows no abnormalities. Which of the following conditions is this patient at increased risk for?

A. Acute leukemia
B. High-output cardiac failure (Correct Answer)
C. Glaucoma
D. Gastrointestinal polyps
E. Renal cell carcinoma

Explanation: ***High-output cardiac failure*** - The patient's presentation with recurrent nosebleeds, bleeding from lips, and multiple **telangiectasias** (dilated capillaries) on lips, nose, and fingers strongly suggests **hereditary hemorrhagic telangiectasia (HHT)**, also known as Osler-Weber-Rendu syndrome. - HHT can lead to **arteriovenous malformations (AVMs)**, particularly in organs like the lungs and liver; extensive AVMs, especially hepatic AVMs, can act as shunts, causing **high-output cardiac failure** due to increased venous return and cardiac workload. *Acute leukemia* - While acute leukemia can cause bleeding tendencies due to **thrombocytopenia** or **coagulation defects**, it would typically present with additional symptoms such as fatigue, fever, pallor, and lymphadenopathy, which are absent here. - The familial history of nosebleeds and characteristic **telangiectasias** are not features of leukemia. *Glaucoma* - **Glaucoma** is an eye condition characterized by damage to the optic nerve, often due to elevated intraocular pressure, and is not directly associated with HHT or its complications. - There is no clinical information provided to suggest any ocular pathology or risk factors for glaucoma in this patient. *Gastrointestinal polyps* - While some genetic syndromes, like **Peutz-Jeghers syndrome**, cause both mucocutaneous pigmentation and gastrointestinal polyps, the telangiectasias in this patient are distinct from the dark brown macules seen in Peutz-Jeghers. - HHT can cause **GI bleeding** from telangiectasias, but not typically the formation of polyps themselves. *Renal cell carcinoma* - **Renal cell carcinoma** is a type of kidney cancer and is not typically associated with HHT. - There are no features in the patient's presentation (e.g., hematuria, flank pain, or a palpable mass) that would suggest an increased risk for renal cell carcinoma.

Question 885: A 29-year-old man presents to the emergency department with chest pain and fatigue for the past week. The patient is homeless and his medical history is not known. His temperature is 103°F (39.4°C), blood pressure is 97/58 mmHg, pulse is 140/min, respirations are 25/min, and oxygen saturation is 95% on room air. Physical exam is notable for scars in the antecubital fossa and a murmur over the left sternal border. The patient is admitted to the intensive care unit and is treated appropriately. On day 3 of his hospital stay, the patient presents with right-sided weakness in his arm and leg and dysarthric speech. Which of the following is the most likely etiology of his current symptoms?

A. Herpes simplex virus encephalitis
B. Septic emboli (Correct Answer)
C. Intracranial hemorrhage
D. Thromboembolic stroke
E. Bacterial meningitis

Explanation: ***Septic emboli*** - The patient's history of **intravenous drug use** (inferred from antecubital scars and homelessness), fever, hypotension, tachycardia, and a new murmur strongly suggest **infective endocarditis**. - **Septic emboli** from an infected heart valve can dislodge and travel to the brain, causing a **stroke-like presentation** with focal neurological deficits such as right-sided weakness and dysarthria. - This is the **most specific etiology** as it identifies both the embolic mechanism AND the infectious source. *Herpes simplex virus encephalitis* - While encephalitis can cause focal neurological deficits, it typically presents with **altered mental status, seizures**, and a distinct pattern on MRI (temporal lobe involvement), which is not the primary presentation here. - The context of infective endocarditis makes **embolic events** a more direct and likely cause of acute focal deficits. *Intracranial hemorrhage* - Intracranial hemorrhage would typically cause a **sudden onset** of neurological deficits, often accompanied by severe headache, altered consciousness, and signs of increased intracranial pressure. - Although endocarditis can rarely lead to mycotic aneurysms that rupture, **ischemic stroke** due to emboli is far more common than hemorrhage in this setting. *Thromboembolic stroke* - While septic emboli do cause an embolic stroke, **"thromboembolic stroke"** is a broader, less specific term that doesn't identify the **infectious etiology**. - The term typically refers to sterile emboli from sources like atrial fibrillation, left ventricular thrombus, or atherosclerotic plaques. - **"Septic emboli"** is the most precise answer as it specifically indicates emboli containing infected material from the endocarditis, which has important implications for treatment and prognosis. *Bacterial meningitis* - Meningitis typically presents with classic symptoms like **fever, headache, nuchal rigidity**, and altered mental status. - While it can cause neurological complications, acute focal deficits like hemiparesis and dysarthria are more characteristic of a stroke or mass lesion, not diffuse meningeal inflammation.

Question 886: A 63-year-old man presents to the clinic with fever accompanied by shortness of breath. The symptoms developed a week ago and have been progressively worsening over the last 2 days. He reports his cough is productive of thick, yellow sputum. He was diagnosed with chronic obstructive pulmonary disease 3 years ago and has been on treatment ever since. He quit smoking 10 years ago but occasionally experiences shortness of breath along with chest tightness that improves with the use of an inhaler. However, this time the symptoms seem to be more severe and unrelenting. His temperature is 38.6°C (101.4°F), the respirations are 21/min, the blood pressure is 100/60 mm Hg, and the pulse is 105/min. Auscultation reveals bilateral crackles and expiratory wheezes. His oxygen saturation is 95% on room air. According to this patient’s history, which of the following should be the next step in the management of this patient?

A. Chest X-ray (Correct Answer)
B. Arterial blood gases
C. Bronchoprovocation test
D. Bronchoscopy
E. CT scan

Explanation: ***Chest X-ray*** - A **chest X-ray** is a crucial initial step to evaluate for **pneumonia** or other acute pulmonary processes, given the fever, productive cough, and worsening respiratory symptoms in a patient with COPD [1]. - It can identify infiltrates, effusions, or other anatomical changes that explain the patient's acute decompensation [1]. *Arterial blood gases* - While important for assessing **respiratory failure** and guiding ventilator management, **ABGs** are usually performed after initial imaging to quantify gas exchange abnormalities once an etiology is suspected [1]. - The patient's **oxygen saturation of 95% on room air** does not immediately suggest severe hypoxemia, although hypercapnia could still be present. *Bronchoprovocation test* - A **bronchoprovocation test** is used to diagnose **asthma** or assess **airway hyperresponsiveness** in stable patients. - It is contraindicated in acute exacerbations due to the risk of worsening bronchoconstriction. *Bronchoscopy* - **Bronchoscopy** is an invasive procedure typically reserved for cases of suspicion of **tumor**, **foreign body aspiration**, or non-resolving infiltrates and would not be the immediate next step for fever and productive cough. - It is not indicated for the initial diagnosis of community-acquired pneumonia or COPD exacerbation. *CT scan* - A **CT scan** provides more detailed imaging but is usually reserved for cases where the chest X-ray is inconclusive or to look for specific pathologies like **pulmonary embolism** or **bronchiectasis**. - It's not the initial imaging choice for suspected **pneumonia** due to cost, radiation exposure, and the adequacy of X-ray for this purpose [1].

Question 887: Please refer to the summary above to answer this question Which of the following is the most likely diagnosis? Patient Information Age: 66 years Gender: M, self-identified Ethnicity: African-American Site of Care: office History Reason for Visit/Chief Concern: "I need to go to the bathroom all the time." History of Present Illness: 1-year history of frequent urination urinates every 2–3 hours during the day and wakes up at least 3 times at night to urinate has had 2 episodes of cystitis treated with antibiotics in the past 4 months has a weak urinary stream has not noticed any blood in the urine does not have any pain with urination or ejaculatory dysfunction Past Medical History: type 2 diabetes mellitus nephrolithiasis, treated with percutaneous nephrolithotomy essential tremor Medications: metformin, canagliflozin, propranolol Allergies: sulfa drugs Social History: sexually active with his wife; does not use condoms consistently has smoked one pack of cigarettes daily for 50 years drinks one to two glasses of beer weekly Physical Examination Temp Pulse Resp BP O2 Sat Ht Wt BMI 37°C (98.6°F) 72/min 16/min 134/81 mm Hg – 183 cm (6 ft) 105 kg (231 lb) 31 kg/m2 Appearance: no acute distress Pulmonary: clear to auscultation Cardiac: regular rate and rhythm; normal S1, S2; S4 gallop Abdominal: overweight; no tenderness, guarding, masses, bruits, or hepatosplenomegaly Extremities: no joint erythema, edema, or warmth; dorsalis pedis, radial, and femoral pulses intact Genitourinary: no lesions or discharge Rectal: slightly enlarged, smooth, nontender prostate Neurologic: alert and oriented; cranial nerves grossly intact; no focal neurologic deficits

A. Urethral stricture
B. Prostate cancer
C. Neurogenic bladder
D. Acute prostatitis
E. Benign prostatic hyperplasia (Correct Answer)

Explanation: ***Benign prostatic hyperplasia*** - The patient's symptoms of **frequent urination**, **nocturia**, **weak urinary stream**, and a **slightly enlarged, smooth, nontender prostate** on rectal exam are classic for BPH. - Recurrent **cystitis** can be a complication of BPH due to incomplete bladder emptying. *Urethral stricture* - While a urethral stricture can cause a **weak urinary stream** and incomplete emptying, it would typically present with more significant difficulty voiding, possibly **pain** during urination, or a history of instrumentation/trauma. - The rectal exam finding of an **enlarged prostate** points away from a primary stricture. *Prostate cancer* - Although prostate cancer can cause similar urinary symptoms, an enlarged prostate due to cancer is often described as **nodular, firm, or asymmetric** on rectal exam, not smooth. - The absence of **hematuria** or significant pain also makes cancer less likely as the primary driver of these symptoms. *Neurogenic bladder* - A neurogenic bladder would involve neurological deficits affecting bladder control, such as spinal cord injury, stroke, or severe neuropathy, which are not described in this patient beyond an **essential tremor** unlikely to cause these specific lower urinary tract symptoms. - The patient has no other neurological symptoms like **focal weakness** or sensory loss. *Acute prostatitis* - Acute prostatitis typically presents with **fever, chills, perineal pain, dysuria**, and a **tender, swollen prostate** on examination, none of which are present in this patient. - The symptoms here are **chronic** (1 year history) rather than acute.

Question 888: A 53-year-old woman comes to the physician because of intermittent heaviness and paresthesia of the right arm for the past 2 months. She has also had multiple episodes of lightheadedness while painting a mural for the past 2 weeks. During these episodes, she was nauseated and had blurred vision. Her symptoms resolved after she drank some juice. She has hypertension, type 2 diabetes mellitus, and hypercholesterolemia. Current medications include metformin, glipizide, enalapril, and atorvastatin. She appears anxious. Examination shows decreased radial and brachial pulses on the right upper extremity. The skin over the right upper extremity is cooler than the left. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Subclavian artery stenosis with vertebral steal phenomenon (Correct Answer)
B. Adverse effect of medications
C. Infarction of the middle cerebral artery
D. Non-enzymatic glycosylation of peripheral nerve
E. Compression of neurovascular structures in the neck

Explanation: ***Subclavian artery stenosis with vertebral steal phenomenon*** - The patient's symptoms of **exercise-induced right arm heaviness, paresthesia, and lightheadedness with blurred vision** (vertebrobasilar insufficiency equivalent) are characteristic of **subclavian steal syndrome**. The **decreased radial and brachial pulses** and **cooler skin** on the right upper extremity further support reduced blood flow to that arm. - Due to **subclavian artery stenosis**, blood is shunted from the vertebral artery away from the brain to supply the exercising arm, causing **vertebrobasilar symptoms** like vertigo and blurred vision. *Adverse effect of medications* - While it's important to consider medication side effects, none of the patient's current medications (**metformin, glipizide, enalapril, atorvastatin**) typically cause the specific constellation of unilateral upper extremity weakness, sensory changes, differential pulses, and exertional vertebrobasilar symptoms. - The symptoms are highly localized and vascular in nature, which is less consistent with a systemic medication side effect. *Infarction of the middle cerebral artery* - An **infarction of the middle cerebral artery (MCA)** would typically present with more focal neurological deficits such as hemiparesis, facial droop, aphasia (if dominant hemisphere), and visual field cuts, which are *not* described in this case. - The intermittent, exertional nature of the symptoms and resolution upon rest, along with vascular signs in the arm, are inconsistent with an MCA stroke. *Non-enzymatic glycosylation of peripheral nerve* - This refers to **diabetic neuropathy**, which could cause paresthesia. However, it typically presents as a **stocking-glove distribution** (distal sensory loss symmetrically) and does *not* explain the unilateral arm heaviness, differential pulses, or the lightheadedness and blurred vision during arm activity. - Diabetic neuropathy does not cause a "steal" phenomenon or exertional vertebrobasilar symptoms. *Compression of neurovascular structures in the neck* - Conditions like **thoracic outlet syndrome** can cause compression of neurovascular structures, leading to arm pain, paresthesia, and weakness. However, it typically does *not* cause **lightheadedness or blurred vision during arm exercise** (vertebrobasilar symptoms) and *rarely* presents with **differential pulses** without other signs of vascular compromise like subclavian stenosis. - The presence of decreased pulses and cooler skin on one side strongly points towards an arterial occlusive process rather than simple compression.

Question 889: A 33-year-old woman presents to the emergency department with weakness. She states that at the end of the day she feels so fatigued and weak that she can hardly care for herself. She currently feels this way. The patient has had multiple illnesses recently and has been traveling, hiking, and camping. Her temperature is 98.0°F (36.7°C), blood pressure is 124/84 mmHg, pulse is 82/min, respirations are 12/min, and oxygen saturation is 98% on room air. Physical exam is notable for 2/5 strength of the upper extremities and 4/5 strength of the lower extremities. Visual exam is notable for mild diplopia. Which of the following is the most likely diagnosis?

A. Guillain-Barre syndrome
B. Myasthenia gravis (Correct Answer)
C. Lambert-Eaton syndrome
D. Amyotrophic lateral sclerosis
E. Tick paralysis

Explanation: ***Myasthenia gravis*** - The patient's **fatigue and weakness that worsen throughout the day** (end-of-day weakness) and are exacerbated by activity (caring for herself) are classic symptoms of myasthenia gravis, caused by **autoantibodies to acetylcholine receptors** at the neuromuscular junction. - The presence of **diplopia** (ocular weakness) along with generalized weakness further supports this diagnosis, as ocular symptoms are very common first manifestations. *Guillain-Barre syndrome* - This presents with **ascending paralysis**, typically starting in the lower extremities and progressing upwards over days to weeks. The patient's weakness is not described as ascending and ocular symptoms are less common as an initial presentation. - Often follows a **viral or bacterial infection** with a monophasic course, while myasthenia gravis has a fluctuating pattern. *Lambert-Eaton syndrome* - Characteristically presents with **proximal muscle weakness** that **improves with exertion** due to increased acetylcholine release with repetitive stimulation, which is opposite to the patient's presentation. - It is frequently associated with **small cell lung cancer** and often includes autonomic dysfunction such as dry mouth or erectile dysfunction, which are not mentioned here. *Amyotrophic lateral sclerosis* - This is a progressive neurodegenerative disease involving both **upper and lower motor neuron signs**, leading to muscle atrophy and fasciculations. - Weakness is typically progressive and permanent, not fluctuating or improving, and **diplopia would be an atypical initial symptom**. *Tick paralysis* - Characterized by **ascending flaccid paralysis** that develops over hours to days after a tick bite, often associated with a discoverable tick. - Weakness is typically rapidly progressive and systemic symptoms like fever or rash might be present, which are not described.

Question 890: A 32-year-old male presents for a new patient visit. He states that he is in good health but has had decreasing exercise tolerance and increased levels of shortness of breath over the past 5 years. He believed that it was due to aging; he has not seen a doctor in 10 years. On auscultation, you note an early diastolic decrescendo blowing murmur that radiates along the left sternal border. In the United States, what is the most likely cause of this patient's condition?

A. Connective tissue disease
B. Congenital bicuspid aortic valve (Correct Answer)
C. Syphilis
D. Rheumatic heart disease
E. Myxomatous degeneration

Explanation: ***Congenital bicuspid aortic valve*** - The patient's age (32 years old), progressive symptoms of **aortic regurgitation** (decreasing exercise tolerance, shortness of breath, early diastolic decrescendo murmur), and location of the murmur are highly suggestive of a **bicuspid aortic valve**. - This is the **most common congenital heart defect**, affecting 1-2% of the population, and is the leading cause of **aortic stenosis** and **aortic insufficiency** in younger adults in developed countries. *Connective tissue disease* - While connective tissue diseases such as **Marfan syndrome** or **Ehlers-Danlos syndrome** can cause aortic root dilation and regurgitation, they are less common than a bicuspid aortic valve as a primary cause of isolated aortic regurgitation in this age group. - These conditions typically present with other systemic features (e.g., arachnodactyly, skin hyperextensibility) that are not mentioned in the patient's history. *Syphilis* - **Syphilitic aortitis** can cause aortic root dilation and aortic regurgitation, typically as a late-stage manifestation of **tertiary syphilis**. - While possible, it is less common in developed countries today due to effective antibiotic treatment, and the patient's asymptomatic progression over 5 years might suggest a congenital rather than an infectious cause in this context. *Rheumatic heart disease* - **Rheumatic fever** is a common cause of valvular heart disease globally, but its incidence has significantly declined in developed countries due to improved hygiene and antibiotic use for **streptococcal infections**. - While it can affect the aortic valve, it more commonly affects the **mitral valve** and usually presents with symptoms earlier in life or with a history of recurrent fevers. *Myxomatous degeneration* - **Myxomatous degeneration** primarily affects the **mitral valve**, leading to **mitral valve prolapse** and regurgitation. - While it can sometimes affect the aortic valve, it is a less common cause of isolated aortic regurgitation and often presents with different clinical features or imaging findings.

Question 891: A 45 year-old gentleman presents to his primary care physician complaining of wrist pain and is diagnosed with carpal tunnel syndrome. Upon further questioning, the patient admits that he has recently been outgrowing his gloves and shoes and has had to purchase a new hat as well due to increased head size. Upon exam, he is found to have new mild hypertension and on basic labs he is found to be hyperglycemic. Which of the following is the best blood test to diagnose his suspected disorder?

A. Hydroxyproline level
B. Cortisol level
C. Alkaline Phosphatase level
D. IGF-1 level (Correct Answer)
E. Growth Hormone level

Explanation: ***IGF-1 level*** - The patient's symptoms of increased glove, shoe, and hat size, along with carpal tunnel syndrome, hypertension, and hyperglycemia, are highly suggestive of **acromegaly**. - **IGF-1 (Insulin-like Growth Factor 1)** levels are generally stable throughout the day and are directly correlated with average growth hormone (GH) levels, making it the **best initial screening test** for acromegaly. *Growth Hormone level* - While acromegaly is caused by **excess growth hormone**, a single random GH level can be misleading due to its **pulsatile secretion**. - A more definitive diagnostic test for acromegaly involves a **glucose suppression test** by measuring GH levels after an oral glucose load, but IGF-1 is the preferred initial screening. *Hydroxyproline level* - **Hydroxyproline** is an amino acid primarily found in **collagen** and its urinary excretion can indicate collagen turnover. - It is not a primary diagnostic marker for acromegaly and is more relevant in conditions involving bone metabolism or collagen degradation. *Cortisol level* - **Cortisol** is a steroid hormone associated with stress response and conditions like **Cushing's syndrome** or **Addison's disease**. - While acromegaly can sometimes coexist with other pituitary disorders, cortisol levels are not the most appropriate initial test for the suspected diagnosis of acromegaly. *Alkaline Phosphatase level* - **Alkaline phosphatase (ALP)** is an enzyme found in various tissues, including bone, liver, and kidneys. - Elevated ALP typically indicates **bone turnover** (e.g., Paget's disease, osteomalacia) or liver disease, and is not a specific diagnostic marker for acromegaly.

Question 892: A 59-year-old male with a history of hypertension presents with chest pain and hoarseness. Patient reports that his hoarseness onset gradually approximately 2 weeks ago and has steadily worsened. He states that approximately 2 hours ago he had sudden onset chest pain which has not improved. The patient describes the chest pain as severe, sharp in character, localized to the midline and radiating to the back. Past medical history is significant for hypertension diagnosed 10 years previously, which was being managed medically, although patient admits he stopped taking his medication and has not been to his doctor in the last couple of years. No current medications. Patient admits to a 20-pack-year smoking history. Vital signs are temperature 37 °C (98.6 °F), blood pressure 169/100 mm Hg, pulse 85/min, respiration rate 19/min, and oxygen saturation 98% on room air. On physical exam, patient is diaphoretic and in distress. Cardiac exam is significant for an early diastolic murmur. Lungs are clear to auscultation. Remainder of physical exam is normal. While performing the exam, the patient suddenly grips his chest and has a syncopal episode. He cannot be roused. Repeat vital signs show blood pressure 85/50 mm Hg, pulse 145/min, respiration rate 25/min, and oxygen saturation 92% on room air. Extremities are pale and cool. Patient is intubated. High flow supplemental oxygen and aggressive fluid resuscitation are initiated. Type and crossmatch are ordered. Which of the following is the next best step in management?

A. EKG
B. Emergency surgery
C. Chest X-ray
D. Cardiac troponins
E. Transthoracic echocardiography (Correct Answer)

Explanation: ***Transthoracic echocardiography*** - The patient presents with classic signs of **aortic dissection**, including sudden onset severe, tearing chest pain radiating to the back, uncontrolled hypertension, new-onset diastolic murmur, and finally a syncopal episode with hemodynamic instability. - In this **hemodynamically unstable patient**, a **transthoracic echocardiogram (TTE)** is the best next step as it is a **rapid, non-invasive bedside investigation** that can be performed without transporting the patient. This is critical as the patient cannot safely be moved to CT scanner. - TTE can visualize dilation of the **aortic root**, an **intimal flap**, and **aortic regurgitation**, which are key findings in aortic dissection. While transesophageal echo (TEE) has higher sensitivity, TTE remains the most appropriate initial bedside imaging in an unstable patient to guide immediate management decisions. *EKG* - While an EKG is often performed for chest pain, it primarily assesses for **myocardial ischemia or infarction** and would likely show non-specific changes or signs of left ventricular hypertrophy in this case, not providing a definitive diagnosis for aortic dissection. - Relying solely on an EKG would delay the necessary diagnostic imaging for a life-threatening condition like aortic dissection. *Emergency surgery* - While emergency surgery is the definitive treatment for **Type A aortic dissection**, it should only be performed after a definitive diagnosis has been established through imaging. - Proceeding directly to surgery without confirming the diagnosis with imaging could lead to unnecessary or inappropriate interventions. *Chest X-ray* - A chest X-ray can show a **widened mediastinum** or **pleural effusion** in aortic dissection, but it is not sensitive or specific enough to confirm the diagnosis definitively. - It would not visualize the **intimal flap** or the extent of the dissection, which is crucial for surgical planning. *Cardiac troponins* - Cardiac troponins are used to diagnose **myocardial infarction** and would likely be elevated if the aortic dissection involved the coronary arteries. - However, troponin elevation in the setting of aortic dissection indicates secondary myocardial damage, not the primary diagnosis, and would not provide the necessary structural information.

Question 893: A 41-year-old man presents to a New Mexico emergency department with a 12 hour history of shortness of breath and a nonproductive cough. He says that last week he experienced fevers, chills, fatigue, and myalgias but assumed that he simply had a cold. The symptoms went away after 3 days and he felt fine for several days afterward until he started experiencing shortness of breath even at rest. He works as an exterminator and recently had a job in a rodent infested home. Physical exam reveals a thin, tachypneic man with diffuse rales bilaterally. The most likely cause of this patient's symptoms is associated with which of the following?

A. Gram-positive cocci in clusters on blood culture
B. Capillary leak syndrome with pulmonary edema (Correct Answer)
C. Acid-fast bacilli on sputum microscopy
D. Encapsulated gram-negative diplococci
E. Intracellular inclusion bodies in respiratory epithelium

Explanation: ***Capillary leak syndrome with pulmonary edema*** - This patient's symptoms (flu-like prodrome, rapid progression to severe dyspnea, nonproductive cough, diffuse rales, history of rodent exposure in New Mexico) are highly classic for **Hantavirus Pulmonary Syndrome (HPS)**. - HPS is characterized by **capillary leak syndrome** leading to rapid **pulmonary edema** and respiratory failure due to increased vascular permeability. *Gram-positive cocci in clusters on blood culture* - This finding suggests a **Staphylococcal infection**, which could cause pneumonia, but the clinical picture (rodent exposure, biphasic illness, rapid progression to pulmonary edema) is not typical. - While *Staphylococcus aureus* can cause severe pneumonia, it usually presents with a more direct onset of respiratory symptoms and often has risk factors such as intravenous drug use or recent surgery, which are not mentioned. *Acid-fast bacilli on sputum microscopy* - This finding is characteristic of **tuberculosis**, which typically presents with a more chronic course of cough, weight loss, and fatigue, rather than the acute, rapidly progressive illness described here. - The acute onset of severe dyspnea and rapid progression after a prodromal illness is inconsistent with typical tuberculosis presentation. *Encapsulated gram-negative diplococci* - This morphology is characteristic of **Neisseria meningitidis** or **Moraxella catarrhalis**, which are typically associated with meningitis or otitis media/bronchitis, respectively. - While *Haemophilus influenzae* (a gram-negative coccobacillus) can cause pneumonia, the described symptoms with rodent exposure are not suggestive of typical bacterial pneumonia. *Intracellular inclusion bodies in respiratory epithelium* - This finding is associated with **viral infections** such as **cytomegalovirus (CMV)** or **adenovirus**, which can cause pneumonia, especially in immunocompromised individuals. - While Hantavirus is a virus, its characteristic pathology in the lungs is primarily diffuse vascular leakage and pulmonary edema due to endothelial damage, not typically cellular inclusion bodies in respiratory epithelium as the dominant diagnostic feature.

Question 894: A 51-year-old woman is brought to the emergency department because of an aggressive cough with copious amounts of thick, foamy, yellow-green sputum. She says she has had this cough for about 11 years with exacerbations similar to her presentation today. She also reports that her cough is worse in the morning. She was evaluated multiple times in the past because of recurrent bouts of bronchitis that have required treatment with antibiotics. She is a non-smoker. On physical examination, the blood pressure is 125/78 mm Hg, pulse rate is 80/min, respiratory rate is 16/min, and temperature is 36.7°C (98.0°F). Chest auscultation reveals crackles and wheezing over the right middle lobe and the rest of her physical examinations are normal. The chest X-ray shows irregular opacities in the right middle lobe and diffuse airway thickening. Based on this history and physical examination, which of the following is the most likely diagnosis?

A. Bronchiectasis (Correct Answer)
B. Tuberculosis
C. Chronic bronchitis
D. Chronic obstructive pulmonary disease
E. Alpha-1-antitrypsin deficiency

Explanation: ***Correct: Bronchiectasis*** - The classic presentation of **chronic cough with copious, purulent sputum** (thick, foamy, yellow-green) lasting 11 years is pathognomonic for bronchiectasis - **Recurrent respiratory infections** requiring multiple antibiotic courses indicate permanent airway damage with impaired mucus clearance - **Morning cough** reflects postural drainage of secretions that accumulated overnight in dilated bronchi - **Non-smoker status** with chronic symptoms points to structural lung disease rather than smoking-related conditions - Chest X-ray findings of **irregular opacities in right middle lobe and diffuse airway thickening** are characteristic of bronchiectasis (permanent dilation and thickening of airways) - Right middle lobe is a common location for bronchiectasis due to anatomical drainage issues *Incorrect: Tuberculosis* - While TB can cause chronic cough and lung lesions, the **copious, foamy, purulent sputum** production is not typical of TB - TB typically presents with **constitutional symptoms** (fever, night sweats, weight loss), which are absent here - Chest X-ray in TB classically shows **apical infiltrates, cavitation, or granulomas**, not diffuse airway thickening - The 11-year history with stable exacerbations would be unusual for untreated TB *Incorrect: Chronic bronchitis* - Chronic bronchitis requires **productive cough for ≥3 months per year for ≥2 consecutive years**, but is **strongly associated with smoking** - This patient is a **non-smoker**, making chronic bronchitis unlikely - The imaging finding of **diffuse airway thickening** suggests permanent structural changes (bronchiectasis) rather than simple mucosal inflammation - Chronic bronchitis doesn't typically cause localized findings in one lobe *Incorrect: Chronic obstructive pulmonary disease* - COPD is characterized by **irreversible airflow limitation** and is almost exclusively seen in **smokers** or those with significant environmental exposure - This **non-smoking patient** lacks the primary risk factor for COPD - The dominant clinical features of **copious purulent sputum and airway thickening** are more consistent with bronchiectasis than the emphysema or chronic bronchitis components of COPD - Physical exam would typically show **hyperinflation, decreased breath sounds, and prolonged expiration** in COPD, not localized crackles *Incorrect: Alpha-1-antitrypsin deficiency* - This genetic condition causes **early-onset emphysema** (typically age 30-40s) in non-smokers and may cause liver disease - While it can present without smoking history, the predominant feature is **lower lobe-predominant emphysema**, not bronchiectasis - The clinical picture of **copious purulent sputum, recurrent infections, and airway thickening** is inconsistent with primary alpha-1-antitrypsin deficiency - This condition would show **hyperinflation and reduced lung markings** on imaging, not airway thickening

Question 895: A 44-year-old woman with recurrent urinary tract infections is brought to the emergency department by ambulance after sudden onset of severe headache 30 minutes ago. She has a history of occasional, mild headaches in the morning. There is no other history of serious illness. Both her father and her paternal grandmother died of chronic kidney disease. Her temperature is 37.2°C (99.1°F) and blood pressure is 145/90 mm Hg. Physical examination shows neck stiffness. When her hip is flexed, she is unable to fully extend her knee because of pain. Lumbar puncture performed 12 hours after headache onset yields 10 mL of yellow-colored fluid with no leukocytes. Which of the following is the most likely predisposing factor for this patient's current condition?

A. Cerebral atrophy
B. Saccular aneurysm (Correct Answer)
C. Arterial atherosclerosis
D. Bacterial infection
E. Hypercoagulable state

Explanation: ***Saccular aneurysm*** - The sudden onset of a **severe headache**, **neck stiffness**, positive **Kernig's sign** (inability to fully extend the knee when the hip is flexed), and **xanthochromic cerebrospinal fluid (CSF)** strongly suggest **subarachnoid hemorrhage (SAH)**. - **Saccular (berry) aneurysms** are the most common cause of non-traumatic SAH, and the patient's family history of chronic kidney disease (potentially indicating **polycystic kidney disease**) is a risk factor for their development. *Cerebral atrophy* - **Cerebral atrophy** is a process involving loss of neurons and neuronal connections, typically associated with aging or neurodegenerative diseases, and does not directly predispose to acute subarachnoid hemorrhage. - While it can be associated with some forms of vascular disease, it is not a primary risk factor for the sudden rupture of a cerebral aneurysm. *Arterial atherosclerosis* - **Atherosclerosis** usually causes **ischemic strokes** or **transient ischemic attacks** due to plaque rupture or stenosis, or intracerebral hemorrhages from rupture of small vessels. - It is not a primary predisposing factor for **saccular aneurysm rupture** leading to subarachnoid hemorrhage, which typically involves congenital or acquired defects in the arterial wall. *Bacterial infection* - A **bacterial infection** of the central nervous system would lead to symptoms of meningitis (fever, altered mental status) and a CSF profile showing **elevated leukocytes**, low glucose, and high protein, none of which are consistent with this patient's presentation. - The patient's CSF showed **no leukocytes**, ruling out a bacterial cause for meningeal irritation. *Hypercoagulable state* - A **hypercoagulable state** increases the risk for **thrombotic events** such as deep vein thrombosis, pulmonary embolism, or ischemic stroke. - It does not predispose to the spontaneous rupture of a cerebral aneurysm and subsequent subarachnoid hemorrhage, which is a bleeding event.

Question 896: A 72-year-old man presents to the emergency department because of difficulty breathing and sharp chest pain. The chest pain increases in intensity with lying down, and it radiates to the scapular ridge. Approximately 3 weeks ago, he had an anterior ST-elevation myocardial infarction, which was treated with intravenous alteplase. He was discharged home in a stable condition. Current vital signs include a temperature of 38.1 (100.5°F), blood pressure of 131/91 mm Hg, and pulse of 99/min. On examination, heart sounds are distant and a scratching sound is heard on the left sternal border. ECG reveals widespread concave ST elevations in the precordial leads and PR depressions in leads V2-V6. Which of the following is the most likely cause of this patient condition?

A. Recurrent infarction
B. Myocarditis
C. Aortic dissection
D. Dressler’s syndrome (Correct Answer)
E. Ventricular aneurysm

Explanation: ***Dressler’s syndrome*** - This syndrome, also known as **post-myocardial infarction syndrome**, typically presents weeks to months after an MI and is characterized by pleuritic chest pain, fever, and pericardial friction rub. - The **widespread ST elevations (concave)** and **PR depressions** on ECG are classic findings of pericarditis, which is the underlying pathology of Dressler's syndrome. *Recurrent infarction* - While an MI can cause chest pain, the pain associated with infarction is typically **retrosternal, crushing**, and does not improve with leaning forward or worsen with lying down. - ECG findings of recurrent MI would show **convex ST elevations** in a specific coronary artery territory, not widespread concave ST elevation. *Myocarditis* - Myocarditis can cause chest pain, fever, and ECG changes (including ST elevations), but it is primarily an **inflammation of the heart muscle** often due to viral infection. - In this case, the **pericardial friction rub** and history of recent MI strongly point towards pericardial inflammation, not primarily myocardial inflammation. *Aortic dissection* - Aortic dissection presents with **severe, tearing chest pain** that often radiates to the back, but it typically has an abrupt onset and is not associated with a pericardial friction rub or widespread ST elevations. - The ECG findings of pericarditis do not support acute aortic dissection. *Ventricular aneurysm* - A ventricular aneurysm is a late complication of MI and can lead to symptoms like heart failure or arrhythmias, but it does **not typically cause acute pericarditic chest pain** or associated ECG findings. - While it can cause persistent ST elevation, it would not be widespread and concave, and it wouldn't be associated with a friction rub.

Question 897: A 20-year-old man comes to the emergency room because of palpitations and mild dyspnea for the last 2 hours. He has had similar episodes in the past that resolved within 20 minutes, but they have been worsening since he started training for his first marathon 1 month ago. Ten years ago, he was treated for streptococcal pharyngitis with a 10-day course of penicillin. His maternal uncle passed away unexpectedly from a heart condition at age 40. He is 180 cm (5 ft 11 in) tall and weighs 85 kg (187 lb); BMI is 26.2 kg/m2. His temperature is 36.5°C (97.7°F), pulse is 70/min, respirations are 18/min, and blood pressure is 132/60 mm Hg. On examination, there is a decrescendo early diastolic murmur heard best along the left sternal border. His head slightly bobs about every second. The remainder of the examination shows no abnormalities. Which of the following is most likely to be present?

A. Bicuspid aortic valve (Correct Answer)
B. Antistreptolysin O antibodies
C. Asymmetric septal hypertrophy
D. Valve vegetation
E. Myxomatous degeneration

Explanation: ***Bicuspid aortic valve*** - The patient presents with classic signs of **aortic regurgitation**, including a **decrescendo early diastolic murmur** and **De Musset's sign** (head bobbing). In a young individual, a **bicuspid aortic valve** is the most common congenital cause of aortic valve disease, often leading to regurgitation or stenosis over time. - The patient's history of palpitations and dyspnea, worsening with exertion, suggests significant hemodynamic compromise related to chronic aortic insufficiency, which can develop secondary to a bicuspid valve. *Antistreptolysin O antibodies* - While the patient had a history of **streptococcal pharyngitis** 10 years ago, there are no other signs of **acute rheumatic fever** or **rheumatic heart disease**, such as migratory polyarthritis, chorea, or erythema marginatum. - The murmur described is typical of aortic regurgitation without specific features pointing to rheumatic involvement, which typically affects the **mitral valve** first. *Asymmetric septal hypertrophy* - **Asymmetric septal hypertrophy** is characteristic of **hypertrophic cardiomyopathy**, which would typically present with a **systolic murmur** that increases with Valsalva maneuver, not an early diastolic murmur. - While sudden cardiac death in a young relative might suggest hypertrophic cardiomyopathy, the physical exam findings here are inconsistent with that diagnosis. *Valve vegetation* - **Valve vegetations** are associated with **infective endocarditis** and would typically present with fever, new or worsening murmur, and signs of systemic infection, none of which are noted in this patient. - The patient's symptoms are chronic and episodic, not acute, subacute, or associated with infectious signs. *Myxomatous degeneration* - **Myxomatous degeneration** primarily affects the **mitral valve**, leading to **mitral valve prolapse** and subsequent regurgitation, which would produce a **mid-systolic click** followed by a late systolic murmur. - This condition is not typically associated with an early diastolic murmur characteristic of aortic regurgitation.

Question 898: A 58-year-old man comes to the physician because of intermittent throbbing headaches over the past year. The headaches are worse when he wakes up and are not accompanied by other symptoms. The patient also reports trouble concentrating on daily tasks at work. His wife has been complaining lately about his snoring during sleep, which he attributes to his chronic sinusitis. He has a history of hypertension and an allergy to dust mites. He has smoked a pack of cigarettes daily for 14 years. His pulse is 72/min and blood pressure is 150/95 mm Hg. He is 178 cm (5 ft 10 in) tall and weighs 120 kg (265 lb); BMI is 37.9 kg/m2. Neurological and cutaneous examination shows no abnormalities. Which of the following is the most likely cause of this patient's hypertension?

A. Hypophyseal neoplasm
B. Hypersecretion of aldosterone
C. Nocturnal upper airway obstruction (Correct Answer)
D. Low synaptic serotonin levels
E. Low circulating free thyroxine levels

Explanation: ***Nocturnal upper airway obstruction*** - The patient's symptoms of **morning headaches**, **trouble concentrating**, **snoring**, and **obesity** (BMI 37.9) are highly suggestive of **obstructive sleep apnea (OSA)** - OSA is a well-known secondary cause of hypertension due to **intermittent hypoxia and sympathetic overactivity** during sleep - The patient's existing hypertension and elevated blood pressure (150/95 mm Hg) are consistent with the cardiovascular complications of untreated OSA *Hypophyseal neoplasm* - While a pituitary tumor can cause hypertension (e.g., in Cushing's disease or acromegaly), this patient lacks classical signs like **moon facies, striae, or characteristic facial/hand changes** - The primary symptoms of snoring and morning headaches point away from a hypophyseal neoplasm as the most likely cause *Hypersecretion of aldosterone* - Primary aldosteronism can cause hypertension often associated with **hypokalemia**, but this is not mentioned and is not typically linked to snoring or morning headaches - This condition involves excessive aldosterone production leading to sodium retention and potassium excretion, but doesn't explain the sleep-related symptoms *Low synaptic serotonin levels* - Low serotonin levels are associated with **depression, anxiety, and sleep disturbances**, but not directly as a primary cause of hypertension or morning headaches - While sleep issues can be related to serotonin, OSA directly causes the symptoms described and hypertension through different mechanisms (intermittent hypoxia and sympathetic activation) *Low circulating free thyroxine levels* - Hypothyroidism can cause hypertension, but other typical symptoms like **fatigue, cold intolerance, and bradycardia** are absent (patient has normal pulse of 72/min) - The specific cluster of snoring, morning headaches, and obesity points more strongly toward obstructive sleep apnea than hypothyroidism

Question 899: A 27-year-old man with a past medical history of type I diabetes mellitus presents to the emergency department with altered mental status. The patient was noted as becoming more lethargic and confused over the past day, prompting his roommates to bring him in. His temperature is 99.0°F (37.2°C), blood pressure is 107/68 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below. Serum: Na+: 144 mEq/L Cl-: 100 mEq/L K+: 6.3 mEq/L HCO3-: 16 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.4 mg/dL Ca2+: 10.2 mg/dL Which of the following is the appropriate endpoint of treatment for this patient?

A. Clinically asymptomatic
B. Normal anion gap (Correct Answer)
C. Normal glucose
D. Vitals stable
E. Normal potassium

Explanation: ***Normal anion gap*** - A **normal anion gap** (approximately 8-12 mEq/L) indicates resolution of the **metabolic acidosis** characteristic of diabetic ketoacidosis (DKA). The current anion gap is high (Na - (Cl + HCO3) = 144 - (100 + 16) = 28 mEq/L). - The patient's presentation with **type 1 diabetes** and **altered mental status**, coupled with **hyperglycemia** (599 mg/dL) and **low bicarbonate** (16 mEq/L), is highly suggestive of DKA, for which anion gap normalization is a key treatment endpoint. *Clinically asymptomatic* - While a desirable outcome, resolution of symptoms occurs gradually and is not the primary biochemical endpoint for DKA treatment. - Patients may have residual symptoms even after metabolic derangements have significantly improved. *Normal glucose* - In DKA treatment, glucose is allowed to drop to a level (e.g., <200 mg/dL) but not necessarily to normal range, before initiating **dextrose-containing intravenous fluids** to prevent hypoglycemia while continuing insulin. - **Normal glucose** alone does not guarantee resolution of ketoacidosis, which is the main life-threatening aspect of DKA. *Vitals stable* - **Stable vital signs** indicate hemodynamic stability, which is crucial but does not confirm the resolution of the underlying DKA metabolic derangements. - Vitals can stabilize or worsen independently of acidosis resolution, especially if complications arise. *Normal potassium* - **Potassium levels** are critical to monitor and correct during DKA treatment, as insulin administration drives potassium into cells, potentially causing **hypokalemia**. - While important for patient safety, achieving a normal potassium level is part of supportive care and not the primary endpoint for resolving the ketoacidotic state itself.

Question 900: A 70-year-old man with a 2 year history of Alzheimer disease is brought in from his nursing facility with altered mental status and recurrent falls during the past few days. Current medications include donepezil and galantamine. His vital signs are as follows: temperature 36.0°C (96.8°F), blood pressure 90/60 mm Hg, heart rate 102/min, respiratory rate 22/min. Physical examination reveals several lacerations on his head and extremities. He is oriented only to the person. Urine and blood cultures are positive for E. coli. The patient is admitted and initial treatment with IV fluids, antibiotics, and subcutaneous prophylactic heparin. On the second day of hospitalization, diffuse bleeding from venipuncture sites and wounds is observed. His blood test results show thrombocytopenia, prolonged PT and PTT, and a positive D-dimer. Which of the following is the most appropriate next step in the management of this patient's condition?

A. Cryoprecipitate, FFP and low dose SC heparin
B. Start prednisone therapy
C. Immediately cease heparin therapy and prescribe an alternative anticoagulant (Correct Answer)
D. Splenectomy
E. Urgent plasma exchange

Explanation: ***Immediately cease heparin therapy and prescribe an alternative anticoagulant*** - This patient presents with **disseminated intravascular coagulation (DIC)** secondary to severe **sepsis** (E. coli bacteremia), characterized by **thrombocytopenia**, **prolonged PT and PTT**, **positive D-dimer**, and **diffuse bleeding**. - In DIC with active bleeding, **heparin must be stopped immediately** as it will worsen the bleeding by preventing clot formation. - The primary management of DIC is **treating the underlying cause** (sepsis with antibiotics and IV fluids, already initiated) and **supportive care** with blood product replacement as needed. - Alternative anticoagulation is generally **not needed acutely** in DIC with bleeding, but stopping heparin is the critical first step to prevent further hemorrhage. *Cryoprecipitate, FFP and low dose SC heparin* - **Cryoprecipitate** (source of fibrinogen and factor VIII) and **FFP** (contains all clotting factors) are appropriate for severe DIC with bleeding to replace consumed coagulation factors. - However, continuing **low-dose subcutaneous heparin** is contraindicated in a patient with active diffuse bleeding from DIC, as it will worsen the hemorrhage. - The correct approach is blood product replacement WITHOUT ongoing anticoagulation when bleeding is the dominant feature. *Start prednisone therapy* - **Corticosteroids** have no role in the management of DIC, which is a consumptive coagulopathy triggered by systemic activation of coagulation. - Steroids are used for immune-mediated thrombocytopenias like **ITP**, not for DIC where platelets are consumed in microthrombi. - The treatment focus in DIC is addressing the underlying trigger (sepsis) and replacing consumed factors. *Splenectomy* - **Splenectomy** is used for refractory immune-mediated conditions like chronic **ITP** or certain hemolytic anemias, not for consumptive coagulopathy. - DIC is managed medically by treating the underlying cause and providing supportive care; surgical intervention has no role. - The spleen is not involved in the pathophysiology of DIC. *Urgent plasma exchange* - **Plasma exchange (plasmapheresis)** is the emergent treatment for **thrombotic thrombocytopenic purpura (TTP)**, which presents with the classic pentad: thrombocytopenia, microangiopathic hemolytic anemia, fever, neurologic symptoms, and renal dysfunction. - While some features overlap (thrombocytopenia, altered mental status), this patient's presentation with **sepsis**, **prolonged PT/PTT**, **positive D-dimer**, and **diffuse bleeding** is diagnostic of **DIC**, not TTP. - TTP typically has **normal coagulation studies** (PT/PTT), distinguishing it from DIC.

Question 901: A 69-year-old male presents to the emergency department for slurred speech and an inability to use his right arm which occurred while he was eating dinner. The patient arrived at the emergency department within one hour. A CT scan was performed of the head and did not reveal any signs of hemorrhage. The patient is given thrombolytics and is then managed on the neurology floor. Three days later, the patient is recovering and is stable. He seems depressed but is doing well with his symptoms gradually improving as compared to his initial presentation. The patient complains of neck pain that has worsened slowly over the past few days for which he is being given ibuprofen. Laboratory values are ordered and return as indicated below: Serum: Na+: 130 mEq/L K+: 3.7 mEq/L Cl-: 100 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 7 mg/dL Glucose: 70 mg/dL Creatinine: 0.9 mg/dL Ca2+: 9.7 mg/dL Urine: Appearance: dark Glucose: negative WBC: 0/hpf Bacterial: none Na+: 320 mEq/L/24 hours His temperature is 99.5°F (37.5°C), pulse is 95/min, blood pressure is 129/70 mmHg, respirations are 10/min, and oxygen saturation is 98% on room air. Which of the following is the best next step in management?

A. Demeclocycline
B. Fluid restriction (Correct Answer)
C. Oral salt tablets
D. Continue conservative management
E. Conivaptan

Explanation: ***Fluid restriction*** - The patient presents with **hyponatremia** (Na+ 130 mEq/L) and elevated urine sodium (320 mEq/L/24 hours) in the setting of recent stroke and possible SIADH (**Syndrome of Inappropriate Antidiuretic Hormone secretion**). - **Fluid restriction** is the initial and most crucial step in managing euvolemic hyponatremia due to SIADH, reducing water intake to allow the kidney to excrete excess water and correct serum sodium. *Demeclocycline* - **Demeclocycline** is a tetracycline derivative that inhibits the action of ADH on renal tubules, used in chronic or refractory cases of SIADH. - It is *not* the first-line treatment for acute, moderate hyponatremia, especially when fluid restriction has not yet been attempted. *Oral salt tablets* - **Oral salt tablets** would increase the solute load but would also draw water, potentially worsening hyponatremia if unrestricted fluid intake persists in SIADH. - This intervention is generally not appropriate for **euvolemic hyponatremia** where the primary issue is excess free water. *Continue conservative management* - With a sodium level of 130 mEq/L, this is considered **mild to moderate hyponatremia** and requires active intervention to prevent potential neurological complications. - Simply continuing conservative management without addressing the underlying **hyponatremia** or its cause would be inadequate and potentially harmful. *Conivaptan* - **Conivaptan** is an ADH receptor antagonist that can be used for persistent or significant hyponatremia in SIADH. - It is typically reserved for more severe or refractory cases of hyponatremia and is usually administered intravenously, making it less suitable as a first-line outpatient management strategy.

Question 902: A 57-year-old man presents for his yearly wellness visit. He says he has been feeling well and has no complaints. No significant past medical history or current medications. The patient reports a 35-pack-year smoking history but says he quit 5 years ago. His family history is significant for lung cancer in his father who died at age 67. His vital signs include: temperature 36.8°C (98.2°F), pulse 95/min, respiratory rate 16/min, blood pressure 100/75 mm Hg. Physical examination is unremarkable. Laboratory findings are significant for the following: Serum potassium 3.9 mEq/L Serum sodium 140 mEq/L Serum chloride 103 mEq/L Serum calcium 2.5 mmol/L BUN 15 mg/dL Creatinine 0.8 mg/dL Glucose 95 mg/dL Magnesium 1.7 mEq/L Phosphate 1.1 mmol/L Hemoglobin 14 g/dL Bicarbonate (HCO3-) 25 mEq/L Bilirubin, total 0.9 mg/dL Bilirubin, indirect 0.4 mg/dL AST 10 U/L ALT 19 U/L Alkaline phosphatase 40 U/L Albumin 3.6 g/dL Which of the following preventative screening tests is recommended for this patient at this time?

A. Abdominal ultrasound
B. No screening indicated
C. Low-dose CT scan (LDCT) of the chest (Correct Answer)
D. ECG
E. Chest X-ray

Explanation: ***Low-dose CT scan (LDCT) of the chest*** - The patient meets the criteria for **lung cancer screening** due to his age (57), significant **smoking history** (35 pack-years), and quitting within the last 15 years (5 years ago). - Guidelines recommend annual **LDCT** for individuals aged 50-80 with a 20+ pack-year smoking history who currently smoke or have quit within the past 15 years. *Abdominal ultrasound* - This test is not routinely recommended for asymptomatic individuals for general screening; its use is typically for specific symptoms or risks (e.g., abdominal pain, family history of abdominal aortic aneurysm). - The patient has no symptoms or risk factors that would suggest the need for an abdominal ultrasound at this time. *No screening indicated* - Given the patient's **heavy smoking history** and age, there is a clear indication for **lung cancer screening**. - Skipping screening would miss an opportunity for early detection of lung cancer, which is crucial for improving outcomes. *ECG* - An **ECG** screens for cardiac abnormalities but is not a primary screening tool for lung cancer. - While smoking is a risk factor for cardiovascular disease, the immediate and most pressing screening need based on his history is related to lung cancer. *Chest X-ray* - A **chest X-ray** is generally not recommended for **lung cancer screening** in high-risk individuals because it has lower sensitivity compared to **LDCT** for detecting early-stage tumors. - **LDCT** is the preferred method for lung cancer screening due to its superior ability to detect small, actionable lesions.

Question 903: A 37-year-old male presents to your clinic with shortness of breath and lower extremity edema. He was born in Southeast Asia and emigrated to America ten years prior. Examination demonstrates 2+ pitting edema to the level of his knees, ascites, and bibasilar crackles, as well as an opening snap followed by a mid-to-late diastolic murmur. The patient undergoes a right heart catheterization that demonstrates a pulmonary capillary wedge pressure (PCWP) of 24 mmHg. The patient is most likely to have which of the following?

A. Normal or decreased left ventricular end diastolic pressure (LVEDP) (Correct Answer)
B. Decreased transmitral gradient
C. Decreased pulmonary artery systolic pressure (PASP)
D. Increased left ventricular end diastolic pressure (LVEDP)
E. Increased pulmonary vascular compliance

Explanation: ***Normal or decreased left ventricular end diastolic pressure (LVEDP)*** - The patient's symptoms (opening snap, mid-to-late diastolic murmur, Southeast Asian origin) strongly suggest **mitral stenosis**. - In mitral stenosis, the obstruction at the **mitral valve** leads to elevated left atrial pressure (reflected by the high PCWP), but the left ventricle itself is not failing, so LVEDP is typically normal or even decreased. *Decreased transmitral gradient* - A **mid-to-late diastolic murmur** and an **opening snap** are classic signs of mitral stenosis, indicating a high pressure gradient across the mitral valve during diastole. - A decreased transmitral gradient would imply reduced obstruction, which contradicts the patient's strong clinical presentation. *Decreased pulmonary artery systolic pressure (PASP)* - Elevated pulmonary capillary wedge pressure (PCWP) of 24 mmHg indicates **pulmonary hypertension secondary to left atrial pressure elevation** in mitral stenosis. - This consistently leads to an **increased pulmonary artery systolic pressure (PASP)**, not a decreased one, as the right ventricle has to work harder to pump blood through the high-pressure pulmonary vasculature. *Increased left ventricular end diastolic pressure (LVEDP)* - While PCWP is elevated due to **left atrial pressure overload** in mitral stenosis, the left ventricle itself is not volume or pressure overloaded during diastole. - The LVEDP would only be increased if there was actual left ventricular dysfunction or aortic valve disease, which is not suggested here. *Increased pulmonary vascular compliance* - Chronic pulmonary hypertension, as seen in advanced mitral stenosis with high PCWP, leads to **pulmonary vascular remodeling** and **decreased pulmonary vascular compliance**. - The pulmonary vessels become stiffer and less distensible, not more compliant.

Question 904: A 75-year-old woman presents to the emergency department because of a brief loss of consciousness, slurred speech, and facial numbness. Family members report that she complained about feeling chest pain and shortness of breath while on her morning walk. Medical history is noncontributory. Physical examination shows decreased pupil reactivity to light and hemiplegic gait. Her pulse is 120/min, respirations are 26/min, temperature is 36.7°C (98.0°F), and blood pressure is 160/80 mm Hg. On heart auscultation, S1 is loud, widely split, and there is a diastolic murmur. Transthoracic echocardiography in a 4-chamber apical view revealed a large oval-shaped and sessile left atrial mass. Which of the following is the most likely complication of this patient's condition?

A. Atrioventricular block
B. Systemic embolization (Correct Answer)
C. Atrial fibrillation
D. Mitral valve obstruction
E. Congestive heart failure

Explanation: ***Systemic embolization*** - This patient presents with **clear evidence of systemic embolization** from a left atrial myxoma: brief loss of consciousness, slurred speech, facial numbness, hemiplegic gait, and decreased pupil reactivity - all classic signs of **cerebral embolism**. - **Systemic embolization is the most common complication** of left atrial myxoma, occurring in **30-40% of cases**, and can lead to stroke, transient ischemic attacks, or peripheral arterial occlusion. - The large, sessile left atrial mass on echocardiography confirms the diagnosis of left atrial myxoma, and the patient is **actively experiencing** this life-threatening complication. *Mitral valve obstruction* - While this patient does have signs of mitral valve obstruction (loud, widely split S1 and diastolic murmur mimicking mitral stenosis), this represents a **chronic mechanical effect** of the tumor rather than an acute complication. - The tumor can obstruct the mitral valve and cause symptoms of dyspnea and chest pain, but the **neurological deficits are the most critical acute complication** requiring immediate intervention. *Congestive heart failure* - Although dyspnea and chest pain could suggest heart failure, these symptoms in the context of a left atrial myxoma are more likely due to **mitral valve obstruction** rather than primary myocardial dysfunction. - Heart failure can develop over time with chronic obstruction, but it is not the **most common or most serious acute complication** of left atrial myxoma. *Atrioventricular block* - AV block is a **rare complication** of left atrial myxoma and would require tumor extension into the conduction system. - The patient's tachycardia (pulse 120/min) and the presence of neurological symptoms point to embolization rather than a conduction abnormality. *Atrial fibrillation* - While atrial arrhythmias can occur due to irritation of the atrial wall by the myxoma, atrial fibrillation is **less common than systemic embolization** as a complication. - The patient's symptoms are dominated by acute neurological deficits from embolic stroke, not rhythm disturbances.

Question 905: A 51-year-old woman comes to the physician because of numbness of her legs and toes for 3 months. She has also had fatigue and occasional shortness of breath for the past 5 months. She is a painter. Examination shows pale conjunctivae. Sensation to vibration and position is absent over the lower extremities. She has a broad-based gait. The patient sways when she stands with her feet together and closes her eyes. Which of the following laboratory findings is most likely to be seen in this patient?

A. Poliovirus RNA in cerebrospinal fluid
B. Positive rapid plasma reagin test
C. Basophilic stippling on peripheral smear
D. Oligoclonal bands in cerebrospinal fluid
E. Elevated methylmalonic acid levels (Correct Answer)

Explanation: ***Elevated methylmalonic acid levels*** - The patient's symptoms (numbness, fatigue, shortness of breath, pale conjunctivae, loss of vibration and position sensation, broad-based gait, positive Romberg sign) are classic for **vitamin B12 deficiency**, which leads to **megaloblastic anemia** and **subacute combined degeneration** of the spinal cord. - **Elevated methylmalonic acid** and homocysteine levels are hallmark laboratory findings in vitamin B12 deficiency, as B12 is a cofactor for the enzyme **methylmalonyl-CoA mutase**. *Poliovirus RNA in cerebrospinal fluid* - **Poliovirus RNA** in CSF indicates poliomyelitis, which typically presents with **acute flaccid paralysis** and meningeal signs, not the chronic sensory and gait disturbances described here. - The disease has largely been eradicated in many parts of the world due to vaccination, making it a less likely diagnosis in this context. *Positive rapid plasma reagin test* - A **positive rapid plasma reagin (RPR) test** indicates syphilis, and neurosyphilis can cause neurological symptoms, but the classic presentation described (numbness, gait disturbance, anemia) is more characteristic of vitamin B12 deficiency. - While neurosyphilis can affect proprioception (tabes dorsalis), the symptom complex presented here, especially with the fatigue and pallor, points away from syphilis as the primary diagnosis. *Basophilic stippling on peripheral smear* - **Basophilic stippling** on a peripheral smear is a characteristic finding in **lead poisoning** (plumbism), which can cause neuropathy and anemia, especially in a painter. However, the specific neurological deficits (loss of vibration and position sense) and the broad-based gait are more prominent in vitamin B12 deficiency. - While lead poisoning should be considered due to her occupation, the constellation of neurological and hematological findings points more strongly toward B12 deficiency. *Oligoclonal bands in cerebrospinal fluid* - **Oligoclonal bands** in CSF are indicative of **multiple sclerosis (MS)** or other inflammatory demyelinating diseases of the central nervous system. - While MS can cause numbness and gait ataxia, the description of pale conjunctivae, fatigue, and specific deficits in vibration and position sense, along with a broad-based gait and a positive Romberg sign, strongly aligns with a nutritional deficiency like B12 rather than MS.

Question 906: A 60-year-old woman presents to the clinic with a 3-month history of shortness of breath that worsens on exertion. She also complains of chronic cough that has lasted for 10 years. Her symptoms are worsened even with light activities like climbing up a flight of stairs. She denies any weight loss, lightheadedness, or fever. Her medical history is significant for hypertension, for which she takes amlodipine daily. She has a 70-pack-year history of cigarette smoking and drinks 3–4 alcoholic beverages per week. Her blood pressure today is 128/84 mm Hg. A chest X-ray shows flattening of the diaphragm bilaterally. Physical examination is notable for coarse wheezing bilaterally. Which of the following is likely to be seen with pulmonary function testing?

A. Decreased FEV1: FVC and decreased total lung capacity
B. Normal FEV1: FVC and decreased total lung capacity
C. Increased FEV1: FVC and decreased total lung capacity
D. Decreased FEV1: FVC and increased total lung capacity (Correct Answer)
E. Increased FEV1: FVC and normal total lung capacity

Explanation: ***Decreased FEV1:FVC ratio and increased total lung capacity*** - This patient's symptoms (shortness of breath on exertion, chronic cough, 70-pack-year smoking history, coarse wheezing, and diaphragmatic flattening on X-ray) are highly suggestive of **Chronic Obstructive Pulmonary Disease (COPD)**, specifically **emphysema**, an obstructive lung disease. - In COPD, there is airflow limitation, causing a **decreased FEV1:FVC ratio** (typically <0.70). Over time, air trapping occurs due to damaged alveoli and loss of elastic recoil, leading to an **increased total lung capacity (TLC)** and residual volume. *Decreased FEV1:FVC ratio and decreased total lung capacity* - A **decreased FEV1:FVC ratio** indicates an **obstructive lung disease**. - However, a **decreased total lung capacity (TLC)** is characteristic of a **restrictive lung disease**, which does not align with the patient's presentation typical of COPD/emphysema. *Normal FEV1:FVC ratio and decreased total lung capacity* - A **normal FEV1:FVC ratio** is inconsistent with the patient's strong history of smoking and symptoms suggestive of airflow obstruction. - A **decreased total lung capacity (TLC)** indicates a restrictive lung disease, which is not the primary diagnosis here. *Increased FEV1:FVC ratio and decreased total lung capacity* - An **increased FEV1:FVC ratio** is not physiologically possible in significant lung disease and is therefore incorrect. - A **decreased total lung capacity (TLC)** would point towards a restrictive pattern not seen in generalized emphysema. *Increased FEV1:FVC ratio and normal total lung capacity* - An **increased FEV1:FVC ratio** is not a characteristic finding in any lung disease and is therefore incorrect. - A **normal total lung capacity** would not be expected in advanced emphysema where air trapping is prominent.

Question 907: A 58-year-old man presents to the emergency department with severe chest pain and uneasiness. He says that symptoms onset acutely half an hour ago while he was watching television. He describes the pain as being 8/10 in intensity, sharp in character, localized to the center of the chest and retrosternal, and radiating to the back and shoulders. The patient denies any associated change in the pain with breathing or body position. He says he has associated nausea but denies any vomiting. He denies any recent history of fever, chills, or chronic cough. His past medical history is significant for hypertension, hyperlipidemia, and diabetes mellitus for which he takes lisinopril, hydrochlorothiazide, simvastatin, and metformin. He reports a 30-pack-year smoking history and has 1–2 alcoholic drinks during the weekend. Family history is significant for hypertension, hyperlipidemia, and an ST elevation myocardial infarction in his father and paternal uncle. His blood pressure is 220/110 mm Hg in the right arm and 180/100 mm Hg in the left arm. On physical examination, the patient is diaphoretic. Cardiac exam reveals a grade 2/6 diastolic decrescendo murmur loudest over the left sternal border. Remainder of the physical examination is normal. The chest radiograph shows a widened mediastinum. The electrocardiogram (ECG) reveals non-specific ST segment and T wave changes. Intravenous morphine and beta-blockers are started. Which of the following is the most likely diagnosis in this patient?

A. Pulmonary embolism
B. Acute myocardial infarction
C. Myocarditis
D. Aortic regurgitation
E. Aortic dissection (Correct Answer)

Explanation: ***Aortic dissection*** - The patient's **sudden onset, sharp tearing chest pain radiating to the back** is the classic presentation of aortic dissection. - The **blood pressure differential between arms** (220/110 mm Hg right vs 180/100 mm Hg left) is a highly specific finding indicating involvement of the brachiocephalic or subclavian arteries. - The **diastolic decrescendo murmur** represents acute aortic regurgitation secondary to the dissection involving the aortic root. - The **widened mediastinum on chest X-ray** is a key radiographic finding strongly suggestive of aortic dissection. - Major risk factors present: **uncontrolled hypertension, smoking history, age, and atherosclerotic disease** (hyperlipidemia, diabetes). *Pulmonary embolism* - While PE can cause acute chest pain and dyspnea, the pain is typically **pleuritic in nature** (worsens with breathing or coughing). - PE does not cause **blood pressure differentials between arms** or a **widened mediastinum**. - The sharp, tearing quality radiating to the back is not characteristic of PE. *Acute myocardial infarction* - MI typically presents with **pressure-like or crushing chest pain**, often radiating to the left arm, jaw, or epigastrium rather than the back. - While the patient has significant MI risk factors, the **unequal blood pressures between arms** and **diastolic murmur** are not explained by isolated MI. - The **widened mediastinum** is not a feature of uncomplicated MI. *Myocarditis* - Myocarditis typically presents with **chest pain following a viral prodrome** (fever, URI symptoms), which this patient denies. - It does not cause **blood pressure differentials**, **widened mediastinum**, or the acute tearing pain radiating to the back. - Myocarditis pain is usually more constant and pressure-like, not sharp and tearing. *Aortic regurgitation* - While the **diastolic decrescendo murmur** indicates aortic regurgitation, this is a **finding rather than the primary diagnosis**. - In this acute presentation, the AR is **secondary to aortic dissection** involving the aortic root. - Chronic AR is typically asymptomatic until heart failure develops; acute severe AR (as in dissection) causes acute decompensation. - The constellation of findings (acute pain, BP differential, widened mediastinum) indicates **aortic dissection as the primary catastrophic event** causing secondary AR.

Question 908: A 21-year-old man comes to the physician's office due to a 3-week history of fatigue and a rash, along with the recent development of joint pain that has moved from his knee to his elbows. The patient reports going camping last month but denies having been bitten by a tick. His past medical history is significant for asthma treated with an albuterol inhaler. His pulse is 54/min and blood pressure is 110/72. Physical examination reveals multiple circular red rings with central clearings on the right arm and chest. There is a normal range of motion in all joints and 5/5 strength bilaterally in the upper and lower extremities. Without proper treatment, the patient is at highest risk for which of the following complications?

A. Liver capsule inflammation
B. Bone marrow failure
C. Heart valve stenosis
D. Glomerular damage
E. Cranial nerve palsy (Correct Answer)

Explanation: ***Cranial nerve palsy*** - This patient presents with classic **Lyme disease** (caused by *Borrelia burgdorferi*), including camping exposure, fatigue, migratory arthralgia, and **erythema migrans** (multiple circular red rings with central clearings on the arm and chest). - The **bradycardia (pulse 54/min)** suggests early **Lyme carditis** with possible first-degree AV block, which typically resolves with treatment and rarely progresses to complete heart block in treated cases. - Without proper antibiotic treatment, **cranial neuropathy** is one of the most common neurological complications in early disseminated Lyme disease, with **facial nerve palsy (Bell's palsy)** being the most frequent, occurring in up to 10% of untreated patients. - Other neurological complications include meningitis, radiculoneuropathy, and peripheral neuropathy, making neurologic involvement a significant risk in untreated disease. *Liver capsule inflammation* - **Perihepatitis (Fitz-Hugh-Curtis syndrome)** is associated with **pelvic inflammatory disease (PID)** caused by *Chlamydia trachomatis* or *Neisseria gonorrhoeae*, not Lyme disease. - This presents with right upper quadrant pain and "violin string" adhesions between the liver capsule and peritoneum. *Bone marrow failure* - **Bone marrow failure** (aplastic anemia) can be caused by parvovirus B19, certain medications, radiation, or idiopathic causes, but is **not a recognized complication of Lyme disease**. - Lyme disease primarily affects the skin, joints, heart (conduction system), and nervous system, not hematopoietic function. *Heart valve stenosis* - **Lyme carditis** affects the **cardiac conduction system**, causing **AV blocks** (first, second, or third degree) and myocarditis, as suggested by this patient's bradycardia. - Lyme does **not cause valvular stenosis or regurgitation**. Valvular disease is associated with rheumatic fever (post-streptococcal), endocarditis, or degenerative changes. - The cardiac manifestations of Lyme typically resolve with appropriate antibiotic therapy and rarely cause permanent structural damage. *Glomerular damage* - **Glomerulonephritis** is not a typical complication of Lyme disease in humans (though "Lyme nephritis" occurs in dogs). - Renal involvement in human Lyme disease is extremely rare and not a significant clinical concern compared to neurological, cardiac, or rheumatological manifestations.

Question 909: A 28-year-old man presents to his primary care provider because of shortness of breath, cough, and wheezing. He reports that in high school, he occasionally had shortness of breath and would wheeze after running. His symptoms have progressively worsened over the past 6 months and are now occurring daily. He also finds himself being woken up from sleep by his wheeze approximately 3 times a week. His medical history is unremarkable. He denies tobacco use or excessive alcohol consumption. His temperature is 37.1°C (98.8°F), blood pressure is 121/82 mm Hg, and heart rate is 82/min. Physical examination is remarkable for expiratory wheezing bilaterally. Spirometry shows an FEV1 of 73% of predicted, which improves by 19% with albuterol. In addition to a short-acting beta-agonist as needed, which of the following is the most appropriate therapy for this patient?

A. A high-dose inhaled corticosteroid and a long-acting beta-agonist
B. A long-acting beta-agonist alone
C. A low-dose inhaled corticosteroid alone
D. A medium-dose inhaled corticosteroid and a long-acting beta-agonist
E. A low-dose inhaled corticosteroid and a long-acting beta-agonist (Correct Answer)

Explanation: ***A low-dose inhaled corticosteroid and a long-acting beta-agonist*** - This patient presents with **persistent asthma symptoms** (daily symptoms, nighttime awakenings 3x/week, and a significant bronchodilator response) that are not controlled by a short-acting beta-agonist alone. This indicates **moderate persistent asthma**. - According to GINA guidelines, the appropriate step-up therapy for moderate persistent asthma is a **low-dose inhaled corticosteroid (ICS) combined with a long-acting beta-agonist (LABA)**. *A high-dose inhaled corticosteroid and a long-acting beta-agonist* - **High-dose ICS/LABA** is reserved for **severe uncontrolled asthma**, typically as Step 4 or 5 therapy, when symptoms persist despite lower-dose combinations or higher-step single agents. - The patient's current symptoms, while persistent, do not warrant immediate initiation of high-dose therapy as initial step-up from mild persistent. *A long-acting beta-agonist alone* - **LABAs should never be used as monotherapy** in asthma due to the risk of severe asthma exacerbations and asthma-related death. - They must always be combined with an **inhaled corticosteroid** to control underlying airway inflammation. *A low-dose inhaled corticosteroid alone* - While a **low-dose ICS alone** is appropriate for **mild persistent asthma** (Step 2), this patient's symptoms (daily symptoms, nighttime awakenings 3x/week) are more severe than mild persistent. - His severity warrants combination therapy (ICS/LABA) to achieve better symptom control. *A medium-dose inhaled corticosteroid and a long-acting beta-agonist* - A **medium-dose ICS/LABA** is typically considered for patients whose asthma remains **uncontrolled on low-dose ICS/LABA**, representing Step 4 therapy. - Given that this is the initial step-up from SABA-only use, medium-dose is generally too aggressive and should be reserved for subsequent steps if the low-dose combination proves insufficient.

Question 910: A 37-year-old man is presented to the emergency department by paramedics after being involved in a serious 3-car collision on an interstate highway while he was driving his motorcycle. On physical examination, he is responsive only to painful stimuli and his pupils are not reactive to light. His upper extremities are involuntarily flexed with hands clenched into fists. The vital signs include temperature 36.1°C (97.0°F), blood pressure 80/60 mm Hg, and pulse 102/min. A non-contrast computed tomography (CT) scan of the head shows a massive intracerebral hemorrhage with a midline shift. Arterial blood gas (ABG) analysis shows partial pressure of carbon dioxide in arterial blood (PaCO2) of 68 mm Hg, and the patient is put on mechanical ventilation. His condition continues to decline while in the emergency department and it is suspected that this patient is brain dead. Which of the following results can be used to confirm brain death and legally remove this patient from the ventilator?

A. Electrocardiogram
B. Apnea test (Correct Answer)
C. Lumbar puncture and CSF culture
D. Electromyography with nerve conduction studies
E. CT scan

Explanation: ***Correct: Apnea test*** - The **apnea test** is a **mandatory component** of brain death determination according to American Academy of Neurology (AAN) guidelines - It directly confirms the **irreversible absence of brainstem function** by demonstrating no respiratory drive despite adequate stimulus (PaCO2 ≥60 mm Hg or 20 mm Hg rise from baseline) - This patient already has a PaCO2 of 68 mm Hg, making the apnea test particularly relevant for confirmation - Brain death requires both **clinical examination** (absent brainstem reflexes, coma) and a **positive apnea test** to legally declare death and discontinue mechanical ventilation - The apnea test is performed by disconnecting the ventilator, providing supplemental oxygen, and observing for any respiratory effort while PaCO2 rises to adequate levels *Incorrect: CT scan* - While a **CT scan showing massive intracerebral hemorrhage with midline shift** provides anatomical evidence of severe, irreversible structural brain damage, it is **NOT sufficient to confirm brain death** - CT imaging is used to establish the **etiology** and rule out reversible causes, but does not directly test brainstem function - Brain death is a **clinical and functional diagnosis**, not purely an anatomical one—imaging alone cannot confirm cessation of all brain function - A patient can have devastating structural damage on CT but still retain some brainstem reflexes *Incorrect: Electrocardiogram* - An **electrocardiogram (ECG)** measures cardiac electrical activity and provides no information about brain or brainstem function - Cardiac activity commonly persists after brain death due to the heart's intrinsic automaticity - ECG findings are irrelevant to brain death determination *Incorrect: Lumbar puncture and CSF culture* - **Lumbar puncture and CSF culture** are used to diagnose CNS infections (meningitis, encephalitis) or inflammatory conditions - These tests are **completely irrelevant** for brain death diagnosis, which is based on irreversible cessation of all brain function, not infection - In this trauma case with known intracerebral hemorrhage, LP would be contraindicated due to increased intracranial pressure and risk of herniation *Incorrect: Electromyography with nerve conduction studies* - **EMG and nerve conduction studies** assess peripheral nerve and muscle function, used for diagnosing neuromuscular disorders - These tests provide no information about brain or brainstem function - They are not part of brain death determination protocols

Question 911: A 65-year-old man comes to the physician because of a 10-month history of crampy left lower extremity pain that is exacerbated by walking and relieved by rest. The pain is especially severe when he walks on an incline. He has a 20-year history of type 2 diabetes mellitus, for which he takes metformin. He has smoked 1 pack of cigarettes daily for 40 years. His blood pressure is 140/92 mm Hg. Physical examination shows dry and hairless skin over the left foot. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Osteophytic compression of the lumbar spinal canal
B. Intimal plaque in the posterior tibial artery (Correct Answer)
C. Systemic hyperplastic arteriolosclerosis
D. Thrombosing vasculitis of the popliteal artery
E. Fibrin clot in the left popliteal vein

Explanation: ***Intimal plaque in the posterior tibial artery*** - The patient's symptoms of **crampy left lower extremity pain** exacerbated by walking and relieved by rest (**intermittent claudication**) are classic for **peripheral arterial disease (PAD)**. - Risk factors like **diabetes mellitus**, **smoking**, and **hypertension** strongly predispose to **atherosclerosis** and **intimal plaque formation** in peripheral arteries, such as the posterior tibial artery, leading to reduced blood flow. *Osteophytic compression of the lumbar spinal canal* - While this can cause leg pain (**neurogenic claudication**), the pain typically **improves with leaning forward** and can be exacerbated by standing still, not necessarily relieved by rest of the legs. - The patient's symptoms would not typically manifest with **dry and hairless skin** over the foot, which is indicative of chronic ischemia. *Systemic hyperplastic arteriolosclerosis* - This condition is usually associated with **severe hypertension** and primarily affects **small arterioles**, leading to **organ damage** (e.g., kidney failure, hypertensive retinopathy). - It would not typically cause isolated, **crampy leg pain** that is specifically exacerbated by walking and relieved by rest, which is a hallmark of large vessel occlusive disease. *Thrombosing vasculitis of the popliteal artery* - **Vasculitis** typically involves **inflammation of blood vessel walls** and can cause a variety of symptoms including pain, skin lesions, and systemic signs. - While it can lead to thrombosis, it's less common than atherosclerosis in a 65-year-old with multiple risk factors, and the presentation of isolated claudication is more characteristic of atherosclerotic disease. *Fibrin clot in the left popliteal vein* - A fibrin clot in a vein would cause **deep vein thrombosis (DVT)**, presenting with **swelling**, **redness**, and **tenderness** in the leg, not typically claudication. - The pain associated with DVT usually **worsens with activity** and does not improve with rest in the same way as arterial claudication.

Question 912: A 51-year-old woman with a history of palpitations is being evaluated by a surgeon for epigastric pain. It is discovered that she has an epigastric hernia that needs repair. During her preoperative evaluation, she is ordered to receive lab testing, an electrocardiogram (ECG), and a chest X-ray. These screening studies are unremarkable except for her chest X-ray, which shows a 2 cm isolated pulmonary nodule in the middle lobe of the right lung. The nodule has poorly defined margins, and it shows a dense, irregular pattern of calcification. The patient is immediately referred to a pulmonologist for evaluation of the lesion. The patient denies any recent illnesses and states that she has not traveled outside of the country since she was a child. She has had no sick contacts or respiratory symptoms, and she does not currently take any medications. She does, however, admit to a 20-pack-year history of smoking. Which of the following is the most appropriate next step in evaluating this patient’s diagnosis with regard to the pulmonary nodule?

A. Order a positron emission tomography scan of the chest
B. Perform a flexible bronchoscopy with biopsy
C. Obtain a contrast-enhanced CT scan of the chest
D. Try to obtain previous chest radiographs for comparison (Correct Answer)
E. Send sputum for cytology

Explanation: ***Try to obtain previous chest radiographs for comparison*** - Comparing current imaging with **previous chest radiographs** is crucial to assess if the nodule is new or has changed in size, an essential factor in determining its malignant potential. - A **stable nodule** for over two years is often considered benign, potentially avoiding unnecessary invasive procedures. *Order a positron emission tomography scan of the chest* - A **PET scan** is useful for assessing the metabolic activity of a nodule, indicating malignancy, but it is typically ordered after evaluating nodule stability and risk factors, not as a primary first step. - While it can help differentiate benign from malignant lesions, it's a more advanced imaging technique and might not be immediately necessary if previous imaging exists. *Perform a flexible bronchoscopy with biopsy* - **Bronchoscopy with biopsy** is an invasive procedure that carries risks and is generally reserved for nodules with a high suspicion of malignancy after initial non-invasive evaluations. - Given the patient's presentation, less invasive steps for diagnosis should be exhausted first including evaluation of previous imaging and further characterization with CT. *Obtain a contrast-enhanced CT scan of the chest* - A **CT scan** provides much more detailed imaging of the nodule than an X-ray and is often the next step after plain radiographs, but comparing with previous films (if available) should precede it to establish nodule kinetics. - While a CT scan can characterize the nodule's features more accurately (e.g., size, borders, calcification pattern), the **stability of the nodule over time** is paramount in risk assessment. *Send sputum for cytology* - **Sputum cytology** has a very low sensitivity for diagnosing pulmonary nodules, especially for small, isolated lesions that are not centrally located. - Its utility is primarily in patients with central masses and productive cough, none of which are descriptive of this patient's presentation.

Question 913: A 51-year-old woman comes to the physician because of a 3-day history of worsening shortness of breath, nonproductive cough, and sharp substernal chest pain. The chest pain worsens on inspiration and on lying down. The patient was diagnosed with breast cancer 2 months ago and was treated with mastectomy followed by adjuvant radiation therapy. She has hypertension and hyperlipidemia. Current medications include tamoxifen, valsartan, and pitavastatin. She has smoked a pack of cigarettes daily for 15 years but quit after being diagnosed with breast cancer. Her pulse is 95/min, respirations are 20/min, and blood pressure is 110/60 mm Hg. Cardiac examination shows a scratching sound best heard at the left lower sternal border. An ECG shows sinus tachycardia and ST segment elevations in leads I, II, avF, and V1–6. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Inflammatory reaction of the pericardium (Correct Answer)
B. Subendothelial fibrosis of coronary arteries
C. Embolic occlusion of a pulmonary artery
D. Dystrophic calcification of the mitral valve
E. Fibrotic thickening of the pericardium

Explanation: ***Inflammatory reaction of the pericardium*** - The patient's symptoms of **sharp substernal chest pain worsening on inspiration and lying down**, a **scratching sound on cardiac auscultation** (pericardial friction rub), and widespread **ST segment elevations on ECG** are classic for **pericarditis**, which is an inflammation of the pericardium. - The recent **radiation therapy for breast cancer** is a significant risk factor for developing pericarditis, as radiation can cause inflammation and damage to the pericardial tissue. *Subendothelial fibrosis of coronary arteries* - This describes **atherosclerosis** of the coronary arteries, which typically presents as **angina** (chest pain with exertion) or **myocardial infarction** (sustained chest pain, potentially with ST elevation, but usually localized and associated with cardiac enzyme elevation). - The widespread ST elevations and pericardial friction rub are not characteristic of acute coronary syndrome or stable angina caused by subendothelial fibrosis. *Embolic occlusion of a pulmonary artery* - This refers to a **pulmonary embolism (PE)**, which typically presents with sudden onset of **shortness of breath**, pleuritic chest pain, and **tachycardia**. - While shortness of breath and tachycardia are present, the widespread ST elevations and pericardial friction rub are not typical findings in PE; ECG in PE usually shows T-wave inversions in V1-V3, right axis deviation, or S1Q3T3 pattern. *Dystrophic calcification of the mitral valve* - This condition is related to **mitral valve stenosis** or **regurgitation**, which can lead to symptoms like shortness of breath due to heart failure. - However, it does not typically cause sharp substernal chest pain that worsens with inspiration and lying down, or the widespread ST segment elevations and pericardial friction rub. *Fibrotic thickening of the pericardium* - This describes **constrictive pericarditis**, a chronic condition where the pericardium becomes fibrotic and thickened, leading to impaired diastolic filling and signs of right-sided heart failure (e.g., elevated JVP, peripheral edema). - While radiation therapy can cause this, the acute onset of sharp chest pain, pericardial friction rub, and widespread ST elevations are more indicative of acute inflammation rather than chronic constriction.

Question 914: A 35-year-old African-American female presents to the emergency room complaining of chest pain. She also complains of recent onset arthritis and increased photosensitivity. Physical examination reveals bilateral facial rash. Which of the following is most likely to be observed in this patient?

A. Pain improves with inspiration
B. High-pitched diastolic murmur
C. Fixed and split S2
D. Mid-systolic click
E. Pain relieved by sitting up and leaning forward (Correct Answer)

Explanation: ***Pain relieved by sitting up and leaning forward*** - This patient's symptoms (chest pain, arthritis, photosensitivity, facial rash) are highly suggestive of **systemic lupus erythematosus (SLE)**. - Among the cardiac manifestations of SLE, **pericarditis** is common. The chest pain of pericarditis is typically relieved by sitting up and leaning forward, as this decreases pressure on the inflamed pericardial sac. *Pain improves with inspiration* - This describes **pleuritic chest pain**, which is often associated with conditions like pleurisy or pneumothorax, where inspiration causes stretching of inflamed pleura. - While pleurisy can occur in SLE, the relief by sitting up and leaning forward is a more classic sign of pericarditis. *High-pitched diastolic murmur* - A high-pitched diastolic murmur is characteristic of **aortic regurgitation** or **pulmonic regurgitation**. - While SLE can cause valvular heart disease (e.g., Libman-Sacks endocarditis, often leading to mitral valve involvement), aortic or pulmonic regurgitation is not the most typical acute cardiac finding associated with these specific chest pain characteristics. *Fixed and split S2* - A fixed and split S2 is a classic finding in an **atrial septal defect (ASD)**. - While rare, SLE can be associated with some congenital heart abnormalities or pulmonary hypertension, but ASD is not a typical direct complication leading to this S2 finding in the context of acute chest pain. *Mid-systolic click* - A mid-systolic click is characteristic of **mitral valve prolapse (MVP)**. - Mitral valve abnormalities, including MVP and mitral regurgitation (due to Libman-Sacks endocarditis), are relatively common in SLE. However, the chest pain associated with pericarditis (relieved by sitting up) is a more direct and common finding given the constellation of symptoms than a mid-systolic click alone.

Question 915: A 67-year-old man with a 55-pack-year smoking history, diabetes type II, and hyperlipidemia presents to his primary care clinic for an annual exam. He has no complaints. He reports that his blood glucose has been under tight control and that he has not smoked a cigarette for the past 5 months. His temperature is 97.5°F (36.4°C), blood pressure is 182/112 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 95% on room air. Physical examination is notable for bruits bilaterally just lateral of midline near his umbilicus. The patient is started on anti-hypertensive medications including a beta-blocker, a thiazide diuretic, and a calcium channel blocker. He returns 1 month later with no change in his blood pressure. Which of the following is the best next step in management?

A. Increase dose of current blood pressure medications
B. Renal ultrasound with Doppler (Correct Answer)
C. Surgical revascularization
D. CT abdomen/pelvis
E. Lisinopril

Explanation: ***Renal ultrasound with Doppler*** - The patient presents with **resistant hypertension** (uncontrolled despite three antihypertensive medications from different classes) and **abdominal bruits**, strongly suggesting renovascular hypertension due to **renal artery stenosis**. - A **renal ultrasound with Doppler** is the initial, non-invasive diagnostic test of choice to assess for renal artery stenosis by measuring blood flow velocities. *Increase dose of current blood pressure medications* - While adjusting medication doses is a common step, the presence of **abdominal bruits** and **resistant hypertension** warrants investigation for a secondary cause before simply escalating current therapy. - Doing so without a definitive diagnosis risks ineffective treatment and delayed identification of the underlying issue. *Surgical revascularization* - **Surgical revascularization** or percutaneous intervention may be indicated if renal artery stenosis is confirmed and severe, but it is not the *next step* in management. - Diagnostic imaging is required first to confirm the diagnosis and assess the severity before considering invasive procedures. *CT abdomen/pelvis* - A **CT scan of the abdomen/pelvis** could identify renal artery stenosis but is not the preferred initial imaging modality in this context. - It involves **radiation exposure** and may require contrast, which could be problematic if renal function is impaired. *Lisinopril* - **Lisinopril**, an ACE inhibitor, could potentially manage hypertension by reducing angiotensin II. - However, in cases of **bilateral renal artery stenosis**, ACE inhibitors can lead to a significant **drop in glomerular filtration rate (GFR)** and acute kidney injury, making it a high-risk choice without prior imaging.

Question 916: A 67-year-old woman presents with right leg pain and swelling of 5 days’ duration. She has a history of hypertension for 15 years and had a recent hospitalization for pneumonia. She had been recuperating at home but on beginning to mobilize and walk, the right leg became painful and swollen. Her temperature is 37.1°C (98.7°F), the blood pressure is 130/80 mm Hg, and the pulse is 75/min. On physical examination, the right calf is 4 cm greater in circumference than the left when measured 10 cm below the tibial tuberosity. Dilated superficial veins are present on the right foot and the right leg is slightly redder than the left. There is some tenderness on palpation in the popliteal fossa behind the knee. Which of the following is the best initial step in the management of this patient’s condition?

A. International normalized ratio (INR)
B. Thrombophilia screen
C. Wells’ clinical probability tool (Correct Answer)
D. Computerized tomography (CT) with contrast
E. Activated partial thromboplastin time (aPTT)

Explanation: ***Wells' clinical probability tool*** - The patient presents with classic signs and symptoms of **deep vein thrombosis (DVT)**, including unilateral leg pain and swelling, dilated superficial veins, and tenderness. The Wells' clinical probability tool helps stratify the risk of DVT, guiding further diagnostic testing. - Using this validated clinical decision rule for risk assessment is the **best initial step** to determine the likelihood of DVT before proceeding with imaging studies (compression ultrasound) or D-dimer testing. - Based on the Wells' score, patients are categorized as low, moderate, or high probability, which then directs appropriate diagnostic testing and potential empiric anticoagulation. *International normalized ratio (INR)* - **INR** is used to monitor the effectiveness of **warfarin** therapy, an anticoagulant, and to assess liver function. - It is not an initial diagnostic tool for DVT; rather, it is used **after a DVT diagnosis** has been made and anticoagulation with warfarin has been initiated. *Thrombophilia screen* - A **thrombophilia screen** investigates underlying genetic or acquired clotting disorders. - This is typically performed **after a DVT diagnosis** in younger patients, those with recurrent DVT, or those with a family history of thrombosis, not as an initial diagnostic step unless there is strong suspicion for an underlying clotting disorder. *Computerized tomography (CT) with contrast* - A **CT with contrast** (specifically **CT venography**) can diagnose DVT, but it is not the **first-line imaging modality** for suspected DVT because of radiation exposure and contrast risks. - **Compression ultrasonography** is generally the preferred initial imaging study for DVT, especially after a risk assessment using the Wells' score. *Activated partial thromboplastin time (aPTT)* - The **aPTT** is a measure of the intrinsic and common pathways of coagulation and is used to monitor **unfractionated heparin** therapy. - It is not an initial diagnostic test for DVT; like INR, it is used **after diagnosis** for monitoring anticoagulant treatment.

Question 917: A 67-year-old man presents to his primary care provider because of fatigue and loss of appetite. He is also concerned that his legs are swollen below the knee. He has had type 2 diabetes for 35 years, for which he takes metformin and glyburide. Today his temperature is 36.5°C (97.7°F), the blood pressure is 165/82 mm Hg, and the pulse is 88/min. Presence of which of the following would make diabetic kidney disease less likely in this patient?

A. Normal-to-large kidneys on ultrasound
B. Gradual reduction of glomerular filtration rate (GFR)
C. Diabetic retinopathy
D. Nephrotic range proteinuria
E. Cellular casts in urinalysis (Correct Answer)

Explanation: ***Cellular casts in urinalysis*** - The presence of **cellular casts**, especially **red blood cell casts** or **white blood cell casts**, suggests an active glomerular inflammatory disease (e.g., glomerulonephritis) or an interstitial nephritis, which are atypical for uncomplicated diabetic kidney disease. - Diabetic kidney disease typically presents with bland urine sediment without significant cellular casts. *Normal-to-large kidneys on ultrasound* - In the early stages of diabetic kidney disease, the kidneys can be **normal in size or even enlarged** due to compensatory hypertrophy and increased renal blood flow. - Only in **advanced stages** of chronic kidney disease from diabetes do the kidneys become atrophic and shrunken. *Gradual reduction of glomerular filtration rate (GFR)* - Diabetic kidney disease is characterized by a **progressive decline in GFR** over time, often correlating with the duration and control of diabetes. - This gradual decline is a hallmark differentiating it from acute kidney injury or rapidly progressive glomerulonephritis. *Diabetic retinopathy* - The presence of **diabetic retinopathy** is a strong indicator of **microvascular complications** of diabetes and is highly correlated with the presence and severity of diabetic kidney disease. - This co-occurrence supports a diagnosis of diabetic kidney disease, not ruling it out. *Nephrotic range proteinuria* - **Nephrotic range proteinuria** (protein excretion > 3.5 g/day) is a common manifestation of diabetic kidney disease, especially as the disease progresses to more advanced stages. - This level of proteinuria suggests significant glomerular damage, consistent with diabetic nephropathy.

Question 918: A 97-year-old man visits the urology clinic 5 days after experiencing urinary retention at an emergency department visit. The patient has a history of hypertension, type II diabetes mellitus, stroke, dyslipidemia, a past myocardial infarction, and severe osteoarthritis in his right hip. He is not compliant with his medications and his multiple comorbidities are poorly managed. In the hospital, the patient’s urinary retention was treated with Foley catheterization. At clinic, the patient’s serum-specific prostate-specific antigen (PSA) is 6.0 ng/mL (normal is < 4 ng/mL). Digital rectal examination (DRE) demonstrates a nontender prostate with several rock hard nodules. The patient's Foley is removed and he is able to urinate on his own. Which is the most appropriate next step in management?

A. Repeat PSA test
B. CT abdomen and pelvis
C. Cystourethroscopy
D. Reassurance
E. Transrectal prostate biopsy (Correct Answer)

Explanation: ***Transrectal prostate biopsy*** - The combination of an elevated **PSA** (6.0 ng/mL) and **palpable, rock-hard nodules** on digital rectal examination is highly suspicious for **prostate cancer**. - A definitive diagnosis requires a **tissue biopsy** to determine the presence of malignancy and its Gleason score. *Repeat PSA test* - While a repeat PSA can sometimes be useful to confirm a trend or rule out transient elevation, the presence of **palpable prostatic nodules** on DRE makes a repeat PSA insufficient given the high suspicion of malignancy. - Delaying definitive workup, such as a biopsy, could be detrimental if cancer is present. *CT abdomen and pelvis* - A CT scan would be more appropriate for **staging** if prostate cancer were confirmed, to assess for metastasis, rather than for initial diagnosis. - It would not provide the definitive **tissue diagnosis** needed to confirm prostate cancer. *Cystourethroscopy* - **Cystourethroscopy** is used to visualize the urethra and bladder, often for issues like hematuria, strictures, or bladder masses. - It is not the primary diagnostic tool for **prostate cancer** originating in the peripheral zone given the DRE findings. *Reassurance* - Given the patient's elevated **PSA** and **palpable rock-hard nodules** on DRE, providing reassurance is inappropriate and could lead to delayed diagnosis and treatment of potentially aggressive prostate cancer. - These findings are highly indicative of prostate pathology requiring further investigation.

Question 919: A 72-year-old man presents to his primary care physician because he feels like his vision has been changing over the last 6 months. In particular, he feels that he cannot see as well out of his right eye as previously. His past medical history is significant for myocardial infarction as well as Lyme disease. On presentation, he is found to have a droopy right eyelid as well as persistent constriction of his right pupil. Additionally, the skin on his right half of his face is found to be cracked and dry. Which of the following is most likely associated with this patient's symptoms?

A. Oculomotor nerve damage
B. Drug use
C. Syphilis
D. Facial nerve damage
E. Pancoast tumor (Correct Answer)

Explanation: ***Pancoast tumor*** - The patient's symptoms (droopy eyelid, constricted pupil, and dry skin on one side of the face) are classic for **Horner's syndrome**, which results from damage to the **sympathetic nerves** to the eye and face. - A **Pancoast tumor** (a tumor in the apex of the lung) can compress the **sympathetic chain** in the neck/chest, leading to Horner's syndrome. *Oculomotor nerve damage* - Oculomotor nerve damage would typically cause a **dilated pupil** (due to unopposed sympathetic innervation) and **ptosis** (drooping eyelid), but not miosis (constricted pupil) or anhidrosis (dry skin). - The patient's **constricted pupil** points away from oculomotor nerve involvement. *Drug use* - While certain drugs can affect pupil size (e.g., opiates cause miosis), drug use alone is unlikely to explain the entire triad of **Horner's syndrome** (ptosis, miosis, anhidrosis) in combination with the focal neurological findings. - No other information in the vignette suggests drug use. *Syphilis* - **Neurosyphilis** can cause pupillary abnormalities, such as **Argyll Robertson pupils** (small, irregular pupils that accommodate but do not react to light). - However, it typically does not present with the specific combination of ptosis, miosis, and anhidrosis characteristic of Horner's syndrome. *Facial nerve damage* - **Facial nerve damage** (e.g., Bell's palsy) affects the muscles of **facial expression** and could cause ipsilateral facial weakness or droop. - It would not cause pupillary changes or anhidrosis, as these symptoms are related to the sympathetic nervous system and superior cervical ganglion, not the facial nerve.

Question 920: A 27-year-old woman presents with a history of repeated episodes of discoloration of the fingers over the last 3 years. She mentions that the episodes are usually triggered by exposure to cold, which leads to a sequential white, blue, and red discoloration of her fingers, followed by resolution of the symptoms. During an episode, she experiences pain and numbness in the affected fingers. The episodes are usually of short duration and do not interfere with her life, so she did not seek medical advice till now. Which of the following additional clinical features in this patient would most likely support the most likely diagnosis?

A. Generalized pruritus
B. Telangiectasia over face (Correct Answer)
C. Calcinosis on the dorsal surface of the forearm
D. Photosensitive skin rash
E. Bilateral symmetrical involvement of the extremities

Explanation: ***Telangiectasia over face*** - The patient's history of **Raynaud phenomenon** (white, blue, red discoloration of fingers triggered by cold) along with associated pain and numbness suggests a secondary form of Raynaud, often seen in **systemic sclerosis (scleroderma)**. - **Telangiectasias** are a highly specific component of **CREST syndrome** (Calcinosis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, Telangiectasias), which is a limited form of systemic sclerosis. - Telangiectasias over the face are particularly characteristic and help distinguish systemic sclerosis from other causes of Raynaud phenomenon. *Generalized pruritus* - While pruritus can occur in various systemic conditions, it is not a classic or specific feature that would strongly support a diagnosis of autoimmune connective tissue disease like systemic sclerosis. - It is more commonly associated with conditions like **dermatitis**, **liver disease**, or **renal failure**. *Calcinosis on the dorsal surface of the forearm* - **Calcinosis** is indeed a feature of **CREST syndrome**, but it typically presents as hard, subcutaneous nodules over pressure points or fingertips, not primarily on the dorsal forearm. - While calcinosis is part of CREST, **telangiectasias are more specific and appear earlier** in the disease course, making them a better distinguishing feature. - Calcinosis tends to develop later and is less commonly the presenting feature. *Photosensitive skin rash* - A **photosensitive skin rash** is a hallmark feature of **systemic lupus erythematosus (SLE)**, particularly the malar rash or discoid lupus. - It is not typically associated with systemic sclerosis or Raynaud phenomenon as a primary distinguishing feature. *Bilateral symmetrical involvement of the extremities* - While some autoimmune diseases can cause bilateral symmetrical involvement, this is a very general description and does not specifically point to systemic sclerosis or help differentiate it from other conditions. - Raynaud phenomenon itself commonly affects both hands, but "symmetrical involvement of extremities" is too broad to be diagnostically specific in this context.

Question 921: A 80-year-old man is brought to the emergency department with complaints that he "can't control his left leg". His symptoms started a few hours ago. He was outside taking a walk with his wife when suddenly his leg shot out and kicked her. His past medical history is notable for diabetes, hypertension, and a myocardial infarction 5 years ago. He smokes 1-2 cigarettes/day. He does not use alcohol or illicit drugs. On exam, the patient has intermittent wide, flinging movements that affect his proximal left arm and left leg. Which of the following parts of his brain is most likely damaged?

A. Ventral posterior thalamic nucleus
B. Left internal capsule
C. Right subthalamic nucleus (Correct Answer)
D. Left subthalamic nucleus
E. Right internal capsule

Explanation: ***Right subthalamic nucleus*** - The patient's symptoms of sudden, uncontrolled, wide-flinging movements, affecting the contralateral (left) side of the body, are characteristic of **hemiballism**. - **Hemiballism** is almost exclusively caused by a lesion in the **contralateral subthalamic nucleus (STN)**, or its afferent/efferent connections, most commonly due to a **lacunar infarct**. *Ventral posterior thalamic nucleus* - Damage to the **ventral posterior thalamic nucleus** primarily causes **sensory deficits**, such as loss of touch, pain, and temperature sensation, on the contralateral side of the body. - While it can be involved in motor control, it does not typically cause the characteristic flinging movements seen in hemiballism. *Left internal capsule* - A lesion in the **left internal capsule** would result in contralateral (right-sided) motor and sensory deficits, including **hemiparesis** or **hemiplegia**, but not the ballistic, uncontrollable movements described. - The internal capsule carries major motor and sensory pathways to and from the cerebral cortex. *Left subthalamic nucleus* - Damage to the **left subthalamic nucleus** would cause hemiballism on the **contralateral (right) side** of the body. - The patient's symptoms are on the left side, indicating a lesion in the right subthalamic nucleus. *Right internal capsule* - A lesion in the **right internal capsule** would primarily cause contralateral (left-sided) motor and sensory deficits, such as **hemiparesis** or **hemiplegia**. - While it affects the contralateral side as described in the patient, it would typically present as weakness rather than uncontrolled flinging movements.

Question 922: A 61-year-old man comes to the physician because of a 3-month history of worsening exertional dyspnea and a persistent dry cough. For 37 years he has worked in a naval shipyard. He has smoked 1 pack of cigarettes daily for the past 40 years. Pulmonary examination shows fine bibasilar end-expiratory crackles. An x-ray of the chest shows diffuse bilateral infiltrates predominantly in the lower lobes and pleural reticulonodular opacities. A CT scan of the chest shows pleural plaques and subpleural linear opacities. The patient is most likely to develop which of the following conditions?

A. Malignant mesothelioma
B. Spontaneous pneumothorax
C. Bronchogenic carcinoma (Correct Answer)
D. Aspergilloma
E. Mycobacterial infection

Explanation: ***Bronchogenic carcinoma*** - This patient has **asbestosis** from 37 years of shipyard work (asbestos exposure) combined with a **40-pack-year smoking history**, creating a **synergistic risk** for lung cancer. - Asbestos exposure alone increases lung cancer risk **5-fold**, smoking alone increases it **10-fold**, but **combined exposure increases the risk 50-fold** due to synergistic effects. - The chest imaging findings (diffuse bilateral infiltrates, pleural reticulonodular opacities, pleural plaques, and subpleural linear opacities) confirm **asbestosis**, making **bronchogenic carcinoma** the most likely future complication. *Malignant mesothelioma* - While strongly associated with **asbestos exposure**, it is **not synergistic with smoking** and has a lower absolute incidence compared to bronchogenic carcinoma in patients with combined exposures. - Mesothelioma typically presents with **unilateral pleural thickening**, pleural effusion, and chest pain rather than the diffuse parenchymal infiltrates and bibasilar crackles seen here. *Spontaneous pneumothorax* - Characterized by sudden lung collapse with acute chest pain and dyspnea, appearing on imaging as air in the pleural space. - While smoking-related emphysema can lead to bullae rupture and pneumothorax, the primary findings here indicate chronic interstitial lung disease and pleural pathology from asbestos exposure. *Mycobacterial infection* - Would typically present with constitutional symptoms (fever, night sweats, weight loss) and possibly hemoptysis, which are not mentioned in this case. - Imaging usually shows cavitary lesions, nodules, or upper lobe predominance, differing from the diffuse lower lobe infiltrates and pleural plaques characteristic of asbestosis. *Aspergilloma* - A fungal ball within a pre-existing cavity, typically seen in patients with tuberculosis, sarcoidosis, or other chronic cavitary lung diseases. - The clinical presentation and imaging findings, particularly the occupational asbestos exposure and smoking history, point toward malignancy risk rather than fungal colonization.

Question 923: A 56-year-old woman presents to the emergency department with a 1-hour history of persistent nasal bleeding. The bleeding started spontaneously. The patient experienced a similar episode last year. Currently, she has hypertension and takes hydrochlorothiazide and losartan. She is anxious. Her blood pressure is 175/88 mm Hg. During the examination, the patient holds a blood-stained gauze against her right nostril. Upon removal of the gauze, blood slowly drips down from her right nostril. Examination of the left nostril reveals no abnormalities. Squeezing the nostrils for 20 minutes fails to control bleeding. Which of the following interventions is the most appropriate next step in the management of this patient?

A. Nasal oxymetazoline
B. Anterior nasal packing with topical antibiotics (Correct Answer)
C. Intravenous infusion of nitroglycerin
D. Oral captopril
E. Silver nitrate cauterization of the bleeding vessel

Explanation: ***Anterior nasal packing with topical antibiotics*** - This is the **most appropriate next step** after failed direct pressure (20 minutes of squeezing the nostrils). - The standard **stepwise management of anterior epistaxis** proceeds from direct pressure → anterior nasal packing → posterior packing if needed. - **Anterior nasal packing** provides direct tamponade of the bleeding site and is the definitive treatment when conservative pressure fails. - **Topical antibiotics** (or antibiotic ointment) are applied to prevent **toxic shock syndrome** and sinusitis, which are rare but serious complications of nasal packing. *Nasal oxymetazoline* - **Oxymetazoline** is a topical vasoconstrictor that can help control mild anterior epistaxis. - It is typically applied **with or before direct pressure**, not after 20 minutes of failed direct pressure. - While it may be applied before packing, at this point with documented failure of prolonged direct pressure, **packing is the definitive next step**. - Oxymetazoline alone would be insufficient given the duration and failure of conservative management. *Silver nitrate cauterization of the bleeding vessel* - **Cauterization** requires visualization of a discrete bleeding point, which is difficult with active ongoing bleeding. - It is more appropriate for **recurrent epistaxis** with an identified bleeding vessel or after bleeding is controlled. - In acute uncontrolled bleeding after failed pressure, **packing takes precedence** over attempting cauterization. *Intravenous infusion of nitroglycerin* - **Nitroglycerin** is a vasodilator used for angina, acute coronary syndrome, or hypertensive emergencies with end-organ damage. - It would **worsen epistaxis** by increasing blood flow and lowering blood pressure. - The elevated BP (175/88 mm Hg) likely reflects anxiety and pain from epistaxis, not a hypertensive emergency requiring immediate IV treatment. *Oral captopril* - While the patient has elevated blood pressure, this does not represent a hypertensive emergency requiring immediate intervention. - The **priority is controlling the bleeding**, not blood pressure management. - **ACE inhibitors** like captopril have a slow onset and are inappropriate for acute epistaxis management.

Question 924: A 74-year-old gentleman presents to his family practitioner with the complaint of an inability to open his left eye since this morning. He also complains of intermittent pain and numbness in his left arm that has been present for the last few days. He denies ocular pain, difficulty swallowing, fatigability, or diplopia. His symptoms remain constant without fluctuation. He has a history of diabetes mellitus type 2, hypertension, and hypercholesterolemia. Further history reveals that he has lost 5.4 kg (12 lb) of weight in the past 4 months. He is a chronic smoker with a 72 pack-year smoking history. His blood pressure is 142/76 mm Hg, the heart rate is 76/min, the respiratory rate is 12/min, the temperature is 36.8°C (98.4°F), and BMI is the 18.2 kg/m2. The patient is awake, alert, and oriented to person, place, and time. He has partial drooping of the left eyelid while the right eyelid appears normal. The left pupil is 1 mm and the right pupil is 3 mm in diameter. Extraocular muscle movements are normal. What additional clinical feature would most likely be present in this patient?

A. Facial asymmetry
B. Urinary retention
C. Ipsilateral loss of touch sensations on the face
D. Tongue deviation to the left side
E. Loss of hemifacial sweating (Correct Answer)

Explanation: ***Loss of hemifacial sweating*** - The patient's presentation with **ptosis**, **miosis**, and an absence of other cranial nerve deficits strongly suggests **Horner's syndrome**. This syndrome is characterized by the classic triad of **ptosis**, **miosis**, and **anhidrosis** (loss of sweating). - The history of **weight loss**, **smoking**, and intermittent left arm pain and numbness raises concern for a **Pancoast tumor** in the lung apex, which can compress the sympathetic chain and cause Horner's syndrome. *Facial asymmetry* - **Facial asymmetry** typically results from lesions affecting the facial nerve (cranial nerve VII), such as in Bell's palsy or stroke. - While ptosis can cause some asymmetry in eye appearance, it does not typically lead to generalized facial asymmetry in the way a CN VII lesion would, as other facial muscles are unaffected. *Urinary retention* - **Urinary retention** is not a typical symptom of Horner's syndrome, which primarily affects the sympathetic innervation to the eye and face. - It could be associated with conditions affecting the bladder's innervation, such as spinal cord lesions or prostate enlargement, which are not directly indicated here. *Ipsilateral loss of touch sensations on the face* - **Loss of touch sensations on the face** would indicate involvement of the trigeminal nerve (cranial nerve V) or its sensory pathways. - Horner's syndrome specifically affects the sympathetic nervous system and does not directly cause sensory deficits on the face. *Tongue deviation to the left side* - **Tongue deviation** to one side is a sign of hypoglossal nerve (cranial nerve XII) palsy, which would affect the ipsilateral tongue muscles. - This symptom is unrelated to Horner's syndrome, which involves oculosympathetic pathways.

Question 925: A 68-year-old male is brought to the emergency department by his wife. An hour earlier, he dropped to the floor and began to violently shake his extremities. He urinated on the carpet and seemed confused for several minutes after. He is now feeling better. He has never experienced an episode like this before, nor does he think anyone in his family has. He and his wife are concerned that he has unintentionally lost 22.6 kg (50 lb) in the past 6 months. He has also been experiencing chest pain and has coughed up blood on a few occasions. He has a 50-pack-year smoking history and quit 2 years ago. His temperature is 36.8°C (98.2°F), heart rate is 98/min, respiratory rate is 15/min, blood pressure is 100/75 mm Hg, and his O2 saturation is 100% on room air. The physical exam, including a full neurologic and cardiac assessment, demonstrates no abnormal findings. Edema, ascites, and skin tenting are notably absent. A brain MRI does not indicate areas of infarction or metastatic lesions. ECG is normal. Urine toxicology screen is negative. EEG is pending. Laboratory findings are shown below: BUN 15 mg/dL N: 7 to 20 mg/dL pCO2 40 mm Hg N: 35-45 mm Hg Creatinine 0.8 mg/dL N: 0.8 to 1.4 mg/dL Glucose 95 mg/dL N: 64 to 128 mg/dL Serum chloride 103 mmol/L N: 101 to 111 mmol/L Serum potassium 3.9 mEq/L N: 3.7 to 5.2 mEq/L Serum sodium 115 mEq/L N: 136 to 144 mEq/L Total calcium 2.3 mmol/L N: 2-2.6 mmol/L Magnesium 1.7 mEq/L N: 1.5-2 mEq/L Phosphate 0.9 mmol/L N: 0.8-1.5 mmol/L Hemoglobin 14 g/dL N: 13-17 g/dL (men), 12-15 g/dL (women) Glycosylated hemoglobin 5.5% N: 4%-6% Total cholesterol 4 mmol/L N: 3-5.5 mmol/L Bicarbonate (HCO3) 19 mmol/L N: 18-22 mmol/L What is indicated first?

A. Chemotherapy
B. Hypertonic saline (Correct Answer)
C. Diazepam
D. Phenytoin
E. Valproic acid

Explanation: ***Hypertonic saline*** - This patient presents with **severe symptomatic hyponatremia** (Na 115 mEq/L) evidenced by a generalized seizure and post-ictal confusion. Rapid correction with **hypertonic saline** is indicated to prevent cerebral edema and further neurological deterioration. - Given the patient's significant weight loss, hemoptysis, and smoking history, an underlying malignancy (e.g., **small cell lung cancer** causing SIADH) is highly suspected, which can lead to chronic hyponatremia and acute symptomatic worsening. *Chemotherapy* - While an underlying malignancy, possibly **small cell lung cancer**, is strongly suggested by the patient's symptoms (weight loss, hemoptysis, smoking history) and likely cause of SIADH, chemotherapy is not the immediate priority for an acute seizure caused by severe hyponatremia. - The patient's **acute neurological symptoms** and severely low sodium level require immediate stabilization before definitive cancer treatment. *Diazepam* - **Diazepam** is a benzodiazepine used to treat acute seizures. However, in this case, the seizure is a direct consequence of **severe hyponatremia**. - While it could temporarily stop the seizure, it does not address the underlying **electrolyte imbalance**, which is the root cause and a life-threatening condition in itself. *Phenytoin* - **Phenytoin** is an antiepileptic drug used for seizure prophylaxis and treatment. However, it is not the primary treatment for seizures directly caused by **metabolic derangements** like severe hyponatremia. - Correcting the underlying **sodium imbalance** is paramount, as antiepileptics alone will not prevent recurrence or address the cerebral edema associated with hyponatremia. *Valproic acid* - **Valproic acid** is an antiepileptic medication used for various seizure types. Similar to phenytoin, it is not the first-line treatment for seizures secondary to **acute symptomatic hyponatremia**. - The immediate focus must be on normalizing the patient's **sodium levels** with hypertonic saline to resolve the seizure and prevent further neurological damage.

Question 926: A 31-year-old man is referred to a neurologist due to his gradually increasing eccentric behavior and involuntary movements, especially the movements of his arms and hands. He also has difficulty with his short-term memory. Past medical history is otherwise noncontributory. His father had similar symptoms before he died but those symptoms started at the age of 33. His blood pressure is 125/92 mm Hg, pulse is 90/min, respiratory rate 12/min, and temperature is 36.6°C (97.9°F). Physical exam reveals involuntary writhing movements of hands, slow eye movements, and sporadic rigidity. The physician explains that this is an inherited disorder where the symptoms occur progressively at an earlier age than the parent and often with increased severity in the future generations. Which of the following is the most likely diagnosis of this patient?

A. Neurofibromatosis
B. Myotonic dystrophy
C. Wilson's disease
D. Huntington's disease (Correct Answer)
E. Friedreich ataxia

Explanation: ***Huntington's disease*** - The patient's **involuntary writhing movements (chorea)**, **eccentric behavior**, and **short-term memory difficulty** are classic symptoms of Huntington's disease. - The family history of similar symptoms starting at an earlier age in the father, along with the physician's comment about progressive earlier onset and increasing severity in future generations, points to **anticipation**, a characteristic genetic feature of Huntington's disease due to expansion of **CAG trinucleotide repeats**. *Neurofibromatosis* - This is a group of genetic disorders that primarily cause **tumors to grow on nerve tissue**, leading to skin changes, bone deformities, and neurological symptoms, but not typically chorea or progressive behavioral changes with anticipation in this manner. - Key features include **café-au-lait spots** and neurofibromas, which are not mentioned in the patient's presentation. *Myotonic dystrophy* - This is characterized by **muscle weakness and myotonia** (prolonged muscle contraction), along with cataracts, heart problems, and endocrine dysfunction. - While it also exhibits anticipation, its primary neurological presentation is not chorea or psychiatric symptoms like those described. *Wilson's disease* - This is an **autosomal recessive disorder** of copper metabolism, leading to copper accumulation in the liver, brain, and other organs. - It can cause neurological symptoms like **tremors**, **dysarthria**, and **dystonia**, and psychiatric symptoms, but **chorea is less common** and **Kayser-Fleischer rings** are a hallmark finding, which are not mentioned here. *Friedreich ataxia* - This is an **autosomal recessive neurodegenerative disorder** characterized by **progressive ataxia**, dysarthria, and loss of proprioception, usually beginning in childhood or adolescence. - It does not involve chorea or the prominent psychiatric symptoms and anticipation pattern described in this patient.

Question 927: A 75-year-old woman with late-onset autoimmune diabetes mellitus, rheumatoid arthritis, coronary artery disease, and idiopathic pulmonary fibrosis presents to the ship medic with altered mental status. While on her current cruise to the Caribbean islands, she experienced nausea, vomiting, and diarrhea. She takes aspirin, simvastatin, low-dose prednisone, glargine, and aspart. She is allergic to amoxicillin and shellfish. She works as a greeter at a warehouse and smokes 5 packs/day. Her temperature is 100.5°F (38.1°C), blood pressure is 90/55 mmHg, pulse is 130/min, and respirations are 30/min. Her pupils are equal and reactive to light bilaterally. Her lungs are clear to auscultation bilaterally, but her breath has a fruity odor. She has an early systolic murmur best appreciated at the left upper sternal border. She has reproducible peri-umbilical tenderness. Which of the following will most likely be present in this patient?

A. Respiratory alkalosis and anion-gap metabolic acidosis (Correct Answer)
B. Respiratory acidosis and anion-gap metabolic acidosis
C. Respiratory alkalosis and non anion-gap metabolic acidosis
D. Respiratory acidosis and contraction metabolic alkalosis
E. Respiratory alkalosis and non-contraction metabolic alkalosis

Explanation: ***Respiratory alkalosis and anion-gap metabolic acidosis*** - The patient's **fruity-smelling breath**, history of diabetes, and symptoms of nausea, vomiting, and diarrhea strongly suggest **diabetic ketoacidosis (DKA)**, which causes a **high anion-gap metabolic acidosis** from accumulation of ketoacids (beta-hydroxybutyrate and acetoacetate). - The markedly increased respiratory rate (30/min) represents **Kussmaul breathing** - a compensatory hyperventilation mechanism attempting to blow off CO2 and normalize pH. While this is technically **respiratory compensation for metabolic acidosis** rather than a primary respiratory alkalosis, the arterial blood gas will show a **low PaCO2** (respiratory alkalosis pattern) alongside the **low pH and low HCO3** (metabolic acidosis). - This represents a **partially compensated metabolic acidosis** with high anion gap, which is the classic acid-base disturbance in DKA. *Respiratory acidosis and anion-gap metabolic acidosis* - **Respiratory acidosis** would imply hypoventilation (decreased respiratory rate or impaired ventilation) with CO2 retention, which is contrary to the patient's markedly elevated respiratory rate (30/min). The patient is hyperventilating, not hypoventilating. - While **anion-gap metabolic acidosis** is correct due to DKA, the respiratory component is incorrect. *Respiratory alkalosis and non anion-gap metabolic acidosis* - While the low PaCO2 from compensatory hyperventilation would be present, **non-anion-gap metabolic acidosis** is incorrect. - **Non-anion-gap metabolic acidosis** is typically caused by conditions like diarrhea (GI HCO3 loss) or renal tubular acidosis, whereas DKA characteristically causes a **high anion-gap metabolic acidosis** due to accumulation of unmeasured anions (ketoacids). *Respiratory acidosis and contraction metabolic alkalosis* - This option incorrectly identifies both acid-base components. The patient is **hyperventilating** (not hypoventilating), ruling out respiratory acidosis. - **Contraction alkalosis** occurs with severe volume depletion and diuretic use when chloride depletion leads to metabolic alkalosis, which does not fit the DKA presentation where ketoacid accumulation causes metabolic acidosis. *Respiratory alkalosis and non-contraction metabolic alkalosis* - While the compensatory hyperventilation results in low PaCO2, **metabolic alkalosis** (whether contraction or non-contraction) is inconsistent with DKA, which causes metabolic **acidosis**, not alkalosis. - **Non-contraction metabolic alkalosis** is associated with conditions like hyperaldosteronism or vomiting with gastric acid loss, not with ketoacid accumulation.

Question 928: A 15-year-old boy is brought to the office by his mother with complaints of facial puffiness and smoky urine. The mother noticed puffiness on her son’s face a week ago, and it has been progressively worsening since then. She also states that her son had a sore throat 3 weeks ago. The patient does not have fever/chills, changes in urinary frequency, or abdominal discomfort. On physical examination, facial edema is noted. The vital signs include: blood pressure 145/85 mm Hg, pulse 96/min, temperature 36.7°C (98.1°F), and respiratory rate 20/min. A complete blood count report shows: Hemoglobin 10.1 g/dL RBC 4.9 million cells/µL Hematocrit 46% Total leukocyte count 6,800 cells/µL Neutrophils 70% Lymphocytes 26% Monocytes 3% Eosinophil 1% Basophils 0% Platelets 210,000 cells/µL ESR 18 mm (1st hour) Urinalysis shows: pH 6.4 Color dark brown RBC plenty WBC 3–4/HPF Protein absent Cast RBC and granular casts Glucose absent Crystal none Ketone absent Nitrite absent Which of the following laboratory findings can be expected in this patient?

A. Increased C3 level
B. Positive streptozyme test (Correct Answer)
C. Normal erythrocyte sedimentation rate
D. Decreased serum creatinine
E. Negative antistreptolysin O (ASO) titer

Explanation: ***Positive streptozyme test*** - The clinical presentation of **facial puffiness**, **smoky urine**, and a history of a **sore throat 3 weeks prior** are highly suggestive of **post-streptococcal glomerulonephritis (PSGN)**. - A **streptozyme test** detects antibodies to several streptococcal antigens (streptolysin O, hyaluronidase, streptokinase, DNase B, and NADase), making it a comprehensive and sensitive indicator of recent streptococcal infection. *Increased C3 level* - In **PSGN**, activation of the complement system by immune complexes typically leads to a **reduction in C3 levels**, not an increase. - While C3 levels usually return to normal within 6-8 weeks, acutely they would be depressed. *Normal erythrocyte sedimentation rate* - The given ESR of **18 mm** is slightly elevated for a healthy child (normal range typically <15 mm/hr for this age group), indicating an ongoing inflammatory process. - In conditions like PSGN, inflammation of the glomeruli would likely cause an **elevated ESR**. *Decreased serum creatinine* - The patient's blood pressure of **145/85 mm Hg** and the active urinary findings (RBC casts, granular casts) point towards **acute kidney injury** or **renal impairment**. - This would lead to an **increased serum creatinine**, reflecting reduced glomerular filtration, rather than a decrease. *Negative antistreptolysin O (ASO) titer* - A **recent streptococcal infection** is the precursor to PSGN, and an **elevated ASO titer** is one of the key laboratory findings supporting this diagnosis. - A negative ASO titer would argue against the diagnosis of PSGN, although other streptococcal antibodies (detected by a streptozyme test) can still be positive.

Question 929: A 37-year-old man presents to the emergency department for a persistent fever. The patient states he has felt unwell for the past week and has felt subjectively febrile. The patient has a past medical history of a suicide attempt and alcohol abuse. He is not currently taking any medications. The patient admits to using heroin and cocaine and drinking 5-8 alcoholic drinks per day. His temperature is 103°F (39.4°C), blood pressure is 92/59 mmHg, pulse is 110/min, respirations are 20/min, and oxygen saturation is 96% on room air. Cardiopulmonary exam is notable for a systolic murmur heard best along the left sternal border. Dermatologic exam reveals scarring in the antecubital fossa. Which of the following is the next best step in management?

A. CT scan
B. Ultrasound
C. Chest radiograph
D. Blood cultures (Correct Answer)
E. Vancomycin and gentamicin

Explanation: ***Blood cultures*** - The patient's history of **intravenous drug use (IVDU)**, persistent fever, and a **new systolic murmur** strongly suggest **infective endocarditis**. - **Blood cultures** are crucial for identifying the causative organism and guiding appropriate antibiotic therapy, serving as the cornerstone of diagnosis in suspected endocarditis. *CT scan* - While CT scans can be useful for identifying complications of endocarditis (e.g., septic emboli in the brain or lungs), they are **not the initial diagnostic step** for identifying the source of infection. - CT scans expose the patient to **radiation** and are more expensive, making them less suitable as a first step compared to blood cultures. *Ultrasound* - An **echocardiogram** (a type of ultrasound) is essential for visualizing vegetations on heart valves, but it is typically performed *after* blood cultures reveal bacteremia to confirm the diagnosis and assess severity. - A general ultrasound of other body areas would be non-specific and **unlikely to pinpoint the cause** of persistent fever in this clinical context. *Chest radiograph* - A chest radiograph can identify **pulmonary infiltrates** or **septic emboli in the lungs**, which are potential complications of right-sided endocarditis (common in IVDU). - However, a chest radiograph **does not identify the causative organism** or confirm the primary diagnosis of endocarditis, making it a secondary investigation. *Vancomycin and gentamicin* - This combination represents a broad-spectrum antibiotic regimen often used for **empiric treatment of infective endocarditis**, particularly in IVDU patients due to concerns for MRSA or resistant streptococcal species. - While ultimately necessary, administering antibiotics *before* obtaining **blood cultures** can significantly reduce the yield of cultures and hinder definitive diagnosis and tailored treatment.

Question 930: A 55-year-old male bodybuilder presents to the emergency department with weakness of his right arm. The patient states he has experienced these symptoms for a few weeks; however, today his hand felt so weak he dropped his cup of tea. The patient has a past medical history of diabetes. He drinks 2-7 alcoholic drinks per day and has smoked 2 packs of cigarettes per day since he was 25. The patient admits to using anabolic steroids. He has lost 17 pounds since he last came to the emergency department 1 month ago. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam reveals decreased sensation in the right arm and 2/5 strength in the right arm and 5/5 strength in the left arm. The patient states that he is experiencing a dull aching and burning pain in his right arm during the exam. Which of the following is the most likely diagnosis?

A. Brachial plexopathy
B. Apical lung tumor (Correct Answer)
C. Subclavian steal syndrome
D. Cerebral infarction
E. Scalenus anticus syndrome

Explanation: ***Apical lung tumor*** - The patient's history of **heavy smoking** and **anabolic steroid use**, along with **unexplained weight loss**, **weakness**, and **sensory deficits in the arm**, are highly suggestive of an apical lung tumor (Pancoast tumor) compressing the brachial plexus. - The **dull aching and burning pain** in the arm is a classic symptom of brachial plexus involvement caused by tumor invasion. *Brachial plexopathy* - While brachial plexopathy explains the **arm weakness and sensory changes**, it is a general term and doesn't identify the underlying cause. - The patient's risk factors (smoking, weight loss) point to a more specific etiology than just idiopathic plexopathy. *Subclavian steal syndrome* - This condition involves **vertebrobasilar insufficiency** due to subclavian artery stenosis, typically presenting with neurologic symptoms like vertigo, syncope, and arm claudication, especially during arm exercise. - It does not typically cause **unilateral arm weakness and sensory deficits** associated with unexplained weight loss. *Cerebral infarction* - A cerebral infarction (stroke) would cause **sudden-onset neurological deficits**, which is inconsistent with the patient's several weeks of symptoms progressing to severe weakness. - While it can cause hemiparesis, the presentation of **dull aching and burning pain** in the arm suggests peripheral nerve involvement rather than a central lesion. *Scalenus anticus syndrome* - Also known as **thoracic outlet syndrome**, this typically involves compression of the brachial plexus or subclavian vessels, often due to anatomical variations or trauma. - While it can cause arm pain and weakness, the patient's significant **smoking history** and **unexplained weight loss** strongly point to a more serious underlying malignancy.

Question 931: A 70-year-old man is accompanied by his wife to the primary care clinic for hand tremors. He states that he first noticed the tremor of his left hand 1 year ago. Since then, the tremor has been worsening and now he can hardly relax when trying to read. His wife says that she is also worried about his memory. She had to take over the finances several weeks ago after learning that he had forgotten to pay the bills for the past few months. The patient’s medical history is significant for hypertension. He takes aspirin and amlodipine. His mother had schizophrenia. The patient drinks 1-2 beers a night and is a former cigar smoker. On physical examination, he speaks softly and has reduced facial expressions. He has a resting tremor that is worse on the left, and he resists manipulation of his bilateral upper extremities. Which of the following is the most likely diagnosis?

A. Dementia with Lewy bodies
B. Parkinson disease (Correct Answer)
C. Essential tremor
D. Progressive supranuclear palsy
E. Tardive dyskinesia

Explanation: ***Parkinson disease*** - The patient exhibits classic symptoms of **Parkinson disease**, including a **unilateral resting tremor** (left hand), **bradykinesia** (soft speech, reduced facial expressions), and **rigidity** (resists manipulation of upper extremities). - The associated **cognitive decline** (memory issues, forgetting to pay bills) is also common in Parkinson disease, developing often after the motor symptoms. *Dementia with Lewy bodies* - While **cognitive fluctuations**, **visual hallucinations**, and **Parkinsonism** can occur in Dementia with Lewy bodies, the **dementia** typically precedes or coincides with the motor symptoms, unlike the progression seen here where motor symptoms appeared first. - Distinctive features like **recurrent visual hallucinations** and **fluctuating cognition** are not explicitly mentioned as prominent in this case. *Essential tremor* - **Essential tremor** is typically an **action tremor** that worsens with movement and improves at rest, whereas this patient has a **resting tremor**. - It usually affects both sides of the body symmetrically and is not typically associated with **bradykinesia**, **rigidity**, or **cognitive decline**. *Progressive supranuclear palsy* - **Progressive supranuclear palsy** is characterized by **early postural instability** and falls, **supranuclear ophthalmoplegia** (especially vertical gaze palsy), and a more **symmetric Parkinsonism** that is often resistant to levodopa. - The predominant **asymmetric resting tremor** and **cogwheel rigidity** observed in this patient are less typical of this condition. *Tardive dyskinesia* - **Tardive dyskinesia** is a unique movement disorder characterized by **involuntary, repetitive, and purposeless movements**, usually of the face (e.g., grimacing, tongue protrusion, lip smacking) and limbs. - It results from **chronic dopamine receptor blockade** typically due to antipsychotic medications, which the patient is not taking, and presents differently from the patient's symptoms.

Question 932: A 69-year-old man presents for a general follow up appointment. He states that he is doing well and wants to be sure he is healthy. The patient’s past medical history is significant for type II diabetes mellitus, peripheral vascular disease, and hypertension. His current medications include metformin, glyburide, lisinopril, metoprolol and hydrochlorothiazide. His blood pressure is 130/90 mmHg and pulse is 80/min. A fasting lipid panel was performed last week demonstrating an LDL of 85 mg/dL and triglycerides of 160 mg/dL. The patient states that he has not experienced any symptoms since his last visit. The patient’s blood glucose at this visit is 100 mg/dL. Which of the following is recommended in this patient?

A. Begin statin therapy (Correct Answer)
B. Increase lisinopril dose
C. Increase HCTZ dose
D. Discontinue metoprolol and start propranolol
E. Increase metformin dose

Explanation: **Begin statin therapy** - The patient has **multiple risk factors** for cardiovascular disease including type 2 diabetes, peripheral vascular disease, and hypertension. His LDL-C of 85 mg/dL, while not excessively high, still warrants statin therapy given his high-risk profile, as guidelines recommend statin use in these patients to reduce cardiovascular events. - Patients with a history of **atherosclerotic cardiovascular disease (ASCVD)**, which includes peripheral vascular disease, should be on a **high-intensity statin** regardless of their baseline LDL-C level, unless contraindicated. *Increase lisinopril dose* - The patient's blood pressure is 130/90 mmHg. While his systolic pressure is within an acceptable range for a patient with diabetes, his **diastolic pressure of 90 mmHg is slightly elevated**, but a single reading may not warrant an immediate dosage increase. - Lisinopril is an ACE inhibitor and is already at an appropriate dose given the blood pressure. Further increasing the dose without evidence of persistent high blood pressure or other compelling indications is not the primary next step. *Increase HCTZ dose* - The patient is already on hydrochlorothiazide (HCTZ) for hypertension. His blood pressure is 130/90 mmHg, which is **not severely elevated**, and his medications are generally well-controlled. - Increasing the dose of HCTZ might lead to side effects such as **electrolyte imbalances** (e.g., hypokalemia, hyponatremia) or worsening glucose control, and is not the most pressing intervention. *Discontinue metoprolol and start propranolol* - Metoprolol is a **selective beta-1 blocker** and is appropriate for this patient's hypertension and cardiac health, especially given his history. - Propranolol is a **non-selective beta-blocker** and is generally less preferred in patients with diabetes or peripheral vascular disease due to potential masking of hypoglycemia symptoms and worsening peripheral circulation. *Increase metformin dose* - The patient's blood glucose is 100 mg/dL, indicating **good glycemic control** on his current regimen of metformin and glyburide. - There is no indication to increase the metformin dose as his current glucose levels are within the target range, and increasing it could risk **hypoglycemia**, especially with concomitant glyburide.

Question 933: A 16-year-old boy with a history of severe, persistent asthma presents to the emergency department with severe shortness of breath and cough. He states that he was outside playing basketball with his friends, forgot to take his inhaler, and began to have severe difficulty breathing. On exam, he is in clear respiratory distress with decreased air movement throughout all lung fields. He is immediately treated with beta-agonists which markedly improve his symptoms. Prior to treatment, which of the following was most likely observed in this patient?

A. Kussmaul's sign
B. Pulsus paradoxus (Correct Answer)
C. Friction rub
D. Inspiratory stridor
E. Increased breath sounds

Explanation: ***Pulsus paradoxus*** * **Pulsus paradoxus** is a classic sign of **severe asthma exacerbation**, characterized by an abnormally large decrease in **systolic blood pressure** during inspiration. * The marked improvement with **beta-agonists** confirms the likely diagnosis of acute severe asthma, making pulsus paradoxus a highly probable finding before treatment. *Kussmaul's sign* * **Kussmaul's sign** is a paradoxical rise in **jugular venous pressure (JVP)** during inspiration, typically seen in conditions like **constrictive pericarditis** or **right heart failure**. * It is not associated with acute asthma exacerbations. *Friction rub* * A **friction rub** is a leathery or grating sound heard on auscultation, indicative of inflammation of the **pleura** (pleurisy) or **pericardium** (pericarditis). * It is not a typical finding in asthma and would suggest an alternative or co-existing pathology. *Inspiratory stridor* * **Inspiratory stridor** is a harsh, high-pitched sound primarily heard during inspiration, caused by **upper airway obstruction** (e.g., croup, epiglottitis, foreign body aspiration). * While severe shortness of breath is present, the symptom relief with beta-agonists points to **lower airway obstruction** characteristic of asthma rather than upper airway issues. *Increased breath sounds* * In **severe asthma exacerbations**, there is significant **bronchoconstriction** and **air trapping**, leading to markedly **decreased or absent breath sounds** on auscultation, not increased. * Increased breath sounds might be heard in consolidation (pneumonia) or early stages of bronchiole inflammation, but not in severe asthma distress.

Question 934: A 68-year-old woman is brought to the emergency department by ambulance after she was found down by her daughter. She lives alone in her apartment so it is unclear when she began to develop symptoms. Her medical history is significant for cardiac arrhythmias, diabetes, pericarditis, and a stroke 2 years ago. On presentation her temperature is 98.1°F (36.7°C), blood pressure is 88/51 mmHg, pulse is 137/min, and respirations are 18/min. On physical exam her skin is cold and clammy. If special tests were obtained, they would reveal dramatically decreased pulmonary capillary wedge pressure, increased systemic vascular resistance, and mildly decreased cardiac output. Which of the following treatments would most directly target the cause of this patient's low blood pressure?

A. Vasopressors
B. Intravenous fluids (Correct Answer)
C. Antibiotic administration
D. Relieve obstruction
E. Intravenous inotropes

Explanation: ***Intravenous fluids*** - The patient exhibits signs of **hypovolemic shock**, including **hypotension** (BP 88/51 mmHg), **tachycardia** (pulse 137/min), and **cold, clammy skin**. The dramatically decreased **pulmonary capillary wedge pressure (PCWP)** indicates low preload, which is characteristic of hypovolemia. - Administration of intravenous fluids directly addresses the underlying cause of this patient's low blood pressure by increasing intravascular volume, thereby improving **cardiac preload** and ultimately **cardiac output** and blood pressure. *Vasopressors* - While vasopressors can temporarily increase blood pressure by causing **vasoconstriction**, they do not address the root cause of hypovolemic shock, which is insufficient circulating blood volume. - Using vasopressors without adequate fluid resuscitation in hypovolemic shock can lead to further **organ hypoperfusion** due to increased afterload on an already compromised heart. *Antibiotic administration* - Although the patient's presentation with hypotension and tachycardia could raise suspicion for **sepsis**, there is no explicit evidence of infection presented (e.g., fever, focal source). - The **decreased PCWP** points more strongly towards hypovolemic shock rather than septic shock, where PCWP can be variable or even normal/elevated. *Relieve obstruction* - Obstruction, such as in **cardiac tamponade** or **pulmonary embolism**, can cause obstructive shock, which presents with hypotension. - However, the dramatically **decreased PCWP** is not typically seen in obstructive shock, where PCWP would likely be normal or elevated due to impedance to cardiac filling or outflow. *Intravenous inotropes* - **Inotropes** like dobutamine increase myocardial contractility and are primarily indicated in **cardiogenic shock** or severe heart failure with reduced ejection fraction to improve cardiac output. - While cardiac output is mildly decreased, the primary issue is reduced preload as indicated by the very low PCWP, making fluid resuscitation a more appropriate initial step than directly increasing contractility.

Question 935: A 72-year-old woman with a medical history significant for chronic kidney disease stage 4, hypertension, and type 2 diabetes mellitus, presents to the office for a scheduled visit. During her last visit, the physician started discussing with her the possibility of starting her on dialysis for her chronic kidney disease. The patient has no complaints about her health and enjoys spending time with her family. At presentation, she is afebrile; the blood pressure is 139/89 mm Hg and the heart rate is 80/min. On physical examination, her pulses are bounding, the complexion is pale, she has a grade ⅙ holosystolic murmur, breath sounds remain clear, and 2+ pedal edema to the knee. The measurement of which of the following laboratory values is most appropriate to screen for renal osteodystrophy in this patient?

A. Erythrocyte sedimentation rate
B. Serum vitamin B-12 level
C. Serum C-reactive protein level
D. Serum thyroid-stimulating hormone level
E. Serum intact parathyroid hormone level (Correct Answer)

Explanation: ***Serum intact parathyroid hormone level*** - **Renal osteodystrophy**, a common complication of **chronic kidney disease (CKD)** stage 4 and 5, is primarily caused by secondary hyperparathyroidism. - **Intact parathyroid hormone (iPTH)** is critical in diagnosing and monitoring this condition, as elevated levels indicate impaired mineral and bone metabolism due to failing kidneys. *Erythrocyte sedimentation rate* - **Erythrocyte sedimentation rate (ESR)** is a general marker of inflammation and is not specific for renal osteodystrophy. - While CKD can be associated with inflammation, ESR does not directly assess mineral and bone disorders. *Serum vitamin B-12 level* - **Vitamin B-12** deficiency can cause anemia and neurological symptoms, but it is not directly involved in the pathogenesis or diagnosis of renal osteodystrophy. - This test would be more relevant if the patient presented with symptoms of **pernicious anemia** or neuropathy. *Serum C-reactive protein level* - **C-reactive protein (CRP)**, like ESR, is a general **inflammatory marker** and does not provide specific information about bone health or mineral metabolism in CKD. - High CRP levels might indicate infection or systemic inflammation but are not used to screen for renal osteodystrophy. *Serum thyroid-stimulating hormone level* - **Thyroid-stimulating hormone (TSH)** assesses **thyroid function**, which is distinct from renal osteodystrophy. - Thyroid disorders can impact bone health, but TSH is not the primary screening test for bone disease related to CKD.

Question 936: A 44-year-old woman presents to her physician’s office for weakness. She reports having some difficulty placing books on a high shelf and getting up from a seated position. She denies muscle pain or any new rashes. She has noticed a tremor that is worse with action and has been having trouble falling asleep and staying asleep. She has lost approximately 10 pounds unintentionally over the course of 2 months. Medical history is significant for type I diabetes mellitus managed with an insulin pump. Family history is notable for systemic lupus erythematosus in her mother and panic disorder in the father. Her temperature is 98.6°F (37 °C), blood pressure is 140/85 mmHg, pulse is 102/min, and respirations are 17/min. On physical exam, she is mildly diaphoretic and restless, she has notable lid retraction, and her hair is thin. She has 4/5 strength in the proximal upper and lower extremities. Biceps and patellar tendon reflexes are 3+. Which of the following laboratory findings are most likely present in this patient?

A. Anti-Mi-2 antibody positivity
B. Decreased thyroid-stimulating hormone (Correct Answer)
C. Anti-nuclear antibody positivity
D. Increased erythrocyte sedimentation rate
E. Normal laboratory results

Explanation: **Decreased thyroid-stimulating hormone** - The patient exhibits classic symptoms of **hyperthyroidism**, including unintended weight loss, heat intolerance (diaphoresis), fine tremor, insomnia, tachycardia (pulse 102/min), and proximal muscle weakness. Lid retraction and thin hair are also characteristic signs. - In primary hyperthyroidism, the excessive production of thyroid hormones (T3 and T4) by the thyroid gland suppresses the pituitary's release of TSH, leading to a **decreased TSH level**. *Anti-Mi-2 antibody positivity* - **Anti-Mi-2 antibodies** are specific to **dermatomyositis**, which typically presents with a characteristic dermatological rash (e.g., heliotrope rash, Gottron papules) in addition to proximal muscle weakness. The patient explicitly denies new rashes. - While proximal weakness is present, the absence of skin findings and the presence of significant hyperthyroid symptoms make dermatomyositis less likely. *Anti-nuclear antibody positivity* - **Anti-nuclear antibodies (ANAs)** are often positive in **autoimmune connective tissue diseases** like systemic lupus erythematosus (SLE), Sjogren's syndrome, and scleroderma. While the mother had SLE, the patient's constellation of symptoms points more directly to thyroid dysfunction. - While ANA can be positive in autoimmune thyroid disease, it's not the most direct or specific laboratory finding for the dominant clinical picture presented. *Increased erythrocyte sedimentation rate* - An **increased ESR** is a non-specific marker of **inflammation** and can be elevated in various conditions, including infections, autoimmune diseases, and certain cancers. - While ESR can be elevated in some cases of hyperthyroidism, it is not as specific or as direct a diagnostic marker for the condition as thyroid hormone levels themselves. *Normal laboratory results* - Given the clear and numerous signs and symptoms of a pathological process, particularly **hyperthyroidism**, it is highly unlikely that all laboratory results would be normal. - The constellation of symptoms like weight loss, tremor, palpitations, insomnia, and muscle weakness strongly indicates a significant underlying medical condition requiring laboratory investigation.

Question 937: A 70-year-old woman presents to the office for a yearly physical. She states she has recently started experiencing pain in her legs and her back. Last year, she experienced a fracture of her left arm while trying to lift groceries. The patient states that she does not consume any dairy and does not go outside often because of the pain in her legs and back. Of note, she takes carbamazepine for seizures. On exam, her vitals are within normal limits. You suspect the patient might have osteomalacia. Testing for which of the following is the next best step to confirm your suspicion?

A. Vitamin D2 (ergocalciferol)
B. 25-hydroxyvitamin D (Correct Answer)
C. Pre-vitamin D3
D. 1,25-hydroxyvitamin D
E. 7-dehydrocholesterol

Explanation: ***25-hydroxyvitamin D*** - This is the **best initial test** for evaluating vitamin D deficiency, which leads to **osteomalacia**. - It reflects the circulating levels of vitamin D and is the **most accurate indicator** of the body's vitamin D stores. *Vitamin D2 (ergocalciferol)* - While D2 is a form of vitamin D, measuring only D2 levels is **not sufficient** to assess overall vitamin D status. - The standard test measures total circulating vitamin D, which includes both D2 and D3, but specifically **25-hydroxyvitamin D** reflects the active usable form. *Pre-vitamin D3* - **Pre-vitamin D3** is a precursor molecule formed in the skin from 7-dehydrocholesterol upon UV exposure, and it rapidly isomerizes to vitamin D3. - It is **not a stable measurable form** in the blood for assessing vitamin D status or diagnosing osteomalacia. *1,25-hydroxyvitamin D* - This is the **active hormonal form of vitamin D**, primarily regulated by parathyroid hormone (PTH) and kidney function. - Levels can be normal or even elevated in early vitamin D deficiency due to increased PTH, making it **less reliable** for initial assessment of deficiency. *7-dehydrocholesterol* - **7-dehydrocholesterol** is a precursor molecule in the skin that is converted to pre-vitamin D3 by UV radiation. - Measuring this precursor is **not clinically significant** for diagnosing osteomalacia or assessing vitamin D deficiency.

Question 938: A 22-year-old man is brought to the emergency department by ambulance 1 hour after a motor vehicle accident. He did not require any circulatory resuscitation at the scene, but he was intubated because he was unresponsive. He has no history of serious illnesses. He is on mechanical ventilation with no sedation. His blood pressure is 121/62 mm Hg, the pulse is 68/min, and the temperature is 36.5°C (97.7°F). His Glasgow coma scale (GCS) is 3. Early laboratory studies show no abnormalities. A search of the state donor registry shows that he has registered as an organ donor. Which of the following is the most appropriate next step in evaluation?

A. Evaluation of brainstem reflexes (Correct Answer)
B. Brain MRI
C. Electroencephalography
D. Cerebral angiography
E. Apnea test

Explanation: ***Evaluation of brainstem reflexes*** - In a patient with a **Glasgow Coma Scale (GCS) of 3** and no response to noxious stimuli/sedation, assessment of **brainstem reflexes** is a critical step in determining brain death. - This evaluation includes checking for pupillary light reflex, corneal reflex, vestibulo-ocular reflex (doll's eyes), oculocephalic reflex, and gag/cough reflexes to ascertain the complete absence of brainstem function. *Brain MRI* - While a brain MRI can provide detailed anatomical information regarding brain injury, it is **not the primary diagnostic test** for determining brain death. - Brain death is a **clinical diagnosis** based on the irreversible loss of brain and brainstem function, which can be confirmed rapidly by clinical examination. *Electroencephalography* - **EEG** measures electrical activity in the brain and can show electrocerebral silence, which is consistent with brain death. - However, EEG is **not always required** for the diagnosis of brain death and is often used as a confirmatory test in specific situations, such as when clinical examination is inconclusive or legal requirements necessitate it. *Cerebral angiography* - **Cerebral angiography** can demonstrate the absence of cerebral blood flow, which is a criterion for brain death. - This is an **invasive procedure** and is generally reserved for situations where clinical examination tests are difficult to perform or interpret (e.g., severe facial trauma, drug intoxication), and is not the initial step. *Apnea test* - The **apnea test** is a critical component of the brain death evaluation, confirming the absence of spontaneous breathing response to hypercapnia. - It is performed **after the absence of brainstem reflexes** has been established and all confounding factors (e.g., hypothermia, hypotension, sedatives) have been ruled out.

Question 939: A 47-year-old woman presents to the clinic complaining of difficulty swallowing that started 1 month ago. The patient also reports a weight loss of 10 lbs during this time, without a change in her appetite. She denies fatigue, cough, hoarseness, pain, or hemoptysis. The patient has a history of childhood lymphoma, which was treated with radiation. She takes no medications. She has smoked 1 pack of cigarettes per day since she was 25 years old. Her physical exam is notable for a palpable nodule on the right side of the thyroid. An ultrasound is performed, which confirms a 1.2 cm hyperechoic nodule in the right lobe. Thyroid function labs are drawn and shown below: Serum TSH: 0.2 mU/L Serum thyroxine (T4): 187 nmol/L Serum triiodothyronine (T3): 3.3 nmol/L Which of the following is the next best step in management?

A. Radioactive iodine
B. Partial thyroidectomy
C. Fine needle aspiration (Correct Answer)
D. Levothyroxine
E. Thyroid scintigraphy

Explanation: ***Fine needle aspiration*** - This patient has several risk factors for **thyroid malignancy**, including a history of **radiation exposure** to the neck (for childhood lymphoma) and a palpable thyroid nodule associated with **dysphagia** and unexplained **weight loss**. Fine needle aspiration (FNA) is the best next step to evaluate for malignancy. - The patient also presents with **hyperthyroidism** (low TSH, elevated T4), but the primary concern given the clinical picture is to rule out thyroid cancer. - Per American Thyroid Association guidelines, FNA is indicated for any nodule in a patient with a history of head/neck radiation exposure. *Radioactive iodine* - Radioactive iodine ablation is used to treat **hyperthyroidism**, especially in cases of **Graves' disease** or toxic nodular goiter. While the patient has hyperthyroidism, the presence of a suspicious nodule warrants investigation for malignancy first. - Administering radioactive iodine without first ruling out malignancy in a suspicious nodule could delay definitive treatment for cancer or complicate its management. *Partial thyroidectomy* - **Partial thyroidectomy** would be considered if the FNA results indicate malignancy or a highly suspicious follicular neoplasm. - Performing surgery without a prior FNA would be premature, as many thyroid nodules are benign and do not require surgical intervention unless causing compressive symptoms or confirmed malignancy. *Levothyroxine* - **Levothyroxine** is used to treat **hypothyroidism** or to suppress TSH in cases of benign thyroid nodules or after thyroid cancer surgery. - This patient is **hyperthyroid**, making exogenous levothyroxine inappropriate. *Thyroid scintigraphy* - **Thyroid scintigraphy** (radioactive iodine uptake scan) is useful in characterizing thyroid nodules as "hot" (functioning) or "cold" (non-functioning) in the context of hyperthyroidism. - "Hot" nodules are rarely malignant, while "cold" nodules have a higher (though still relatively low) risk of malignancy. However, given the patient's strong risk factors for thyroid cancer and compressive symptoms, an FNA is more direct and informative for assessing malignancy than scintigraphy at this stage.

Question 940: A 52-year-old woman presents to her primary care physician with symptoms of heat intolerance, unintentional weight loss, feelings of anxiety, and excessive energy that hinder her from falling asleep at night. On physical exam, the patient is found to have mildly protuberant eyes bilaterally as well as discoloration and swelling of her shins. Which of the following lab results would most likely be present in this patient?

A. Decreased serum TSH (Correct Answer)
B. Increased anti-mitochondrial antibodies
C. Decreased free T4
D. Increased serum TSH
E. Decreased anti-TSH receptor antibodies

Explanation: ***Decreased serum TSH*** - The patient's symptoms (heat intolerance, weight loss, anxiety, insomnia, protuberant eyes, pretibial myxedema) are classic for **hyperthyroidism**, specifically **Graves' disease**. - In primary hyperthyroidism, the thyroid gland overproduces thyroid hormones (T3 and T4), which **negatively feedback** on the pituitary, leading to a decreased or **undetectable serum TSH**. *Increased anti-mitochondrial antibodies* - **Anti-mitochondrial antibodies (AMAs)** are the hallmark of **primary biliary cholangitis**, a chronic autoimmune liver disease. - This condition presents with symptoms like **fatigue, pruritus, and jaundice**, which are not observed in this patient. *Decreased free T4* - A **decreased free T4** indicates **hypothyroidism**, where the thyroid gland produces insufficient thyroid hormones. - This would present with symptoms opposite to those described, such as **cold intolerance, weight gain, fatigue, and bradycardia**. *Decreased anti-TSH receptor antibodies* - **Anti-TSH receptor antibodies (TRAb)** are characteristic of Graves' disease, and they are typically **stimulatory** (thyroid-stimulating immunoglobulins), meaning they mimic TSH and **increase** thyroid hormone production. - A decrease in these antibodies would suggest a *reduction* in the autoimmune stimulation, which is inconsistent with the patient's active hyperthyroid state. - In this patient with clear Graves' disease, these antibodies would be **elevated**, not decreased. *Increased serum TSH* - An **increased serum TSH** is indicative of **primary hypothyroidism**, where the pituitary gland attempts to stimulate an underactive thyroid. - This would lead to symptoms of **fatigue, weight gain, cold intolerance, and bradycardia**, which contradict the patient's presentation.

Question 941: Five days after admission into the ICU for drug-induced acute kidney injury, a 27-year-old woman develops fever. She is currently on a ventilator and sedatives. Hemodialysis is performed via a catheter placed in the right internal jugular vein. Feeding is via a nasogastric tube. An indwelling urinary catheter shows minimum output. Her blood pressure is 85/45 mm Hg, the pulse is 112/min, the respirations are 32/min, and the temperature is 39.6°C (103.3°F). The examination of the central catheter shows erythema around the insertion site with no discharge. Lung auscultation shows rhonchi. Cardiac examination shows no new findings. A chest CT scan shows bilateral pleural effusions with no lung infiltration. Empirical antibiotic therapy is initiated. Blood cultures obtained from peripheral blood and the catheter tip show S. aureus with a similar antibiogram. Urinary culture obtained from the indwelling catheter shows polymicrobial growth. Which of the following best explains this patient’s recent findings?

A. Catheter-associated urinary tract infection
B. Central catheter-related bacteremia (Correct Answer)
C. Endocarditis
D. Ventilator-associated pneumonia
E. Naso-gastric tube sinusitis

Explanation: ***Central catheter-related bacteremia*** - The presence of **erythema at the catheter insertion site** and the isolation of **_S. aureus_ with a similar antibiogram from both peripheral blood and the catheter tip** are highly indicative of a catheter-related bloodstream infection. - This type of infection is common in critically ill patients with central venous catheters due to the direct access provided for bacteria to enter the bloodstream. *Catheter-associated urinary tract infection* - While a **polymicrobial growth** in the urinary culture suggests a urinary tract infection, the isolation of **_S. aureus_ in blood cultures** with signs of local catheter infection points away from the urinary tract as the primary source of bacteremia. - The patient has an **indwelling urinary catheter**, which is a risk factor for UTIs, but the systemic infection with _S. aureus_ is better explained by the central line. *Endocarditis* - Although **_S. aureus_ bacteremia** can lead to endocarditis, the case states that the **cardiac examination shows no new findings**, making endocarditis less likely as the primary explanation for the acute deterioration without other supporting evidence like a new murmur or imaging findings. - Endocarditis is a potential complication of bacteremia, not typically the initial source, especially with a clear source like a central line. *Ventilator-associated pneumonia* - Pulmonary symptoms like **rhonchi** and **bilateral pleural effusions** are present, but the **lack of lung infiltration on CT** and the **isolation of _S. aureus_ from blood and catheter tip** (not respiratory samples) make VAP unlikely to be the primary cause of this systemic infection. - The patient is also on a ventilator, which is a risk factor for VAP, but the microbiologic and imaging evidence does not fully support it as the main diagnosis. *Naso-gastric tube sinusitis* - While nasogastric tubes can cause sinusitis, which could manifest with fever, it is less likely to result in **_S. aureus_ bacteremia with a positive catheter tip culture**. - Sinusitis would explain fever, but not the specific microbiological findings of _S. aureus_ in blood and catheter tip, nor the local erythema at the catheter site.

Question 942: Six days after undergoing a left hemicolectomy for colorectal carcinoma, a 59-year-old man collapses in the hospital hallway and is unconscious for 30 seconds. Afterwards, he complains of shortness of breath and chest pain with deep inhalation. He has hypertension and hyperlipidemia. He smoked one pack of cigarettes daily for 35 years but quit prior to admission to the hospital. He does not drink alcohol. He is in distress and appears ill. His temperature is 36.5°C (97.7°F), blood pressure is 80/50 mm Hg, and pulse is 135/min and weak. Oxygen saturation is 88% on room air. Physical examination shows elevated jugular venous distention. Cardiac examination shows a regular, rapid heart rate and a holosystolic murmur that increases during inspiration. His abdomen is soft and mildly tender to palpation around the surgical site. Examination of his extremities shows pitting edema of the left leg. His skin is cold and clammy. Further examination is most likely to reveal which of the following findings?

A. Reduced regional ventricular wall motion
B. Rapid, aberrant contractions of the atria
C. Stenosis of the carotid arteries
D. Dilated right ventricular cavity (Correct Answer)
E. Anechoic space between pericardium and epicardium

Explanation: ***Dilated right ventricular cavity*** - The patient's symptoms (shortness of breath, chest pain with deep inspiration, hypotension, tachycardia, hypoxemia, elevated JVD, holosystolic murmur increasing with inspiration, and leg edema) are highly suggestive of **acute pulmonary embolism (PE)**. - An acute PE can lead to increased pulmonary vascular resistance and **acute right ventricular (RV) overload**, causing RV dilation and dysfunction, which is often visible on echocardiography. *Reduced regional ventricular wall motion* - This finding is characteristic of **myocardial ischemia or infarction**, which typically presents with anginal chest pain and ECG changes; in this case, the chest pain is pleuritic and the overall picture points away from ischemia. - While PE can cause RV dysfunction, the primary finding is RV overload and dilation, not necessarily isolated regional wall motion abnormalities often seen in left ventricular ischemia. *Rapid, aberrant contractions of the atria* - This describes **atrial fibrillation** or **atrial flutter**, which can occur in critically ill patients but is not the most direct consequence or expected finding from an acute pulmonary embolism in a previously stable patient. - While atrial arrhythmias can be precipitated by acute stress, they are not the primary direct consequence of massive PE explaining these specific cardiovascular findings. *Stenosis of the carotid arteries* - **Carotid artery stenosis** is a risk factor for stroke but does not explain the acute cardiopulmonary collapse, hypoxemia, chest pain, and signs of right heart strain presented in the clinical scenario. - This finding is unrelated to the acute presentation of shortness of breath, chest pain, and hemodynamic instability following surgery. *Anechoic space between pericardium and epicardium* - This finding represents a **pericardial effusion**, which can lead to cardiac tamponade if large and rapid in onset, but the associated holosystolic murmur increasing with inspiration and left leg edema are not typical for cardiac tamponade. - While pericardial effusion can cause hypotension and shock, the specific constellation of symptoms, including pleuritic chest pain and signs of right heart strain, makes acute PE with RV dilation a more fitting diagnosis.

Question 943: A 63-year-old man presents to his primary care physician complaining of excessive daytime sleepiness. He explains that this problem has worsened slowly over the past few years but is now interfering with his ability to play with his grandchildren. He worked previously as an overnight train conductor, but he has been retired for the past 3 years. He sleeps approximately 8-9 hours per night and believes his sleep quality is good; however, his wife notes that he often snores loudly during sleep. He has never experienced muscle weakness or hallucinations. He has also been experiencing headaches in the morning and endorses a depressed mood. His physical exam is most notable for his large body habitus, with a BMI of 34. What is the best description of the underlying mechanism for this patient's excessive daytime sleepiness?

A. Poor oropharyngeal tone (Correct Answer)
B. Circadian rhythm sleep-wake disorder
C. Deficiency of the neuropeptides, orexin-A and orexin-B
D. Insufficient sleep duration
E. Psychiatric disorder

Explanation: ***Poor oropharyngeal tone*** - This patient's symptoms, including **excessive daytime sleepiness**, loud **snoring**, **morning headaches**, **obesity (BMI 34)**, and depressed mood, are all highly suggestive of **obstructive sleep apnea (OSA)**. - In OSA, poor oropharyngeal tone, often exacerbated by obesity, leads to the collapse of the upper airway during sleep, causing interrupted breathing and subsequent sleep fragmentation, which manifests as daytime sleepiness. *Circadian rhythm sleep-wake disorder* - This disorder typically involves a **misalignment between endogenous sleep-wake rhythms** and external environmental cues, often seen in shift workers or with jet lag. - While the patient previously worked as an overnight conductor, he has been retired for 3 years, and his symptoms are more aligned with chronic airway obstruction rather than a desynchronized internal clock. *Deficiency of the neuropeptides, orexin-A and orexin-B* - A deficiency in **orexin (hypocretin)** is the underlying mechanism for **narcolepsy type 1**, characterized by excessive daytime sleepiness, cataplexy (sudden loss of muscle tone triggered by strong emotions), and sleep paralysis/hypnagogic hallucinations. - This patient specifically denies muscle weakness or hallucinations, which makes narcolepsy less likely. *Insufficient sleep duration* - While insufficient sleep duration can cause excessive daytime sleepiness, the patient reports sleeping approximately **8-9 hours per night**, which is generally considered an adequate duration for adults. - The loud snoring and other symptoms point towards a **qualitative problem with sleep**, despite seemingly adequate hours. *Psychiatric disorder* - While **depressed mood** is present, it is often a **consequence or comorbidity of chronic sleep deprivation** and fragmented sleep rather than the primary cause of the patient's excessive daytime sleepiness and loud snoring. - Depression alone does not explain the physical signs like snoring and morning headaches without an underlying sleep disorder.

Question 944: A 48-year-old woman presents to her primary care physician with complaints of persistent fatigue, dizziness, and weight loss for the past 3 months. She has a history of hypothyroidism and takes thyroxine replacement. Her blood pressure is 90/60 mm Hg in a supine position and 65/40 mm Hg while sitting, temperature is 36.8°C (98.2°F), and pulse is 75/min. On physical examination, there is a mild increase in thyroid size, with a rubbery consistency. Her skin shows diffuse hyperpigmentation, more pronounced in the oral mucosa and palmar creases. Which of the following best represent the etiology of this patient’s condition?

A. Prolonged corticosteroid therapy
B. ↓ corticotropin-releasing hormone secretion from the hypothalamus
C. Autoimmune destruction of the adrenal gland (Correct Answer)
D. ↓ adrenocorticotropic hormone secretion from the pituitary gland
E. ↑ iron absorption and deposition in the body

Explanation: ***Autoimmune destruction of the adrenal gland*** - The patient's symptoms, including **fatigue**, **dizziness**, **weight loss**, **hypotension**, and especially **diffuse hyperpigmentation of the skin and oral mucosa**, are classic signs of **primary adrenal insufficiency (Addison's disease)**. - Given the history of **hypothyroidism** (another autoimmune disorder), **autoimmune destruction of the adrenal glands** is the most likely underlying cause. *Prolonged corticosteroid therapy* - **Prolonged corticosteroid therapy** can lead to **secondary adrenal insufficiency** by suppressing the **hypothalamic-pituitary-adrenal (HPA) axis**. - However, this would typically cause **ACTH deficiency**, leading to **pale skin** rather than hyperpigmentation, as the melanocyte-stimulating hormone (MSH) levels would also be low. *↓ corticotropin-releasing hormone secretion from the hypothalamus* - Decreased **CRH secretion** would result in **secondary adrenal insufficiency**, characterized by **low ACTH** and subsequently low cortisol. - This condition does not cause **hyperpigmentation** because MSH levels, which are co-secreted with ACTH from a common precursor (POMC), would also be low. *↓ adrenocorticotropic hormone secretion from the pituitary gland* - A reduction in **ACTH secretion** (secondary adrenal insufficiency) causes symptoms of **cortisol deficiency** but typically leads to **pallor** due to the lack of MSH stimulation. - It does not cause the **hyperpigmentation** seen in this patient, which is a hallmark of primary adrenal insufficiency where high ACTH (and MSH) levels stimulate melanocytes. *↑ iron absorption and deposition in the body* - Increased **iron absorption and deposition** is characteristic of **hemochromatosis**, which can cause fatigue and skin bronzing, but not the specific hyperpigmentation patterns (oral mucosa, palmar creases) or the significant hypotension and weight loss seen here. - Hemochromatosis primarily affects the liver, heart, and pancreas, and does not involve adrenal gland dysfunction in this manner.

Question 945: A 23-year-old woman presents with ongoing diplopia for 1 week. She has noticed that her diplopia is more prominent when she looks at objects in her periphery. It does not present when looking straight ahead. She does not have a fever, headache, ocular pain, lacrimation, blurring of vision, or changes in her color vision. She is a college student and is otherwise healthy. The neurological examination reveals that when she looks to the left, her right eye does not adduct while her left eye abducts with nystagmus. Furthermore, when she looks to the right, her left eye does not adduct while her right eye abducts with prominent nystagmus. Her pupils are bilateral, equal and reactive to light and accommodation. The convergence is normal. The rest of the cranial nerve examination is unremarkable. What is the next best step in the management of this patient?

A. Lumbar puncture
B. Magnetic resonance imaging (MRI) of the brain (Correct Answer)
C. Computed tomography (CT) scan of the head
D. Ophthalmology referral
E. Visual evoked potential

Explanation: ***Magnetic resonance imaging (MRI) of the brain*** - This patient's symptoms are highly suggestive of **bilateral internuclear ophthalmoplegia (INO)**, characterized by impaired adduction of one eye when the other abducts with nystagmus. In young adults, bilateral INO is a classic presentation of **multiple sclerosis (MS)**. - An **MRI of the brain** is the most sensitive imaging modality to detect **demyelinating lesions** characteristic of MS, especially in the brainstem, which would explain the INO. *Lumbar puncture* - A lumbar puncture to analyze **cerebrospinal fluid (CSF)** for **oligoclonal bands** and **IgG index** is part of the workup for MS but is typically performed *after* an MRI confirms suggestive lesions, or when clinical suspicion remains high despite a non-diagnostic MRI. - It is an **invasive procedure** and not the initial diagnostic test for suspected MS, especially when imaging can provide valuable information non-invasively. *Computed tomography (CT) scan of the head* - A **CT scan** has limited sensitivity for detecting subtle **demyelinating plaques** in the brainstem and other areas affected by MS. - While it can rule out acute hemorrhage or large masses, it is **inferior to MRI** for visualizing white matter lesions characteristic of MS. *Ophthalmology referral* - An ophthalmology referral is appropriate for evaluating primary ocular conditions, but the patient's neurological examination findings (bilateral INO) strongly point to a **central nervous system (CNS) cause** rather than an isolated eye problem. - The examination has already ruled out common ocular causes for diplopia, making a neurological workup including imaging the priority. *Visual evoked potential* - **Visual evoked potentials (VEPs)** measure the electrical activity of the brain in response to visual stimuli and can detect **optic nerve demyelination**, which is common in MS. - While VEPs can support a diagnosis of MS, they are **not the optimal initial step** compared to an MRI, which can directly visualize the characteristic lesions and confirm the etiology of the INO.

Question 946: A 65-year-old man with hypertension and type 2 diabetes mellitus is brought to the emergency department 20 minutes after the onset of severe anterior chest pain and shortness of breath. He has smoked one pack of cigarettes daily for 30 years. He appears distressed. His pulse is 116/min, respirations are 22/min, and blood pressure is 156/88 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. A grade 3/6, high-pitched, blowing, diastolic murmur is heard over the right upper sternal border. Which of the following is the most likely cause of this patient's symptoms?

A. Rupture of a bulla in the lung
B. Perforation of the esophageal wall
C. Obstruction of the pulmonary arteries
D. Fibrofatty plaque in the aortic wall
E. Tear in the tunica intima (Correct Answer)

Explanation: ***Tear in the tunica intima*** - The sudden onset of **severe anterior chest pain**, hypertension, and a **diastolic murmur** consistent with **aortic insufficiency** points strongly to an **aortic dissection**, which begins with a tear in the tunica intima. - Risk factors like **hypertension**, **smoking**, and **advanced age** increase the likelihood of aortic dissection. *Rupture of a bulla in the lung* - This would typically cause **pneumothorax**, leading to **sharp, pleuritic chest pain** and **dyspnea**, often with diminished breath sounds on the affected side. - A **cardiac murmur** and severe distress in the context of vascular risk factors are not characteristic of a ruptured bulla. *Perforation of the esophageal wall* - Esophageal perforation (Boerhaave syndrome) presents with **severe chest pain**, **vomiting**, and often **subcutaneous emphysema** or **pleural effusion**. - While it causes severe chest pain, the described **diastolic murmur** and absence of vomiting or other specific signs make this less likely. *Obstruction of the pulmonary arteries* - **Pulmonary embolism** (obstruction of pulmonary arteries) typically causes **sudden onset dyspnea**, **pleuritic chest pain**, **tachycardia**, and **hypoxia**, often without a significant cardiac murmur of this nature. - The oxygen saturation of 98% makes a large pulmonary embolism less probable. *Fibrofatty plaque in the aortic wall* - While common in patients with hypertension and smoking history, an **atherosclerotic plaque** in the aortic wall itself rarely causes acute, severe chest pain and a new diastolic murmur unless it leads to an **aortic dissection** or **rupture**. - This option describes a precursor to diseases like aortic dissection but not the acute event itself.

Question 947: A 39-year-old woman presents with progressive weakness, exercise intolerance, and occasional dizziness for the past 3 months. Past medical history is unremarkable. She reports an 18-pack-year smoking history and drinks alcohol rarely. Her vital signs include: temperature 36.6°C (97.8°F), blood pressure 139/82 mm Hg, pulse 98/min. Physical examination is unremarkable. Her laboratory results are significant for the following: Hemoglobin 9.2 g/dL Erythrocyte count 2.1 million/mm3 Mean corpuscular volume (MCV) 88 μm3 Mean corpuscular hemoglobin (MCH) 32 pg/cell Leukocyte count 7,500/mm3 Which of the following is the best next step in the management of this patient’s condition?

A. Serum ferritin level
B. Direct antiglobulin test
C. C-reactive protein (CRP)
D. Bone marrow biopsy
E. Reticulocyte count (Correct Answer)

Explanation: ***Reticulocyte count*** - A **normocytic anemia** (MCV 88) with signs of weakness and exercise intolerance requires evaluation of **red blood cell production**. - A reticulocyte count helps differentiate between **hypoproliferative** (low count) and **hyperproliferative** (high count) anemias, guiding further diagnostic steps. *Serum ferritin level* - While often low in **iron-deficiency anemia**, this patient’s **normocytic MCV** makes iron deficiency less likely as the primary cause without other features. - A normal ferritin doesn't rule out other causes of anemia, and a high ferritin could indicate **anemia of chronic disease**, but further understanding of RBC production is needed first. *Direct antiglobulin test* - This test is used to diagnose **autoimmune hemolytic anemia**, which typically presents with **jaundice**, **splenomegaly**, and elevated **lactate dehydrogenase (LDH)**, none of which are noted here. - While anemia can result from hemolysis, the initial presentation doesn't strongly suggest an immune-mediated destruction process, and determining the bone marrow's response is more immediate. *C-reactive protein (CRP)* - CRP is a marker of **inflammation**, and elevated levels could suggest **anemia of chronic disease**. - However, knowing the **reticulocyte count** will provide more direct information about bone marrow function, which is crucial for characterizing the anemia. *Bone marrow biopsy* - A bone marrow biopsy is an **invasive procedure** typically reserved for complex anemias where initial, less invasive tests have failed to provide a diagnosis or when conditions like **aplastic anemia** or **myelodysplastic syndromes** are strongly suspected. - It is not the appropriate **first diagnostic step** in evaluating an undifferentiated normocytic anemia like this.

Question 948: A 45-year-old woman comes to the physician because of fatigue, irregular menses, and recurrent respiratory infections for the past 6 months. Her blood pressure is 151/82 mm Hg. Physical examination shows a round face, thinning of the skin, and multiple bruises on her arms. Further studies confirm the diagnosis of an ACTH-secreting pituitary adenoma. This patient is at greatest risk for which of the following?

A. Weight loss
B. Eosinophilia
C. Bitemporal hemianopsia
D. Hypoglycemia
E. Pathologic fracture (Correct Answer)

Explanation: ***Pathologic fracture*** - This patient has **Cushing's disease** due to an **ACTH-secreting pituitary adenoma**, leading to excess cortisol. - **Excess cortisol** causes **osteoporosis** by increasing bone resorption and decreasing bone formation, significantly raising the risk of **pathologic fractures**. - This is the **greatest risk** because **all patients** with chronic hypercortisolism develop bone loss, making fractures highly likely. *Weight loss* - Patients with Cushing's disease typically experience **weight gain**, particularly centrally (truncal obesity), due to **cortisol-induced fat redistribution**. - **Fatigue** is common, but weight loss is not a characteristic feature of Cushing's syndrome. *Eosinophilia* - **Hypercortisolism** (Cushing's syndrome) usually causes **eosinopenia** (decreased eosinophil count) and **lymphopenia**, not eosinophilia. - Cortisol has an anti-inflammatory and immunosuppressive effect, leading to a reduction in circulating eosinophils and lymphocytes. *Bitemporal hemianopsia* - While an **ACTH-secreting pituitary adenoma** is present, **bitemporal hemianopsia** occurs only when a pituitary tumor becomes a **macroadenoma** (>10mm) and compresses the **optic chiasm**. - Most ACTH-secreting adenomas are **microadenomas** (<10mm) that cause symptoms through **hormonal excess**, not mass effect. - The clinical picture here reflects **Cushing's syndrome** from hypercortisolism, which affects **all patients** regardless of tumor size, whereas visual field defects occur only with large tumors. *Hypoglycemia* - **Excess cortisol** **increases gluconeogenesis** and **insulin resistance**, leading to **hyperglycemia**, not hypoglycemia. - This is a common metabolic complication of Cushing's syndrome, often progressing to **steroid-induced diabetes mellitus**.

Question 949: A 54-year-old man comes to the emergency department because of a 3-week history of intermittent swelling of his left arm and feeling of fullness in his head that is exacerbated by lying down and bending over to tie his shoes. Physical examination shows left-sided facial edema and distention of superficial veins in the neck and left chest wall. Which of the following is the most likely cause of this patient's symptoms?

A. Cervical rib
B. Mediastinal lymphoma
C. Subclavian steal syndrome
D. Apical lung tumor (Correct Answer)
E. Right heart failure

Explanation: ***Apical lung tumor*** - The symptoms of **facial edema**, **neck vein distention**, and **swelling of the left arm**, particularly when exacerbated by positional changes such as lying down or bending over, are classic signs of **superior vena cava (SVC) syndrome**. - An **apical lung tumor (Pancoast tumor)** is a common cause of SVC syndrome due to its proximity to the SVC and surrounding structures, leading to compression. - The **left-sided predominance** (left arm swelling, left facial edema, left chest wall venous distention) specifically points to a left apical mass compressing the left brachiocephalic vein and/or SVC. *Cervical rib* - A cervical rib can cause **thoracic outlet syndrome**, leading to neurovascular compression, but it typically presents with neurological symptoms (pain, numbness, weakness in the arm/hand) or arterial insufficiency rather than widespread facial and neck edema. - While it can cause *venous compression*, resulting in arm swelling, the **facial edema and neck vein distention** suggest a more central venous obstruction like SVC syndrome rather than peripheral thoracic outlet compression. *Mediastinal lymphoma* - Malignancies in the mediastinum, such as lymphoma, can indeed cause SVC syndrome by compressing the SVC. - However, mediastinal lymphomas typically cause **bilateral** symptoms due to their central location, whereas this patient has **predominant left-sided findings** (left arm swelling, left facial edema, left chest wall veins), which more specifically suggests a left apical lung mass. - Additionally, lymphoma commonly presents with systemic "B symptoms" (fever, night sweats, weight loss) and generalized lymphadenopathy, which are not mentioned here. *Subclavian steal syndrome* - This syndrome results from **subclavian artery stenosis** proximal to the vertebral artery origin, causing **retrograde blood flow** in the vertebral artery to supply the arm. - It presents with **arm claudication**, dizziness, and syncope, especially with arm exercise, rather than venous congestion and swelling of the face, neck, and arm. - This is an **arterial** syndrome, not a **venous** syndrome. *Right heart failure* - **Right heart failure** causes systemic venous congestion, leading to symptoms like **peripheral edema** (especially in the lower extremities), **jugular venous distention**, and **hepatomegaly**. - While it can cause jugular venous distension, it typically presents with **bilateral lower extremity edema** and *rarely* causes unilateral arm swelling or predominant facial edema, as seen here. - The **positional exacerbation** and **unilateral left-sided findings** are not characteristic of right heart failure.

Question 950: A 45-year-old male presents to his primary care physician for complaints of dizziness. The patient reports he experiences room-spinning dizziness lasting several hours at a time, approximately 2-3 times a month, starting 3 months ago. Upon questioning, the patient also reports right sided diminished hearing, tinnitus, and a sensation of ear fullness. His temperature is 99 deg F (37.2 deg C), pulse 70/min, respirations 12, blood pressure 130 mmHg/85 mmHg, SpO2 99%. You decide to order an audiometric evaluation. What is the most likely finding of the audiogram?

A. Low frequency sensorineural hearing loss (Correct Answer)
B. Normal audiogram
C. High frequency conductive hearing loss
D. High frequency sensorineural hearing loss
E. Low frequency conductive hearing loss

Explanation: ***Low frequency sensorineural hearing loss*** - The constellation of **episodic vertigo**, **tinnitus**, **aural fullness**, and **fluctuating hearing loss** is classic for **Ménière's disease**. - In Ménière's disease, the characteristic audiogram finding is a **sensorineural hearing loss** that predominantly affects the **low frequencies**. *Normal audiogram* - A normal audiogram would not explain the patient's reported symptoms of **diminished hearing** and **tinnitus**. - These symptoms indicate an underlying auditory dysfunction, which a normal audiogram would rule out. *High frequency conductive hearing loss* - **Conductive hearing loss** indicates an issue with sound transmission through the outer or middle ear (e.g., **otosclerosis**, **cerumen impaction**). - The reported symptoms and the characteristic low-frequency involvement in Ménière's disease do not align with high-frequency conductive hearing loss. *High frequency sensorineural hearing loss* - While sensorineural hearing loss is correct, **high-frequency loss** is more typical of **presbycusis** (age-related hearing loss) or **noise-induced hearing loss**. - Ménière's disease characteristically affects the **low frequencies** initially. *Low frequency conductive hearing loss* - **Conductive hearing loss** implies a problem in the outer or middle ear, which is not consistent with the pathology of **Ménière's disease** (endolymphatic hydrops affecting the inner ear). - While the frequency range is correct, the type of hearing loss (conductive vs. sensorineural) is incorrect for Ménière's disease.

Question 951: A 32-year-old man comes to the physician for a follow-up examination 1 week after being admitted to the hospital for oral candidiasis and esophagitis. His CD4+ T lymphocyte count is 180 cells/μL. An HIV antibody test is positive. Genotypic resistance assay shows the virus to be susceptible to all antiretroviral therapy regimens and therapy with dolutegravir, tenofovir, and emtricitabine is initiated. Which of the following sets of laboratory findings would be most likely on follow-up evaluation 3 months later? $$$ CD4 +/CD8 ratio %%% HIV RNA %%% HIV antibody test $$$

A. ↓ ↓ negative
B. ↑ ↑ negative
C. ↓ ↑ negative
D. ↑ ↓ positive (Correct Answer)
E. ↓ ↑ positive

Explanation: ***↑ ↓ positive*** - With effective **antiretroviral therapy (ART)**, the **CD4+/CD8 ratio** would increase as **CD4+ T cell counts rise** and **CD8+ T cell counts decrease**. - **HIV RNA (viral load)** would significantly decrease (ideally to undetectable levels) due to the suppression of viral replication, but HIV antibodies would remain positive indefinitely. *↓ ↓ negative* - A decrease in the **CD4+/CD8 ratio** and **HIV RNA** (viral load) along with a negative **HIV antibody test** is inconsistent with successful ART. - A negative HIV antibody test would mean the patient was never infected, which contradicts the initial positive result and symptoms. *↑ ↑ negative* - An increase in the **CD4+/CD8 ratio** is expected with ART, but an increase in **HIV RNA** (viral load) indicates treatment failure. - A negative **HIV antibody test** is impossible after a confirmed positive result, regardless of treatment success. *↓ ↑ negative* - A decrease in the **CD4+/CD8 ratio** would suggest worsening immune function, while an increase in **HIV RNA** indicates treatment failure. - A negative **HIV antibody test** is not possible once a patient has developed antibodies to HIV. *↓ ↑ positive* - A decrease in the **CD4+/CD8 ratio** would indicate immune decline, contrary to the expected improvement with effective ART. - An increase in **HIV RNA (viral load)** would signify treatment failure, even if HIV antibodies remain positive.

Question 952: A 62-year-old woman comes to the physician because of involuntary, rhythmic movements of her hands for the past 5 months. Her symptoms initially affected her left hand only, but now both hands are affected. She also reports that her symptoms are worse at rest and that performing tasks such as tying her shoelaces and writing have become more difficult. Her husband thinks that she has been more withdrawn lately. She used to drink a half a bottle of sherry every day for the past 18 years but has not consumed alcohol in the past year. She has chronic liver disease, hypertension, and peripheral artery disease. Current medications include aspirin and propanolol. She appears anxious. She is oriented to time, place, and person. Her temperature is 37°C (98.6°F), pulse is 98/min, and blood pressure is 144/82 mm Hg. Examination shows a rhythmic, low-frequency tremor that is more prominent in the left hand. Range of motion in the arms and legs is normal. Increased resistance to passive flexion and extension is present in the left upper limb. Muscle strength is 4/5 in all limbs. Sensations to pinprick and light touch are preserved. The finger-to-nose test is normal bilaterally. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Cerebellar infarction
B. Copper accumulation in the basal ganglia
C. Increased serum free T4 levels
D. Infarction of the red nucleus
E. Degeneration of the substantia nigra (Correct Answer)

Explanation: ***Degeneration of the substantia nigra*** - The patient's symptoms, including a **rhythmic, low-frequency tremor** at rest, worsening with activity, and increased resistance to passive movement (**rigidity**) in the left upper limb, are highly characteristic of **Parkinson's disease**, which is caused by the degeneration of dopaminergic neurons in the **substantia nigra**. - The asymmetric onset (left hand initially), progression to both hands, and difficulties with fine motor tasks like tying shoelaces and writing further support this diagnosis. *Cerebellar infarction* - A cerebellar infarction would typically cause **ataxia**, intention tremor (tremor worse with movement), dysmetria, and nystagmus, which are not described as the primary symptoms here. - The patient's **finger-to-nose test is normal**, which argues against significant cerebellar dysfunction. *Copper accumulation in the basal ganglia* - This condition, known as **Wilson's disease**, typically presents at a younger age and involves hepatic, neurologic, and psychiatric symptoms, including tremor, dystonia, and neuropsychiatric changes. However, the tremor in Wilson's disease is often a **wing-beating tremor** or postural/action tremor, distinct from the rest tremor seen here. - While the patient has chronic liver disease, there's no mention of Kayser-Fleischer rings or other specific findings of Wilson's disease, and the described tremor strongly points to Parkinsonism. *Increased serum free T4 levels* - Increased serum free T4 levels (hyperthyroidism) can cause a **fine, rapid postural tremor** and other symptoms like weight loss, palpitations, and anxiety. - Her tremor is described as low-frequency and prominent at rest, which is not typical for hyperthyroidism. *Infarction of the red nucleus* - Infarction of the red nucleus, or damage to its pathways, can cause a **rubral tremor** (also known as midbrain tremor or Holmes tremor), which is a combination of rest, postural, and kinetic tremor, often large amplitude and irregular. - While a possibility for tremor, a rubral tremor typically doesn't present with the classic rigidity and bradykinesia (implied by difficulty with fine tasks) seen in Parkinson's disease, and the other features strongly point to substantia nigra degeneration.

Question 953: A 68-year-old Caucasian male complains of severe headache and pain while chewing. Upon examination, he is found to have a left visual field deficit. Laboratory results show elevated erythrocyte sedimentation rate. Which of the following drugs would be the best choice for treatment of this patient?

A. Pilocarpine
B. Prednisone (Correct Answer)
C. Propranolol
D. Sumatriptan
E. Clopidogrel

Explanation: ***Prednisone*** - This patient's symptoms (severe headache, jaw claudication, visual deficit, elevated ESR) are highly suggestive of **giant cell arteritis (GCA)**, a medical emergency. - **High-dose systemic corticosteroids (e.g., prednisone)** are the cornerstone of treatment for GCA to prevent irreversible vision loss. *Pilocarpine* - **Pilocarpine** is a parasympathomimetic used primarily for glaucoma and dry mouth. - It has no role in the treatment of giant cell arteritis or its associated symptoms. *Propranolol* - **Propranolol** is a non-selective beta-blocker used for conditions like hypertension, angina, and migraine prophylaxis. - It would not address the underlying inflammatory process of giant cell arteritis or prevent its major complications. *Sumatriptan* - **Sumatriptan** is a triptan medication used specifically for acute migraine and cluster headache relief. - It is ineffective for headaches caused by inflammatory vasculitis like giant cell arteritis. *Clopidogrel* - **Clopidogrel** is an antiplatelet agent used to prevent thrombotic events in cardiovascular disease. - While GCA can lead to thrombotic complications, antiplatelet therapy is secondary to corticosteroids and does not treat the acute inflammation or vision loss directly.

Question 954: A 76-year-old male with a history of chronic uncontrolled hypertension presents to the emergency room following an episode of syncope. He reports that he felt lightheaded and experienced chest pain while walking his dog earlier in the morning. He notes that he has experienced multiple similar episodes over the past year. A trans-esophageal echocardiogram demonstrates a thickened, calcified aortic valve with left ventricular hypertrophy. Which of the following heart sounds would likely be heard on auscultation of this patient?

A. Crescendo-decrescendo murmur radiating to the carotids that is loudest at the right upper sternal border (Correct Answer)
B. Diastolic rumble following an opening snap with an accentuated S1
C. Early diastolic high-pitched blowing decrescendo murmur that is loudest at the left sternal border
D. Holosystolic murmur radiating to the axilla that is loudest at the apex
E. Midsystolic click that is loudest at the apex

Explanation: ***Crescendo-decrescendo murmur radiating to the carotids that is loudest at the right upper sternal border*** - The patient's symptoms of **syncope**, **chest pain**, and findings of a **thickened, calcified aortic valve** with **left ventricular hypertrophy** are classic for **aortic stenosis**. - Aortic stenosis classically presents with a **systolic ejecting crescendo-decrescendo murmur** which is loudest at the **right upper sternal border**, and often **radiates to the carotids**. *Diastolic rumble following an opening snap with an accentuated S1* - This description is characteristic of **mitral stenosis**, which is typically caused by **rheumatic fever**. - Mitral stenosis would present with dyspnea and fatigue, unlike the syncope and chest pain seen in this patient. *Early diastolic high-pitched blowing decrescendo murmur that is loudest at the left sternal border* - This murmur describes **aortic regurgitation**, where blood flows back into the left ventricle during diastole. - While aortic regurgitation can cause heart failure symptoms, the echocardiogram shows a thickened, calcified valve more consistent with stenosis. *Midsystolic click that is most prominent that is loudest at the apex* - A **midsystolic click** followed by a **late systolic murmur** is characteristic of **mitral valve prolapse**. - Symptoms of mitral valve prolapse can include atypical chest pain and palpitations, but not generally exertional syncope or the severe structural changes seen in the aortic valve. *Holosystolic murmur radiating to the axilla that is loudest at the apex* - This is the classic description of **mitral regurgitation**, indicating blood flow back into the left atrium during systole. - Mitral regurgitation is associated with symptoms of heart failure and fatigue, but not usually the anginal chest pain and syncope in a patient with a calcified aortic valve.

Question 955: A 21-year-old Cambodian patient with a history of rheumatic heart disease presents to his primary care physician for a routine check-up. He reports being compliant with monthly penicillin G injections since being diagnosed with rheumatic fever at age 15. He denies any major side effects from the treatment, except for the inconvenience of organizing transportation to a physician's office every month. On exam, the patient is found to have a loud first heart sound and a mid-diastolic rumble that is best heard at the apex. Which of the following is the next best step?

A. Switch to intramuscular cefotaxime, which has fewer side effects
B. Continue intramuscular penicillin therapy (Correct Answer)
C. Stop penicillin therapy
D. Stop penicillin therapy in 4 years
E. Decrease frequency of injections to bimonthly

Explanation: ***Continue intramuscular penicillin therapy*** - This patient has a history of **rheumatic heart disease** and is showing signs of **mitral stenosis** (loud S1, mid-diastolic rumble at the apex), indicating previous rheumatic fever and the effectiveness of current prophylaxis. - Continuing prophylaxis is crucial to prevent further episodes of **rheumatic fever** and progression of cardiac damage, especially in regions with endemic rheumatic fever. *Switch to intramuscular cefotaxime, which has fewer side effects* - **Cefotaxime** is a third-generation cephalosporin and is not typically used for rheumatic fever prophylaxis, nor is it proven to have significantly fewer side effects in this context. - **Penicillin G** is the gold standard for preventing recurrent rheumatic fever due to its proven efficacy and low cost. *Stop penicillin therapy* - Stopping prophylaxis would put the patient at high risk for **recurrent rheumatic fever** and worsening of their established **rheumatic heart disease**, which can lead to severe cardiac complications. - The patient's current heart sounds suggest ongoing valvular disease, making continued prevention of exacerbations critical. *Stop penicillin therapy in 4 years* - The duration of **rheumatic fever prophylaxis** is determined by the patient's age and the presence of **rheumatic heart disease**. For patients with documented rheumatic heart disease, prophylaxis often continues for much longer periods, often until age 40 or even lifelong. - Stopping at "4 years" from age 21 (i.e., at age 25) is too early for a patient with established rheumatic heart disease. *Decrease frequency of injections to bimonthly* - Monthly intramuscular **penicillin G** is the standard and most effective regimen for secondary prophylaxis of rheumatic fever. - Decreasing the frequency would reduce the drug's therapeutic levels and significantly increase the risk of breakthrough streptococcal infections and subsequent episodes of **rheumatic fever**.

Question 956: A 30-year-old patient comes to the emergency room with a chief complaint of left chest pain and a productive cough with purulent sputum for 1 week. He also complains of shortness of breath. He said he had been previously diagnosed with influenza but did not follow the doctor’s instructions. His vitals include: heart rate 70/min, respiratory rate 22/min, temperature 38.7°C (101.7°F), blood pressure 120/60 mm Hg, and SO2 80%. His hemogram and chest X-ray findings are as follows: Hemoglobin 14 mg/dL Hematocrit 45% Leukocyte count 12,000/mm3 Neutrophils 82% Lymphocytes 15% Monocytes 3% Platelet count 270,000/mm3 Chest X-ray alveolar infiltrates in the left base with air bronchograms What is the most likely diagnosis?

A. Histoplasmosis
B. Pneumonia (Correct Answer)
C. Tuberculosis
D. Lung cancer
E. Sarcoidosis

Explanation: ***Pneumonia*** - The patient presents with classic symptoms of **pneumonia**, including **chest pain**, **productive cough** with purulent sputum, and **shortness of breath**, along with **fever** and **hypoxia (SO2 80%)**. - The elevated **leukocyte count** with **neutrophil predominance** and the chest X-ray showing **alveolar infiltrates** with **air bronchograms** are highly consistent with bacterial pneumonia. *Histoplasmosis* - This is a **fungal infection** typically seen in immunocompromised individuals or those with exposure to **bird/bat droppings**. - While it can cause pulmonary symptoms, the acute presentation with purulent sputum and marked neutrophilic leukocytosis points away from a primary fungal infection in an otherwise healthy 30-year-old. *Tuberculosis* - While TB can cause cough and chest pain, it usually presents with a **chronic cough**, **night sweats**, and **weight loss**, and the sputum may be bloody rather than purulent. - The chest X-ray findings of alveolar infiltrates with air bronchograms are more characteristic of acute bacterial pneumonia than the typical cavitary lesions or miliary pattern of TB. *Lung cancer* - Lung cancer typically presents with a more **chronic cough**, **hemoptysis**, weight loss, and fatigue, rather than an acute febrile illness with purulent sputum. - While it can cause lung infiltrates, the acute inflammatory markers and clinical picture do not fit lung cancer as the primary diagnosis. *Sarcoidosis* - Sarcoidosis is a systemic **granulomatous disease** that often affects the lungs and lymph nodes, presenting with **non-caseating granulomas**. - It usually presents with **insidious onset** of cough, dyspnea, and fatigue, and chest X-rays often show **hilar lymphadenopathy** or interstitial infiltrates, not the acute alveolar infiltrates seen here.

Question 957: A 32-year-old woman comes to the physician because of worsening fatigue and shortness of breath. Her symptoms began 8 months ago and have progressively worsened since then. She had recurrent episodes of joint pain and fever during childhood. She does not smoke or drink alcohol. She emigrated from the Congo with her parents when she was 12 years old. Her temperature is 37.4°C (99.3°F), pulse is 90/min and regular, respirations are 18/min, and blood pressure is 140/90 mm Hg. There is an opening snap followed by a diastolic murmur at the fifth left intercostal space in the midclavicular line. If left untreated, this patient is at greatest risk for which of the following complications?

A. Pulmonary edema
B. Systemic thromboembolism
C. Pulmonary hypertension
D. Right heart failure
E. Atrial fibrillation (Correct Answer)

Explanation: ***Atrial fibrillation*** - The patient's history of **recurrent joint pain and fever in childhood**, originating from the Congo, points towards a diagnosis of **rheumatic heart disease** causing **mitral stenosis**. - **Mitral stenosis** leads to increased left atrial pressure and dilation, which are significant risk factors for developing **atrial fibrillation**. The presence of an **opening snap and diastolic murmur** further supports mitral stenosis. *Pulmonary edema* - While **pulmonary edema** can be a complication of severe **mitral stenosis** due to increased left atrial pressure and elevated pulmonary venous pressures, it is often precipitated by an acute event or occurs later in the disease course. - **Atrial fibrillation** significantly exacerbates intra-atrial pressures and worsens symptoms, often preceding or coexisting with pulmonary edema, making it a more immediate and common long-term risk. *Systemic thromboembolism* - **Systemic thromboembolism** is a serious complication of untreated **mitral stenosis**, particularly when complicated by **atrial fibrillation**, due to stasis of blood in the dilated left atrium. - However, the primary mechanism leading to an increased risk of thromboembolism in this context is the development of **atrial fibrillation**, which sets the stage for clot formation. *Pulmonary hypertension* - **Pulmonary hypertension** is a common consequence of chronic **mitral stenosis** as elevated left atrial pressures are transmitted to the pulmonary vasculature. - While a severe complication that contributes to symptoms like shortness of breath, **atrial fibrillation** is a critical arrhythmia that can both worsen pulmonary hypertension and lead to other life-threatening complications. *Right heart failure* - **Right heart failure** eventually develops in severe, long-standing **mitral stenosis** due to sustained **pulmonary hypertension**, which increases the afterload on the right ventricle. - While it represents an advanced stage of the disease, **atrial fibrillation** is a more immediate and common rhythm disturbance that contributes to the hemodynamic compromise and often predates overt right heart failure.

Question 958: A 62-year-old man presents to the emergency department with confusion. The patient’s wife states that her husband has become more somnolent over the past several days and now is very confused. The patient has no complaints himself, but is answering questions inappropriately. The patient has a past medical history of diabetes and hypertension. His temperature is 98.3°F (36.8°C), blood pressure is 127/85 mmHg, pulse is 138/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for a confused man with dry mucous membranes. Initial laboratory studies are ordered as seen below. Serum: Na+: 135 mEq/L Cl-: 100 mEq/L K+: 3.0 mEq/L HCO3-: 23 mEq/L BUN: 30 mg/dL Glucose: 1,299 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most appropriate initial treatment for this patient?

A. Insulin, normal saline, and potassium (Correct Answer)
B. Normal saline and potassium
C. Insulin and potassium
D. Insulin
E. Insulin and normal saline

Explanation: ***Insulin, normal saline, and potassium*** - This patient is presenting with **hyperosmolar hyperglycemic state (HHS)**, characterized by severe hyperglycemia (glucose 1299 mg/dL), dehydration (dry mucous membranes, high BUN and creatinine), and altered mental status. The initial treatment involves intravenous fluids to correct dehydration, insulin to lower blood glucose, and potassium supplementation due to potential shifts as insulin is administered. - **Normal saline** addresses the severe dehydration, **insulin** corrects hyperglycemia, and **potassium supplementation** prevents hypokalemia, which is common during HHS treatment as glucose and potassium shift intracellularly. *Normal saline and potassium* - While **normal saline** and **potassium** are crucial for rehydration and electrolyte balance, omitting **insulin** would fail to address the core problem of severe hyperglycemia in HHS. - Without insulin, blood glucose levels will remain dangerously high, leading to persistent osmotic diuresis and worsening dehydration. *Insulin and potassium* - Administering **insulin** without addressing the profound **dehydration** with intravenous fluids can lead to **hypovolemic shock** as insulin further drives glucose and water into cells. - Rehydration is the priority in HHS management before or concurrent with insulin administration. *Insulin* - Giving only **insulin** would be detrimental, as the patient is severely dehydrated and hypokalemic (K+ 3.0 mEq/L, and will drop further with insulin). - This approach would exacerbate dehydration and could cause life-threatening arrhythmias due to severe hypokalemia. *Insulin and normal saline* - While addressing hyperglycemia and dehydration, omitting **potassium supplementation** is dangerous because insulin drives potassium into cells, potentially causing severe **hypokalemia** and cardiac arrhythmias. - The patient already has a low-normal potassium level, which will likely drop further with insulin treatment.

Question 959: A 55-year-old man presents for physical and preventive health screening, specifically for prostate cancer. He has not been to the doctor in a long time. Past medical history is significant for hypertension that is well-managed. Current medication is hydrochlorothiazide. He has one uncle who died of prostate cancer. He drinks one or two alcoholic drinks on the weekends and does not smoke. Today his temperature is 37.0°C (98.6°F), blood pressure is 125/75 mm Hg, pulse is 82/min, respiratory rate is 15/min, and oxygen saturation is 99% on room air. There are no significant findings on physical examination. Which of the following would be the most appropriate recommendation for prostate cancer screening in this patient?

A. Contrast CT of the abdomen and pelvis
B. Serum PSA level (Correct Answer)
C. Digital rectal examination
D. No screening indicated at this time
E. Transrectal ultrasound (TRUS)

Explanation: ***Serum PSA level*** - This patient is 55 years old and has a family history of prostate cancer (uncle), placing him at **average to increased risk** for prostate cancer. - **Serum PSA (prostate-specific antigen) testing** is the primary screening tool for prostate cancer, often combined with shared decision-making with the patient. *Contrast CT of the abdomen and pelvis* - A CT scan is not a primary screening tool for prostate cancer but is used for **staging** once cancer is diagnosed or to investigate specific symptoms. - It involves **radiation exposure** and **contrast dye risks** which are not justified for routine screening in an asymptomatic patient. *Digital rectal examination* - While DRE can detect prostate abnormalities, it has a **lower sensitivity and specificity** as a stand-alone screening test compared to PSA. - Current guidelines often recommend DRE in conjunction with PSA, but **PSA remains the initial and most important screening test**. *No screening indicated at this time* - The patient's age (55) and family history (uncle with prostate cancer) warrant discussion about prostate cancer screening. - The **American Cancer Society (ACS)** recommends starting discussions about screening at age 50 for average-risk men, and earlier for those with risk factors. *Transrectal ultrasound (TRUS)* - TRUS is not a screening test but is typically used to **guide prostate biopsies** if PSA levels are elevated or a DRE is abnormal. - It is an **invasive procedure** and not appropriate for initial prostate cancer screening in asymptomatic individuals.

Question 960: A 27-year-old woman comes to the emergency department because of progressive numbness and weakness in her left arm and left leg for 2 days. During this period, she has also had urinary urgency and incontinence. Three months ago, she had blurry vision, difficulty distinguishing colors, and headache for one week, all of which have resolved. The patient has smoked a half pack of cigarettes daily for 10 years and drinks four glasses of wine each week. Her temperature is 37°C (98.6°F), pulse is 78/min, respirations are 14/min, and blood pressure is 110/68 mm Hg. Examination shows 3/5 strength in the left arm and leg, and 5/5 strength on the right side. Upon flexion of the neck, the patient experiences a shooting electric sensation that travels down the spine. MRI of the brain shows gadolinium-enhancing lesions in the right central sulcus, cervical spinal cord, and optic nerve. Which of the following is the most appropriate next step in the management of this patient?

A. Administer lorazepam
B. Plasmapheresis
C. Administer IV methylprednisolone (Correct Answer)
D. Glatiramer acetate therapy
E. Administer tissue plasminogen activator

Explanation: ***Administer IV methylprednisolone*** - This patient presents with an acute exacerbation of **multiple sclerosis (MS)**, characterized by new neurological deficits (numbness, weakness, urinary urgency) and resolving symptoms that point to prior demyelination (blurry vision). - High-dose **intravenous corticosteroids** like methylprednisolone are the first-line treatment for acute MS relapses to reduce inflammation and shorten the duration of the attack. *Administer lorazepam* - **Lorazepam** is a benzodiazepine primarily used for anxiety, seizures, or agitation and does not address the underlying inflammatory process of an acute MS exacerbation. - While some MS patients may experience anxiety, it is not the indicated treatment for acute neurological deficits. *Plasmapheresis* - **Plasmapheresis** is considered for severe MS exacerbations that are refractory to high-dose corticosteroids. - It is not typically the first-line treatment in an acute relapse unless corticosteroids have failed. *Glatiramer acetate therapy* - **Glatiramer acetate** is a disease-modifying therapy (DMT) for MS, used to reduce the frequency of relapses and prevent disease progression. - It is administered long-term but is not an appropriate treatment for an acute MS exacerbation. *Administer tissue plasminogen activator* - **Tissue plasminogen activator (tPA)** is a thrombolytic agent used to treat acute ischemic stroke by dissolving blood clots. - This patient's symptoms are neurological but are consistent with demyelination rather than an ischemic event, making tPA inappropriate.

Question 961: A 21-year-old man presents to a physician because of extreme fatigue, palpitations, fever, and weight loss. He developed these symptoms gradually over the past 3 months. His blood pressure is 110/80 mm Hg, heart rate is 109/min, respiratory rate is 17/min, and temperature is 38.1°C (100.6°F). The patient is emaciated and pale. There are conjunctival hemorrhages and several bruises noted in the inner cubital area bilaterally. There are also a few lesions on the left foot. The cardiac examination reveals a holosystolic murmur best heard at the 4th intercostal space at the left sternal edge. Two blood cultures grew Staphylococcus aureus, and echocardiography shows a tricuspid valve vegetation. Which of the following would most likely be revealed in a detailed history from this patient?

A. Lung abscess evacuation 3 months ago
B. Chronic intravenous drug usage (Correct Answer)
C. Catheterization of the urinary bladder
D. Percutaneous nephrostomy for acute ureterolithiasis 5 months ago
E. Adenoidectomy 6 months ago

Explanation: ***Chronic intravenous drug usage*** - The constellation of **fever**, **fatigue**, **palpitations**, **weight loss**, signs of **embolism** (conjunctival hemorrhages, foot lesions, bruises in cubital area), and particularly a **tricuspid valve aneurysm** with **Staphylococcus aureus** bacteremia, is highly suggestive of **infective endocarditis** in an intravenous drug user. The bruises in the cubital area could represent track marks. - **Staphylococcus aureus** is the most common pathogen in **IVDU-associated endocarditis**, and the **tricuspid valve** is most frequently involved due to the direct injection of bacteria into the venous system. *Lung abscess evacuation 3 months ago* - While a lung abscess could be a source of infection, an evacuation procedure is less directly linked to subsequent **tricuspid valve endocarditis** than IV drug use, especially with the characteristic signs of repeated venipuncture. - A lung abscess is more likely to be a **sequela** of endocarditis (septic emboli to the lungs) rather than the primary cause of *S. aureus* tricuspid valve endocarditis. *Catheterization of the urinary bladder* - Urinary catheterization can be a risk factor for bacteremia, but it typically leads to **urinary tract infections** and subsequently endocarditis with organisms like **Enterococcus** or gram-negative rods, not typically *Staphylococcus aureus* on the tricuspid valve. - There are no symptoms suggesting a recent **urinary tract infection** in this patient. *Percutaneous nephrostomy for acute ureterolithiasis 5 months ago* - A percutaneous nephrostomy, although an invasive procedure, is less commonly associated with **staphylococcal tricuspid valve endocarditis** than IV drug use. - The timeline of 5 months ago is also a bit remote for directly causing the current, 3-month-onset symptoms unless there was chronic infection associated with the nephrostomy, which is not mentioned. *Adenoidectomy 6 months ago* - An adenoidectomy is a procedure of the lymphatic system that can cause transient bacteremia, but it is not typically associated with **Staphylococcus aureus endocarditis** or tricuspid valve involvement. - The 6-month timeline makes it an unlikely direct cause of the current acute presentation.

Question 962: A 64-year-old man presents to the office for an annual physical examination. He has no complaints at this visit. His chart states that he has a history of hypertension, chronic obstructive pulmonary disease (emphysema), Raynaud’s disease, and glaucoma. He is a 30 pack-year smoker. His medications included lisinopril, tiotropium, albuterol, nifedipine, and latanoprost. The blood pressure is 139/96 mm Hg, the pulse is 86/min, the respiration rate is 16/min, and the temperature is 37.2°C (99.1°F). On physical examination, his pupils are equal, round, and reactive to light. The cardiac auscultation reveals an S4 gallop without murmur, and the lungs are clear to auscultation bilaterally. However, the inspection of the chest wall shows an enlarged anterior to posterior diameter. Which of the following is the most appropriate screening test for this patient?

A. Low-dose CT (Correct Answer)
B. Bronchoalveolar lavage with cytology
C. Magnetic resonance imaging
D. Pulmonary function tests
E. Chest radiograph

Explanation: ***Low-dose CT*** - This patient, a 64-year-old with a 30 pack-year smoking history and current emphysema (COPD), falls precisely within the **high-risk criteria** for lung cancer screening. - The **USPSTF guidelines** recommend annual **low-dose computed tomography (LDCT)** for individuals aged 50-80 years with a 20 pack-year smoking history who currently smoke or have quit within the past 15 years. *Bronchoalveolar lavage with cytology* - This is an **invasive diagnostic procedure** used to collect cells and fluid directly from the airways, typically performed when there is already suspicion of a lung malignancy or infection. - It is not a recommended **screening test** for asymptomatic individuals due to its invasiveness and the absence of clear evidence of benefit as a primary screening tool. *Magnetic resonance imaging* - **MRI** is primarily used for evaluating soft tissue structures, defining tumor extent, and assessing metastatic disease, but it is **not the preferred imaging modality for lung cancer screening** due to its lower spatial resolution for pulmonary nodules compared to CT and higher cost. - It involves longer scan times and is not routinely used for primary lung screening. *Pulmonary function tests* - **PFTs** are used to assess lung function, diagnose and monitor respiratory conditions like COPD, and evaluate the severity of airflow obstruction. - While important for managing his **emphysema**, PFTs do not directly screen for **lung cancer**; they measure how well the lungs work. *Chest radiograph* - A **chest X-ray** is less sensitive than LDCT for detecting small lung nodules and early-stage lung cancer due to its two-dimensional nature and potential for superimposition of structures. - While readily available and less expensive, it is **not recommended for lung cancer screening** as it has not shown a mortality benefit in randomized controlled trials compared to no screening.

Question 963: A 78-year-old man is brought to the emergency department because of a 3-week history of productive cough, swelling of the legs and feet, and fatigue. He has had progressive dyspnea on exertion for the past 2 months. Twelve years ago, he received a porcine valve replacement for severe mitral valve regurgitation. He has coronary artery disease, type 2 diabetes mellitus, and hypertension. He has smoked one pack of cigarettes daily for 60 years and drinks one beer daily. Current medications include aspirin, simvastatin, ramipril, metoprolol, metformin, and hydrochlorothiazide. He appears pale. He is 179 cm (5 ft 9 in) tall and weighs 127 kg (279.9 lb); BMI is 41.3 kg/m2. His temperature is 37.1°C (98.9°F), respirations are 22/min, pulse is 96/min, and blood pressure is 146/94 mm Hg. Bilateral basilar rales are heard on auscultation of the lungs. Cardiac examination shows a laterally displaced apical heartbeat. A grade 3/6, holosystolic murmur is heard over the apex, radiating to the axilla. There is bilateral pitting edema of the feet and ankles. The remainder of the examination shows no abnormalities. Which of the following is the most likely cause of this patient's symptoms?

A. Infective endocarditis
B. Pneumonia
C. Valve degeneration (Correct Answer)
D. Chronic obstructive pulmonary disease
E. Pulmonary embolism

Explanation: ***Valve degeneration*** - The patient has a history of a **porcine mitral valve replacement** 12 years ago. **Bioprosthetic valves** (like porcine valves) typically have a limited lifespan, often degenerating after 10-15 years, leading to **regurgitation** or less commonly stenosis. - The presence of a **grade 3/6 holosystolic murmur** over the apex radiating to the axilla is the classic finding of **mitral regurgitation**, indicating the bioprosthetic valve has degenerated and is now incompetent. - The **bilateral basilar rales**, **peripheral edema**, **laterally displaced apex**, and **progressive dyspnea on exertion** are all classic signs of **left-sided heart failure** caused by severe **mitral regurgitation** from the degenerated valve. - **Bioprosthetic valves most commonly fail by developing regurgitation**, particularly after 10-15 years, making this the most likely diagnosis in this patient with a 12-year-old valve. *Infective endocarditis* - While a possibility in patients with prosthetic valves, **infective endocarditis** typically presents with symptoms such as **fever, new or worsening murmur, and embolic phenomena** (splinter hemorrhages, Janeway lesions, Osler nodes, Roth spots). - The patient is **afebrile** (37.1°C), and the symptoms are more chronic and progressive over 3 weeks to 2 months, rather than the more acute onset often seen with bacterial infections on heart valves. - The absence of fever and other stigmata of endocarditis makes this diagnosis less likely. *Pneumonia* - **Pneumonia** would likely present with more acute symptoms like **high fever, chills, and productive cough with purulent sputum**, along with focal findings on chest auscultation (e.g., bronchial breath sounds, egophony, dullness to percussion). - While he has a productive cough and basilar rales, the dominant features of **progressive dyspnea**, **bilateral peripheral edema**, **laterally displaced apex**, and the specific **mitral regurgitation murmur** point away from primary pneumonia and towards cardiac causes. - The bilateral basilar rales are better explained by pulmonary edema from heart failure rather than infectious consolidation. *Chronic obstructive pulmonary disease* - The patient has a long smoking history (60 pack-years), making **COPD** a likely comorbidity. However, the new prominent **holosystolic cardiac murmur**, **bilateral rales**, and **bilateral peripheral edema** are not typical primary presentations of a COPD exacerbation. - **COPD exacerbations** typically present with increased cough, purulent sputum, and wheezing, but do not cause the cardiac findings (murmur, laterally displaced apex, peripheral edema) seen in this patient. - While chronic dyspnea can occur with COPD, the acute decompensation with clear cardiac signs points to valvular dysfunction. *Pulmonary embolism* - **Pulmonary embolism** usually presents with **acute onset dyspnea, pleuritic chest pain, tachycardia, and sometimes hemoptysis**. - The **progressive nature** of symptoms over 2 months and the prominent cardiac murmur with signs of volume overload (peripheral edema, displaced apex) are not typical for PE. - The absence of acute onset, pleuritic chest pain, and significant risk factors for thromboembolism (recent surgery, prolonged immobility, malignancy) makes this diagnosis unlikely.

Question 964: A 16-year-old girl presents with a sore throat. The patient says symptoms onset acutely 3 days ago and have progressively worsened. She denies any history of cough, nasal congestion or rhinorrhea. No significant past medical history or current medications. The vital signs include: temperature 37.7°C (99.9°F), blood pressure 110/70 mm Hg, pulse 74/min, respiratory rate 20/min, and oxygen saturation 99% on room air. Physical examination is significant for anterior cervical lymphadenopathy. There is edema of the oropharynx and tonsillar swelling but no tonsillar exudate. Which of the following is the next best step in management?

A. Reassurance
B. Empiric treatment with antibiotics
C. Empiric treatment with antivirals
D. Rapid strep test (Correct Answer)
E. Ultrasound of the anterior cervical lymph nodes

Explanation: ***Rapid strep test*** - This patient presents with symptoms suggestive of **Streptococcal pharyngitis (Centor criteria)**, including acute onset sore throat, anterior cervical lymphadenopathy, tonsillar swelling, and absence of cough. A rapid strep test is crucial to confirm the diagnosis and guide antibiotic therapy. - While tonsillar exudates are often present in strep throat, their absence does not rule out the diagnosis, especially given the other strong indicators. *Reassurance* - Reassurance alone is insufficient given the patient's symptoms are highly suggestive of a **bacterial infection** that could lead to serious complications if left untreated. - Untreated **Streptococcal pharyngitis** can lead to complications such as acute rheumatic fever and peritonsillar abscess. *Empiric treatment with antibiotics* - Empiric antibiotic treatment without confirmation can contribute to **antibiotic resistance** and is not the best approach when a diagnostic test is readily available. - Without a positive rapid strep test, the patient could be unnecessarily exposed to antibiotics, potentially leading to **adverse drug reactions** or masking other underlying conditions. *Empiric treatment with antivirals* - The patient's symptoms are more consistent with a **bacterial infection** (strep throat) rather than a viral illness that would benefit from antiviral treatment. - Antivirals are generally reserved for specific viral infections like influenza or herpes, and there is no indication for their use in this clinical scenario. *Ultrasound of the anterior cervical lymph nodes* - While the patient has **anterior cervical lymphadenopathy**, this is a common finding in pharyngitis and an ultrasound is not necessary as a first step to diagnose the cause of a sore throat. - Imaging of the lymph nodes would be considered if there were concerns for an **abscess** or malignancy, which are not suggested by the current presentation.

Question 965: A 43-year-old woman comes to the physician for a 3-month history of redness and itching in both eyes. She has also had swelling and pain in the index and middle fingers of both hands and wrist joints over the past 5 months. She has had multiple dental treatments for oral infections over the past year. She has type 2 diabetes mellitus and eczema. Her sister has vitiligo. Current medications include metformin and a daily multivitamin. Vital signs are within normal limits. Examination shows lichenified lesions over her wrists and knees. Bilateral wrist and first metacarpophalengeal joints show swelling and tenderness; range of motion is limited by pain. Oropharyngeal examination shows dry mucous membranes and multiple dental caries. Visual acuity is slightly decreased in both eyes. There are multiple corneal punctate spots on fluorescein staining. Laboratory studies show: Hemoglobin 10.7 g/dL Leukocyte count 4,100/mm3 Platelet count 155,000/mm3 Erythrocyte sedimentation rate 48 mm/h Serum Creatinine 1.0 mg/dL Anti-nuclear antibody positive Rheumatoid factor positive Urinalysis is within normal limits. This patient's condition is most likely associated with which of the following antibodies?

A. Anti-Jo1 antibodies
B. Anti-topoisomerase I antibodies
C. Anti-Ro antibodies (Correct Answer)
D. Anti-dsDNA antibodies
E. Anti-U1 RNP antibodies

Explanation: ***Anti-Ro antibodies*** - The patient exhibits classic symptoms of **Sjogren's syndrome**, including **dry eyes** (redness, itching, corneal punctate spots), **dry mouth** (multiple dental caries, dry mucous membranes), and **arthralgia/arthritis** (swelling and pain in fingers and wrists). - **Anti-Ro/SSA antibodies** are highly specific for Sjogren's syndrome, making this the most likely associated antibody. *Anti-Jo1 antibodies* - These antibodies are characteristic of **polymyositis** and **dermatomyositis**, which primarily present with **proximal muscle weakness** and specific skin rashes (e.g., heliotrope rash, Gottron's papules). - While arthritis can occur, the prominent dry eyes and mouth, coupled with dental issues, are not typical for these conditions. *Anti-topoisomerase I antibodies* - Also known as anti-Scl-70 antibodies, these are strongly associated with **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form. - Scleroderma is characterized by **skin thickening** and **fibrosis** of internal organs, which are not described in this patient's presentation. *Anti-dsDNA antibodies* - These antibodies are highly specific for **Systemic Lupus Erythematosus (SLE)** and are often associated with **lupus nephritis**. - While SLE can cause arthritis and dry eyes/mouth, the overall clinical picture with prominent sicca symptoms points more strongly to Sjogren's in the absence of other SLE features like malar rash, serositis, or significant renal involvement. *Anti-U1 RNP antibodies* - These antibodies are characteristic of **Mixed Connective Tissue Disease (MCTD)**, which features overlapping symptoms of SLE, scleroderma, and polymyositis. - While some features like arthritis and perhaps mild sicca symptoms could occur, the isolated and prominent sicca complex described here and the absence of clear features from other conditions makes Sjogren's a more direct fit.

Question 966: A 43-year-old man presents to his primary care physician for his yearly check-up exam. He has no new concerns but wants to make sure that his hypertension and diabetes are properly controlled. His past medical history is otherwise unremarkable and his only medications are metformin and lisinopril. He has smoked a pack of cigarettes per day since he was 16 years of age and drinks 3 beers per night. Physical exam is remarkable for a murmur best heard in the 5th intercostal space at the left mid-clavicular line. The murmur is high-pitched and blowing in character and can be heard throughout systole. Which of the following properties is characteristic of this patient's most likely disorder?

A. Radiation of murmur to the axilla (Correct Answer)
B. Results in mixing of blood between left and right ventricles
C. Radiation of murmur to the right sternal border
D. Presents with an opening snap
E. Radiation of murmur to the neck

Explanation: ***Radiation of murmur to the axilla*** - The patient's presentation of a **systolic murmur** best heard at the **5th intercostal space at the left mid-clavicular line** (the apex) strongly suggests **mitral regurgitation**. - A characteristic feature of **mitral regurgitation** is the **radiation of the murmur to the axilla**. *Results in mixing of blood between left and right ventricles* - This describes a **ventricular septal defect (VSD)**, which presents with a holosystolic murmur typically loudest at the **left sternal border** and not the apex. - While VSD is a systolic murmur, its location and consequence of intracardiac shunting differ from the described clinical picture. *Radiation of murmur to the right sternal border* - This type of radiation is commonly associated with benign flow murmurs or sometimes **tricuspid regurgitation**, though tricuspid regurgitation is typically heard loudest at the **lower left sternal border** and increases with inspiration. - It is not characteristic of a murmur heard best at the apex with the described qualities. *Presents with an opening snap* - An **opening snap** is a characteristic finding of **mitral stenosis**, which is a **diastolic murmur**, not a systolic murmur as described in the patient. - The murmur in this patient is heard throughout systole, ruling out mitral stenosis. *Radiation of murmur to the neck* - Radiation to the neck is a classic feature of **aortic stenosis**, which is typically a **systolic ejection murmur** heard best at the **right upper sternal border**, radiating to the carotid arteries. - This differs significantly from a murmur heard maximally at the apex.

Question 967: A 59-year-old woman comes to the physician because of progressively worsening coordination and involuntary movements in her left hand for the past 6 months. Her husband also reports that she has been withdrawn and apathetic during this period. She is oriented to time, place, and person. Examination shows a bimanual, rhythmic, low-frequency tremor that is more prominent in the left hand. There is normal range of motion in the arms and legs; active movements are very slow. Muscle strength is normal, and there is increased resistance to passive flexion and extension in the limbs. She walks with a shuffling gait and takes small steps. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Proliferation of beta-adrenergic receptors from excessive circulating T4
B. Neuronal degeneration due to α-synuclein protein misfolding (Correct Answer)
C. Accumulation of neurotoxic metabolites secondary to hepatocyte damage
D. Copper accumulation due to mutations in hepatocyte copper-transporting ATPase
E. Cerebellar ischemia due to chronic hypertension

Explanation: ***Neuronal degeneration due to α-synuclein protein misfolding*** - This describes **Parkinson's disease (PD)**, characterized by the degeneration of dopaminergic neurons in the **substantia nigra** due to the accumulation of misfolded **α-synuclein** into Lewy bodies. - The patient's symptoms—**bradykinesia (slow movements), resting tremor (rhythmic, low-frequency tremor), rigidity (increased resistance to passive movement), and shuffling gait**—are classic signs of PD. Apathy and withdrawal are common non-motor symptoms. *Proliferation of beta-adrenergic receptors from excessive circulating T4* - This describes symptoms of **hyperthyroidism**, which can cause a fine tremor, but not the **low-frequency resting tremor** and **rigidity** seen in this patient. - Hyperthyroidism is also associated with weight loss, heat intolerance, and tachycardia, which are not mentioned. *Accumulation of neurotoxic metabolites secondary to hepatocyte damage* - This is characteristic of **hepatic encephalopathy**, which presents with altered mental status, asterixis (flapping tremor), and generalized slowness. - However, the patient's specific motor symptoms like **rigidity, shuffling gait**, and a distinct **resting tremor** are not typical features of hepatic encephalopathy. *Copper accumulation due to mutations in hepatocyte copper-transporting ATPase* - This describes **Wilson's disease**, an inherited disorder of copper metabolism. It can cause neurological symptoms, including tremor, dystonia, and ataxia, along with liver disease. - However, the patient's age (59 years) and the specific presentation of a **resting tremor, bradykinesia, and rigidity** are more consistent with Parkinson's disease than Wilson's, which typically presents in younger individuals. *Cerebellar ischemia due to chronic hypertension* - **Cerebellar ischemia** would lead to **ataxia, dysarthria, and intention tremor**, which is a tremor that worsens with voluntary movement, unlike the **resting tremor** observed in this patient. - **Rigidity and bradykinesia** are not primary symptoms of cerebellar lesions.

Question 968: A 56-year-old woman presents to the emergency department with severe pain in her legs. She has had these pains in the past but access to a doctor was not readily available in her remote village back home. She and her family have recently moved to the United States. She is seen walking to her stretcher with a broad-based gait. Ophthalmic examination shows an absent pupillary light reflex, and pupillary constriction with accommodation and convergence. What other sign or symptom is most likely present in this patient?

A. Painless ulcerated papules
B. Negative Romberg sign
C. Deep tendon hyperreflexia
D. Bell's Palsy
E. Loss of vibration sensation (Correct Answer)

Explanation: ***Loss of vibration sensation*** - The patient's presentation with **severe leg pain** (tabes dorsalis), a **broad-based gait** (sensory ataxia), and **Argyll Robertson pupils** (absent pupillary light reflex but present accommodation reflex) are classic signs of **neurosyphilis**. - **Demyelination** of the dorsal columns in the spinal cord, characteristic of neurosyphilis, specifically impairs **proprioception** and **vibration sensation**. *Painless ulcerated papules* - **Painless chancres** are typically associated with **primary syphilis**, an earlier stage of the disease, and would likely have resolved by the time neurosyphilis manifests. - While syphilis causes lesions, **ulcerated papules** are not a direct manifestation of **neurosyphilis** itself. *Negative Romberg sign* - A **positive Romberg sign** is typically observed in patients with **sensory ataxia** due to impaired proprioception, which is present in neurosyphilis. - A **negative Romberg sign** would indicate intact proprioception, which contradicts the clinical picture of **broad-based gait** and the underlying pathology. *Deep tendon hyperreflexia* - **Tabes dorsalis** (a form of neurosyphilis) is characterized by **degeneration of the dorsal columns and dorsal roots**, leading to **hyporeflexia** or **areflexia** (absent deep tendon reflexes), not hyperreflexia. - **Hyperreflexia** would suggest an **upper motor neuron lesion**, which is not the primary pathology in this presentation. *Bell's Palsy* - **Bell's palsy** is an **idiopathic facial nerve paralysis** and is not a specific or most likely symptom of neurosyphilis. - While syphilis can cause cranial neuropathies, including facial nerve involvement, the defining features in this case point more strongly to **tabes dorsalis** rather than cranial nerve palsy as the most likely additional symptom.

Question 969: A 52-year-old man comes to the physician for a routine health maintenance examination. He has not seen a physician for 10 years. He works as a telemarketer and does not exercise. Cardiac examination shows a dull, low-pitched sound during late diastole that is best heard at the apex. The sound is loudest in the left lateral decubitus position and during end-expiration. Which of the following is the most likely cause of this finding?

A. Fusion of mitral valve leaflets
B. Dilation of both ventricles
C. Concentric left ventricular hypertrophy (Correct Answer)
D. Aortic root dilatation
E. Right bundle branch block

Explanation: ***Concentric left ventricular hypertrophy*** - The described **dull, low-pitched sound** during **late diastole**, best heard at the apex in the left lateral decubitus position and during end-expiration, is consistent with a **S4 gallop**. - An **S4 heart sound** is caused by the **atrial kick** into a **stiff, non-compliant ventricle**, which is characteristic of **concentric left ventricular hypertrophy** due to long-standing hypertension or aortic stenosis. *Fusion of mitral valve leaflets* - This condition, known as **mitral stenosis**, typically causes a **mid-diastolic rumble** with an opening snap, not an S4 sound. - The associated murmur would be loudest closer to the S2 sound and might have a snapping quality. *Dilation of both ventricles* - **Dilated cardiomyopathy** with compromised systolic function can lead to an **S3 gallop** (early diastolic sound) due to rapid ventricular filling into an already overloaded ventricle. - It does not typically cause an S4 sound, which is associated with ventricular stiffness. *Aortic root dilatation* - This can lead to **aortic regurgitation**, which is typically characterized by an **early diastolic decrescendo murmur** heard best at the left sternal border. - It is not associated with an S4 sound. *Right bundle branch block* - A **right bundle branch block (RBBB)** is an electrical conduction abnormality that results in a **widely split S2 heart sound** due to delayed pulmonic valve closure. - It does not directly produce an S4 sound, which is a mechanical event related to ventricular compliance.

Question 970: A 33-year-old woman comes to the physician because of a 3-week history of fatigue and worsening shortness of breath on exertion. There is no family history of serious illness. She does not smoke. She takes diethylpropion to control her appetite and, as a result, has had a 4.5-kg (10-lb) weight loss during the past 5 months. She is 163 cm (5 ft 4 in) tall and weighs 115 kg (254 lb); BMI is 44 kg/m2. Her pulse is 83/min and blood pressure is 125/85 mm Hg. Cardiac examination shows a loud pulmonary component of the S2. Abdominal examination shows no abnormalities. Which of the following is the most likely underlying cause of this patient's shortness of breath?

A. Hypertrophy of interventricular septum
B. Calcification of the pulmonary valve
C. Blockade of the right bundle branch
D. Hyperplasia of pulmonary vascular walls (Correct Answer)
E. Fibrosis of pulmonary interstitium

Explanation: ***Hyperplasia of pulmonary vascular walls*** - **Diethylpropion** is an anorectic agent (appetite suppressant) that, like fenfluramine derivatives, is associated with **drug-induced pulmonary arterial hypertension (PAH)**. - The mechanism involves **hyperplasia and remodeling of pulmonary vascular walls** (medial hypertrophy, intimal proliferation), leading to increased pulmonary vascular resistance. - This manifests clinically as a **loud pulmonary component of S2** (loud P2 from elevated pulmonary artery pressure) and **exertional dyspnea** due to right ventricular strain and reduced cardiac output. - The patient's **obesity** is an additional risk factor for developing pulmonary hypertension. *Hypertrophy of interventricular septum* - While obesity can lead to **cardiac remodeling**, isolated interventricular septal hypertrophy without other signs of hypertrophic cardiomyopathy is less likely to be the primary cause of these symptoms. - This condition is often associated with **genetic mutations** or severe, longstanding **systemic hypertension**, not specifically linked to diethylpropion or the loud P2 finding. *Calcification of the pulmonary valve* - **Pulmonary valve calcification** leading to significant stenosis is rare in adults, particularly in a 33-year-old with no history of congenital heart disease or rheumatic fever. - This would typically cause a systolic ejection murmur, which is not described in this case. *Blockade of the right bundle branch* - A **right bundle branch block (RBBB)** is an electrical conduction abnormality that does not directly cause shortness of breath or a loud P2. - While RBBB can be associated with right ventricular strain from pulmonary hypertension, it is a consequence or co-occurring finding, not the underlying pathophysiologic cause. *Fibrosis of pulmonary interstitium* - **Pulmonary interstitial fibrosis** would typically be suggested by a history of autoimmune disease, environmental exposures, or specific drug toxicities (diethylpropion is not a common cause). - It would often present with **bibasilar crackles** on lung auscultation and characteristic findings on chest imaging, none of which are mentioned in this case.

Question 971: A 25-year-old woman with bipolar disorder and schizophrenia presents to the emergency room stating that she is pregnant. She says that she has been pregnant since she was 20 years old and is expecting a baby now that she is breathing much harder and feeling more faint with chest pain caused by deep breaths. Her hospital medical record shows multiple negative pregnancy tests over the past 5 years. The patient has a 20 pack-year smoking history. Her temperature is 98°F (37°C), blood pressure is 100/60 mmHg, pulse is 110/min, respirations are 28/min, and oxygen saturation is 90% on room air. Her fingerstick glucose is 100 mg/dL. She has a large abdominal pannus which is soft and nontender. Her legs are symmetric and non-tender. Oxygen is provided via nasal cannula. Her urine pregnancy test comes back positive and an initial chest radiograph is unremarkable. What is the next best step in diagnosis?

A. Ultrasound
B. D-dimer
C. Ventilation-perfusion scan (Correct Answer)
D. CT angiogram
E. Psychiatry consult for pseudocyesis

Explanation: ***Ventilation-perfusion scan*** - The patient presents with **dyspnea, chest pain exacerbated by deep breaths, tachypnea, tachycardia**, and **hypoxia**, all suggestive of a **pulmonary embolism (PE)**. Despite a positive pregnancy test, the long history of claimed pregnancy without prior confirmation and an unremarkable chest X-ray prioritizes immediate investigation for PE. - While other imaging modalities exist, a **V/Q scan** is a safer initial choice for evaluating PE in pregnant patients compared to a CT angiogram, as it involves less radiation exposure to the fetus, especially when the chest X-ray is normal. *Ultrasound* - An ultrasound would confirm **intrauterine pregnancy** and fetal viability, but it would not address the patient's acute respiratory symptoms or rule out a life-threatening pulmonary embolism. - While important for obstetrical management, it is not the most immediate next step for the patient's acute respiratory distress. *D-dimer* - A D-dimer test can be **falsely elevated in pregnancy**, making it less reliable for ruling out acute pulmonary embolism in this context. - While a negative D-dimer can rule out PE in low-risk patients, a positive D-dimer is nonspecific during pregnancy and would not definitively confirm or exclude PE in this symptomatic patient. *CT angiogram* - A **CT pulmonary angiogram (CTPA)** is highly sensitive for PE but involves a higher radiation dose to the fetus compared to a V/Q scan. - Given the patient's acute symptoms and the availability of a less invasive imaging option (V/Q scan) for PE in pregnant patients with a normal chest X-ray, CTPA is typically reserved if a V/Q scan is nondiagnostic or unavailable. *Psychiatry consult for pseudocyesis* - While the patient's history of claiming pregnancy for years and her psychiatric conditions (bipolar and schizophrenia) raise suspicion for **pseudocyesis (false pregnancy)**, her current positive urine pregnancy test means a true pregnancy cannot be immediately ruled out. - Addressing her acute respiratory symptoms and potential pulmonary embolism takes precedence over a psychiatric consultation, as PE is a medical emergency.

Question 972: A 75-year-old man is brought to the emergency department 20 minutes after an episode of being unconscious. He was playing with his 3-year-old granddaughter when he suddenly fell down and was unresponsive for 1-minute. He responded normally after regaining consciousness. He has had episodes of mild chest pain and abdominal discomfort for the past 2 months, especially while working on his car. He has hypertension treated with hydrochlorothiazide. He appears alert. His temperature is 37.1°C (98.8°F), pulse is 89/min and regular, and blood pressure is 110/88 mm Hg. Examination shows a 3/6 crescendo-decrescendo systolic ejection murmur at the right sternal border that radiates to the carotids. There is no swelling or erythema of the lower extremities. Neurologic examination shows no focal findings. Which of the following is the most likely cause of this patient's symptoms?

A. Fibrosis of the sinus node
B. Asymmetric septal hypertrophy
C. Rupture of the chordae tendineae
D. Embolus in the pulmonary artery
E. Calcification of the aortic valve (Correct Answer)

Explanation: ***Calcification of the aortic valve*** - The patient's presentation with **syncope** following exertion, combined with a **late systolic murmur radiating to the carotids**, is highly suggestive of **aortic stenosis**. - In an elderly patient, the most common cause of aortic stenosis is **degenerative calcification of the aortic valve**. *Fibrosis of the sinus node* - **Sick sinus syndrome** due to fibrosis of the sinus node typically causes bradycardia, pauses, or tachy-brady syndrome. - While it can cause syncope, it wouldn't explain the characteristic **cardiac murmur** described in the patient. *Asymmetric septal hypertrophy* - **Hypertrophic obstructive cardiomyopathy (HOCM)** can cause syncope and a systolic murmur, but the murmur typically **increases with Valsalva** and is due to dynamic outflow tract obstruction. - HOCM commonly presents at a younger age and lacks the strong association with a **late systolic murmur radiating to the carotids** seen in aortic stenosis. *Rupture of the chordae tendineae* - Rupture of the chordae tendineae primarily affects the **mitral valve**, leading to acute **mitral regurgitation**. - This would typically present with a **holosystolic murmur** best heard at the apex and signs of acute heart failure, which are not depicted in this case. *Embolus in the pulmonary artery* - A pulmonary embolus would cause sudden onset **dyspnea, pleuritic chest pain, and hypoxemia**, with potential for syncope due to right heart strain. - It would not explain the **cardiac murmur** and history of exertional chest pain and abdominal discomfort observed over months.

Question 973: A 56-year-old man comes to the clinic complaining of back pain for the past 1 month. The pain is described as a dull ache that intensifies intermittently to an 8/10 in severity about 1-2 times a day. It intensified about 2 weeks ago following a fall during a ski trip. He reports that he noticed some pain at his buttocks and lower back following the fall but he wasn’t bothered by it. Hot packs and Tylenol seem to alleviate the pain somewhat. He denies lower extremity weakness, loss of sensation, fever, incontinence, or prior cancers; however, he reveals that his cousin was recently diagnosed with prostate cancer. Physical examination demonstrates normal range of motion and diffuse tenderness at the L4/L5 region with no point tenderness or vertebral step-offs. What is the next best step in the management of this patient?

A. Exercise therapy with NSAIDs/acetaminophen (Correct Answer)
B. Morphine as needed
C. Back bracing
D. Bed rest with return to activity in 1 week
E. Radiograph of lumbar spine

Explanation: ***Exercise therapy with NSAIDs/acetaminophen*** - This patient presents with acute **non-radicular low back pain** with no red flags (fever, weakness, saddle anesthesia, incontinence) or signs of specific underlying pathology (no vertebral step-offs or point tenderness suggesting fracture). - For such cases, **conservative management** including exercise, maintaining activity, and pain relief with NSAIDs or acetaminophen is the first-line treatment. *Morphine as needed* - **Opioids like morphine** are generally avoided as first-line treatment for acute low back pain due to risks of dependence and limited long-term efficacy compared to other modalities. - Their use is typically reserved for severe, intractable pain unresponsive to less potent analgesics, and under careful consideration. *Back bracing* - **Back bracing** is not recommended for acute non-specific low back pain, as it can lead to muscle deconditioning and does not accelerate recovery. - Braces may be considered in specific cases like spinal fractures or post-operative stabilization, which are not suggested here. *Bed rest with return to activity in 1 week* - **Prolonged bed rest** is largely discouraged for acute low back pain because it can lead to deconditioning, stiffness, and delayed recovery. - Current guidelines emphasize maintaining **activity as tolerated** and early mobilization to prevent chronicity. *Radiograph of lumbar spine* - **Imaging (radiographs)** is generally not indicated for acute low back pain without specific red flags (e.g., suspicious for fracture, infection, malignancy) because it rarely changes management in uncomplicated cases. - The patient has no neurological deficits, history of cancer, or signs of fracture, making immediate imaging unnecessary.

Question 974: A 32-year-old man comes to the emergency department because of sharp chest pain for 3 days. The pain is retrosternal, 8 out of 10 in intensity, increases with respiration, and decreases while sitting upright and leaning forward. He has nausea and myalgia. He has not had fever or a cough. He has asthma and was treated for bronchitis 6 months ago with azithromycin. His mother has hypertension. He uses an over-the-counter inhaler. His temperature is 37.3°C (99.1°F), pulse is 110/min, and blood pressure is 130/84 mm Hg. Breath sounds are normal. Cardiac examination shows a high-pitched grating sound between S1 and S2. The remainder of the examination shows no abnormalities. Serum studies show: Urea nitrogen 16 mg/dl Glucose 103 mg/dL Creatinine 0.7 mg/dL Troponin I 0.230 ng/mL (N < 0.1 ng/mL) An ECG shows diffuse ST elevations in all leads. The patient is at increased risk for which of the following conditions?

A. Cardiac tamponade (Correct Answer)
B. Papillary muscle rupture
C. Pulmonary infarction
D. Ventricular aneurysm
E. Mediastinitis

Explanation: ***Cardiac tamponade*** - The patient's symptoms (sharp chest pain relieving with sitting upright and leaning forward, pericardial friction rub on exam, diffuse ST elevations on ECG, and elevated troponin) are highly suggestive of **acute pericarditis**. - **Cardiac tamponade** is a serious complication of pericarditis, occurring when excessive fluid accumulation in the pericardial sac compresses the heart, impairing its filling and leading to hemodynamic compromise. *Papillary muscle rupture* - **Papillary muscle rupture** is typically a complication of acute myocardial infarction, leading to severe **mitral regurgitation** and acute heart failure. - The patient's ECG shows diffuse ST elevations, not localized changes indicative of transmural infarction, and there is no mention of a new murmur or signs of heart failure. *Pulmonary infarction* - **Pulmonary infarction** usually presents with pleuritic chest pain, dyspnea, and hemoptysis, often in the context of a **pulmonary embolism**. - The patient's current presentation, including the characteristic pain relief with leaning forward and the ECG findings, is not consistent with pulmonary infarction. *Ventricular aneurysm* - A **ventricular aneurysm** is a late complication of a transmural myocardial infarction, typically manifesting weeks to months after the event with persistent ST elevation on ECG in the affected leads. - While there are diffuse ST elevations, the acute onset of symptoms and pericardial rub point away from a chronic complication like a ventricular aneurysm. *Mediastinitis* - **Mediastinitis** is a severe infection of the mediastinum, often presenting with fever, severe chest pain (usually constant), and systemic signs of infection. - The patient is afebrile, and his chest pain characteristics, physical exam (pericardial rub), and ECG findings are not typical for mediastinitis.

Question 975: A 70-year-old man presents to the clinic with right-sided chest pain and difficulty breathing for the past 10 days. When it began, the pain was mild, but as time went on, it increased to a level at which the man found it difficult to breathe. Two years ago, he was diagnosed with clear cell carcinoma of the kidney. Vital signs include: pulse rate is 72/min, blood pressure is 122/80 mm Hg, respiratory rate is 16/min, and temperature is 37.0°C (98.6°F). On physical examination, the trachea appears to have deviated to the left, respiratory movements are diminished, there is decreased resonance on percussion, and there is an absence of breath sounds over the right hemithorax. Which of the following is the most likely clinical diagnosis in this patient?

A. Atelectasis
B. Pneumothorax
C. Pleural effusion (Correct Answer)
D. Pulmonary embolism
E. Pneumonia

Explanation: **Pleural effusion** - The presence of **chest pain**, **dyspnea**, **tracheal deviation away from the affected side**, diminished respiratory movements, **decreased resonance on percussion**, and absence of breath sounds are classic signs of a large **pleural effusion**. - The patient's history of **clear cell carcinoma** of the kidney suggests a metastatic cause, like **malignant pleural effusion**, contributing to the progressive symptoms. *Atelectasis* - While atelectasis presents with **dyspnea** and **decreased breath sounds**, the trachea typically deviates **towards the affected side** due to volume loss, which contradicts the presented leftward deviation. - Percussion in atelectasis would typically yield **dullness**, but not necessarily decreased resonance with the degree of tracheal shift seen in a large effusion. *Pneumothorax* - A pneumothorax would present with **hyperresonance on percussion** due to air accumulation, not decreased resonance. - Tracheal deviation in a tension pneumothorax would be **away from the affected side**, but the characteristic percussion finding differentiates it from pleural effusion. *Pulmonary embolism* - Pulmonary embolism primarily causes **acute dyspnea** and **pleuritic chest pain**, but typically does not produce the pronounced physical exam findings of tracheal deviation, decreased resonance, and absent breath sounds associated with a large space-occupying lesion in the pleural space. - While it can cause a small pleural effusion, the extensive findings point against PE as the primary diagnosis. *Pneumonia* - Pneumonia presents with **fever**, **cough**, and usually **bronchial breath sounds** or **crackles** over the affected area, with **dullness to percussion**. - It does not typically cause significant tracheal deviation, nor the complete absence of breath sounds over an entire hemithorax.

Question 976: A 66-year-old white man comes to the physician because of a 10-day history of fatigue and lower leg swelling. Over the past 6 months, he has had a 3.6-kg (8-lb) weight loss. He has chronic bronchitis and uses an albuterol inhaler as needed. He has smoked one pack of cigarettes daily for 44 years and drinks one alcoholic beverage daily. His temperature is 37°C (98.6°F), pulse is 88/min, and blood pressure is 120/75 mm Hg. He appears thin. Examination shows 2+ pretibial edema bilaterally. Cardiopulmonary examination shows no abnormalities. Laboratory studies show: Hemoglobin 11.2 g/dL Leukocyte count 8500/mm3 Platelet count 130,000/mm3 Serum Urea nitrogen 23 mg/dL Glucose 77 mg/dL Creatinine 1.6 mg/dL Albumin 1.8 mg/dL Total cholesterol 475 mg/dL Urine Blood negative Glucose negative Protein 4+ WBC 0–1/hpf Fatty casts numerous An x-ray of the chest shows a right upper lobe density. A CT scan of the chest shows a 2.5 x 3.5 x 2-cm right upper lobe mass. Which of the following is the most likely diagnosis?

A. Thin basement membrane disease
B. Granulomatosis with polyangiitis
C. Rapidly progressive glomerulonephritis
D. Membranous nephropathy (Correct Answer)
E. Focal segmental glomerulosclerosis

Explanation: ***Membranous nephropathy*** - This patient presents with signs of **nephrotic syndrome**: pronounced **proteinuria (4+)**, **hypoalbuminemia** (1.8 mg/dL), **hyperlipidemia** (total cholesterol 475 mg/dL), and **edema**. - The chest x-ray and CT findings of a **right upper lobe mass** in a long-term smoker raise suspicion for a **paraneoplastic syndrome**, with **membranous nephropathy** being a common cause of nephrotic syndrome associated with solid tumors, particularly lung cancer. *Thin basement membrane disease* - This condition is typically associated with **microscopic hematuria** but usually **not significant proteinuria** leading to nephrotic syndrome. - It is often asymptomatic or presents with recurrent hematuria, not the systemic symptoms of nephrotic syndrome seen here. *Granulomatosis with polyangiitis* - This is a **vasculitis** often affecting the kidneys, presenting as **rapidly progressive glomerulonephritis** with hematuria, red cell casts, and mild proteinuria. - It would typically cause **systemic vasculitic symptoms** (e.g., upper and lower respiratory tract involvement, skin lesions), and the proteinuria would not typically be in the nephrotic range. *Rapidly progressive glomerulonephritis* - Characterized by **rapid decline in renal function** and a **nephritic urine sediment** (hematuria, red cell casts, mild proteinuria), not nephrotic-range proteinuria with fatty casts. - While lung involvement can occur (e.g., Goodpasture syndrome, vasculitis), the presentation here is strongly indicative of nephrotic syndrome. *Focal segmental glomerulosclerosis* - While it causes **nephrotic syndrome**, it does not typically present with a clear **underlying malignancy** as a paraneoplastic manifestation. - The presence of a lung mass strongly suggests a secondary cause for the glomerulopathy, making membranous nephropathy a more direct fit.

Question 977: A 17-year-old African-American male presents to his family physician after noticing red-tinged urine the week before, when he was suffering from a cold. The patient states that he had experienced that before. His father is with him and says that this happens to him on occasion as well. What is the most likely diagnosis for this patient?

A. Hemophilia
B. Sickle cell trait (Correct Answer)
C. Acute interstitial nephritis
D. Acute glomerulonephritis
E. Acute cystitis

Explanation: ***Sickle cell trait*** - Patients with **sickle cell trait** (heterozygous for the sickle hemoglobin gene) can experience recurrent, painless **hematuria**, especially under conditions of low oxygen tension or dehydration, as seen during a **cold** or illness. - The patient's **African-American ethnicity**, the recurrent nature of the hematuria often triggered by illness, and a positive **family history** strongly suggest sickle cell trait, which is typically benign but can manifest with hematuria. *Hemophilia* - Hemophilia causes **spontaneous bleeding** into joints, muscles, and internal organs, and while it can cause hematuria, the presentation is typically more severe, with prolonged bleeding episodes rather than isolated, red-tinged urine during a cold. - Hemophilia is an **X-linked recessive disorder** affecting primarily males, but the characteristic symptoms of **easy bruising** or **prolonged bleeding** from minor cuts are not mentioned, and sickle cell trait is a more common cause of painless hematuria in this demographic. *Acute interstitial nephritis* - **Acute interstitial nephritis** typically presents with acute kidney injury, fever, rash, and eosinophilia, often triggered by drugs (e.g., NSAIDs, antibiotics) or infections. - The isolated, recurrent **hematuria** associated with a cold and a family history makes this diagnosis less likely, as it primarily involves inflammation of the renal tubules and interstitium. *Acute glomerulonephritis* - **Acute glomerulonephritis** often presents with hematuria, proteinuria, edema, hypertension, and reduced GFR, usually occurring **7-10 days after a strep infection** (post-streptococcal glomerulonephritis) or immediately after a concurrent infection (IgA nephropathy). - While **IgA nephropathy** can present with gross hematuria during a cold, its recurrent nature in multiple family members points more towards an underlying genetic predisposition like sickle cell trait, also the patient's symptoms are generally milder and resolve quickly in sickle cell trait compared to glomerulonephritis. *Acute cystitis* - **Acute cystitis** is a **urinary tract infection** that typically causes dysuria, frequency, urgency, and suprapubic pain, in addition to hematuria. - The lack of other urinary symptoms, the recurrent nature associated with illness, and the family history make a simple infection like cystitis less likely as the primary diagnosis.

Question 978: An 80-year-old male with known metastatic prostate cancer presents to your office with vague complaints of "achy bones." Strangely, he refers to you using the name of another physician. On physical exam, he is afebrile, but mildly tachycardic at 100 beats/min. Mucous membranes are dry. Cardiac exam shows regular rhythm and no murmurs. The patient has diffuse, nonfocal abdominal pain. He cannot articulate the correct date. You check the patient's serum calcium level, which is found to be 15.3 mg/dL. What is the best next step in management?

A. Calcitonin
B. Intravenous normal saline (Correct Answer)
C. Furosemide
D. Pamidronate
E. Hemodialysis

Explanation: ***Intravenous normal saline*** - The patient exhibits classic symptoms of **hypercalcemia** (vague bone aches, confusion, dry mucous membranes, tachycardia, diffuse nonfocal abdominal pain) in the context of metastatic prostate cancer and a severely elevated serum calcium level of 15.3 mg/dL. - **Volume expansion with intravenous normal saline** is the initial and most crucial step in managing severe hypercalcemia, as it helps to restore hydration and promote renal calcium excretion. *Calcitonin* - **Calcitonin** can rapidly lower serum calcium by inhibiting osteoclastic bone resorption and increasing renal calcium excretion, but its effect is typically transient and less potent than initial hydration. - It is often used as an adjunct to saline and bisphosphonates, especially in cases where a rapid but temporary decrease in calcium is needed. *Furosemide* - **Furosemide** (a loop diuretic) should only be considered *after* adequate volume repletion has been achieved, as it can worsen dehydration and electrolyte abnormalities if given prematurely. - It works by inhibiting calcium reabsorption in the loop of Henle, but **dehydration must be corrected first** to ensure effective GFR and avoid electrolyte imbalance. *Pamidronate* - **Pamidronate** (a bisphosphonate) is a potent inhibitor of osteoclast-mediated bone resorption and is effective in long-term management of hypercalcemia of malignancy. - However, its onset of action is slow (2-4 days) and therefore it is not the best *initial step* for acutely symptomatic and severely hypercalcemic patients. *Hemodialysis* - **Hemodialysis** is reserved for severe, refractory hypercalcemia, particularly in patients with **renal failure** who cannot handle large fluid loads or excrete calcium effectively. - While effective, it is an invasive procedure and not typically the first-line treatment for hypercalcemia of malignancy in a patient with presumably intact renal function capable of responding to hydration.

Question 979: A 12-year-old boy is brought by his mother to the emergency room because of a swollen, hot, and tender knee that he sustained after falling on his way home. He has never had a swollen joint before; however, he has had frequent nosebleeds throughout his life. His mother is worried because they live with her parents who are currently on blood thinners. Every morning she puts the blood thinner pill in the boy's grandfather's milk and was concerned that she may have switched it this morning. Family history reveals a number of uncles who have had bleeding disorders; however, the mother does not know the exact disorder suffered by these relatives. A hematologic panel reveals the following findings: Bleeding time: Increased Prothrombin time: 12 seconds Partial thromboplastin time (PTT): 55 seconds PTT after factor mixing study: 37 seconds Which of the following most likely explains the abnormal partial thromboplastin time in this patient?

A. Inhibition of reductase enzyme
B. Antibodies to factor VIII
C. Activation of inhibitory factors
D. Mutation in factor VIII
E. Mutation in carrying protein (Correct Answer)

Explanation: ***Mutation in carrying protein*** - This scenario describes **von Willebrand disease**, characterized by an **increased bleeding time** and an **elevated PTT** that corrects with a mixing study. The **mutation in the von Willebrand factor (vWF) protein**, which carries and protects factor VIII, leads to its rapid degradation. - The **normal PT** rules out common pathway or extrinsic pathway coagulation defects, while the prolonged PTT points to an intrinsic pathway issue. The family history of bleeding disorders and frequent nosebleeds further supports this diagnosis, as vWF is essential for **platelet adhesion** and stabilizing factor VIII. *Inhibition of reductase enzyme* - Inhibition of the **reductase enzyme** (specifically **vitamin K epoxide reductase**) by drugs like warfarin would lead to deficiencies in **vitamin K-dependent clotting factors (II, VII, IX, X)**. - This would result in a **prolonged PT** (due to reduced factor VII) and often a prolonged PTT, which is not seen here as PT is normal. *Antibodies to factor VIII* - **Antibodies to factor VIII** (acquired hemophilia) would lead to a prolonged PTT that **would not correct** with a mixing study, as the inhibitor would neutralize the added factor VIII. - While acquired hemophilia can lead to severe bleeding, the correction with the mixing study points away from an inhibitor. *Activation of inhibitory factors* - **Activation of inhibitory factors** (e.g., lupus anticoagulant) would typically result in a prolonged PTT that **does not correct** with a mixing study (or only partially corrects), similar to an acquired factor VIII inhibitor. - The complete correction of PTT in the mixing study makes this option less likely. *Mutation in factor VIII* - A **mutation in factor VIII** itself (hemophilia A) would cause a **prolonged PTT** that **corrects with a mixing study**, as the added normal plasma would supply the missing factor VIII. - However, in this case, the **increased bleeding time** and the mention of a "carrying protein" point more specifically to **von Willebrand disease**, where vWF helps stabilize factor VIII.

Question 980: A 42-year-old man comes to the physician for a health maintenance examination. He has had generalized fatigue and muscle aches since his previous visit 6 months ago. He has hypertension and gastroesophageal reflux disease. Current medications include amlodipine and omeprazole. His temperature is 37.1°C (98.1°F), pulse is 88/min and blood pressure is 156/102 mm Hg. Physical examination shows no abnormalities. Serum studies show: Na+ 143 mEq/L K+ 2.3 mEq/L Cl- 100 mEq/L HCO3- 31 mEq/L Urea nitrogen 14 mg/dL Creatinine 1 mg/dL His blood pressure medication is discontinued. One week later his plasma aldosterone concentration is 35 ng/dL (N=3.6 - 24.0 ng/dL) and plasma renin activity is 0.4 ng/mL/h (N=0.3 to 4.2 ng/mL/h). An oral sodium loading test over 3 days fails to reduce aldosterone. A contrast-enhanced CT scan of the abdomen and pelvis shows a 3-cm, homogenous, right-sided adrenal mass with rapid contrast washout. He is counseled about his treatment options and chooses to pursue surgery. Which of the following is the most appropriate next step in management?

A. Right adrenalectomy
B. Fludrocortisone suppression test
C. Adrenal vein sampling (Correct Answer)
D. Spironolactone therapy
E. Bilateral adrenalectomy

Explanation: ***Adrenal vein sampling*** - This patient presents with **hypokalemia**, **hypertension**, elevated **plasma aldosterone concentration** with suppressed **plasma renin activity**, and unsuppressed aldosterone after a sodium loading test, all highly suggestive of **primary hyperaldosteronism**. - Given the **3-cm adrenal mass** on the right side and the patient's choice for surgery, **adrenal vein sampling (AVS)** is crucial to confirm that the right adrenal gland is the sole source of excess aldosterone production, ensuring that surgery will be curative. *Right adrenalectomy* - Although surgery on the right adrenal gland is the desired outcome, performing a **right adrenalectomy** without prior adrenal vein sampling is premature and potentially harmful. - AVS is essential to differentiate between a unilateral aldosterone-producing adenoma and bilateral adrenal hyperplasia, as the latter would not be cured by unilateral surgery. *Fludrocortisone suppression test* - The **fludrocortisone suppression test** is used to confirm the diagnosis of primary hyperaldosteronism, but the diagnosis in this patient is already strongly supported by the elevated aldosterone-to-renin ratio and lack of suppression with the oral sodium loading test. - This test would not help in localizing the source of aldosterone excess. *Spironolactone therapy* - **Spironolactone** is an **aldosterone antagonist** that can be used to manage primary hyperaldosteronism, especially in cases of bilateral adrenal hyperplasia or if surgery is contraindicated or declined. - However, given the patient's desire for surgery and the presence of a unilateral mass, the goal is curative resection, which requires further localization with AVS. *Bilateral adrenalectomy* - **Bilateral adrenalectomy** is generally reserved for rare cases of bilateral adrenal hyperplasia that are unresponsive to medical therapy or when AVS confirms bilateral disease and surgery is absolutely necessary. - Performing a bilateral adrenalectomy would lead to permanent **adrenal insufficiency**, requiring lifelong corticosteroid replacement, which is a major drawback.

Question 981: A 68-year-old female presents to the emergency room with acute onset of dyspnea and hemoptysis. Her past medical history is unremarkable and she has had no prior surgeries. A ventilation-perfusion scan demonstrates a large perfusion defect that is not matched by a ventilation defect in the left lower lobe. Which of the following would you also expect to find in this patient:

A. Bradycardia
B. Increased inspiratory capacity
C. Claudication
D. Aortic dilation
E. Pleuritic chest pain (Correct Answer)

Explanation: ***Pleuritic chest pain*** - The presented symptoms (dyspnea, hemoptysis, V/Q scan showing unmatched perfusion defect) are highly suggestive of **pulmonary embolism (PE)**. **Pleuritic chest pain** is a common symptom of PE, resulting from inflammation of the pleura often associated with a pulmonary infarct. - **Pleuritic chest pain** is classically described as sharp, localized pain that worsens with deep inspiration or coughing, which aligns with the potential for pleural irritation in PE. *Bradycardia* - **Tachycardia**, not bradycardia, is a common finding in pulmonary embolism, often due to the body's compensatory response to hypoxemia and increased cardiovascular strain. - Bradycardia would be atypical and likely unrelated to the acute presentation of PE in a previously healthy individual. *Increased inspiratory capacity* - In a patient with an acute pulmonary embolism, the inspiratory capacity is more likely to be normal or **decreased** due to discomfort from pleuritic chest pain, dyspnea, and potential V/Q mismatch affecting lung mechanics. - Increased inspiratory capacity is not a typical physiological response to an acute PE; instead, patients often experience **restrictive breathing patterns**. *Claudication* - **Claudication** refers to pain, usually in the legs, caused by too little blood flow during exercise; it typically indicates **peripheral artery disease**. - While PE is a thrombotic event, claudication is a symptom of chronic arterial insufficiency and is not directly related to acute pulmonary embolism. *Aortic dilation* - **Aortic dilation** is associated with conditions like aortic aneurysm or Marfan syndrome and is not a direct consequence or expected finding in acute pulmonary embolism. - There is no pathophysiological link between acute PE and the immediate development or presence of aortic dilation.

Question 982: A 45-year-old African American woman presents to her family physician for a routine examination. Past medical history is positive for amyloidosis and non-rhythm-based cardiac abnormalities secondary to the amyloidosis. Which of the following cardiac parameters would be expected in this patient?

A. Increased ejection fraction and decreased compliance
B. Preserved ejection fraction and increased compliance
C. Preserved ejection fraction and decreased compliance (Correct Answer)
D. Increased ejection fraction and increased compliance
E. Decreased ejection fraction and normal compliance

Explanation: ***Preserved ejection fraction and decreased compliance*** - Cardiac amyloidosis typically leads to **restrictive cardiomyopathy**, where amyloid deposits stiffen the ventricular walls. - This stiffness impairs the heart's ability to fill properly (**decreased compliance**) but often maintains contractility and thus a **preserved ejection fraction** in the early stages, classifying it as **heart failure with preserved ejection fraction (HFpEF)**. *Increased ejection fraction and decreased compliance* - While **decreased compliance** is characteristic of cardiac amyloidosis, an **increased ejection fraction** is generally not expected in this condition. - A true increase in ejection fraction is rare and not a primary feature of restrictive physiology; rather, the heart struggles to fill, but ejects a normal percentage of the reduced filled volume. *Preserved ejection fraction and increased compliance* - **Increased compliance** means the heart chambers are easily stretched and filled, which is the opposite of what occurs in cardiac amyloidosis. - Patients with amyloidosis have stiff hearts that are difficult to fill, leading to **decreased compliance**. *Increased ejection fraction and increased compliance* - Neither **increased ejection fraction** nor **increased compliance** is consistent with cardiac amyloidosis, which is characterized by a stiff, poorly filling ventricle. - This combination would suggest a hyperdynamic heart with excellent filling, not restrictive cardiomyopathy. *Decreased ejection fraction and normal compliance* - While later stages of cardiac amyloidosis can lead to a **decreased ejection fraction** due to severe myocardial dysfunction, it is typically preceded by a stage with **preserved ejection fraction**. - **Normal compliance** is inconsistent with amyloid infiltration, which inherently reduces the heart's ability to stretch and fill.

Question 983: A 34-year-old man comes to the physician for a routine health maintenance examination. He was diagnosed with HIV 8 years ago. He is currently receiving triple antiretroviral therapy. He is sexually active and uses condoms consistently. He is planning a trip to Thailand with his partner to celebrate his 35th birthday in 6 weeks. His last tetanus and diphtheria booster was given 4 years ago. He received three vaccinations against hepatitis B 5 years ago. He had chickenpox as a child. Other immunization records are unknown. Vital signs are within normal limits. Cardiopulmonary examination shows no abnormalities. Leukocyte count shows 8,700/mm3, and CD4+ T-lymphocyte count is 480 cells/mm3 (Normal ≥ 500); anti-HBs is 150 mIU/mL. Which of the following recommendations is most appropriate at this time?

A. Yellow fever vaccine
B. Hepatitis B vaccine
C. Tetanus, diphtheria, pertussis vaccine (Tdap)
D. Measles, mumps, rubella vaccine
E. No vaccination (Correct Answer)

Explanation: ***Correct: No vaccination*** - Given the patient's current immunization status and clinical scenario, **none of the listed vaccines are indicated at this time**. - His CD4+ count of 480 cells/mm³ indicates relatively preserved immune function on effective antiretroviral therapy. - His **anti-HBs level of 150 mIU/mL** demonstrates **adequate hepatitis B immunity** (protective level ≥10 mIU/mL). - His **tetanus-diphtheria booster was given 4 years ago**, and routine boosters are recommended every **10 years**, so he is not due for another 6 years. *Incorrect: Yellow fever vaccine* - **Thailand is not a yellow fever endemic country**, so yellow fever vaccination is **not required or recommended** for travel there. - Yellow fever vaccine is a **live attenuated vaccine** that can be given to HIV-positive patients with **CD4+ counts ≥200 cells/mm³** when travel to endemic areas (parts of Africa and South America) is necessary. - Since the patient has a CD4+ count of 480 and Thailand doesn't require this vaccine, this is not applicable. *Incorrect: Hepatitis B vaccine* - The patient's **anti-HBs level of 150 mIU/mL** indicates **adequate protective immunity** against hepatitis B. - A level ≥10 mIU/mL is considered protective, so **no booster is needed**. *Incorrect: Tetanus, diphtheria, pertussis vaccine (Tdap)* - **Tetanus-diphtheria boosters are recommended every 10 years**. - The patient received his last booster **4 years ago**, so he is **not due** for another booster at this time. - There is no specific indication for **pertussis vaccination** (e.g., pregnancy, close contact with infants). *Incorrect: Measles, mumps, rubella vaccine* - **MMR is a live attenuated vaccine** that is **contraindicated** in HIV-positive individuals with **CD4+ counts <200 cells/mm³**. - While this patient's CD4+ count is 480, MMR should only be given to HIV patients if they lack immunity and have CD4 ≥200. - There is **no documented need** for MMR based on the clinical scenario provided, and his immunity status to these infections is unknown. - Without evidence of susceptibility or specific exposure risk, vaccination is not indicated.

Question 984: Two days after admission to the hospital, a 74-year-old man develops confusion and headache. He has also been vomiting over the past hour. His temperature is 36.7°C (98°F), pulse is 98/min, respirations are 22/min, and blood pressure is 140/80 mm Hg. He is lethargic and oriented only to person. Examination shows flushed skin. Fundoscopic examination shows bright red retinal veins. Serum studies show: Na+ 138 mEq/L K+ 3.5 mEq/L Cl- 100 mEq/L HCO3- 17 mEq/L Creatinine 1.2 mg/dL Urea nitrogen 19 mg/dL Lactate 8.0 mEq/L (N = 0.5 - 2.2 mEq/L) Glucose 75 mg/dL Arterial blood gas analysis on room air shows a pH of 7.13. This patient's current presentation is most likely due to complications from treatment of which of the following conditions?

A. Acute coronary syndrome
B. Diabetic ketoacidosis
C. Hypertensive crisis (Correct Answer)
D. Seizure disorder
E. Septic shock

Explanation: ***Hypertensive crisis*** - This patient's presentation is most consistent with **cyanide toxicity from sodium nitroprusside** treatment of hypertensive crisis. - Sodium nitroprusside is commonly used for rapid blood pressure reduction in hypertensive emergencies but releases cyanide as a metabolite, especially with prolonged use (>48-72 hours) or in patients with renal dysfunction. - Classic features of cyanide toxicity include: **bright red/cherry-red retinal veins** (due to impaired oxygen extraction by tissues), **flushed skin**, **severe lactic acidosis** (lactate 8.0 mEq/L with high anion gap metabolic acidosis), altered mental status, headache, and vomiting. - Cyanide inhibits cytochrome c oxidase in the mitochondrial electron transport chain, causing **cellular hypoxia despite adequate oxygen delivery**, leading to anaerobic metabolism and lactic acidosis. - Treatment involves stopping nitroprusside and administering **hydroxocobalamin or sodium thiosulfate** as antidotes. *Acute coronary syndrome* - Would present with chest pain, ECG changes, and elevated cardiac biomarkers (troponin). - Lactic acidosis can occur in cardiogenic shock, but the **cherry-red retinal veins and flushed skin** are not features of ACS. - Treatment of ACS (anticoagulation, antiplatelet therapy) would not cause this specific presentation. *Diabetic ketoacidosis* - Would show **hyperglycemia** (typically >250 mg/dL), not normal glucose (75 mg/dL). - Would have **ketonemia and ketonuria**, elevated anion gap, but not the cherry-red retinal findings. - Treatment with insulin would lower, not cause, lactic acidosis. *Septic shock* - Can cause lactic acidosis and altered mental status but typically presents with **fever or hypothermia, hypotension**, and elevated white blood cell count. - Would not cause the characteristic **cherry-red retinal veins**. - Treatment of sepsis (antibiotics, fluids) would not produce this toxic presentation. *Seizure disorder* - Post-ictal confusion can occur, but seizures cause **transient lactic acidosis** that typically resolves within 60-90 minutes. - Would not explain the **persistent severe lactic acidosis (8.0 mEq/L), cherry-red retinal veins, or flushed skin**. - Antiepileptic drugs do not cause cyanide toxicity or this metabolic picture.

Question 985: A 30-year-old African American woman comes to the physician because of a 3-month history of increasing shortness of breath, cough, and intermittent fever. She works in a local factory that manufactures components for airplanes. She drinks 2–3 glasses of wine daily and has smoked half a pack of cigarettes daily for the past 5 years. Physical examination shows a purple rash on her cheeks and nose. An x-ray of the chest shows bilateral hilar adenopathy and a calcified nodule in the left lower lobe. A bronchoalveolar lavage shows a CD4:CD8 T-lymphocyte ratio of 10:1 (N=2:1). A biopsy of the nodule shows a noncaseating granuloma. Which of the following is the strongest predisposing factor for the development of this patient's condition?

A. Exposure to beryllium
B. Alcohol consumption
C. Exposure to acid-fast bacilli
D. Race (Correct Answer)
E. Smoking

Explanation: ***Race*** - **African Americans** have a significantly higher incidence and prevalence of **sarcoidosis** compared to other racial groups. - They also tend to experience more severe disease and a higher risk of chronicity and multiorgan involvement. *Exposure to beryllium* - **Berylliosis** is a granulomatous disease that can mimic sarcoidosis, especially with lung involvement and noncaseating granulomas. - However, the overall clinical picture, including the widespread organ involvement implied by the rash and the specific CD4:CD8 ratio, points more strongly to sarcoidosis. *Alcohol consumption* - While chronic alcohol consumption can affect immune function and organ health, it is **not a recognized predisposing factor** for sarcoidosis development. - There is no direct causal link between alcohol intake and sarcoidosis. *Exposure to acid-fast bacilli* - Exposure to **acid-fast bacilli** (e.g., *Mycobacterium tuberculosis*) causes **tuberculosis**, which is characterized by **caseating granulomas**. - This patient's biopsy shows **noncaseating granulomas**, differentiating it from tuberculosis. *Smoking* - Smoking is generally linked to **worse outcomes** in sarcoidosis but is not considered a primary predisposing factor for its development. - Some studies even suggest a potential inverse relationship or no significant association with incidence.

Question 986: A 25-year-old man is in the middle of an ascent up a mountain, at an elevation of about 4,500 meters. This is the 4th day of his expedition. His friend notices that in the last few hours, he has been coughing frequently and appears to be short of breath. He has used his albuterol inhaler twice in the past 4 hours, but it does not seem to help. Within the past hour, he has coughed up some frothy, slightly pink sputum and is now complaining of nausea and headache. Other than his asthma, which has been well-controlled on a steroid inhaler, he is healthy. Which of the following is the most likely cause of this man’s symptoms?

A. An acute asthma exacerbation
B. Non-cardiogenic pulmonary edema (Correct Answer)
C. Pneumothorax
D. Pulmonary embolism
E. Acute heart failure

Explanation: ***Non-cardiogenic pulmonary edema*** - The patient's symptoms of **dyspnea**, cough, and **frothy, pink sputum** at high altitude (4,500 meters) are classic signs of **High-Altitude Pulmonary Edema (HAPE)**, a form of non-cardiogenic pulmonary edema. - The headache and nausea are consistent with **acute mountain sickness**, which often precedes HAPE, and the ineffectiveness of albuterol points away from asthma. *An acute asthma exacerbation* - While the patient has a history of asthma, the **frothy, pink sputum** is atypical for asthma and strongly suggests alveolar fluid. - The ineffectiveness of albuterol, a bronchodilator, further suggests a cause other than **bronchoconstriction** as the primary issue. *Pneumothorax* - A pneumothorax typically presents with **sudden onset unilateral pleuritic chest pain** and dyspnea, which can be severe. - It would not usually cause frothy, pink sputum and is not directly linked to high altitude in the absence of trauma. *Pulmonary embolism* - A pulmonary embolism often causes **sudden onset dyspnea, pleuritic chest pain, and sometimes hemoptysis**, but **pink, frothy sputum** is less common. - There are no risk factors for PE mentioned, such as prolonged immobility or recent surgery. *Acute heart failure* - While acute heart failure can cause **pulmonary edema with frothy, pink sputum**, the patient is a young, otherwise healthy man with no cardiac risk factors. - The context of **high altitude** strongly points to HAPE over acute heart failure as the cause of pulmonary edema.

Question 987: A 45-year-old woman presents to the office with a complaint of generalized weakness that has been getting worse over the last few months. She says that she just does not have the energy for her daily activities. She gets winded quite easily when she takes her dog for a walk in the evening. She says that her mood is generally ok and she gets together with her friends every weekend. She works as a teacher at a local elementary school and used to have frequent headaches while at work. Her husband is a commercial pilot and is frequently away for extended periods of time. Her only son is a sophomore in college and visits her every other week. She has had issues in the past with hypertension, but her blood pressure is currently well-controlled because she is compliant with her medication. She is currently taking atorvastatin and lisinopril. The blood pressure is 130/80 mm Hg, the pulse is 90/min, the temperature is 36.7°C (98.0°F), and the respirations are 16/min. On examination, she appears slightly pale and lethargic. Her ECG today is normal and recent lab work shows the following: Serum creatinine 1.5 mg/dL Estimated GFR 37.6 mL/min Hemoglobin (Hb%) 9 mg/dL Mean corpuscular hemoglobin (MCH) 27 pg Mean corpuscular hemoglobin concentration (MCHC) 36 g/dL Mean corpuscular volume (MCV) 85 fL Reticulocyte count 0.1% Erythrocyte count 2.5 million/mm3 Serum iron 160 μg/dL Serum ferritin 150 ng/mL Total iron binding capacity 105 μg/dL Serum vitamin B12 254 pg/mL Serum folic acid 18 ng/mL Thyroid stimulating hormone 3.5 μU/mL Which of the following will most likely help her?

A. Start vitamin B12 with folic acid.
B. Transfuse red blood cells.
C. Start her on fluoxetine.
D. Start her on erythropoietin. (Correct Answer)
E. Start oral iron supplements.

Explanation: ***Start her on erythropoietin.*** - This patient presents with symptoms of **anemia** (weakness, fatigue, dyspnea on exertion) and has laboratory findings consistent with **normocytic, normochromic anemia** (Hb 9 mg/dL, MCV 85 fL, MCH 27 pg, normal MCHC), a **low reticulocyte count (0.1%)**, and **chronic kidney disease (CKD)** stage 3 (GFR 37.6 mL/min). - The combination of **CKD and anemia with appropriate iron stores** (normal serum iron and ferritin, low TIBC, high transferrin saturation) strongly suggests **anemia of chronic kidney disease**, which is caused by inadequate **erythropoietin (EPO) production** by the kidneys. Therefore, exogenous erythropoietin is the most appropriate treatment. *Start vitamin B12 with folic acid.* - The patient's **serum vitamin B12 (254 pg/mL)** and **folic acid (18 ng/mL)** levels are within normal limits, ruling out deficiencies of these vitamins as the cause of her anemia. - Deficiencies in B12 or folate typically cause **macrocytic anemia** (elevated MCV), which is not observed in this patient (MCV 85 fL). *Transfuse red blood cells.* - While red blood cell transfusion can rapidly increase hemoglobin, it is typically reserved for **symptomatic severe anemia** or in situations requiring quick correction, for example, active bleeding. - The patient's anemia, although symptomatic, is chronic, and her cardiovascular status, including a normal ECG and stable blood pressure, does not indicate an immediate life-threatening need for transfusion. **Long-term management** with erythropoietin is safer and more appropriate. *Start her on fluoxetine.* - The patient reports her **mood is generally okay**, and she actively socializes, making **depression less likely** as the primary cause of her generalized weakness or fatigue. Her fatigue is primarily due to anemia. - While chronic illness can sometimes lead to depression, there's no strong indication for antidepressant therapy based on the provided symptoms. *Start oral iron supplements.* - The patient's **iron studies (serum iron 160 μg/dL, serum ferritin 150 ng/mL, total iron binding capacity 105 μg/dL)** indicate that she has **adequate iron stores** and is not iron deficient. - Iron supplementation would not be beneficial and could be harmful if there is no iron deficiency.

Question 988: A 54-year-old man presents to his primary care physician for back pain. His back pain worsens with standing for a prolonged period of time or climbing down the stairs and improves with sitting. Medical history is significant for hypertension, type II diabetes mellitus, and hypercholesterolemia. Neurologic exam demonstrates normal tone, 5/5 strength, and a normal sensory exam throughout the bilateral lower extremity. Skin exam is unremarkable and dorsalis pedis and posterior tibialis pulses are 3+. Which of the following is the best next step in management?

A. Surgical spinal decompression
B. MRI of the lumbosacral spine (Correct Answer)
C. Ankle-brachial index
D. Radiography of the lumbosacral spine
E. Naproxen

Explanation: ***MRI of the lumbosacral spine*** - The patient's symptoms of back pain worsening with standing/climbing downstairs and improving with sitting are classic for **neurogenic claudication** due to **lumbar spinal stenosis**. - An **MRI** is the gold standard for visualizing the spinal canal, nerve roots, and any potential compression, providing the most detailed imaging to confirm the diagnosis and guide further management. *Surgical spinal decompression* - This is a definitive treatment option for severe **spinal stenosis** but should only be considered after a confirmed diagnosis and failed conservative management. - Jumping straight to surgery without proper imaging and assessment of the severity would be premature and potentially unnecessary. *Ankle-brachial index* - This test is primarily used to diagnose **peripheral artery disease (PAD)**, which causes **vascular claudication**. - While it's important to differentiate vascular from neurogenic claudication, the patient's symptoms (pain relief with sitting, no mention of exertional leg pain specifically) and normal pulses make vascular claudication less likely, and an MRI is more directly indicated for the suspected neurogenic cause. *Radiography of the lumbosacral spine* - While X-rays can show bone anomalies and degenerative changes like **osteophytes** and decreased disc space, they do not visualize soft tissues (spinal cord, nerve roots) or the extent of spinal canal narrowing. - Therefore, X-rays are insufficient for diagnosing **spinal stenosis** and its impact on neural structures. *Naproxen* - **Naproxen**, an NSAID, can provide symptomatic relief for musculoskeletal pain but does not address the underlying structural issue of **spinal stenosis**. - It would be a component of conservative management but not the definitive "next step" for diagnosing the cause of neurogenic claudication as described.

Question 989: A 36-year-old man presents to the physician with difficulty in breathing for 3 hours. There is no history of chest pain, cough or palpitation. He is a chronic smoker and underwent elective cholecystectomy one month back. There is no history of chronic or recurrent cough, wheezing or breathlessness. His temperature is 38.2°C (100.8°F), pulse is 108/min, blood pressure is 124/80 mm Hg, and respirations are 25/min. His arterial oxygen saturation is 98% in room air as shown by pulse oximetry. After a detailed physical examination, the physician orders a plasma D-dimer level, which was elevated. A contrast-enhanced computed tomography (CT) of the chest shows a filling defect in a segmental pulmonary artery on the left side. Which of the following signs is most likely to have been observed by the physician during the physical examination of this patient’s chest?

A. Pleural friction rub
B. Bilateral wheezing
C. Systolic murmur at the left sternal border
D. Localized rales (Correct Answer)
E. S3 gallop

Explanation: ***Localized rales*** - The patient's presentation with **sudden onset dyspnea**, risk factors (recent surgery, smoking), elevated D-dimer, and a CT scan showing a filling defect in the pulmonary artery strongly points to a **pulmonary embolism (PE)**. - While PE often presents with normal lung auscultation, localized rales or crackles can be heard if there is an associated **pulmonary infarction** or local inflammation. *Pleural friction rub* - A **pleural friction rub** indicates inflammation of the pleura, which can occur in PE if the infarct involves the pleural surface. - However, it is a less common finding than localized rales and is more characteristic of conditions like pleurisy or pneumonia. *Bilateral wheezing* - **Bilateral wheezing** is typically associated with diffuse airway obstruction, as seen in asthma or chronic obstructive pulmonary disease (COPD). - This patient has no history of chronic respiratory conditions and the presentation is acute dyspnea, making diffuse airway obstruction less likely. *Systolic murmur at the left sternal border* - A **systolic murmur at the left sternal border** can be indicative of tricuspid regurgitation, often seen in the setting of **pulmonary hypertension** and right heart strain associated with a massive PE. - However, with a stable blood pressure and moderate heart rate, severe right heart strain leading to a murmur is less likely in this scenario of a segmental PE. *S3 gallop* - An **S3 gallop** is a low-pitched sound heard during early diastole, often indicating **volume overload** or **ventricular dysfunction**. - In the context of PE, an S3 often suggests significant **right ventricular dysfunction** due to acute pressure overload; this is more common with large or massive PEs causing hemodynamic instability, which is not indicated here.

Question 990: A 41-year-old man presents to his primary care provider because of chest pain with activity for the past 6 months. Past medical history is significant for appendectomy at age 12 and hypertension, and diabetes mellitus type 2 that is poorly controlled. He takes metformin and lisinopril but admits that he is bad at remembering to take them everyday. His father had a heart attack at 41 and 2 stents were placed in his heart. His mother is healthy. He drinks alcohol occasionally and smokes a half of a pack of cigarettes a day. He is a sales executive and describes his work as stressful. Today, the blood pressure is 142/85 and the body mass index (BMI) is 28.5 kg/m2. A coronary angiogram shows > 75% narrowing of the left anterior descending coronary artery. Which of the following is most significant in this patient?

A. Obesity
B. Family history
C. Hypertension
D. Smoking
E. Diabetes mellitus (Correct Answer)

Explanation: ***Diabetes mellitus*** - **Diabetes mellitus** is a significant risk factor for **atherosclerosis** and contributes to accelerated progression of **coronary artery disease (CAD)**, often leading to more widespread and severe disease. - Poorly controlled diabetes can cause **endothelial dysfunction**, increasing oxidative stress and inflammation, which are key processes in **plaque formation** and destabilization. *Obesity* - **Obesity** (BMI 28.5 kg/m2) is a risk factor for **CAD** but often acts through associated conditions like **hypertension**, **diabetes**, and **dyslipidemia**. - While it contributes to overall cardiovascular risk, it is less directly pathogenic than diabetes which independently accelerates **atherosclerosis**. *Family history* - The patient's father had a **heart attack at 41**, which is a significant risk factor for **early-onset CAD**. - However, the patient has multiple modifiable risk factors (smoking, hypertension, diabetes) that are independently and more directly contributing to his current presentation. *Hypertension* - **Hypertension** (142/85 mmHg) is a major modifiable risk factor that causes **endothelial damage** and promotes **atherosclerosis**. - While important, the patient's **poorly controlled diabetes mellitus** often creates a more aggressive environment for plaque formation and progression compared to hypertension alone. *Smoking* - **Smoking** is a potent, modifiable risk factor that causes direct vascular injury, promotes **thrombogenesis**, and contributes to **atherosclerosis**. - Although highly detrimental, smoking is one of several significant risk factors; **diabetes mellitus**, with its systemic metabolic impact, can be considered more broadly influential in the severity and diffuse nature of **CAD**.

Question 991: A 46-year-old Caucasian male with past medical history of HIV (CD4: 77/mm^3), hypertension, hyperlipidemia, and osteoarthritis presents to the emergency department with sudden weakness of his right hand. He reports that the weakness has gradually been getting worse and that this morning he dropped his cup of coffee. He has never had anything like this happen to him before, although he was hospitalized last year for pneumonia. He reports inconsistent adherence to his home medications, which include raltegravir, tenofovir, emtricitabine, TMP-SMX, hydrochlorothiazide, pravastatin, and occasional ibuprofen. His father died of a myocardial infarction at the age of 60, and his mother suffered a stroke at the age of 72. The patient's temperature is 102.6°F (39.2°C), blood pressure is 156/92 mmHg, pulse is 88/min, and respirations are 18/min. On neurological exam, he has 3/5 strength in the distal muscles of the right extremity with preserved sensation. His neurological exam is normal in all other extremities. Which of the following is the best next step in management?

A. Serology for Toxoplasma-specific IgG antibodies
B. Empiric treatment with pyrimethamine-sulfadiazine
C. Head CT (Correct Answer)
D. Empiric treatment with itraconazole
E. Lumbar puncture

Explanation: ***Head CT*** - The patient presents with **focal neurological deficits** (right hand weakness) and has several risk factors, including poorly controlled **HIV with a low CD4 count** (increased risk of opportunistic infections or CNS lesions) and uncontrolled hypertension (increased risk of stroke). A **head CT** is crucial to rapidly identify potential causes like a mass lesion, hemorrhage, or infarct, which would guide immediate management. - The **fever** and **subacute onset** of weakness (gradually worsening with acute exacerbation) also point towards an intracranial process that needs urgent imaging. *Serology for Toxoplasma-specific IgG antibodies* - While **Toxoplasmosis** is a strong consideration given the patient's low CD4 count, **serology alone is not the best initial step** for acute neurological deficits. - A positive IgG indicates past exposure but not necessarily active infection, and it doesn't provide real-time information on the cause of the focal neurological symptoms. Imaging is needed first to identify a lesion. *Empiric treatment with pyrimethamine-sulfadiazine* - This is the treatment for **cerebral toxoplasmosis**, but **empiric treatment should only be initiated after imaging** (CT or MRI) confirms the presence of a lesion consistent with toxoplasmosis, especially in a patient with acute focal deficits. - Starting treatment without imaging may delay diagnosis of other potentially critical conditions like a brain abscess, lymphoma, or stroke. *Empiric treatment with itraconazole* - **Itraconazole** is an antifungal medication, typically used for histoplasmosis, blastomycosis, or aspergillosis, which are less common causes of acute focal neurological deficits in HIV than toxoplasmosis or lymphoma. - There is no specific clinical indication or risk factor (e.g., endemic area for fungal infections) that would make **empiric antifungal treatment** the best next step compared to diagnostic imaging for this presentation. *Lumbar puncture* - A **lumbar puncture** can be useful in diagnosing CNS infections (e.g., cryptococcal meningitis, viral encephalitis) or other inflammatory conditions, but it is typically performed *after* ruling out a mass lesion or increased intracranial pressure with imaging (CT or MRI) to prevent herniation. - Given the patient's focal neurological deficit and potential for a mass or hemorrhage, **LP carries a risk of brain herniation** and is not the best initial step.

Question 992: A 61-year-old man comes to the emergency department because of a 3-hour history of pain and redness of both eyes. He has new blurry vision and difficulty opening his eyes in bright surroundings. He has not had any recent trauma. He uses contact lenses daily. He had surgery on his left eye 6 months ago after a penetrative trauma caused by a splinter. His vital signs are within normal limits. Physical examination shows congestion of the perilimbal conjunctivae bilaterally. Visual acuity is decreased bilaterally. Ocular movements are normal. Slit-lamp examination shows a cornea with normal contours and leukocytes in the anterior chambers of both eyes. The eyelids, eyelashes, and lacrimal ducts show no abnormalities. Which of the following is the most likely cause of this patient's condition?

A. Impaired drainage of aqueous humor
B. Age-related denaturation of lens proteins
C. Reactivation of herpes zoster virus
D. Corneal infection with Pseudomonas aeruginosa
E. Autoimmune reaction against retinal antigens (Correct Answer)

Explanation: ***Autoimmune reaction against retinal antigens*** - The patient's history of **penetrating ocular trauma** (splinter injury) in the left eye 6 months ago, followed by bilateral eye symptoms (pain, redness, blurry vision, photophobia) and **uveitis** (leukocytes in the anterior chambers), is highly suggestive of **sympathetic ophthalmia**. - **Sympathetic ophthalmia** is an autoimmune process where trauma to one eye exposes hidden retinal antigens, triggering a delayed-type hypersensitivity reaction that affects both the injured (exciting) and the uninjured (sympathizing) eye. *Impaired drainage of aqueous humor* - **Impaired drainage of aqueous humor** is characteristic of **glaucoma**, which typically presents with elevated intraocular pressure, optic nerve damage, and visual field loss. - While blurry vision can occur, the acute pain, redness, and **leukocytes in the anterior chamber** (uveitis) are not typical features of primary glaucoma. *Age-related denaturation of lens proteins* - **Age-related denaturation of lens proteins** describes the formation of cataracts, which cause gradually progressive, painless blurry vision and glare. - The acute onset of pain, redness, and significant inflammation (leukocytes in the anterior chamber) are inconsistent with a straightforward cataract presentation. *Reactivation of herpes zoster virus* - **Reactivation of herpes zoster virus** (herpes zoster ophthalmicus) would typically present with a vesicular rash in the dermatomal distribution of the trigeminal nerve (often affecting the forehead and nose), along with eye involvement. - The absence of a characteristic skin rash makes this diagnosis less likely, and while it can cause uveitis, the historical context strongly points elsewhere. *Corneal infection with Pseudomonas aeruginosa* - **Corneal infection with Pseudomonas aeruginosa**, especially in contact lens wearers, can cause severe and rapid corneal damage, pain, redness, and vision loss. - However, the slit-lamp examination specifically notes a **cornea with normal contours**, which rules out significant corneal ulceration or infection as the primary cause here; the inflammation is in the anterior chamber.

Question 993: A 45-year-old man presents to his primary care physician complaining of increasingly frequent headaches. He also reports that his hats and wedding ring do not fit anymore. His temperature is 99°F (37.2°C), blood pressure is 145/80 mmHg, pulse is 85/min, and respirations are 16/min. Physical examination is notable for frontal bossing, a prominent jaw, and an enlarged tongue. A chest radiograph reveals mild cardiomegaly. Serum insulin-like growth factor 1 levels are significantly elevated. Which of the following complications is this patient most likely to develop?

A. Medullary thyroid carcinoma
B. Pheochromocytoma
C. Osteoid osteoma
D. Osteosarcoma
E. Carpal tunnel syndrome (Correct Answer)

Explanation: ***Carpal tunnel syndrome*** - This patient presents with classic signs and symptoms of **acromegaly**, including new-onset headaches, increasing hat and ring size, frontal bossing, prominent jaw, enlarged tongue, and elevated **insulin-like growth factor 1 (IGF-1)**. Acromegaly results from excess **growth hormone**, typically from a pituitary adenoma. - **Carpal tunnel syndrome** is one of the **most common complications** of acromegaly, affecting approximately **50% of patients**. The increased soft tissue and bone growth leads to narrowing of the carpal tunnel and compression of the **median nerve**. - Other common complications of acromegaly include **diabetes mellitus, hypertension, cardiomegaly, sleep apnea, arthropathy, and colon polyps**. *Medullary thyroid carcinoma* - This condition is associated with **Multiple Endocrine Neoplasia type 2 (MEN 2)** and is characterized by elevated **calcitonin** levels, not IGF-1. - It does not present with the characteristic physical findings of acromegaly such as frontal bossing and jaw enlargement. *Pheochromocytoma* - This is a tumor of the adrenal medulla that secretes **catecholamines**, leading to symptoms like **paroxysmal hypertension**, palpitations, diaphoresis, and headaches. - While it can be associated with MEN 2, it is not a complication of acromegaly and does not explain the progressive growth-related symptoms. *Osteoid osteoma* - This is a **benign bone tumor** characterized by localized bone pain that is typically worse at night and relieved by **NSAIDs**. - It is not associated with acromegaly or systemic hormone excess, and does not explain the generalized overgrowth features. *Osteosarcoma* - This is a **malignant bone tumor** that typically presents with localized bone pain and swelling, often near the **metaphysis of long bones** in adolescents and young adults. - While acromegaly may carry a slightly increased risk of certain malignancies (particularly colon cancer), osteosarcoma is not a recognized complication of this condition.

Question 994: A 75-year-old man is brought to the emergency room after being found unresponsive in his home. His medical history is unknown. On physical examination he does not demonstrate any spontaneous movement of his extremities and is unable to respond to voice or painful stimuli. You notice that he is able blink and move his eyes in the vertical plane. Based on these physical exam findings, you expect that magnetic resonance angiogram will most likely reveal an occlusion in which of the following vessels?

A. Basilar artery (Correct Answer)
B. Anterior cerebral artery
C. Anterior spinal artery
D. Posterior cerebral artery
E. Anterior inferior cerebellar artery

Explanation: ***Basilar artery*** - The patient's presentation with **quadriplegia**, inability to respond to stimuli, and preserved **vertical eye movements** and blinking is characteristic of **locked-in syndrome**. - **Locked-in syndrome** is most commonly caused by an **occlusion of the basilar artery**, leading to infarction of the ventral pons while sparing the tegmentum. *Anterior cerebral artery* - Occlusion of the **anterior cerebral artery** typically causes **contralateral leg weakness** and sensory loss, and sometimes **abulia** or urinary incontinence. - It does not explain the widespread motor paralysis affecting all four limbs or the preservation of vertical eye movements in an otherwise unresponsive patient. *Anterior spinal artery* - Occlusion of the **anterior spinal artery** causes an **anterior spinal cord syndrome**, characterized by bilateral weakness and loss of pain/temperature sensation below the lesion, with preserved proprioception and vibration sense. - This presentation does not include the characteristic signs of **brainstem dysfunction** seen in locked-in syndrome. *Posterior cerebral artery* - An occlusion in the **posterior cerebral artery** typically leads to **contralateral homonymous hemianopia**, and depending on the branch occluded, can also cause memory deficits or thalamic pain. - It does not account for the extensive motor paralysis or the pattern of preserved vertical eye movements seen in locked-in syndrome. *Anterior inferior cerebellar artery* - Occlusion of the **anterior inferior cerebellar artery (AICA)** typically results in **lateral pontine syndrome**, which includes ipsilateral facial weakness, hearing loss, cerebellar ataxia, and contralateral loss of pain and temperature sensation. - While it affects the pons, AICA occlusion does not typically cause the complete quadriplegia and preservation of vertical eye movements characteristic of locked-in syndrome.

Question 995: A 78-year-old woman comes to the physician because of a 2-month history of right-sided headache and generalized fatigue. She also has pain, weakness, and stiffness of her shoulders and hips. The stiffness is worse in the morning and usually improves after 60–90 minutes of activity. Three months ago, she fell and hit her head on the kitchen countertop. Her temperature is 38.1°C (100.6°F). Examination shows normal muscle strength in bilateral upper and lower extremities; range of motion of the shoulder and hip is mildly limited by pain. Deep tendon reflexes are 2+ bilaterally. Her erythrocyte sedimentation rate is 68 mm/h and serum creatine kinase is 36 mg/dL. Which of the following is the most likely underlying cause of this patient's headache?

A. Hyperthyroidism
B. Cluster headache
C. Tension headache
D. Polyarteritis nodosa
E. Large-vessel vasculitis (Correct Answer)

Explanation: ***Large-vessel vasculitis*** - The patient's age (78 years), new-onset **right-sided headache**, and elevated **ESR** (68 mm/h) are highly suggestive of **giant cell arteritis (GCA)**, which is a form of large-vessel vasculitis. - The associated symptoms of **polymyalgia rheumatica** (pain, weakness, and stiffness in shoulders and hips, worse in the morning, improving with activity) further support this diagnosis. *Hyperthyroidism* - While hyperthyroidism can cause fatigue and muscle weakness, it is typically associated with **tachycardia**, **weight loss**, and **tremors**, which are not reported here. - An elevated **ESR** and localized headache would not be primary features of hyperthyroidism. *Cluster headache* - Characterized by **severe, unilateral periorbital or temporal pain**, often accompanied by ipsilateral **autonomic symptoms** (e.g., lacrimation, nasal congestion, ptosis). - It typically occurs in younger men and does not present with systemic symptoms like elevated ESR or polymyalgia rheumatica. *Tension headache* - Usually described as a **bilateral, pressing or tightening pain** of mild to moderate intensity, without associated systemic symptoms. - It is not associated with an elevated **ESR** or the symptoms of polymyalgia rheumatica. *Polyarteritis nodosa* - This is a **necrotizing vasculitis** primarily affecting medium-sized arteries, often presenting with symptoms like **skin lesions**, **neuropathy**, and **renal involvement**. - It does not typically cause headache from direct cranial artery inflammation or polymyalgia rheumatica, as seen in GCA.

Question 996: A 76-year-old woman comes in for a routine checkup with her doctor. She is concerned that she feels tired most days and has difficulty doing her household chores. She complains that she gets fatigued and breathless with mild exertion. Past medical history is significant for diabetes mellitus, chronic kidney disease from prolonged elevated blood sugar, and primary biliary cirrhosis. Medications include lisinopril, insulin, and metformin. Family medicine is noncontributory. She drinks one beer every day. Today, she has a heart rate of 98/min, respiratory rate of 17/min, blood pressure of 110/65 mm Hg, and a temperature of 37.0°C (98.6°F). General examination shows that she is pale and haggard looking. She has a heartbeat with a regular rate and rhythm and her lungs are clear to auscultation bilaterally. A complete blood count (CBC) is as follows: Leukocyte count: 12,000/mm3 Red blood cell count: 3.1 million/mm3 Hemoglobin: 11.0 g/dL MCV: 85 fL MCH: 27 pg/cell Platelet count: 450,000/mm3 Fecal occult blood test is negative. What is the most likely cause of her anemia?

A. Chronic kidney disease (Correct Answer)
B. Acute bleeding
C. Alcoholism
D. Liver disease
E. Colorectal cancer

Explanation: ***Chronic kidney disease*** - **Chronic kidney disease (CKD)** is a common cause of **normocytic, normochromic anemia** due to decreased production of **erythropoietin** by the kidneys. - This patient's history of CKD, alongside her **normocytic anemia (MCV 85 fL)**, makes this the most likely cause. *Acute bleeding* - Acute bleeding would typically present with signs of **hypovolemia** (e.g., hypotension, tachycardia) and potentially a **reticulocytosis** as the bone marrow compensates, neither of which are seen here. - The **negative fecal occult blood test** and stable vital signs also argue against acute or chronic gastrointestinal bleeding. *Alcoholism* - Chronic alcoholism can lead to anemia, often **macrocytic** due to **folate deficiency**, or less commonly microcytic if associated with iron deficiency from GI bleeding. - While she drinks one beer daily, this amount is unlikely to directly cause significant anemia, especially given her **normocytic MCV**. *Liver disease* - **Primary biliary cirrhosis (PBC)** can cause anemia through various mechanisms, including **hemolysis**, **folate deficiency**, or bleeding from **portal hypertension**. - However, PBC-related anemia is often microcytic or macrocytic, and her **normocytic MCV** and the more direct link to CKD make it less likely to be the primary cause. *Colorectal cancer* - **Colorectal cancer** can cause anemia due to **chronic blood loss**, which would typically lead to **iron deficiency anemia** (microcytic anemia). - The patient has a **normocytic anemia (MCV 85 fL)** and a **negative fecal occult blood test**, making this diagnosis highly unlikely.

Question 997: A 27-year-old man presents to the emergency department with weakness and a fever for the past week. The patient is homeless and has a past medical history of alcohol and IV drug abuse. His temperature is 102°F (38.9°C), blood pressure is 107/68 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a tremulous patient with antecubital scars and a murmur over the left lower sternal border. Blood cultures are drawn and the patient is started on vancomycin and ceftriaxone and is admitted to the ICU. The patient's fever and symptoms do not improve despite antibiotic therapy for which the initial identified organism is susceptible. Cultures currently reveal MRSA as one of the infective organisms. Which of the following is the best next step in management?

A. Transesophageal echocardiography (Correct Answer)
B. Obtain new blood cultures
C. CT scan of the chest
D. Nafcillin and piperacillin-tazobactam
E. Vancomycin and gentamicin

Explanation: ***Transesophageal echocardiography*** - The patient's history of **IV drug abuse**, **fever**, **new murmur**, and identification of **MRSA** strongly suggest **infective endocarditis**. - A Transesophageal echocardiography (TEE) is the **most sensitive and specific imaging modality** to detect vegetations, abscesses, or valvular damage, which is crucial for guiding further management. *Obtain new blood cultures* - While repeating blood cultures can be useful to confirm eradication or identify new pathogens, the initial blood cultures already revealed MRSA, which is a common cause of **endocarditis in IV drug users**. - The immediate priority given the lack of improvement and high suspicion of endocarditis is to visualize the heart valves for vegetations. *CT scan of the chest* - A CT scan of the chest would be useful to look for complications such as **septic emboli in the lungs** or other pulmonary pathologies. - However, it would not provide the detailed visualization of heart valves necessary to diagnose or rule out valvular vegetations characteristic of endocarditis. *Nafcillin and piperacillin-tazobactam* - **Nafcillin** is active against **methicillin-susceptible Staphylococcus aureus (MSSA)**, but the patient's cultures already identified **MRSA**. - **Piperacillin-tazobactam** is a broad-spectrum antibiotic but not a first-line treatment for MRSA infections and would not be appropriate given the identified pathogen. *Vancomycin and gentamicin* - The patient is already on **Vancomycin**, which is appropriate for MRSA, but adding **gentamicin** without clear indication would not be the best next step. - While gentamicin is sometimes used as an adjunct in specific endocarditis regimens (e.g., enterococcal), the primary concern here is the lack of clinical improvement despite appropriate MRSA coverage, pointing towards a structural cardiac issue.

Question 998: A 61-year-old white man presents to the emergency department because of progressive fatigue and shortness of breath on exertion and while lying down. He has had type 2 diabetes mellitus for 25 years and hypertension for 15 years. He is taking metformin and captopril for his diabetes and hypertension. He has smoked 10 cigarettes per day for the past 12 years and drinks alcohol occasionally. His temperature is 36.7°C (98.0°F) and blood pressure is 130/60 mm Hg. On physical examination, his arterial pulse shows a rapid rise and a quick collapse. An early diastolic murmur is audible over the left upper sternal border. Echocardiography shows severe chronic aortic regurgitation with a left ventricular ejection fraction of 55%–60% and mild left ventricular hypertrophy. Which of the following is an indication for aortic valve replacement in this patient?

A. Old age
B. Ejection fraction > 55%
C. Long history of diabetes mellitus
D. Presence of symptoms of left ventricular dysfunction (Correct Answer)
E. Long history of systemic hypertension

Explanation: ***Presence of symptoms of left ventricular dysfunction*** - The patient's symptoms of **progressive fatigue**, **shortness of breath on exertion**, and **orthopnea** (shortness of breath while lying down) are clear indicators of **left ventricular dysfunction** due to severe aortic regurgitation. - In patients with **severe chronic aortic regurgitation**, the development of symptoms is a Class I indication for **aortic valve replacement**, regardless of the ejection fraction. *Old age* - While age can influence surgical risk, it is **not an independent indication** for aortic valve replacement in the absence of severe symptoms or significant ventricular dysfunction. - The decision for surgery is primarily based on **symptom status** and objective measures of cardiac function. *Ejection fraction > 55%* - An ejection fraction of 55%-60% is considered **normal** or mildly reduced, indicating that the left ventricle still effectively pumps blood. - Aortic valve replacement is typically indicated when the **ejection fraction falls below 50%**, even in asymptomatic patients, or with symptoms. *Long history of diabetes mellitus* - A long history of diabetes mellitus is a significant **comorbidity** that increases surgical risk and cardiovascular complications but is **not an independent indication** for valve replacement itself. - The decision to operate is based on valve disease severity and its impact on cardiac function, not the duration of other chronic illnesses. *Long history of systemic hypertension* - Similar to diabetes, hypertension is a significant **comorbidity** that can exacerbate cardiac disease and increase surgical risk but does **not directly indicate** the need for aortic valve replacement. - Hypertension management is crucial, but the primary indication for surgery stems from the **severity of aortic regurgitation** and its symptomatic consequences.

Question 999: A 38-year-old man is brought to the emergency department after losing consciousness upon rising from his chair at work. The patient has had progressive cough, shortness of breath, fever, and chills for 6 days but did not seek medical attention for these symptoms. He appears distressed, flushed, and diaphoretic. He is 170 cm (5 ft 7 in) tall and weighs 120 kg (265 lbs); BMI is 41.5 kg/m2. His temperature is 39.4°C (102.9°F), pulse is 129/min, respirations are 22/min, and blood pressure is 91/50 mm Hg when supine. Crackles and bronchial breath sounds are heard over the right posterior hemithorax. A 2/6 midsystolic blowing murmur is heard along the left upper sternal border. Examination shows diffuse diaphoresis, flushed extremities, and dullness to percussion over the right posterior hemithorax. The abdomen is soft and nontender. Multiple nurses and physicians have been unable to attain intravenous access. A large-bore central venous catheter is inserted into the right internal jugular vein by standard sterile procedure. Which of the following is the most appropriate next step in the management of this patient?

A. Bronchoscopy
B. Chest X-ray
C. CT scan of the chest
D. Echocardiogram
E. Administer intravenous levofloxacin (Correct Answer)

Explanation: ***Correct: Administer intravenous levofloxacin*** - This patient has **septic shock from severe community-acquired pneumonia**, evidenced by hypotension (91/50 mmHg), tachycardia (129/min), fever (39.4°C), and respiratory findings (crackles, bronchial breath sounds, dullness to percussion). - **Surviving Sepsis Campaign guidelines** mandate **broad-spectrum antibiotics within 1 hour** of recognizing septic shock, as each hour of delay increases mortality by approximately 7-10%. - The clinical diagnosis of pneumonia is already established by physical examination; central venous access is now secured, making immediate antibiotic administration the priority. - **Levofloxacin** provides appropriate coverage for community-acquired pneumonia including atypical organisms, though combination therapy (e.g., with ceftriaxone) would be ideal. - Chest X-ray should be obtained **concurrently** but must **not delay** antibiotic administration in septic shock. *Incorrect: Chest X-ray* - While chest X-ray is important for confirming pneumonia and assessing complications, it should **never delay antibiotic administration** in a patient with septic shock. - The physical examination findings (crackles, bronchial breath sounds, dullness to percussion) already provide strong clinical evidence of pneumonia. - Chest X-ray can be obtained **simultaneously** with or immediately after starting antibiotics, but the time-sensitive nature of septic shock management makes antibiotics the priority. - In sepsis protocols, imaging should not delay the "hour-1 bundle" which includes blood cultures and antibiotics. *Incorrect: Bronchoscopy* - This is an **invasive procedure** not indicated as an immediate intervention in unstable septic shock. - Bronchoscopy may be considered later if the patient fails to respond to antibiotics or if there are specific diagnostic uncertainties, but it has no role in initial emergency management. - The procedure would further delay critical antibiotic therapy and carries risks in a hemodynamically unstable patient. *Incorrect: Echocardiogram* - While the patient has a murmur, the **primary clinical picture is septic shock from pneumonia**, not primary cardiac pathology. - The murmur is likely a **flow murmur** from fever, tachycardia, and hyperdynamic circulation in sepsis. - Echocardiography may be considered later if endocarditis is suspected or if the patient has refractory shock, but it should not precede immediate antibiotic therapy. - Treating the underlying infection takes precedence over cardiac evaluation in this presentation. *Incorrect: CT scan of the chest* - CT provides more detailed imaging than chest X-ray but is **not appropriate** as the immediate next step in an unstable patient with septic shock. - Moving a critically ill, hypotensive patient to the CT scanner delays time-sensitive interventions and poses safety risks. - CT scan may be useful later if complications arise (empyema, abscess) or if initial therapy fails, but has no role before antibiotic administration in acute septic shock.

Question 1000: A 62-year-old man comes to the physician because of increased frequency of urination. He also says that he needs to urinate 4 to 5 times nightly and has difficulty initiating a urinary stream. He has had several episodes of acute cystitis treated with ciprofloxacin during the past year. Digital rectal examination shows a firm, symmetrically enlarged, non-tender prostate. This patient is most likely to develop which of the following complications?

A. Inflammation of the renal interstitium
B. Blastic bone lesions
C. Abscess formation in the prostate
D. Impaired intracavernosal blood flow
E. Irreversible decrease in renal function (Correct Answer)

Explanation: ***Irreversible decrease in renal function*** - The patient's symptoms of **increased urinary frequency**, **nocturia**, **difficulty initiating stream**, and **recurrent cystitis** in the context of a **symmetrically enlarged, firm prostate** are highly suggestive of **benign prostatic hyperplasia (BPH)** with progressive outflow obstruction. - Chronic urinary outflow obstruction can lead to **hydronephrosis** and **backpressure on the kidneys**, eventually causing **renal parenchymal damage** and an irreversible decrease in renal function. *Inflammation of the renal interstitium* - While chronic obstruction can lead to **chronic pyelonephritis**, which involves interstitial inflammation, **irreversible renal function decrease** is a more encompassing and severe long-term complication of sustained BPH with urinary retention. - **Acute interstitial nephritis** is typically associated with drug reactions or systemic diseases, rather than primarily BPH. *Blastic bone lesions* - **Blastic bone lesions** are characteristic of **metastatic prostate cancer**, which typically presents with an **asymmetrically firm or nodular prostate** on DRE, unlike the symmetric enlargement described here. - Although the patient's age and prostate exam warrant consideration of prostate cancer, the clinical picture strongly favors BPH, making blastic bone lesions less likely as the primary complication. *Abscess formation in the prostate* - **Prostatic abscesses** typically present with acute systemic symptoms like **fever, chills, and perineal pain**, which are not mentioned in this patient's presentation. - While recurrent urinary tract infections can increase the risk of prostatic abscess, the dominant concern here is the long-term impact of chronic obstruction. *Impaired intracavernosal blood flow* - **Impaired intracavernosal blood flow** is a common cause of **erectile dysfunction**, which can coexist with BPH due to shared risk factors or age, but it's not a direct complication of the urinary outflow obstruction itself. - The patient's reported symptoms are primarily related to urination and bladder emptying, not sexual function.

Question 1001: A 37-year-old woman is being evaluated for difficulty with swallowing for the past few months. She explains that she experiences difficulty swallowing solid foods only. Her medical history is relevant for hypothyroidism and migraines. Her current medications include daily levothyroxine and acetaminophen as needed for pain. The vital signs include blood pressure 110/90 mm Hg, pulse rate 55/min, and respiratory rate 12/min. On physical examination, her abdomen is non-tender. Her voice is hoarse, but there is no pharyngeal hyperemia on oral examination. On cardiac auscultation, an opening snap followed by an early to mid-diastolic rumble is heard over the apex. A barium swallow X-ray is performed and is unremarkable. Echocardiography shows an enlarged left atrium and abnormal blood flow through 1 of the atrioventricular valves. What is the most likely valve abnormality seen in this patient?

A. Aortic valve stenosis
B. Mitral valve regurgitation
C. Mitral valve prolapse
D. Mitral valve stenosis (Correct Answer)
E. Aortic valve regurgitation

Explanation: ***Mitral valve stenosis*** - The classic auscultation findings of an **opening snap** followed by an **early to mid-diastolic rumble** at the apex are pathognomonic for **mitral stenosis**. - **Dysphagia** (difficulty swallowing) in this context is likely due to the **enlarged left atrium compressing the esophagus**, and the patient's hoarse voice suggests possible **recurrent laryngeal nerve compression (Ortner’s syndrome)**, both common complications of severe mitral stenosis. *Aortic valve stenosis* - Typically presents with a **systolic ejection murmur**, often radiating to the carotid arteries, and usually associated with symptoms like syncope, angina, and dyspnea on exertion. - While it can cause left ventricular hypertrophy, it does not directly lead to **left atrial enlargement** or the auscultation findings described. *Mitral valve regurgitation* - Characterized by a **holosystolic murmur** best heard at the apex and radiating to the axilla; it does not produce a diastolic rumble or an opening snap. - While it can cause left atrial enlargement, the murmur and other clinical findings like dysphagia from esophageal compression are not characteristic. *Mitral valve prolapse* - Typically presents with a **mid-systolic click** and often a **late systolic murmur**, not a diastolic rumble or opening snap. - It usually does not lead to the degree of left atrial enlargement that would cause dysphagia or hoarseness. *Aortic valve regurgitation* - Produces a **diastolic decrescendo murmur** best heard at the left sternal border and is associated with a wide pulse pressure and hyperdynamic circulation. - It does not cause an opening snap or a diastolic rumble, nor does it typically lead to significant left atrial enlargement causing esophageal compression.

Question 1002: A 60-year-old man comes to the physician because of a 6-month history of progressively worsening urinary frequency. He feels the urge to urinate every hour or two, which restricts his daily activities and interferes with his sleep. He has no fever, hematuria, or burning pain on micturition. He has hypertension and type 2 diabetes mellitus. Current medications include metformin and amlodipine. He does not smoke and drinks 1 to 2 beers daily. His vital signs are within normal limits. Abdominal examination shows no abnormalities. Digital rectal examination shows a nontender, firm, symmetrically enlarged prostate with no nodules. Which of the following is the most appropriate next step in management?

A. Uroflowmetry
B. Urine cytology
C. Urinalysis (Correct Answer)
D. Prostate ultrasonography
E. Serum prostate-specific antigen level

Explanation: ***Urinalysis*** - A **urinalysis** is the most appropriate initial diagnostic test to rule out urinary tract infection (UTI), hematuria, and other urinary pathologies before proceeding with further investigations for **benign prostatic hyperplasia (BPH)**. - Although the patient has no fever or dysuria, **urinary frequency** is a common symptom of UTIs, and ruling it out is essential for appropriate diagnosis and treatment. *Uroflowmetry* - **Uroflowmetry** measures the rate of urine flow and can assess the degree of obstruction, but it is typically performed after a basic workup, including urinalysis, to further evaluate the cause of **lower urinary tract symptoms (LUTS)**. - While useful for BPH evaluation, it is not the initial step when infection or other causes of frequency have not been excluded. *Urine cytology* - **Urine cytology** is used to detect malignant cells in the urine and is usually reserved for patients with risk factors for bladder cancer, such as **gross hematuria**, irritative voiding symptoms, or a history of smoking, which are not primary concerns here. - Given the patient's symptoms and physical exam findings suggestive of BPH, cancer is less likely to be the initial concern. *Prostate ultrasonography* - **Prostate ultrasonography** can determine prostate size and screen for nodules, but it is more invasive and typically reserved for later stages of investigation if BPH is suspected and symptoms are severe, or if the digital rectal exam (DRE) is concerning. - A **nontender, firm, symmetrically enlarged prostate** on DRE is consistent with BPH, but an ultrasound is not the first diagnostic step. *Serum prostate-specific antigen level* - **Serum prostate-specific antigen (PSA)** level is used for prostate cancer screening and monitoring, but it is not recommended as an initial test solely for evaluating LUTS unless there are other risk factors or findings suggestive of prostate cancer (e.g., nodularity on DRE). - Given the symmetrical enlargement and absence of nodules, initial cancer screening with PSA is not the most immediate priority.

Question 1003: A 64-year-old man presents to his primary care physician's office for a routine check-up. His past medical history is significant for type 2 diabetes mellitus, hypertension, chronic atrial fibrillation, and ischemic cardiomyopathy. On his last visit three months ago, he was found to have hyperkalemia, at which time lisinopril and spironolactone were removed from his medication regimen. Currently, his medications include coumadin, aspirin, metformin, glyburide, metoprolol, furosemide, and amlodipine. His T is 37 C (98.6 F), BP 154/92 mm Hg, HR 80/min, and RR 16/min. His physical exam is notable for elevated jugular venous pressure, an S3 heart sound, and 1+ pitting pedal edema. His repeat lab work at the current visit is as follows: Sodium: 138 mEq/L, potassium: 5.7 mEq/L, chloride 112 mEq/L, bicarbonate 18 mEq/L, BUN 29 mg/dL, and creatinine 2.1 mg/dL. Which of the following is the most likely cause of this patient's acid-base and electrolyte abnormalities?

A. Furosemide
B. Amlodipine
C. Renal tubular acidosis
D. Glyburide
E. Chronic renal failure (Correct Answer)

Explanation: ***Chronic renal failure*** - This patient presents with **hyperkalemia**, **metabolic acidosis** (low bicarbonate), **elevated BUN and creatinine**, and signs of fluid overload, all consistent with **worsening renal function**. - **Chronic kidney disease** impairs the kidneys' ability to excrete potassium and acids, leading to these electrolyte and acid-base disturbances. *Furosemide* - **Furosemide** is a loop diuretic that typically causes **hypokalemia** and **metabolic alkalosis** due to increased potassium and hydrogen ion excretion. - While it can worsen renal function in hypovolemic states, it primarily causes **potassium wasting**, not retention. *Amlodipine* - **Amlodipine** is a calcium channel blocker that may cause **peripheral edema** but is not directly associated with hyperkalemia or metabolic acidosis. - It does not directly impact **renal electrolyte handling** or acid-base balance in this manner. *Renal tubular acidosis* - **Renal tubular acidosis (RTA)** specifically refers to impaired tubular handling of acid or bicarbonate, but it is not the most likely cause here given the **elevated BUN and creatinine** indicative of overall renal failure. - While RTA can cause metabolic acidosis, it typically doesn't fully explain the degree of hyperkalemia or the overall picture of **reduced GFR**. *Glyburide* - **Glyburide** is a sulfonylurea used to manage type 2 diabetes by increasing **insulin secretion**. - It is not directly associated with **hyperkalemia**, **metabolic acidosis**, or the observed renal function abnormalities.

Question 1004: A 40-year-old man comes to the physician for a follow-up examination. He feels well. He has no urinary urgency, increased frequency, dysuria, or gross hematuria. He has a history of recurrent urinary tract infections. His last urinary tract infection was 3 months ago and was treated with ciprofloxacin. Current medications include a multivitamin. He has smoked one pack of cigarettes daily for 18 years. Vital signs are within normal limits. The abdomen is soft and nontender. There is no costovertebral angle tenderness. Laboratory studies show: Hemoglobin 11.2 g/dL Leukocyte count 9,500/mm3 Platelet count 170,000/mm3 Serum Na+ 135 mEq/L K+ 4.9 mEq/L Cl- 101 mEq/L Urea nitrogen 18 mg/dL Creatinine 0.6 mg/dL Urine Blood 2+ Protein negative RBC 5–7/hpf, normal shape and size RBC casts negative WBC 0–2/hpf Bacteria negative Urine cultures are negative. Urine analysis is repeated and shows similar results. A cystoscopy shows no abnormalities. Which of the following is the most appropriate next step in management?

A. Annual urinalysis
B. Reassurance
C. CT urography (Correct Answer)
D. Voided urine cytology
E. Transrectal ultrasound

Explanation: ***CT urography*** - The patient has **microscopic hematuria** with **2+ blood on urinalysis** and **5-7 RBCs/hpf**, in the absence of infection or other identifiable causes, which warrants further investigation for potential malignancy. - Given the patient's **smoking history** (18 pack-years) and age, which are significant risk factors for **urothelial carcinoma** (bladder, renal pelvis, ureters), imaging with CT urography is crucial to visualize the entire urinary tract for tumors or other structural abnormalities. *Annual urinalysis* - This option represents a passive approach to monitoring, which is inadequate given the presence of **unexplained microscopic hematuria** and risk factors for malignancy. - Delaying definitive investigation could lead to a missed or delayed diagnosis of a potentially treatable condition like **urothelial cancer**. *Reassurance* - Reassurance is inappropriate when **microscopic hematuria** is present without a clear benign cause, especially in a patient with risk factors like **smoking history**. - This could lead to a false sense of security and delay the diagnosis and treatment of a serious underlying condition. *Voided urine cytology* - **Urine cytology** has a low sensitivity for detecting low-grade bladder cancers, though it can be useful for high-grade cancers and carcinoma in situ. - While it may be considered in conjunction with imaging, it is not the most appropriate *initial* next step to identify the source of hematuria throughout the entire urinary tract, especially when imaging can detect other pathologies. *Transrectal ultrasound* - A **transrectal ultrasound** is primarily used to evaluate the **prostate gland**, typically in the context of prostate-specific antigen elevation or prostatic symptoms. - It would not effectively visualize the bladder, ureters, or kidneys, which are the primary concerns for microscopic hematuria in this patient's demographic and risk factors.

Question 1005: A 42-year-old man comes to the physician for 1 month of worsening right knee pain. He has not had any trauma other than stubbing his toe 3 days ago at the garage where he works as a mechanic. Examination of the right knee shows swelling and erythema with fluctuance over the inferior patella. There is tenderness on palpation of the patella but no joint line tenderness or warmth. The range of flexion is limited because of the pain. Which of the following is the most likely underlying cause of this patient's symptoms?

A. Inflammation of the patellar tendon
B. Deposition of crystals in the joint
C. Noninflammatory degeneration of the joint
D. Inflammation of periarticular fluid-filled sac (Correct Answer)
E. Infection of the joint

Explanation: ***Inflammation of periarticular fluid-filled sac*** - The patient's symptoms (swelling, erythema, fluctuance over the inferior patella, tenderness on palpation of the patella, and limited flexion due to pain) are highly suggestive of **prepatellar bursitis**. The history of stubbing his toe and working as a mechanic (suggesting kneeling) further supports this. - A periarticular fluid-filled sac (bursa) becomes inflamed, causing localized pain, swelling, and tenderness, specifically in the prepatellar region, without true intra-articular involvement. *Inflammation of the patellar tendon* - **Patellar tendinitis** (jumper's knee) typically presents with pain directly over the patellar tendon, usually exacerbated by activities involving jumping or forceful knee extension, not necessarily with fluctuant swelling over the patella itself. - While there can be swelling, it's usually less diffuse and fluctuant compared to bursitis, and primarily involves the tendon structure rather than a fluid-filled sac. *Deposition of crystals in the joint* - Crystal arthropathies like **gout** or **pseudogout** typically cause sudden, severe monoarticular arthritis with exquisite pain, redness, and swelling, often affecting the great toe (gout) or knee with true intra-articular inflammation. - While very possible given the stubbed toe, the description of **fluctuance over the inferior patella** and lack of joint line tenderness makes a bursitis more likely than an intra-articular crystal deposition. Analysis of synovial fluid would confirm. *Noninflammatory degeneration of the joint* - **Osteoarthritis** typically presents with gradual onset of pain, stiffness, and crepitus, often worse with activity and relieved by rest. It is characterized by **joint line tenderness**, osteophytes, and narrowing of the joint space. - The acute onset of significant swelling, erythema, and fluctuance points away from noninflammatory degeneration as the primary cause. *Infection of the joint* - **Septic arthritis** would cause severe pain, swelling, erythema, and warmth of the entire joint, often with systemic symptoms like fever and chills, and marked limitation of both active and passive range of motion. - While infection of a bursa (**septic bursitis**) is a possibility, the question asks for the most likely underlying cause given the overall presentation, and sterile inflammatory bursitis is often more common initially, especially with mechanical irritation like repetitive kneeling or minor trauma. The description of **no joint line tenderness or warmth** makes septic arthritis less likely.

Question 1006: A 42-year-old woman presents to her primary care provider with vision loss. She reports that twice over the last 2 weeks she has had sudden “black out” of the vision in her right eye. She notes that both episodes were painless and self-resolved over approximately a minute. The patient’s past medical history is significant for hypertension, diet-controlled diabetes mellitus, and hypothyroidism. Her family history is notable for coronary artery disease in the patient’s father and multiple sclerosis in her mother. Ophthalmologic and neurologic exam is unremarkable. Which of the following is the best next step in management?

A. Intravenous dexamethasone
B. Emergent referral to ophthalmology
C. Ultrasound of the carotid arteries (Correct Answer)
D. Check serum inflammatory markers
E. MRI of the brain

Explanation: **Ultrasound of the carotid arteries** - The patient's symptoms of **transient monocular vision loss** ("black out" vision in one eye that self-resolved) are highly suggestive of **amaurosis fugax**. - Amaurosis fugax is often caused by **atheroembolic disease** originating from the ipsilateral carotid artery, making carotid ultrasound the best next step to assess for **carotid stenosis**. *Intravenous dexamethasone* - This treatment is typically used for **acute inflammation** or **autoimmune conditions**, such as optic neuritis related to multiple sclerosis, which is less likely given the painless, transient, and self-resolving nature of the vision loss. - While the mother has multiple sclerosis, the daughter's symptoms do not align with a typical demyelinating event, and the primary concern is underlying vascular pathology. *Emergent referral to ophthalmology* - While an ophthalmology consult may eventually be warranted, the immediate concern is to identify the **underlying systemic cause** of the **embolic event** to prevent future, more severe cerebrovascular events like a stroke. - The vision loss in amaurosis fugax is usually a symptom of a more serious **systemic vascular problem** originating proximal to the eye. *Check serum inflammatory markers* - Inflammatory markers (e.g., ESR, CRP) would be elevated in conditions like **temporal arteritis**, but the patient's vision loss is painless and self-resolving, which is inconsistent with the typical presentation of temporal arteritis. - Furthermore, temporal arteritis usually presents in older patients (>50 years old), and would cause more persistent vision loss, often accompanied by tenderness over the temporal artery and jaw claudication. *MRI of the brain* - An MRI of the brain would be appropriate if there were concerns for a **stroke** or **demyelinating disease** affecting the optic pathways or brain, but the transient monocular vision loss points to an issue with the retinal circulation, not necessarily the brain. - While a stroke is a concern, the acute vision loss is more indicative of a **retinal event**, which originates from a more proximal arterial source.

Question 1007: A 47-year-old man presents to the emergency department due to a rash. He states the rash started last night and is very concerning to him. The patient cannot remember being exposed to any environmental stimuli such as new detergents or poison ivy. The patient recently started following with a primary care provider who is helping him manage his arthritis and a new onset cough. His temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 125/min, respirations are 18/min, and oxygen saturation is 98% on room air. Physical exam is notable for the findings of coalescing erythematous macules, bullae, desquamation, and mucositis only on the upper half of his back. Cardiopulmonary exam and abdominal exam are within normal limits. Inspection of the patient’s oropharynx reveals ulcers and erythema. Which of the following is the most likely diagnosis?

A. Stevens-Johnson syndrome (Correct Answer)
B. Erythema multiforme
C. Herpes zoster
D. Herpes simplex virus
E. Toxic epidermal necrolysis

Explanation: ***Stevens-Johnson syndrome*** - This patient presents with a **rash of coalescing erythematous macules, bullae, desquamation, and mucositis in the oropharynx**, which are characteristic of SJS. - The recent initiation of new medication for arthritis and a cough suggests a **drug-induced etiology**, a common trigger for SJS. *Erythema multiforme* - While erythema multiforme can present with a rash and some **mucosal involvement**, it typically manifests with **targetoid lesions** (target lesions with distinct rings), which are not described here. - It is generally a less severe condition than SJS and typically involves less extensive skin detachment. *Herpes zoster* - Herpes zoster (shingles) presents as a **unilateral, dermatomal rash** of vesicles on an erythematous base, often accompanied by pain and itching. - The described rash is **diffuse and coalescing**, not dermatomal, making herpes zoster unlikely. *Herpes simplex virus* - Herpes simplex virus (HSV) typically causes **localized clusters of vesicles** on an erythematous base, most commonly around the mouth (cold sores) or genitals. - The extensive, diffuse rash with desquamation and bullae is inconsistent with typical HSV infection. *Toxic epidermal necrolysis* - **Toxic epidermal necrolysis (TEN)** is a more severe form of SJS, often considered a continuum of the same disease, but it involves **>30% body surface area** skin detachment. - The patient's rash is noted "only on the upper half of his back," suggesting less extensive involvement than typically seen in TEN.

Question 1008: A 42-year-old woman presents to her family physician with a headache. The patient reports that the symptoms started about 2 hours ago when she woke up and have not improved. She states the pain is moderate, throbbing, tight in character, and is located in the occipital region bilaterally. The patient denies any visual and audio disturbances, nausea, and vomiting. She recalls 2 similar headaches in the past month. She has no other relevant medical history. Current medications are alendronate and a daily multivitamin. The patient works long hours as a corporate attorney. A review of systems is significant for mild photophobia. Her temperature is 37.0°C (98.6°F), the blood pressure is 110/70 mm Hg, the pulse is 70/min, the respiratory rate is 18/min, and the oxygen saturation is 98% on room air. On physical exam, the patient is alert and oriented. There is moderate tenderness to palpation diffusely over the upper posterior cervical muscles and occipital region of the scalp. The remainder of the physical exam is normal. Laboratory tests are normal. Urine pregnancy test is negative. What is the next best step in management?

A. Administer high-flow oxygen, ibuprofen 200 mg orally, and sumatriptan 6 mg subcutaneously
B. Non-contrast CT of the head and neck
C. Recommend lifestyle changes, relaxation techniques, and massage therapy (Correct Answer)
D. T1/T2 MRI of the head and neck
E. Temporal artery biopsy

Explanation: ***Recommend lifestyle changes, relaxation techniques, and massage therapy*** - The patient's presentation with a **moderate, throbbing, tight, bilateral occipital headache**, associated with stress from long work hours and **tenderness in the posterior cervical and occipital muscles**, is highly suggestive of a **tension-type headache**. - Given the lack of red flag symptoms (e.g., focal neurological deficits, fever, severe sudden onset headache), and mild photophobia, **non-pharmacological approaches** (lifestyle changes, relaxation, massage) are the most appropriate first-line symptomatic and prophylactic management for frequent tension-type headaches. *Administer high-flow oxygen, ibuprofen 200 mg orally, and sumatriptan 6 mg subcutaneously* - This combination of treatments (high-flow oxygen, sumatriptan) is typically reserved for **cluster headaches** and **migraines**, not tension-type headaches. - While ibuprofen can be used for tension headaches, the **sumatriptan and oxygen are not indicated** and could lead to unnecessary side effects. *Non-contrast CT of the head and neck* - **Neuroimaging (CT or MRI) is not indicated** for a recurrent headache with typical tension-type features and no red flag symptoms like sudden onset "thunderclap" headache, focal neurological deficits, papilledema, or new headache in an immunocompromised patient. - Doing so would expose the patient to **unnecessary radiation** and cost. *T1/T2 MRI of the head and neck* - Similar to CT, **MRI is not indicated** at this stage for a headache that is consistent with a benign primary headache disorder. - MRI is generally reserved for headache evaluation when there are concerns for **structural brain abnormalities** (e.g., tumors, vascular malformations) or neurological deficits. *Temporal artery biopsy* - **Temporal artery biopsy** is the gold standard for diagnosing **giant cell arteritis (GCA)**, a condition typically seen in patients over 50 years old with symptoms like new-onset headache, jaw claudication, visual disturbances, and elevated inflammatory markers (ESR, CRP). - The patient's age (42), lack of systemic symptoms of GCA, and normal laboratory tests make this diagnosis **highly unlikely**.

Question 1009: A 32-year-old woman comes to the physician because of weight gain, generalized weakness, and irregular menstrual cycles for the past 16 months. She began having symptoms of insomnia and depression 10 months ago. More recently, she has been having difficulties rising from a chair. She has a 2-year history of hypertension. Current medications include citalopram and hydrochlorothiazide. She is 168 cm (5 ft 6 in) tall and weighs 100 kg (220 lb). BMI is 36 kg/m2. Her pulse is 92/min, respirations are 18/min, and blood pressure is 134/76 mm Hg. She appears tired and has a full, plethoric face and central obesity. Examination of the skin shows violaceous linear striations on her lower abdomen. Two midnight serum cortisol studies show measurements of 288 μg/L and 253 μg/L (N < 90); a 24-hour urinary cortisol measurement was 395 μg (N < 300). Upon follow-up laboratory examination, the patient's serum ACTH levels were also elevated at 136 pg/mL (N = 7–50). Which of the following is the most appropriate next step in evaluation?

A. MRI of the head with contrast
B. High-dose dexamethasone suppression test (Correct Answer)
C. Measure ACTH levels in inferior petrosal sinuses
D. Bilateral adrenalectomy
E. CT scan of the abdomen with contrast

Explanation: ***High-dose dexamethasone suppression test*** - Elevated **midnight serum cortisol** and **24-hour urinary cortisol**, combined with elevated **ACTH levels**, confirm **ACTH-dependent Cushing's syndrome**. - A high-dose dexamethasone suppression test helps **differentiate** between a pituitary adenoma (Cushing's disease), which typically suppresses with high-dose dexamethasone, and ectopic ACTH production, which usually does not. *MRI of the head with contrast* - While an MRI of the head might eventually be performed to localize a pituitary adenoma, it is **not the immediate next step** after establishing ACTH dependency. - The high-dose dexamethasone suppression test provides crucial **functional information** about the source of ACTH prior to imaging. *Measure ACTH levels in inferior petrosal sinuses* - **Inferior petrosal sinus sampling (IPSS)** is used to **confirm and lateralize** a pituitary source of ACTH when imaging studies are equivocal or negative. - This is an **invasive procedure** typically reserved for after the high-dose dexamethasone suppression test has been performed and further distinction is needed. *Bilateral adrenalectomy* - **Bilateral adrenalectomy** is a treatment option for Cushing's syndrome, particularly for severe cases or when other treatments fail. - It is an **irreversible surgical procedure** and would only be considered after a definitive diagnosis and localization of the source of excess cortisol. *CT scan of the abdomen with contrast* - A CT scan of the abdomen is primarily used to evaluate for **adrenal adenomas or carcinomas** in cases of **ACTH-independent Cushing's syndrome**. - Given the **elevated ACTH levels**, an adrenal etiology is less likely, making this an inappropriate next step.

Question 1010: A 17-year-old male presents to your office complaining of polyuria, polydipsia, and unintentional weight loss of 12 pounds over the past 3 months. On physical examination, the patient is tachypneic with labored breathing. Which of the following electrolyte abnormalities would you most likely observe in this patient?

A. Hypophosphatemia
B. Hypermagnesemia
C. Hyperkalemia
D. Hyponatremia (Correct Answer)
E. Hyperphosphatemia

Explanation: ***Hyponatremia*** - This patient's symptoms of polyuria, polydipsia, and weight loss, along with **tachypnea and labored breathing**, are highly suggestive of **diabetic ketoacidosis (DKA)**. - **Hyponatremia** is the **most consistently observed** electrolyte abnormality in DKA, present in nearly all cases at initial presentation. - This is typically **pseudohyponatremia** caused by the osmotic effect of severe hyperglycemia—glucose pulls water into the extracellular space, diluting the measured sodium concentration. - The **corrected sodium** can be calculated using: Corrected Na = Measured Na + 0.016 × (Glucose - 100), which typically reveals a more normal sodium level. - True hyponatremia from sodium loss via **osmotic diuresis** can also occur but is usually masked by the dilutional effect. *Hyperkalemia* - While serum potassium may appear normal or even elevated initially due to **transcellular shifts** (acidosis causes potassium to move from intracellular to extracellular space in exchange for hydrogen ions), this is not the most consistently observed abnormality. - **Total body potassium is always depleted** in DKA due to osmotic diuresis and vomiting. - Many patients present with normal or even low potassium levels despite acidosis. - Potassium levels require careful monitoring during treatment as insulin therapy drives potassium back into cells, potentially causing life-threatening hypokalemia. *Hypophosphatemia* - While **phosphate levels** can fluctuate in DKA due to osmotic diuresis, initial presentation often involves normal or even elevated phosphate levels due to cellular shifts. - Significant **hypophosphatemia** is more typically observed during treatment as insulin drives phosphate back into the cells, similar to potassium. *Hypermagnesemia* - **Hypermagnesemia** is uncommon in DKA and is usually associated with impaired renal excretion or excessive magnesium intake. - The symptoms described do not point towards magnesium imbalance. *Hyperphosphatemia* - Although cellular shifts can initially raise serum phosphate, sustained **hyperphosphatemia** is not a characteristic or common electrolyte abnormality seen in the acute presentation of DKA. - More typically, total body phosphate is depleted due to **osmotic diuresis**.

Question 1011: A 53-year-old Asian woman comes to the physician because of a 2-month history of severe pain in her right leg while walking. She used to be able to walk a half-mile (800-m) to the grocery store but has been unable to walk 200 meters without stopping because of the pain over the past month. She can continue to walk after a break of around 5 minutes. She has hypertension, atrial fibrillation, and type 2 diabetes mellitus. She has smoked one pack of cigarettes daily for the past 32 years. Current medications include metformin, enalapril, aspirin, and warfarin. Vital signs are within normal limits. Examination shows an irregularly irregular pulse. The right lower extremity is cooler than the left lower extremity. The skin over the right leg appears shiny and dry. Femoral pulses are palpated bilaterally; pedal pulses are diminished on the right side. Which of the following is the most appropriate next step in management?

A. MRI spine screening
B. Duplex ultrasonography
C. Ankle-brachial index (Correct Answer)
D. Nerve conduction studies
E. Biopsy of tibial artery

Explanation: ***Ankle-brachial index*** - The patient's symptoms of **intermittent claudication** (leg pain with exertion relieved by rest) and risk factors (smoking, diabetes, atrial fibrillation, hypertension) are highly suggestive of **peripheral artery disease (PAD)**. The **ankle-brachial index (ABI)** is the most appropriate initial diagnostic step as it is a quick, non-invasive, and reliable test to screen for PAD by comparing blood pressure in the ankles to blood pressure in the arms. - A **diminished pedal pulse** on the right side and **cooler, shiny, dry skin** further support the suspicion of PAD, making ABI crucial for confirming the diagnosis and assessing its severity. *MRI spine screening* - While spinal pathology can cause leg pain, symptoms like **neurogenic claudication** typically improve with leaning forward or sitting and are not consistently relieved by standing still. The patient's pain relief with rest after walking points away from spinal stenosis. - The patient's specific peripheral signs like a **cooler leg**, **diminished pedal pulses**, and **trophic changes** are not typical findings for spinal compression. *Duplex ultrasonography* - **Duplex ultrasonography** is a more advanced imaging technique used to visualize the blood vessels and assess blood flow, typically performed *after* an abnormal ABI confirms the presence of PAD. - It helps in **localizing stenoses** and assessing their severity, but it is not the primary diagnostic screening tool in the initial evaluation of suspected PAD. *Nerve conduction studies* - **Nerve conduction studies (NCS)** are used to diagnose neuropathies. While diabetes is a risk factor for neuropathy, the patient's symptoms are classic for **vascular claudication** (pain with exertion, relieved by rest), rather than neuropathic pain, which is often described as burning, tingling, or numbing and does not typically resolve promptly with rest. - The physical exam findings of a **cool leg** and **diminished pulses** are not consistent with a primary neurological problem. *Biopsy of tibial artery* - A **biopsy of the tibial artery** is an invasive procedure generally reserved for specific types of vasculitis (e.g., giant cell arteritis, polyarteritis nodosa) when other less invasive diagnostics have been inconclusive or raised suspicion for these conditions. - It is not indicated for the initial workup of suspected **atherosclerotic peripheral artery disease**, which is the most likely diagnosis given the patient's risk factors and symptoms.

Question 1012: A 68-year-old woman comes to the physician for a follow-up visit for elevated blood pressure. Two weeks ago, her blood pressure was 154/78 mm Hg at a routine visit. Subsequent home blood pressure measurements at days 5, 10, and 14 have been: 156/76 mm Hg, 158/80 mm Hg, and 160/80 mm Hg. She has trouble falling asleep but otherwise feels well. She had a cold that resolved with over-the-counter medication 2 weeks ago. She has a history of primary hypothyroidism and a cyst in the right kidney, which was found incidentally 20 years ago. She takes levothyroxine. She is 178 cm (5 ft 10 in) tall and weighs 67 kg (148 lb); BMI is 21.3 kg/m2. Her pulse is 82/min, and blood pressure is 162/79 mm Hg. Examination shows no abnormalities. Laboratory studies, including thyroid function studies, serum electrolytes, and serum creatinine, are within normal limits. Which of the following is the most likely underlying cause of this patient's blood pressure findings?

A. Medication-induced vasoconstriction
B. Decrease in baroreceptor sensitivity
C. Increase in kidney size
D. Increase in aldosterone production
E. Decrease in arterial compliance (Correct Answer)

Explanation: ***Decrease in arterial compliance*** - As individuals **age**, the large elastic arteries become stiffer and less compliant due to changes in **collagen and elastin**, leading to an increase in **systolic blood pressure** and pulse pressure. This patient's blood pressure readings consistently show elevated systolic pressure without other identifiable causes. - The patient's age (68 years old) and the absence of other specific causes for secondary hypertension, combined with an isolated **systolic hypertension**, strongly suggest age-related decrease in arterial compliance as the underlying mechanism. *Medication-induced vasoconstriction* - While certain over-the-counter medications like **decongestants (e.g., pseudoephedrine)** can cause vasoconstriction and elevate blood pressure, the patient's cold resolved two weeks ago, making it unlikely to be a persistent cause of her current blood pressure readings. - There is no mention of her currently taking any medications known to cause vasoconstriction beyond the short-term use for her cold, which should have resolved. *Decrease in baroreceptor sensitivity* - **Baroreceptor sensitivity** can decrease with age, leading to impaired short-term blood pressure regulation and an increased risk of orthostatic hypotension, but it does not directly cause sustained **essential hypertension** or primarily elevated systolic pressure in this manner. - While decreased baroreflex sensitivity is common in the elderly, it is not the primary mechanism behind the patient's sustained high systolic blood pressure; rather, it relates more to blood pressure variability and postural changes. *Increase in kidney size* - An **increase in kidney size** is not typically associated with hypertension; rather, conditions like polycystic kidney disease, which causes renal enlargement, can cause hypertension through **renal ischemia** and **RAAS activation**, but the patient has a single simple cyst and normal renal function. - The patient's history of a simple renal cyst and normal renal function tests do not suggest any kidney-related pathology causing hypertension. *Increase in aldosterone production* - An **increase in aldosterone production** (primary hyperaldosteronism) typically causes **hypertension** along with **hypokalemia**, which is not present in this patient as her serum electrolytes are normal. - Primary hyperaldosteronism would likely present with **resistant hypertension** and often **metabolic alkalosis**, none of which are indicated by the patient's symptoms or laboratory findings.

Question 1013: A 58-year-old woman presents to the physician with a throbbing headache. She says she had it for the last year and it’s usually located in the right temporal area. There is localized tenderness over the scalp. During the last 2 weeks, she experienced 3 episodes of transient loss of vision on the right side, without ocular pain. On physical examination, her vital signs are normal. Palpation reveals that the pulsations of the superficial temporal artery on the right side are reduced in amplitude. Laboratory studies show: Blood hemoglobin 10.7 g/dL (6.64 mmol/L) Leukocyte count 8,000/mm3 (8.0 x 109/L) Platelet count 470,000/mm3 (470 x 109/L) Erythrocyte sedimentation rate 60 mm/h (60 mm/h) Which of the following conditions is most likely to co-exist with the presenting complaint in this woman?

A. Amyloidosis
B. Sjogren’s syndrome
C. Fibromyalgia
D. Polymyalgia rheumatica (Correct Answer)
E. Dermatomyositis

Explanation: ***Polymyalgia rheumatica*** - This patient's symptoms are highly suggestive of **giant cell arteritis** (temporal arteritis) due to the throbbing headache, temporal tenderness, reduced temporal artery pulsation, **amaurosis fugax**, and elevated ESR. - **Polymyalgia rheumatica** is closely associated with giant cell arteritis, often co-existing in up to 50% of patients. Both conditions are characterized by systemic inflammation. *Amyloidosis* - **Amyloidosis** is a disorder caused by the deposition of abnormal proteins in various tissues, leading to organ dysfunction. - It does not typically present with the acute inflammatory symptoms or vascular complications seen in this patient, and there is no direct link to giant cell arteritis. *Sjogren’s syndrome* - **Sjogren's syndrome** is an autoimmune disease primarily affecting the **exocrine glands**, leading to dry eyes and dry mouth. - While it can cause systemic symptoms, it does not typically manifest with temporal arteritis or its specific visual and cranial symptoms. *Fibromyalgia* - **Fibromyalgia** is a chronic condition characterized by widespread musculoskeletal pain, fatigue, and sleep disturbances, often without clear inflammation markers. - It is not associated with giant cell arteritis or the inflammatory markers (high ESR) and vascular occlusion symptoms (amaurosis fugax) seen in this patient. *Dermatomyositis* - **Dermatomyositis** is an inflammatory myopathy characterized by muscle weakness and distinctive skin rashes. - While it is an inflammatory condition, it does not typically present with the specific headache, temporal artery abnormalities, or visual symptoms that are hallmarks of giant cell arteritis.

Question 1014: A 15-year-old boy is brought to the physician by his father because he has been waking up frequently during the night to urinate. Apart from occasional headaches, he has no other complaints. His family recently emigrated from Tanzania and his medical history is unknown. His father was diagnosed with sickle cell disease at the age of 5. Physical examination shows no abnormalities. Laboratory studies show: Hemoglobin 14.5 g/dL Hematocrit 44% MCV 90 fL Reticulocytes 1.5% A hemoglobin electrophoresis shows: HbA 55% HbS 43% HbF 1% This patient is at greatest risk for which of the following conditions?

A. Avascular osteonecrosis
B. Renal papillary necrosis (Correct Answer)
C. Clear cell renal carcinoma
D. Functional asplenia
E. Ischemic stroke

Explanation: ***Renal papillary necrosis*** - The patient has **sickle cell trait (HbAS)**, evidenced by **55% HbA** and **43% HbS**. Individuals with sickle cell trait are at increased risk for **renal papillary necrosis** due to vaso-occlusive events in the renal medulla, exacerbated by the hypoxic, hyperosmolar, and acidic environment. - Clinical manifestations of renal papillary necrosis include **hematuria**, **flank pain**, and **polyuria/nocturia**, which aligns with the patient's presenting symptom of frequent nighttime urination. *Avascular osteonecrosis* - While individuals with **sickle cell disease (HbSS)** are at high risk for **avascular osteonecrosis** due to bone infarction, it is *less common* in those with sickle cell trait. - The patient's hemoglobin electrophoresis results (HbA 55%, HbS 43%) confirm **sickle cell trait**, not sickle cell disease. *Clear cell renal carcinoma* - **Clear cell renal carcinoma** is not directly associated with sickle cell trait. - While other renal malignancies like **renal medullary carcinoma** can occur in sickle cell trait patients, clear cell renal carcinoma typically presents later in life and is not the most likely complication given the patient's symptoms and genetic profile. *Functional asplenia* - **Functional asplenia** is a common and serious complication of **sickle cell disease (HbSS)**, leading to increased susceptibility to encapsulated bacterial infections. - It is *not typically seen* nor is it a major risk in individuals with **sickle cell trait**. *Ischemic stroke* - **Ischemic stroke** is a significant complication in patients with **sickle cell disease (HbSS)** due to chronic hemolysis and vaso-occlusion. - While there might be a *slightly increased risk* in sickle cell trait compared to the general population, it is *not as pronounced* as in sickle cell disease, and the presenting symptoms do not suggest an acute stroke.

Question 1015: A 59-year-old woman comes to the physician because of a 1-month history of episodic cough and shortness of breath. The cough is nonproductive and worsens when she climbs stairs and during the night. She has not had chest pain or palpitations. Eight weeks ago, she had fever, sore throat, and nasal congestion. She has a 10-year history of hypertension. She has smoked half a pack of cigarettes daily for 16 years. Her only medication is enalapril. Her pulse is 78/min, respirations are 18/min, and blood pressure is 145/95 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Diffuse end-expiratory wheezes are heard on pulmonary auscultation. An x-ray of the chest shows no abnormalities. Spirometry shows an FEV1:FVC ratio of 65% and an FEV1 of 60%. Which of the following is the most likely diagnosis?

A. Pneumonia
B. Side effect of medication
C. Asthma (Correct Answer)
D. Chronic bronchitis
E. Gastroesophageal reflux disease

Explanation: ***Asthma*** - The **episodic nature** of cough and shortness of breath, worsening with exertion and at night, along with diffuse **end-expiratory wheezes** and **obstructive spirometry** (FEV1:FVC ratio of 65% and FEV1 of 60%), strongly suggests asthma. The prior viral illness could have triggered airway hyperresponsiveness. - While she has a smoking history, the **episodic symptoms** and the degree of reversibility often seen in asthma (though not tested here) make it more likely than purely chronic obstructive conditions. *Pneumonia* - Pneumonia typically presents with a **productive cough**, fever, and often **abnormal chest X-ray findings**, none of which are consistent with this patient's presentation. - The symptoms of pneumonia are usually more acute and progressive, rather than episodic and triggered by activity or at night. *Side effect of medication* - **Enalapril**, an ACE inhibitor, can cause a **nonproductive cough**, but it's typically persistent and not episodic, nocturnal, or associated with wheezing or shortness of breath. - The spirometry findings of obstruction are not a typical side effect of enalapril, which primarily irritates the airways. *Chronic bronchitis* - Chronic bronchitis is characterized by a **chronic productive cough** for at least 3 months in 2 consecutive years, which is not described. - While chronic bronchitis can cause obstructive spirometry, the **episodic nature** of symptoms and nocturnal worsening are more characteristic of asthma. *Gastroesophageal reflux disease* - GERD can cause a **chronic cough**, often nocturnal or post-prandial, but it is typically not associated with **wheezing** or **shortness of breath** or the specific obstructive spirometry pattern seen. - Treatment for GERD would typically target acid suppression, and symptoms are not typically exercise-induced.

Question 1016: A previously healthy 13-year-old girl is brought to the physician for evaluation of a 2-month history of fatigue. She reports recurrent episodes of pain in her right wrist and left knee. During this period, she has had a 4-kg (8.8-lb) weight loss. Her mother has rheumatoid arthritis. Her temperature is 38°C (100.4°F). Examination shows diffuse lymphadenopathy. Oral examination shows several painless oral ulcers. The right wrist and the left knee are swollen and tender. Laboratory studies show a hemoglobin concentration of 9.8 g/dL, a leukocyte count of 2,000/mm3, and a platelet count of 75,000/mm3. Urinalysis shows excessive protein. This patient's condition is associated with which of the following laboratory findings?

A. Anti-citrullinated peptide antibodies
B. Anti-dsDNA antibodies (Correct Answer)
C. Leukocytoclastic vasculitis with IgA and C3 immune complex deposition
D. Positive HLA-B27 test
E. Excessive lymphoblasts

Explanation: ***Anti-dsDNA antibodies*** - The patient presents with **fatigue, fever, weight loss, lymphadenopathy, oral ulcers**, **arthralgia/arthritis**, and **proteinuria**, along with **anemia, leukopenia, and thrombocytopenia**. This constellation of symptoms is highly suggestive of **Systemic Lupus Erythematosus (SLE)**. - **Anti-dsDNA antibodies** are highly specific for SLE and are often associated with active disease, particularly **lupus nephritis**, which is indicated by the proteinuria. *Anti-citrullinated peptide antibodies* - These antibodies are highly specific for **rheumatoid arthritis (RA)**, a disease primarily affecting joints in a symmetrical pattern. - While the patient's mother has RA, the patient's systemic symptoms (fever, weight loss, anemia, leukopenia, thrombocytopenia, proteinuria) and oral ulcers are not typical features of RA, especially in a 13-year-old. *Leukocytoclastic vasculitis with IgA and C3 immune complex deposition* - This finding is characteristic of **IgA vasculitis (Henoch-Schönlein Purpura)**, which typically presents with a palpable purpuric rash, arthritis, abdominal pain, and renal involvement (hematuria/proteinuria). - The patient's presentation lacks the characteristic rash and GI symptoms, making this diagnosis less likely. *Positive HLA-B27 test* - A positive **HLA-B27** is associated with **spondyloarthropathies** such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis. - These conditions primarily affect the spine and sacroiliac joints, often with enthesitis, and do not typically present with the multi-systemic features like cytopenias, oral ulcers, and significant proteinuria observed in this patient. *Excessive lymphoblasts* - The presence of **excessive lymphoblasts** in the bone marrow or blood is indicative of **acute lymphoblastic leukemia (ALL)**. - Although ALL can present with fatigue, fever, weight loss, anemia, and thrombocytopenia, it is less commonly associated with oral ulcers, arthritis, and significant proteinuria. Additionally, while the patient has leukopenia (2,000/mm3), the presence of circulating lymphoblasts would be a key distinguishing feature of ALL that is not mentioned in this case.

Question 1017: A 27-year-old Asian woman presents to her primary care physician with joint pain and a headache. She has had intermittent joint and muscle pain for the past several months in the setting of a chronic headache. She states that the pain seems to migrate from joint to joint, and her muscles typically ache making it hard for her to sleep. The patient's past medical history is non-contributory, and she is currently taking ibuprofen for joint pain. Physical exam is notable for an asymmetrical pulse in the upper extremities. The patient has lost 10 pounds since her previous visit 2 months ago. Laboratory values are notable for an elevated C-reactive protein and erythrocyte sedimentation rate. Which of the following is the best next step in management?

A. Methotrexate
B. Recommend exercise and optimize the patient's sleep regimen
C. Prednisone (Correct Answer)
D. Temporal artery biopsy
E. Anti-dsDNA level

Explanation: ***Prednisone*** - The patient's presentation with **migratory joint pain**, headache, **asymmetrical pulses**, and elevated inflammatory markers (CRP, ESR) in a young Asian woman suggests **Takayasu arteritis**. - **Corticosteroids** like prednisone are the cornerstone of initial treatment for active Takayasu arteritis to suppress inflammation and prevent further vascular damage. *Methotrexate* - **Methotrexate** is an immunosuppressant often used in conjunction with corticosteroids or as a steroid-sparing agent in rheumatic conditions. - However, it's not the initial monotherapy of choice for active, severe vasculitis requiring rapid inflammation control. *Recommend exercise and optimize the patient's sleep regimen* - While exercise and sleep are important for overall well-being, they do not address the underlying **severe inflammatory vasculitis** and are not an appropriate primary intervention for Takayasu arteritis. - Delaying proper medical treatment can lead to irreversible vascular damage. *Temporal artery biopsy* - A **temporal artery biopsy** is the diagnostic gold standard for **Giant Cell Arteritis (GCA)**, which typically affects older individuals (>50 years). - The patient's age (27 years) and other clinical features are more consistent with Takayasu arteritis, which affects larger arteries and often presents at a younger age. *Anti-dsDNA level* - An **anti-dsDNA level** is a specific marker for **Systemic Lupus Erythematosus (SLE)**. - While SLE can cause joint pain and headaches, the presence of **asymmetrical pulses** and the demographic (young Asian woman) are more indicative of Takayasu arteritis, not SLE.

Question 1018: A 49-year-old woman presents to her primary care physician for a routine health maintenance examination. She says that she is currently feeling well and has not noticed any acute changes in her health. She exercises 3 times a week and has tried to increase the amount of fruits and vegetables in her diet. She has smoked approximately 1 pack of cigarettes every 2 days for the last 20 years. Her last pap smear was performed 2 years ago, which was unremarkable. Her past medical history includes hypertension and type II diabetes. Her mother was diagnosed with breast cancer at 62 years of age. The patient is 5 ft 5 in (165.1 cm), weighs 185 lbs (84 kg), and has a BMI of 30.8 kg/m^2. Her blood pressure is 155/98 mmHg, pulse is 90/min, and respirations are 18/min. Physical examination is unremarkable. Lipid studies demonstrate an LDL cholesterol of 130 mg/dL and an HDL cholesterol of 42 mg/dL. Which of the following is the best next step in management?

A. Colonoscopy
B. Pap smear
C. Mammogram
D. Chest radiography
E. Statin therapy (Correct Answer)

Explanation: ***Statin therapy*** - This patient has multiple **cardiovascular risk factors**, including a BMI of 30.8 kg/m^2 (obesity), hypertension, type II diabetes, and a history of smoking, placing her at high risk for **atherosclerotic cardiovascular disease (ASCVD)**. - Her **LDL cholesterol of 130 mg/dL** is elevated in the context of these risk factors, warranting **statin therapy** to reduce her ASCVD risk. *Colonoscopy* - **Routine colorectal cancer screening** with colonoscopy typically begins at age **45-50 for average-risk individuals**, or earlier for those with specific risk factors like a strong family history of early-onset colorectal cancer. - While this patient is 49, there is nothing in her history to suggest the need for urgent colonoscopy over managing her significant cardiovascular risks. *Pap smear* - The patient's last **Pap smear was 2 years ago and unremarkable**. Guidelines for cervical cancer screening generally recommend a Pap smear every **3 years for women aged 21-65 years** with normal results. - This recommendation suggests she is not yet due for another routine Pap smear. *Mammogram* - **Routine mammography screening** for breast cancer typically begins at age **40-50 for average-risk women**, depending on specific guideline recommendations (e.g., annually from 40, or biennially from 50). - While her mother had breast cancer at 62, this is not considered "early-onset" and does not necessarily warrant immediate mammography over other pressing health concerns, although it should be considered. *Chest radiography* - **Routine chest radiography** is generally **not recommended for asymptomatic adults**, even in smokers, for general health maintenance. - It is typically reserved for evaluating specific respiratory symptoms, abnormal physical exam findings, or occupational exposures.

Question 1019: A 28-year-old woman presents with severe vertigo. She also reports multiple episodes of vomiting and difficulty walking. The vertigo is continuous, not related to the position, and not associated with tinnitus or hearing disturbances. She has a past history of acute vision loss in her right eye that resolved spontaneously several years ago. She also experienced left-sided body numbness 3 years ago that also resolved rapidly. She only recently purchased health insurance and could not fully evaluate the cause of her previous symptoms at the time they presented. The patient is afebrile and her vital signs are within normal limits. On physical examination, she is alert and oriented. An ophthalmic exam reveals horizontal strabismus. There is no facial asymmetry and her tongue is central on the protrusion. Gag and cough reflexes are intact. Muscle strength is 5/5 bilaterally. She has difficulty maintaining her balance while walking and is unable to perform repetitive alternating movements with her hands. Which of the following is the best course of treatment for this patient’s condition?

A. Acyclovir
B. Azathioprine
C. Plasma exchange
D. High doses of glucose
E. High-dose corticosteroids (Correct Answer)

Explanation: ***High-doses of corticosteroids*** - The patient presents with a **neurological deficit**, specifically **vertigo**, in the context of a history of **disseminated neurological symptoms** (vision loss, numbness) that resolved spontaneously at different times. This clinical picture is highly suggestive of a **multiple sclerosis (MS) flare**. - **High-dose corticosteroids** (e.g., intravenous methylprednisolone) are the mainstay treatment for acute MS exacerbations to reduce inflammation and speed recovery. *Acyclovir* - **Acyclovir** is an antiviral medication used to treat viral infections, especially **herpes simplex virus** or **varicella-zoster virus**. - There is no evidence of a viral infection causing the patient's symptoms; MS is an **autoimmune demyelinating disease**, not a viral one. *Azathioprine* - **Azathioprine** is an **immunomodulatory drug** used as a disease-modifying therapy in MS to prevent relapses in the long term. - It is not used for the **acute treatment of an MS exacerbation** due to its slow onset of action. *Plasma exchange* - **Plasma exchange (plasmapheresis)** is considered for **severe acute MS attacks** that are refractory to corticosteroid therapy. - It is a second-line treatment, and high-dose corticosteroids should be tried first. *High doses of glucose* - **High doses of glucose** are used to treat conditions like **hypoglycemia** or in specific metabolic disorders. - This patient's symptoms are neurological and consistent with an inflammatory demyelinating process, for which glucose is not an appropriate treatment.

Question 1020: A 50-year-old woman comes to the physician because of worsening pain and swelling of her left knee. For the past year, she has had pain in her knees and hands bilaterally, but never this severe. During this period, she has also had difficulties moving around for about an hour in the mornings and has been sweating more than usual, especially at night. She has been sexually active with a new partner for the past 4 weeks, and they use condoms inconsistently. She occasionally drinks alcohol. The day before she drank 6 beers because she was celebrating a friend's birthday. Her temperature is 38.5°C (101.3°F), blood pressure is 110/70 mm Hg, and pulse is 92/min. The left knee is erythematous, swollen, and tender; movement is restricted due to pain. There is swelling of the metacarpophalangeal joints and proximal interphalangeal joints bilaterally. Arthrocentesis of the knee with synovial fluid analysis shows a greenish, turbid fluid, a cell count of 68,000 WBC/μL and Gram-negative diplococci. An x-ray of the affected knee is most likely to show which of the following findings?

A. Osteophytes and subchondral cysts
B. Calcifications and osteolysis with moth-eaten appearance
C. Irregularity or fragmentation of the tubercle
D. Calcification of the meniscal and hyaline cartilage
E. Joint space narrowing and bone erosions (Correct Answer)

Explanation: ***Joint space narrowing and bone erosions*** - The patient presents with symptoms and signs consistent with **septic arthritis** due to **Gram-negative diplococci**, likely *N. gonorrhoeae*, superimposed on a history suggestive of **rheumatoid arthritis** (morning stiffness, symmetrical polyarthritis of small joints). - Both conditions can cause **joint space narrowing** and **bone erosions** on X-ray; septic arthritis causes rapid destruction, while rheumatoid arthritis leads to chronic inflammatory erosion. *Osteophytes and subchondral cysts* - These findings are characteristic of **osteoarthritis**, a degenerative joint disease. - While the patient has chronic joint pain, the acute inflammatory signs (fever, erythema, high WBC count in synovial fluid, Gram-negative diplococci) point away from primary osteoarthritis. *Calcifications and osteolysis with moth-eaten appearance* - **Calcifications** in bones or joints can be seen in various conditions, but **osteolysis with a moth-eaten appearance** is more indicative of aggressive bone lesions, such as those caused by **malignancy** or severe osteomyelitis, which is not suggested by the clinical picture. - The predominant issue here is acute and chronic inflammatory arthritis, not a destructive bone tumor. *Irregularity or fragmentation of the tubercle* - This finding, particularly of the tibial tubercle, is commonly associated with conditions like **Osgood-Schlatter disease** in adolescents due to repetitive stress. - It is not a typical X-ray finding for either septic arthritis or rheumatoid arthritis in an adult knee. *Calcification of the meniscal and hyaline cartilage* - This is known as **chondrocalcinosis** and is a hallmark of **calcium pyrophosphate deposition disease (CPPD)**, also known as pseudogout. - While CPPD can cause acute arthritis, the presence of Gram-negative diplococci and systemic symptoms points to an infectious etiology, and the chronic symmetrical polyarthritis is inconsistent with typical CPPD.

Question 1021: A 74-year-old man presents to the emergency room with abdominal pain. He reports acute onset of left lower quadrant abdominal pain and nausea three hours prior to presentation. The pain is severe, constant, and non-radiating. He has had two maroon-colored bowel movements since the pain started. His past medical history is notable for hypertension, hyperlipidemia, atrial fibrillation, insulin-dependent diabetes mellitus, and rheumatoid arthritis. He takes lisinopril, hydrochlorothiazide, atorvastatin, dabigatran, methotrexate. He has a 60 pack-year smoking history and drinks 1-2 beers per day. He admits to missing some of his medications recently because he was on vacation in Hawaii. His last colonoscopy was 4 years ago which showed diverticular disease in the descending colon and multiple sessile polyps in the sigmoid colon which were removed. His temperature is 100.1°F (37.8°C), blood pressure is 145/85 mmHg, pulse is 100/min, and respirations are 20/min. On exam, he has notable abdominal distention and is exquisitely tender to palpation in all four abdominal quadrants. Bowel sounds are absent. Which of the following is the most likely cause of this patient’s condition?

A. Cardiac thromboembolism
B. Splanchnic vasoconstriction
C. Perforated intestinal mucosal herniation (Correct Answer)
D. Paradoxical thromboembolism
E. Duodenal compression

Explanation: ***Perforated intestinal mucosal herniation*** - This patient's presentation with acute abdominal pain, maroon-colored bowel movements, fever, abdominal distention, diffuse tenderness, and absent bowel sounds, in the context of a history of **diverticular disease**, strongly suggests **perforated diverticulitis**. The "intestinal mucosal herniation" refers to a diverticulum, which can perforate. - The history of **diverticular disease** and involvement of the **left lower quadrant pain** followed by generalized peritonitis and GI bleeding (maroon stools) makes this the most likely diagnosis. *Cardiac thromboembolism* - While the patient has **atrial fibrillation** and is on **dabigatran** (which he may have missed), a cardiac thromboembolism would typically lead to **ischemic enteritis** or **mesenteric ischemia**, presenting with severe pain out of proportion to exam findings, but diffuse peritonitis and perforation are less common primary presentations. - The clinical picture strongly points towards a localized process that progressed to peritonitis rather than a primary embolic event causing perforation directly without prior significant ischemia symptoms. *Splanchnic vasoconstriction* - This mechanism is associated with **non-occlusive mesenteric ischemia**, often seen in critically ill patients, those on vasoconstrictors, or with **low cardiac output states**. - While the patient has risk factors for vascular disease, the acute onset, localized pain progressing to diffuse peritonitis, and history of diverticula make a perforated diverticulum more probable than primary non-occlusive ischemia leading to perforation. *Paradoxical thromboembolism* - A paradoxical embolism involves a clot from the venous system bypassing the pulmonary circulation to enter the systemic circulation, typically through a **patent foramen ovale** or **atrial septal defect**. - There is no clinical evidence in the patient's history to suggest such a defect or a venous thrombosis as the origin of the embolus, making it a less likely mechanism for the presenting symptoms. *Duodenal compression* - **Duodenal compression** (e.g., from superior mesenteric artery syndrome) typically causes **proximal bowel obstruction** symptoms like nausea, vomiting, and epigastric pain, often worse postprandially. - This patient's symptoms of left lower quadrant pain, diffuse peritonitis, and maroon-colored stools are not consistent with duodenal compression.

Question 1022: A 66-year-old man undergoes a coronary artery bypass grafting. Upon regaining consciousness, he reports that he cannot see from either eye and cannot move his arms. Physical examination shows bilaterally equal, reactive pupils. A fundoscopy shows no abnormalities. An MRI of the brain shows wedge-shaped cortical infarcts in both occipital lobes. Which of the following is the most likely cause of this patient's current symptoms?

A. Lipohyalinosis
B. Atherothrombosis
C. Amyloid angiopathy
D. Cardiac embolism
E. Systemic hypotension (Correct Answer)

Explanation: ***Systemic hypotension*** - **Watershed infarcts** secondary to systemic hypotension often occur in areas supplied by the most distal branches of major arteries, such as the regions between the middle and posterior cerebral arteries that supply the **occipital lobes**. - **Bilateral occipital lobe infarcts** would explain the blindness (**cortical blindness**) despite normal pupillary reflexes and fundoscopy, as the primary visual cortex is affected, while the brainstem pathway for pupillary reflexes is spared. *Lipohyalinosis* - This is a process affecting **small, penetrating arteries**, leading to **lacunar infarcts** and is typically associated with chronic hypertension and diabetes. - It would not typically cause large, wedge-shaped cortical infarcts in multiple arterial territories like the occipital lobes. *Atherothrombosis* - This involves the formation of a **thrombus on an atherosclerotic plaque**, commonly in large or medium-sized arteries. - While it can cause strokes, atherothrombosis is less likely to cause widespread, bilateral watershed infarcts, which are more indicative of a global hypoperfusion event. *Amyloid angiopathy* - This condition involves **amyloid deposition in small and medium-sized cerebral arteries**, primarily causing lobar hemorrhages or microinfarcts. - It is not a common cause of acute, large bilateral occipital lobe infarcts, especially in the context of perioperative complications. *Cardiac embolism* - A cardiac embolus would typically cause an **infarct in a single arterial territory**, often affecting unilateral cerebral hemisphere or a single lobe. - It is less likely to cause **bilateral, symmetrical watershed infarcts**, which are characteristic of global hypoperfusion rather than focal embolic occlusion.

Question 1023: A 27-year-old woman comes to the physician because of a 3-day history of a sore throat and fever. Her temperature is 38.5°C (101.3°F). Examination shows edematous oropharyngeal mucosa and enlarged tonsils with purulent exudate. There is tender cervical lymphadenopathy. If left untreated, which of the following conditions is most likely to occur in this patient?

A. Rheumatic fever (Correct Answer)
B. Rheumatoid arthritis
C. Erythema multiforme
D. Toxic shock syndrome
E. Post-streptococcal glomerulonephritis

Explanation: ***Rheumatic fever*** - The patient presents with classic symptoms of **streptococcal pharyngitis** (sore throat, fever, tonsillar exudate, tender cervical lymphadenopathy), which, if left untreated, is a major risk factor for developing **acute rheumatic fever**. - **Acute rheumatic fever** is a serious inflammatory disease that can affect the **heart valves**, joints, brain, and skin, occurring in approximately **3% of untreated cases** of Group A Streptococcal pharyngitis. *Rheumatoid arthritis* - This is a **chronic autoimmune inflammatory disease** primarily affecting the synovial joints, not typically associated with an acute streptococcal infection. - It involves a different pathophysiological mechanism and is not a direct complication of untreated streptococcal pharyngitis. *Erythema multiforme* - This is an **acute, self-limiting skin condition** often triggered by infections (e.g., Herpes simplex virus) or medications, resulting in target lesions. - While infections can cause it, **streptococcal pharyngitis** is not a common or direct cause, and it's not a systemic complication similar to rheumatic fever. *Toxic shock syndrome* - This is a **rapidly progressing infectious disease** characterized by fever, rash, hypotension, and multi-organ failure, most often caused by toxins produced by *Staphylococcus aureus* or *Streptococcus pyogenes*. - While *Streptococcus pyogenes* (Group A Strep) can cause it, toxic shock syndrome is an **acute complication** rather than a late sequela of untreated infection, making **rheumatic fever** the more characteristic delayed complication. *Post-streptococcal glomerulonephritis* - While this is another serious immune-mediated complication of **streptococcal infections**, it **more commonly follows skin infections (impetigo)** than pharyngitis. - **Rheumatic fever** is the most characteristic and clinically significant late complication of untreated streptococcal **pharyngitis** specifically, with greater emphasis in clinical practice due to its potential for permanent cardiac valve damage.

Question 1024: A 54-year-old man is brought to the physician by his wife because of progressive difficulty walking during the past 3 months. He has not been able to walk without assistance for the past month and has started to use a wheelchair. He also reports having urinary incontinence for 1 year. His wife says that he has begun to slur his words and has become very difficult to understand. His temperature is 37.0°C (98.6°F), pulse is 70/min, and respirations are 16/min. His blood pressure is 130/80mm Hg while sitting and 110/65mm Hg when standing. He is oriented to person and place but not to time. Neurological examination shows a mild tremor in his right hand and rigidity in his upper and lower extremities. He is unable to perform repetitive rotary forearm movements. Which of the following is the most likely diagnosis?

A. Parkinson disease
B. Corticobasal degeneration
C. Friedreich ataxia
D. Normal pressure hydrocephalus
E. Multiple system atrophy (Correct Answer)

Explanation: ***Multiple system atrophy*** - This patient presents with the classic triad of **parkinsonism** (rigidity, tremor), **cerebellar dysfunction** (ataxia, slurred speech, inability to perform repetitive rotary forearm movements indicating dysdiadochokinesia), and prominent **autonomic dysfunction** (urinary incontinence, orthostatic hypotension). - The rapid progression of symptoms within a few months, including gait instability requiring a wheelchair and severe dysarthria, also points toward an aggressive neurodegenerative disorder like MSA rather than a slower progressing one. *Parkinson disease* - While patients with Parkinson disease can present with **parkinsonism** (tremor, rigidity), they typically do not exhibit early and severe **autonomic dysfunction** (like orthostatic hypotension and urinary incontinence) or prominent **cerebellar signs** (ataxia, severe dysarthria, dysdiadochokinesia) at this early stage. - The progression in Parkinson disease is usually much slower, and requiring a wheelchair within months is atypical. *Corticobasal degeneration* - This condition is characterized by marked **asymmetry** of motor symptoms, often with **apraxia**, **alien limb phenomenon**, and cortical sensory deficits, which are not described here. - While it can cause rigidity and gait disturbance, the significant autonomic dysfunction and cerebellar signs are not typical features. *Friedreich ataxia* - This is an inherited neurodegenerative disease that primarily affects the **spinal cord and cerebellum**, leading to **ataxia**, dysarthria, and pyramidal signs. - However, Friedreich ataxia typically presents in childhood or adolescence, and while it causes ataxia and dysarthria, prominent parkinsonism and severe autonomic dysfunction are not characteristic. *Normal pressure hydrocephalus* - This condition is characterized by a triad of **gait disturbance**, **urinary incontinence**, and **dementia**. While these are present, the patient also exhibits clear signs of **parkinsonism** (tremor, rigidity) and **cerebellar dysfunction** (dysarthria, dysdiadochokinesia) that are not features of NPH. - The orthostatic hypotension is also not a typical finding in NPH.

Question 1025: A 50-year-old man is brought to the emergency department by his wife because of lethargy and confusion for the past 24 hours. He has also had a productive cough for the past year and has had a 10-kg (22-lb) weight loss over the past 6 months. He has a history of multiple sclerosis and has not had an acute exacerbation in over 10 years. For the past 30 years, he has smoked 2 packs of cigarettes daily. He drinks 2 beers every day after work. His temperature is 37.0°C (98.6°F), pulse is 90/min, blood pressure is 130/90 mm Hg, and respirations are 22/min. On examination, the patient appears lethargic and cannot state his name or his location. Physical examination reveals scattered wheezing bilaterally. Deep tendon reflexes cannot be elicited. Laboratory studies show: Serum Na+ 115 mEq/L K+ 4.5 mEq/L HCO3- 22 mEq/L Glucose 70 mg/dL Blood urea nitrogen 8 mg/dL Urine osmolality 450 mOsmol/kg H2O Urine sodium 70 mEq/L An x-ray of the chest reveals a central lung mass. Which of the following is the next best step in management?

A. Order CT scan of the chest
B. Administer hypertonic saline (Correct Answer)
C. Administer conivaptan
D. Administer demeclocycline
E. Administer furosemide

Explanation: **Administer hypertonic saline** - The patient presents with **severe symptomatic hyponatremia** (Na+ 115 mEq/L) accompanied by neurological symptoms like lethargy and confusion, which necessitates urgent correction to prevent cerebral edema and herniation. - The constellation of a central lung mass, chronic cough, weight loss, and inappropriate ADH secretion (evidenced by concentrated urine with high urine sodium despite hyponatremia) is highly suggestive of **Small Cell Lung Cancer (SCLC)** causing **SIADH**. Rapid correction with hypertonic saline is indicated for severe symptomatic hyponatremia, especially when likely due to SIADH. *Order CT scan of the chest* - While a CT scan of the chest is crucial for further investigating the suspected lung mass, addressing the **life-threatening symptomatic hyponatremia** takes immediate precedence over diagnostic imaging. - The CT scan should be performed after initial stabilization to evaluate the extent of the suspected lung cancer and guide definitive treatment for the underlying cause of SIADH. *Administer conivaptan* - Conivaptan is a **vasopressin receptor antagonist** used to treat hyponatremia, particularly in cases of SIADH or heart failure. - However, for **severe symptomatic hyponatremia**, particularly with neurological compromise, conivaptan's onset of action may be too slow, and initial management typically involves **hypertonic saline** for rapid correction. *Administer demeclocycline* - Demeclocycline is an **antibiotic** that can inhibit ADH action in the renal tubules, making it useful for chronic mild-to-moderate SIADH, particularly for long-term management. - It is **not suitable for acute, severe symptomatic hyponatremia** requiring rapid correction, as its effects are not immediate. *Administer furosemide* - Furosemide is a **loop diuretic** that can be used in SIADH, often in conjunction with hypertonic saline, to induce a water diuresis and prevent volume overload during hypertonic saline administration, especially in patients who are euvolemic or mildly hypervolemic. - However, administering furosemide alone would worsen volume depletion if present, and it does not directly address the urgent need for sodium replacement in **severe symptomatic hyponatremia**.

Question 1026: A 55-year-old man with no significant medical history returns for follow-up of a fasting blood glucose (FBG) of 110 mg/dL. His mother had a myocardial infarction at age 52. He weighs 90 kg and his body mass index is 35 kg/m2. His repeat FBG is 160 mg/dL and hemoglobin A1c (HbA1c) is 7.0%. He is started on metformin but is lost to follow-up. Two years later, his HbA1c is 7.6% despite maximal metformin usage, so the patient is started on glyburide. Three months later, his HbA1c is 7.3% while on both medications, and subsequently prescribed glargine and aspart. Three months later, he is brought by his wife to the emergency department for evaluation of altered mental status. His electronic medical record notes that he was started on nitrofurantoin recently for a urinary tract infection. He is disoriented to place and time. His temperature is 99°F (37.2°C), blood pressure is 90/60 mmHg, pulse is 130/min, respirations are 26/min. His basic metabolic panel is shown below: Serum: Na+: 119 mEq/L Cl-: 90 mEq/L K+: 4.2 mEq/L HCO3-: 24 mEq/L BUN: 25 mg/dL Glucose: 1,400 mg/dL Creatinine: 1.9 mg/dL His urine dipstick is negative for ketones. A peripheral intravenous line is established. What is the best initial step in management?

A. Glargine insulin
B. 3% hypertonic saline
C. Regular insulin
D. Regular insulin and potassium
E. Lactated ringer's solution (Correct Answer)

Explanation: ***Lactated ringer's solution*** * The patient presents with **hyperglycemic hyperosmolar state (HHS)**, characterized by severe hyperglycemia (glucose 1400 mg/dL), altered mental status, and severe dehydration (hypotension, tachycardia). Initial management prioritizes **aggressive intravenous fluid resuscitation** to correct dehydration and lower osmolality. * **Lactated Ringer's solution** or **0.9% normal saline** are appropriate initial fluids to restore intravascular volume and improve renal perfusion, preparing the patient for insulin therapy. *Glargine insulin* * While insulin is essential for treating HHS, **glargine is a long-acting insulin** and not appropriate for the immediate, acute management of severe hyperglycemia and dehydration in HHS. * **Rapid-acting or regular insulin** is needed, but only after initial fluid resuscitation has begun and the patient's fluid status is stabilized. *3% hypertonic saline* * **Hypotonic hyponatremia** (Na+ 119 mEq/L) despite severe hyperglycemia is likely **pseudohyponatremia** due to the osmotic effect of very high glucose. The corrected sodium should be calculated. * **3% hypertonic saline** is used for severe, symptomatic hyponatremia, especially when it is true hyponatremia causing cerebral edema, which is not the primary immediate concern here; the immediate priority is fluid repletion for dehydration. *Regular insulin* * **Regular insulin** is the correct type of insulin for HHS management, but it should generally be initiated **after volume resuscitation** has begun to avoid precipitating rapid osmotic shifts and hypokalemia. * Administering insulin first without adequate fluids can worsen dehydration and electrolyte imbalances, particularly **hypokalemia** as insulin drives potassium into cells. *Regular insulin and potassium* * While **regular insulin** is eventually needed and **potassium** may be required later, initiating both simultaneously as the *best initial step* is incorrect. * The immediate and most critical step is **fluid resuscitation** to address profound dehydration and hypovolemic shock. Potassium levels need to be monitored closely during insulin therapy, but in this case, initial potassium is normal (4.2 mEq/L).

Question 1027: A 70-year-old man presented to a medical clinic for a routine follow-up. He has had hypertension for 20 years and is currently on multiple anti-hypertensive medications. The blood pressure is 150/100 mm Hg. The remainder of the examinations were within normal limits. Echocardiography showed some changes in the left ventricle. What is the most likely reason for the change?

A. Disordered growth of the cardiac cells
B. Increase in number of normal cardiac cells
C. Replacement of cardiac cells into stronger red fiber skeletal cells
D. Decrease in cardiac cell size
E. Increase in cardiac cell size (Correct Answer)

Explanation: ***Increase in cardiac cell size*** - Chronic **hypertension** increases the afterload on the left ventricle, causing the cardiac muscle cells (myocytes) to **hypertrophy** (increase in size) to generate greater force to eject blood. - This adaptive change is a compensatory mechanism to maintain cardiac output against increased systemic vascular resistance. *Disordered growth of the cardiac cells* - This description typically refers to **dysplasia**, which involves abnormal cell growth and organization, often raising suspicion for pre-cancerous conditions. - Cardiac muscle cells, being terminally differentiated, do not commonly undergo dysplastic changes in response to hypertension. *Increase in number of normal cardiac cells* - An increase in the number of cells is known as **hyperplasia**, a process that occurs in tissues with high regenerative capacity. - Mature **cardiac myocytes** have very limited proliferative capacity, so an increase in their number is not the primary mechanism of ventricular adaptation to hypertension. *Replacement of cardiac cells into stronger red fiber skeletal cells* - This scenario describes **metaplasia**, where one differentiated cell type is replaced by another. - Such a transformation from cardiac muscle to skeletal muscle cells does not occur in response to hypertension and is biologically impossible within the heart. *Decrease in cardiac cell size* - A decrease in cell size, or **atrophy**, occurs due to decreased workload, nutrition, or hormonal stimulation. - In hypertension, the workload on the heart is significantly increased, leading to hypertrophy rather than atrophy.

Question 1028: A 14-year-old male presents to the emergency department with altered mental status. His friends who accompanied him said that he complained of abdominal pain while camping. They denied his consumption of anything unusual from the wilderness, or any vomiting or diarrhea. His temperature is 100.5°F (38.1°C), blood pressure is 95/55 mmHg, pulse is 130/min, and respirations are 30/min. His pupils are equal and reactive to light bilaterally. The remainder of the physical exam is unremarkable. His basic metabolic panel is displayed below: Serum: Na+: 116 mEq/L Cl-: 70 mEq/L K+: 4.0 mEq/L HCO3-: 2 mEq/L BUN: 50 mg/dL Glucose: 1010 mg/dL Creatinine: 1.2 mg/dL While the remainder of his labs are pending, the patient becomes bradypneic and is intubated. His ventilator is adjusted to volume control assist-control with a respiratory rate (RR) of 14/min, tidal volume (Vt) of 350 mL, positive end-expiratory pressure (PEEP) of 5 cm H2O, and fractional inspired oxygen (FiO2) of 40%. His height is 5 feet 5 inches. Intravenous fluids and additional medical therapy are administered. An arterial blood gas obtained after 30 minutes on these settings shows the following: pH: 7.05 pCO2 :40 mmHg pO2: 150 mmHg SaO2: 98% What is the best next step in management?

A. Increase respiratory rate
B. Increase respiratory rate and tidal volume (Correct Answer)
C. Increase tidal volume
D. Increase tidal volume and positive end-expiratory pressure
E. Increase positive end-expiratory pressure

Explanation: ***Increase respiratory rate and tidal volume*** - The patient presents with **severe metabolic acidosis** (pH 7.05, HCO3- 2 mEq/L) due to likely **diabetic ketoacidosis** given the hyperglycemia and altered mental status. - To compensate for metabolic acidosis, the body attempts to lower pCO2 through **hyperventilation**; therefore, increasing both the **respiratory rate** and **tidal volume** will increase minute ventilation and help "blow off" CO2, thus improving the pH. *Increase respiratory rate* - While increasing the respiratory rate will help decrease pCO2 and improve pH, it may not be sufficient on its own to correct the severe acidosis. - **Tidal volume** also plays a crucial role in minute ventilation and CO2 elimination; addressing both components is more effective. *Increase tidal volume* - Increasing tidal volume alone will also increase minute ventilation and help reduce pCO2. - However, combining it with an increased respiratory rate is more effective for severe acidosis, as both parameters contribute to **CO2 clearance**. *Increase tidal volume and positive end-expiratory pressure* - Increasing tidal volume helps reduce pCO2, but increasing PEEP primarily improves **oxygenation** by preventing alveolar collapse and increasing functional residual capacity. - The patient's pO2 is already high (150 mmHg) with 98% SaO2, so **oxygenation is not the primary concern**; the focus should be on correcting the acidosis by reducing pCO2. *Increase positive end-expiratory pressure* - As mentioned, PEEP is primarily used to improve **oxygenation** and manage conditions like acute respiratory distress syndrome (ARDS), which is not the immediate problem here. - The patient's **pO2 is adequate**, and PEEP will not directly address the **severe metabolic acidosis** or aid significantly in CO2 removal.

Question 1029: A 65-year-old man presents to the emergency department for sudden weakness. The patient states that he was at home enjoying his morning coffee when his symptoms began. He says that his left arm suddenly felt very odd and weak thus prompting him to come to the ED. The patient has a past medical history of diabetes, COPD, hypertension, anxiety, alcohol abuse, and PTSD. He recently fell off a horse while horseback riding but claims to not have experienced any significant injuries. He typically drinks 5-7 drinks per day and his last drink was yesterday afternoon. His current medications include insulin, metformin, atorvastatin, lisinopril, albuterol, and fluoxetine. His temperature is 99.5°F (37.5°C), blood pressure is 177/118 mmHg, pulse is 120/min, respirations are 18/min, and oxygen saturation is 93% on room air. On physical exam, you note an elderly man who is mildly confused. Cardiopulmonary exam demonstrates bilateral expiratory wheezes and a systolic murmur along the right upper sternal border that radiates to the carotids. Neurological exam reveals cranial nerves II-XII as grossly intact with finger-nose exam mildly abnormal on the left and heel-shin exam within normal limits. The patient has 5/5 strength in his right arm and 3/5 strength in his left arm. The patient struggles to manipulate objects such as a pen with his left hand. The patient is given a dose of diazepam and started on IV fluids. Which of the following is the most likely diagnosis in this patient?

A. Bridging vein tear
B. Cerebellar bleeding
C. Berry aneurysm rupture
D. Hypertensive encephalopathy
E. Lipohyalinosis (Correct Answer)

Explanation: ***Lipohyalinosis*** - This patient's history of **hypertension** and **diabetes** are major risk factors for **lipohyalinosis**, which leads to **lacunar infarcts** and presents with sudden onset **pure motor hemiparesis**, as seen with the left arm weakness. - The elevated blood pressure of 177/118 mmHg further supports a diagnosis involving **cerebral small vessel disease** secondary to chronic hypertension. *Bridging vein tear* - A bridging vein tear would typically lead to a **subdural hematoma**, characterized by a **gradual onset of symptoms** like headache, confusion, and neurological deficits, often following trauma, which is inconsistent with the sudden onset in this case. - While the patient recently fell off a horse, his symptoms are acute and focal, not typical of the delayed presentation often seen with subdural hematomas. *Cerebellar bleeding* - **Cerebellar bleeding** usually presents with symptoms such as **ataxia**, **nystagmus**, vertigo, and vomiting, along with potential truncal instability, which are not the primary symptoms observed here. - While the patient has some mild abnormality on the finger-nose test, the predominant symptom is **pure motor weakness** of the left arm, making a cerebellar bleed less likely. *Berry aneurysm rupture* - A **berry aneurysm rupture** typically causes a **sudden, severe headache** (thunderclap headache), neck stiffness, photophobia, and altered mental status due to subarachnoid hemorrhage, which are not reported by the patient. - The patient's primary complaint is **focal motor weakness** and mild confusion, not the classic diffuse hemorrhagic symptoms of aneurysm rupture. *Hypertensive encephalopathy* - **Hypertensive encephalopathy** presents with a more generalized and rapidly progressive decline in neurological function, including severe headache, altered mental status, seizures, and visual disturbances, usually with **diastolic blood pressure >120 mmHg**. - While the patient's blood pressure is high, the presentation of **focal motor deficit without severe headache** or global neurological decline makes this less likely than a lacunar stroke due to lipohyalinosis.

Question 1030: A 40-year-old woman with a past medical history significant for pernicious anemia and vitiligo presents to the physician with the chief complaints of heat intolerance and frequent palpitations. The patient does not take birth control and her urine pregnancy test is negative today. Physical exam reveals a patient that is hyper-reflexive with a non-tender symmetrically enlarged thyroid gland. You order thyroid function tests for workup. What thyroid function values are most expected?

A. T4 decreased, free T4 decreased, T3 decreased, TSH decreased
B. T4 elevated, free T4 normal, T3 elevated, thyroid stimulating hormone (TSH) normal
C. T4 elevated, free T4 elevated, T3 elevated, TSH elevated
D. T4 normal, free T4 normal, T3 normal, TSH elevated
E. T4 elevated, free T4 elevated, T3 elevated, TSH decreased (Correct Answer)

Explanation: ***T4 elevated, free T4 elevated, T3 elevated, TSH decreased*** - The patient's symptoms (heat intolerance, palpitations, hyper-reflexia) and signs (non-tender symmetrically enlarged thyroid gland) are classic for **hyperthyroidism**, specifically **Graves' disease** given the autoimmune comorbidities (pernicious anemia, vitiligo). - In primary hyperthyroidism, the thyroid gland overproduces T3 and T4, leading to **elevated T3 and T4 levels**, which in turn suppress TSH secretion, resulting in a **decreased TSH**. *T4 decreased, free T4 decreased, T3 decreased, TSH decreased* - This pattern (low T3, T4, and TSH) is indicative of **central hypothyroidism** (secondary or tertiary hypothyroidism), where the pituitary or hypothalamus is unable to produce sufficient TSH. - This contrasts with the patient's symptoms and signs, which are clearly suggestive of an overactive thyroid gland. *T4 elevated, free T4 normal, T3 elevated, thyroid stimulating hormone (TSH) normal* - This combination is not consistent with a typical thyroid disorder scenario. While T4 and T3 could be elevated in hyperthyroidism, a **normal TSH** alongside elevated thyroid hormones is generally anomalous unless there is resistance to thyroid hormones or a TSH-secreting pituitary adenoma. - The elevated T3 and T4 would typically suppress TSH in primary hyperthyroidism, making a normal TSH unlikely. *T4 elevated, free T4 elevated, T3 elevated, TSH elevated* - This pattern (elevated TSH with elevated T3 and T4) is characteristic of **secondary hyperthyroidism**, such as a **TSH-secreting pituitary adenoma**. - While it represents hyperthyroidism, the patient's presentation with a symmetrically enlarged thyroid and autoimmune history strongly points towards Graves' disease, which is primary hyperthyroidism with suppressed TSH. *T4 normal, free T4 normal, T3 normal, TSH elevated* - This profile represents **subclinical hypothyroidism**, where the thyroid hormone levels are within the normal range, but the pituitary is working harder (elevated TSH) to maintain this normal state. - This contradicts the patient's overt symptoms of hyperthyroidism (heat intolerance, palpitations, hyper-reflexia).

Question 1031: A 25-year-old man is brought to the physician because of fatigue, lethargy, and lower leg swelling for 2 weeks. He also noticed that his urine appeared darker than usual and for the last 2 days he has passed only small amounts of urine. His temperature is 37.5°C (98.6°F), pulse is 88/min, respirations are 15/min, and blood pressure is 154/98 mm Hg. Examination shows 2+ pretibial edema bilaterally. Laboratory studies show: Hemoglobin 10.9 g/dL Leukocyte count 8200/mm3 Platelet count 220,000/mm3 Serum Na+ 137 mEq/L Cl- 102 mEq/L K+ 4.8 mEq/L HCO3- 22 mEq/L Glucose 85 mg/dL Urea nitrogen 34 mg/dL Creatinine 1.4 mg/dL Urine Blood 2+ Protein 3+ Glucose negative RBC 10–12/HPF with dysmorphic features RBC casts numerous Renal biopsy specimen shows a crescent formation in the glomeruli with extracapillary cell proliferation. Which of the following is the most appropriate next step in management?

A. Administer methylprednisolone (Correct Answer)
B. Administer lisinopril
C. Administer cyclosporine A
D. Perform hemodialysis
E. Administer rituximab

Explanation: ***Administer methylprednisolone*** - The patient presents with **rapidly progressive glomerulonephritis (RPGN)**, characterized by acute renal failure, nephritic-range proteinuria, dysmorphic red blood cells, RBC casts, and crescent formation on biopsy. **High-dose corticosteroids (e.g., methylprednisolone)** are the first-line treatment to suppress inflammation and preserve renal function in RPGN. - The presence of **crescent formation** in the glomeruli indicates severe glomerular injury and is a hallmark of RPGN, necessitating aggressive immunosuppressive therapy like corticosteroids. *Administer lisinopril* - **Lisinopril**, an **ACE inhibitor**, is primarily used to manage hypertension and reduce proteinuria in chronic kidney disease, but it is not the initial treatment for acute, rapidly progressing glomerulonephritis with active inflammation. - While the patient has hypertension (154/98 mm Hg), addressing the underlying inflammatory process with immunosuppression takes precedence over symptomatic blood pressure management in this acute setting. *Administer cyclosporine A* - **Cyclosporine A** is an immunosuppressant that can be used in certain forms of glomerulonephritis, but it is typically reserved for cases that are **refractory to corticosteroids** or as a second-line agent. - It's not typically the initial therapy for RPGN due to its potential **nephrotoxicity** and slower onset of action compared to high-dose corticosteroids. *Perform hemodialysis* - **Hemodialysis** is indicated for **end-stage renal disease** or severe complications of acute kidney injury, such as refractory anasarca, severe metabolic acidosis, or hyperkalemia. - While the patient has elevated creatinine and oliguria, his condition is acute and potentially reversible with immunosuppressive therapy. Hemodialysis would be considered if medical management fails or if life-threatening complications develop. *Administer rituximab* - **Rituximab**, an anti-CD20 monoclonal antibody, is used in specific types of glomerulonephritis, such as **ANCA-associated vasculitis** or **membranous nephropathy** that is refractory to other treatments. - It is not the initial treatment for undifferentiated RPGN, especially without specific serologic markers like ANCA being positive or an established diagnosis for which rituximab is the primary agent.

Question 1032: A 58-year-old woman is brought to the emergency department for shortness of breath and chest pain. Pulmonary angiography shows a large saddle embolus in the pulmonary arteries. Emergency drug therapy is administered and she is admitted to the hospital for observation. A follow-up CT scan of the chest shortly after admission shows that the thrombus has disappeared. Five hours later, the patient is found to be lethargic with slurred speech. Physical examination shows decreased consciousness, dysarthria, and optic disc swelling bilaterally. Which of the following is the most likely cause of her neurological symptoms?

A. Acute metabolic encephalopathy
B. Embolic cerebrovascular accident
C. Idiopathic intracranial hypertension
D. Intracerebral hemorrhage (Correct Answer)
E. Drug-induced hypotension

Explanation: ***Intracerebral hemorrhage*** - The patient was treated for a **saddle pulmonary embolism** with drug therapy (likely thrombolytics). This type of therapy carries a significant risk of **intracerebral hemorrhage**, especially in older patients or those with underlying risks. The sudden onset of neurological symptoms, including decreased consciousness, dysarthria, and **bilateral optic disc swelling** (indicating increased intracranial pressure), five hours after receiving thrombolytic therapy, is highly suspicious for a hemorrhagic stroke. - The rapid dissolution of the pulmonary thrombus followed by new neurological deficits strongly suggests a side effect of aggressive anticoagulation or thrombolysis. *Acute metabolic encephalopathy* - While metabolic encephalopathy can cause decreased consciousness and lethargy, it typically does not present with focal neurological signs like **dysarthria** or **optic disc swelling** indicating increased intracranial pressure. - The rapid onset immediately following thrombolytic treatment for a significant thromboembolic event points away from a primary metabolic cause. *Embolic cerebrovascular accident* - An embolic stroke could cause similar neurological symptoms, but the history of massive thrombolysis for a pulmonary embolism makes **hemorrhage** a more immediate concern given the treatment. Additionally, an embolic stroke would not typically cause **bilateral optic disc swelling** so rapidly. - While theoretically possible if a paradoxical embolism occurred (e.g., via a patent foramen ovale), the administration of powerful anticoagulants/thrombolytics makes hemorrhage the more probable complication. *Idiopathic intracranial hypertension* - This condition is characterized by **increased intracranial pressure without an identifiable cause** and primarily affects young, obese women. It typically presents with chronic headaches and visual disturbances, but rarely acute neurological deterioration with decreased consciousness or dysarthria. - The acute, post-treatment onset of symptoms is inconsistent with the chronic nature of idiopathic intracranial hypertension. *Drug-induced hypotension* - Severe hypotension could lead to global cerebral hypoperfusion and altered mental status, but it usually causes more generalized symptoms, and is less likely to produce focal neurological signs like **dysarthria** or **bilateral optic disc swelling** within such a short timeframe as the primary cause. - While hypotension can be a side effect of some drugs, the specific constellation of symptoms, particularly the optic disc swelling, points more directly towards an acute intracranial event like hemorrhage.

Question 1033: A 67-year-old man comes to the office due to pain in the lower part of his calves on his afternoon walk to get the mail. The pain is relieved by rest. It started slowly about 6 months ago and has become more painful over time. He has a history of hypertension, hyperlipidemia, diabetes mellitus, and a 20-pack-year smoking history. Medications include hydrochlorothiazide, atorvastatin, metformin, and a multivitamin that he takes daily. The patient quit smoking 2 years ago and only drinks socially. Today, his blood pressure is 145/90 mm Hg, pulse is 75/min, respiratory rate is 17/min, and temperature is 37.6°C (99.6°F). On physical exam, he appears mildly obese and healthy. His heart has a regular rate and rhythm, and his lungs are clear to auscultation bilaterally. Examination of the legs shows atrophic changes and diminished pedal pulses. A measure of his ankle brachial index (ABI) is 0.89. Which of the following is the most appropriate initial treatment?

A. A recommendation to walk more
B. Metoprolol
C. A recommendation to perform pedal pumping exercises
D. A referral to a supervised exercise program (Correct Answer)
E. Enoxaparin

Explanation: ***A referral to a supervised exercise program*** - The patient's symptoms (claudication, relief with rest), risk factors (**hypertension, hyperlipidemia, diabetes, smoking history**), physical exam findings (**atrophic changes, diminished pedal pulses**), and **ABI of 0.89** (indicating mild peripheral artery disease) all point to **peripheral arterial disease (PAD)**. - A **supervised exercise program**, particularly walking, is the most effective initial non-pharmacological treatment for improving walking distance and quality of life in patients with claudication due to PAD. *A recommendation to walk more* - While walking is beneficial, simply recommending "walking more" without specific guidance or supervision is less effective than a structured program. - An unsupervised general walking recommendation may not optimize the **duration**, **intensity**, or **frequency** needed for therapeutic benefit in PAD. *Metoprolol* - **Beta-blockers** like metoprolol can worsen claudication symptoms by decreasing blood flow to the extremities, especially in patients with PAD. - They are generally **contraindicated** or used with caution in PAD patients experiencing claudication. *A recommendation to perform pedal pumping exercises* - **Pedal pumping exercises** are primarily used to prevent **venous stasis** and **deep vein thrombosis**, typically post-surgery or during prolonged immobility. - They do not address the underlying arterial insufficiency causing claudication and are not an effective treatment for PAD. *Enoxaparin* - **Enoxaparin** is a low molecular weight heparin, an **anticoagulant** used for conditions like deep vein thrombosis or acute coronary syndromes. - It is not indicated for the chronic management of stable claudication in peripheral artery disease, where antiplatelet therapy is generally preferred if medication is needed.

Question 1034: A 51-year-old female presents to her primary care physician complaining of body aches and constipation. She reports that her "bones hurt" and that she has experienced worsening constipation over the past few months. Her medical history is notable for three kidney stones within the past year that both passed spontaneously. Her vital signs are stable. Physical examination reveals a small nodule near the right inferior pole of the thyroid, consistent with a parathyroid adenoma. Which of the following sets of serum findings is most likely in this patient?

A. Increased calcium, decreased phosphate, increased parathyroid hormone (Correct Answer)
B. Decreased calcium, increased phosphate, decreased parathyroid hormone
C. Normal calcium, normal phosphate, normal parathyroid hormone
D. Decreased calcium, increased phosphate, increased parathyroid hormone
E. Increased calcium, decreased phosphate, decreased parathyroid hormone

Explanation: ***Increased calcium, decreased phosphate, increased parathyroid hormone*** - This patient's symptoms, including "bones hurt" (bone pain), constipation, and a history of kidney stones (kidney groans), are classic manifestations of **hyperparathyroidism**, often associated with a parathyroid adenoma (nodule near the thyroid). - Primary hyperparathyroidism is characterized by inappropriately high **PTH levels** leading to increased calcium reabsorption from bone and kidneys, resulting in **hypercalcemia**, and increased phosphate excretion, leading to **hypophosphatemia**. *Decreased calcium, increased phosphate, decreased parathyroid hormone* - This profile suggests **hypoparathyroidism**, where reduced PTH leads to decreased calcium mobilization and renal phosphate clearance. - This scenario would not explain the patient's symptoms of bone pain, constipation, or kidney stones, which are related to elevated calcium. *Normal calcium, normal phosphate, normal parathyroid hormone* - This indicates **normal parathyroid function** and calcium homeostasis, which contradicts the presented symptoms pointing towards a significant metabolic disturbance. - The patient's clinical presentation strongly suggests an endocrine disorder affecting calcium regulation. *Decreased calcium, increased phosphate, increased parathyroid hormone* - This set of findings is characteristic of **secondary hyperparathyroidism**, often seen in chronic kidney disease where low calcium (due to impaired vitamin D activation) stimulates PTH release. - However, the patient's presentation with hypercalcemia-related symptoms like bone pain and kidney stones, along with a discrete parathyroid nodule, points more towards primary hyperparathyroidism. *Increased calcium, decreased phosphate, decreased parathyroid hormone* - This profile, with **hypercalcemia** and **low PTH**, is typical of **humoral hypercalcemia of malignancy** or vitamin D toxicity, where an external source of calcium raises levels without PTH involvement. - However, the presence of a palpable parathyroid nodule and the specific constellation of "stones, bones, groans" are highly indicative of primary hyperparathyroidism, which involves increased PTH.

Question 1035: A 42-year-old woman comes to the physician because of a 12 month history of progressive fatigue and shortness of breath with exertion. Five years ago, she emigrated from Eastern Europe. She has smoked one pack of cigarettes daily for 20 years. She has a history of using methamphetamines and cocaine but quit 5 years ago. Vital signs are within normal limits. Physical examination shows jugular venous pulsations 9 cm above the sternal angle. The lungs are clear to auscultation. There is a normal S1 and a loud, split S2. An impulse can be felt with the fingers left of the sternum. The abdomen is soft and nontender. The fingertips are enlarged and the nails are curved. There is pitting edema around the ankles bilaterally. An x-ray of the chest shows pronounced central pulmonary arteries and a prominent right heart border. Which of the following is most likely to confirm the diagnosis?

A. CT angiography
B. Serologic testing
C. Doppler echocardiography
D. High-resolution CT of the lung
E. Right-heart catheterization (Correct Answer)

Explanation: ***Right-heart catheterization*** - This is the **gold standard** for diagnosing **pulmonary hypertension** by directly measuring pulmonary artery pressure, pulmonary wedge pressure, and cardiac output. The patient's symptoms (fatigue, shortness of breath, loud split S2, prominent right heart border, JVP elevation, peripheral edema, digital clubbing) strongly suggest pulmonary hypertension. - It helps classify the type of pulmonary hypertension and guides treatment strategies, as **mean pulmonary artery pressure (mPAP) > 20 mmHg** at rest is diagnostic. *CT angiography* - Primarily used to diagnose **pulmonary embolism** or to evaluate for chronic thromboembolic pulmonary hypertension (CTEPH). While helpful in some cases of pulmonary hypertension, it does not directly measure pressures. - It would show emboli or chronic organized thrombi if present but doesn't provide the hemodynamic data needed to confirm the severity and type of pulmonary hypertension. *Serologic testing* - Used to identify underlying systemic diseases (e.g., **autoimmune conditions like scleroderma**) that can cause pulmonary hypertension. However, it does not directly confirm the diagnosis of pulmonary hypertension itself. - While it may uncover **etiological factors**, serological markers are not diagnostic for the presence or severity of pulmonary hypertension. *Doppler echocardiography* - A crucial initial screening tool that **estimates pulmonary artery pressure** and assesses right ventricular function, often prompting further investigation for pulmonary hypertension. - While highly suggestive, it is **indirect and an estimation**, and thus not considered definitive for confirming the diagnosis or for precise hemodynamic measurements. *High-resolution CT of the lung* - Used to evaluate for **interstitial lung disease** or other parenchymal lung conditions that can cause secondary pulmonary hypertension. - It provides detailed images of the lung parenchyma but does not directly measure pulmonary pressures or confirm the diagnosis of pulmonary hypertension.

Question 1036: A 57-year-old man presents to his physician with dyspnea on exertion and rapid heartbeat. He denies any pain during these episodes. He works as a machine operator at a solar panels manufacturer. He has a 21-pack-year history of smoking. The medical history is significant for a perforated ulcer, in which he had to undergo gastric resection and bypass. He also has a history of depression, and he is currently taking escitalopram. The family history is unremarkable. The patient weighs 69 kg (152 lb). His height is 169 cm (5 ft 7 in). The vital signs include: blood pressure 140/90 mm Hg, heart rate 95/min, respiratory rate 12/min, and temperature 36.6℃ (97.9℉). Lung auscultation reveals widespread wheezes. Cardiac auscultation shows decreased S1 and grade 1/6 midsystolic murmur best heard at the apex. Abdominal and neurological examinations show no abnormalities. A subsequent echocardiogram shows increased left ventricular mass and an ejection fraction of 50%. Which of the options is a risk factor for the condition detected in the patient?

A. History of gastric bypass surgery
B. Exposure to heavy metals
C. Escitalopram intake
D. The patient’s body mass
E. Smoking (Correct Answer)

Explanation: ***Smoking*** - The patient's 21-pack-year smoking history is a significant risk factor for **hypertension** and **cardiovascular disease**, contributing to increased left ventricular mass and cardiac dysfunction. - Smoking directly damages blood vessels and the heart, leading to increased afterload and subsequent **left ventricular hypertrophy** (LVH), as seen on this patient's echocardiogram. *History of gastric bypass surgery* - While gastric bypass surgery is associated with malabsorption and nutritional deficiencies (including thiamine deficiency leading to wet beriberi), it is not a direct risk factor for **hypertensive heart disease** with LVH. - The patient's elevated blood pressure (140/90 mm Hg) and smoking history are more directly responsible for the cardiac findings. *Exposure to heavy metals* - Exposure to certain heavy metals (e.g., lead, cadmium) can be associated with cardiovascular disease, but the patient's job as a machine operator at a solar panel manufacturer does not inherently imply significant exposure to these specific toxins. - The presenting symptoms and echocardiogram findings are more directly attributable to **hypertension** and **smoking**, which are clearly documented risk factors in this patient. *Escitalopram intake* - Escitalopram is an SSRI antidepressant with a generally low cardiotoxicity profile; it is not associated with **left ventricular hypertrophy** or the development of structural heart disease. - While some medications can affect cardiac function, escitalopram is not a primary risk factor for the observed changes. *The patient's body mass* - The patient's BMI can be calculated as 69 kg / (1.69 m)² ≈ 24.1 kg/m², which falls within the **normal weight range** (18.5-24.9 kg/m²). - Therefore, obesity and its associated cardiac risks (which can contribute to hypertension and LVH) are not applicable to this patient's presentation.

Question 1037: A 71-year-old male presents to the emergency department after having a generalized tonic-clonic seizure. His son reports that he does not have a history of seizures but has had increasing confusion and weakness over the last several weeks. An electrolyte panel reveals a sodium level of 120 mEq/L and a serum osmolality of 248 mOsm/kg. His urine is found to have a high urine osmolality. His temperature is 37° C (98.6° F), respirations are 15/min, pulse is 67/min, and blood pressure is 122/88 mm Hg. On examination he is disoriented, his pupils are round and reactive to light and accommodation and his mucous membranes are moist. His heart has a regular rhythm without murmurs, his lungs are clear to auscultation bilaterally, the abdomen is soft, and his extremities have no edema but his muscular strength is 3/5 bilaterally. There is hyporeflexia of all four extremities. What is the most likely cause of his symptoms?

A. Hereditary diabetes insipidus
B. Sheehan’s syndrome
C. Syndrome of Inappropriate Antidiuretic Hormone (SIADH) (Correct Answer)
D. Diabetic ketoacidosis
E. Lithium use

Explanation: ***Syndrome of Inappropriate Antidiuretic Hormone (SIADH)*** - This patient presents with **hypotonic hyponatremia** (serum Na 120 mEq/L, osmolality 248 mOsm/kg) in the setting of a **high urine osmolality**, indicating the kidney is inappropriately concentrating urine despite low plasma osmolality. - The symptoms of **confusion, weakness, generalized tonic-clonic seizure**, and **hyporeflexia** are consistent with severe hyponatremia affecting neurological function. *Hereditary diabetes insipidus* - This condition is characterized by the inability to concentrate urine, leading to **polyuria** and **polydipsia**, and often hypernatremia, which is the opposite of this patient's presentation. - Patients typically have **low urine osmolality** and high serum osmolality due to excessive water loss. *Sheehan's syndrome* - This syndrome is a cause of **hypopituitarism** due to postpartum hemorrhage, leading to deficiencies in various pituitary hormones, including ADH if the posterior pituitary is affected. - ADH deficiency would lead to **diabetes insipidus-like symptoms** (high serum osmolality, low urine osmolality, polyuria) and not the hyponatremia seen in this patient unless there's profound adrenal insufficiency (cortisol deficiency), but the primary lab findings contradict ADH excess. *Diabetic ketoacidosis* - This condition is characterized by **hyperglycemia**, metabolic acidosis, and ketonemia, often leading to polyuria and polydipsia, and can cause **hypernatremia** or pseudohyponatremia. - The patient's blood pressure, heart rate, and lack of symptoms like Kussmaul respirations or fruity breath do not support DKA, and his sodium is low, not high. *Lithium use* - Chronic lithium use can cause **nephrogenic diabetes insipidus** by interfering with ADH action in the renal tubules, leading to an inability to concentrate urine. - This would result in **polyuria, polydipsia**, and potentially hypernatremia and low urine osmolality, which is inconsistent with the patient's findings of hyponatremia and high urine osmolality.

Question 1038: A 71-year-old African American man is brought to the emergency department with sudden onset lower limb paralysis and back pain. He has had generalized bone pain for 2 months. He has no history of severe illnesses. He takes ibuprofen for pain. On examination, he is pale. The vital signs include: temperature 37.1°C (98.8°F), pulse 68/min, respiratory rate 16/min, and blood pressure 155/90 mm Hg. The neurologic examination shows paraparesis. The 8th thoracic vertebra is tender to palpation. X-ray of the thoracic vertebrae confirms a compression fracture at the same level. The laboratory studies show the following: Laboratory test Hemoglobin 9 g/dL Mean corpuscular volume 95 μm3 Leukocyte count 5,000/mm3 Platelet count 240,000/mm3 ESR 85 mm/hr Serum Na+ 135 mEq/L K+ 4.2 mEq/L Cl− 113 mEq/L HCO3− 20 mEq/L Ca+ 11.8 mg/dL Albumin 4 g/dL Urea nitrogen 38 mg/dL Creatinine 2.2 mg/dL Which of the following is the most likely mechanism underlying this patient’s vertebral fracture?

A. Increased mechanical pressure
B. Proliferation of tumor cells (Correct Answer)
C. Bone demineralization
D. Increased osteoblastic activity
E. Acidosis-induced bone lysis

Explanation: ***Proliferation of tumor cells*** - The patient's presentation with **bone pain**, **hypercalcemia** (11.8 mg/dL), **anemia** (Hb 9 g/dL), **elevated ESR** (85 mm/hr), and **vertebral compression fracture** is highly suggestive of **multiple myeloma**. - **Multiple myeloma** is characterized by the proliferation of malignant plasma cells in the bone marrow, which leads to bone destruction through **osteoclast activation** and inhibition of osteoblasts, making the bone susceptible to **pathological fractures**. *Increased mechanical pressure* - While mechanical pressure can contribute to fractures, it is typically seen in the context of trauma or repetitive stress on already weakened bone. - The clinical picture of systemic symptoms like **anemia, hypercalcemia**, and **elevated ESR** points to an underlying pathological process rather than solely mechanical forces. *Bone demineralization* - **Bone demineralization** can occur due to various conditions like osteoporosis or vitamin D deficiency, leading to weaker bones. - However, the patient's specific constellation of symptoms, including **paraparesis, hypercalcemia**, and a **compression fracture** in an older adult, points more directly toward a plasma cell dyscrasia rather than simple demineralization. *Increased osteoblastic activity* - Increased osteoblastic activity leads to **bone formation**, which would strengthen bones rather than predispose them to compression fractures. - Conditions with increased osteoblastic activity, such as Paget's disease, would typically present with different clinical and laboratory findings. *Acidosis-induced bone lysis* - **Chronic metabolic acidosis** can lead to bone demineralization and bone lysis over time, as the bone buffers the excess acid. - However, the patient's **bicarbonate level is 20 mEq/L**, which indicates a mild metabolic acidosis that is unlikely to be the primary cause of such severe, acute bone lysis and compression fracture in this context, especially with other strong indicators of **multiple myeloma**.

Question 1039: A 48-year-old man with a 30-pack-year history comes to the physician for a follow-up examination 6 months after a chest CT showed a solitary 5-mm solid nodule in the upper lobe of the right lung. The follow-up CT shows that the size of the nodule has increased to 2 cm. Ipsilateral mediastinal lymph node involvement is noted. A biopsy of the pulmonary nodule shows small, dark blue tumor cells with hyperchromatic nuclei and scarce cytoplasm. Cranial MRI and skeletal scintigraphy show no evidence of other metastases. Which of the following is the most appropriate next step in management?

A. Cisplatin-etoposide therapy and radiotherapy (Correct Answer)
B. Gefitinib therapy
C. Wedge resection
D. Radiation therapy
E. Right lobectomy

Explanation: ***Cisplatin-etoposide therapy and radiotherapy*** - The biopsy findings of **small, dark blue cells with hyperchromatic nuclei** are classic for **small cell lung cancer (SCLC)**. The rapid growth of the nodule and **ipsilateral mediastinal lymph node involvement** indicate locally advanced disease, which is best treated with combined **chemotherapy (cisplatin-etoposide)** and **radiotherapy**. - SCLC is highly aggressive and metastasizes early, rendering surgery typically ineffective for curative intent in this stage. Combined modality therapy improves survival in patients with limited-stage SCLC. *Gefitinib therapy* - **Gefitinib** is an **EGFR tyrosine kinase inhibitor** used for **non-small cell lung cancer (NSCLC)** that harbors specific sensitizing **EGFR mutations**. - It is not indicated for SCLC, as this type of cancer typically lacks these mutations and responds poorly to EGFR inhibitors. *Wedge resection* - **Wedge resection** is a surgical procedure typically reserved for **early-stage, peripheral NSCLC** or benign nodules. - Given the diagnosis of SCLC with mediastinal lymph node involvement, **surgical resection is generally not curative** and would be an inadequate treatment. *Radiation therapy* - While radiation therapy is a crucial component in SCLC treatment, particularly for **local control**, it is **insufficient as a monotherapy** for limited-stage SCLC. - **Systemic chemotherapy** is essential to address potential micrometastases and is always combined with radiation for this stage of SCLC. *Right lobectomy* - A **lobectomy** is a surgical procedure to remove an entire lobe of the lung, usually considered for **resectable NSCLC** without significant nodal involvement. - For SCLC with **mediastinal lymph node involvement**, a lobectomy alone is highly unlikely to be curative, and **combined chemoradiotherapy** is the standard primary treatment.

Question 1040: A 69-year-old woman presents with pain in her hip and groin. She states that the pain is present in the morning, and by the end of the day it is nearly unbearable. Her past medical history is notable for a treated episode of acute renal failure, diabetes mellitus, obesity, and hypertension. Her current medications include losartan, metformin, insulin, and ibuprofen. The patient recently started taking high doses of vitamin D as she believes that it could help her symptoms. She also states that she recently fell off the treadmill while exercising at the gym. On physical exam you note an obese woman. There is pain, decreased range of motion, and crepitus on physical exam of her right hip. The patient points to the areas that cause her pain stating that it is mostly over the groin. The patient's skin turgor reveals tenting. Radiography is ordered. Which of the following is most likely to be found on radiography?

A. Loss of joint space and osteophytes (Correct Answer)
B. Posterior displacement of the femoral head
C. Hyperdense foci in the ureters
D. Femoral neck fracture
E. Normal radiography

Explanation: ***Loss of joint space and osteophytes*** - The patient's presentation with **hip and groin pain worsened by activity**, improved with rest, and associated with **crepitus** and **decreased range of motion**, is highly suggestive of **osteoarthritis**. - **Osteoarthritis** is characterized radiographically by **loss of joint space**, **osteophytes** (bone spurs), subchondral sclerosis, and subchondral cysts. *Posterior displacement of the femoral head* - This finding is characteristic of a **posterior hip dislocation**, which usually presents with severe pain and an inability to bear weight after a significant traumatic event. - While the patient fell, her symptoms are chronic and progressive, and she has signs of arthritis rather than acute dislocation. *Hyperdense foci in the ureters* - These would indicate **kidney stones**, which typically present with acute, severe flank pain radiating to the groin, and hematuria. - The patient's symptoms are chronic and localized to the hip joint, making kidney stones an unlikely cause of her primary complaint. *Femoral neck fracture* - A **femoral neck fracture** would cause acute, severe hip pain, inability to bear weight, and often external rotation and shortening of the leg, usually following a fall. - Although she fell, her chronic, activity-related pain and crepitus are more indicative of a degenerative process. *Normal radiography* - Given the patient's age, chronic and worsening hip pain, physical exam findings of crepitus and decreased range of motion, and risk factors like obesity, it is highly improbable that her hip X-rays would be normal. - These symptoms are classic for **osteoarthritis**, which shows distinct radiographic changes.

Question 1041: A 62-year-old woman presents to the emergency department with a 2-hour history of sharp chest pain. She says that the pain is worse when she inhales and is relieved by sitting up and leaning forward. Her past medical history is significant for rheumatoid arthritis, myocardial infarction status post coronary artery bypass graft, and radiation for breast cancer 20 years ago. Physical exam reveals a rubbing sound upon cardiac auscultation as well as increased jugular venous distention on inspiration. Pericardiocentesis is performed revealing grossly bloody fluid. Which of the following is most specifically associated with this patient's presentation?

A. Myocardial infarction
B. Malignancy (Correct Answer)
C. Uremia
D. Rheumatoid arthritis
E. Viral illness

Explanation: ***Malignancy*** - The presence of **grossly bloody (hemorrhagic) pericardial fluid** is the key finding that most specifically points to **malignancy** as the underlying cause. - **Hemorrhagic pericardial effusion** is most commonly associated with: (1) malignancy, (2) tuberculosis, or (3) trauma. Given the patient's **history of radiation therapy for breast cancer 20 years ago**, malignancy (either metastatic breast cancer or radiation-induced secondary malignancy) is the most likely cause. - Clinical features like **chest pain** worse on inspiration and relieved by leaning forward, a **pericardial friction rub**, and **increased jugular venous distention on inspiration (Kussmaul sign)** indicate pericarditis with possible cardiac tamponade. *Myocardial infarction* - While myocardial infarction can lead to pericarditis (acute post-MI pericarditis or delayed Dressler's syndrome), the pericardial fluid is typically **serous or serosanguinous, not grossly bloody**. - The patient's history of prior MI and CABG makes this less likely to be the cause of this acute presentation with hemorrhagic effusion. - Post-MI pericarditis usually occurs within days to weeks after the MI event. *Uremia* - **Uremic pericarditis** occurs in patients with severe kidney failure (uremia) and typically presents with **serofibrinous exudate**, not grossly bloody effusion. - There is no clinical indication of renal failure or uremia in this patient's presentation. *Rheumatoid arthritis* - **Rheumatoid pericarditis** can occur in patients with RA, but the pericardial effusion is usually **sterile and serofibrinous**, rarely resulting in frankly hemorrhagic fluid. - While this patient has RA, the **grossly bloody fluid** and **history of breast cancer radiation** make malignancy a much more specific and likely diagnosis. *Viral illness* - **Viral pericarditis** is a common cause of acute pericarditis and typically presents with chest pain and a pericardial friction rub. - However, viral pericarditis usually produces **serous or serofibrinous effusions, not grossly bloody fluid**. - There is no mention of prodromal viral symptoms, and the hemorrhagic nature of the fluid strongly argues against a viral etiology.

Question 1042: A previously healthy 44-year-old man is brought by his coworkers to the emergency department 45 minutes after he became light-headed and collapsed while working in the boiler room of a factory. He did not lose consciousness. His coworkers report that 30 minutes prior to collapsing, he told them he was nauseous and had a headache. The patient appears sweaty and lethargic. He is not oriented to time, place, or person. The patient’s vital signs are as follows: temperature 41°C (105.8°F); heart rate 133/min; respiratory rate 22/min; and blood pressure 90/52 mm Hg. Examination shows equal and reactive pupils. Deep tendon reflexes are 2+ bilaterally. His neck is supple. A 0.9% saline infusion is administered. A urinary catheter is inserted and dark brown urine is collected. The patient’s laboratory test results are as follows: Laboratory test Blood Hemoglobin 15 g/dL Leukocyte count 18,000/mm3 Platelet count 51,000/mm3 Serum Na+ 149 mEq/L K+ 5.0 mEq/L Cl- 98 mEq/L Urea nitrogen 42 mg/dL Glucose 88 mg/dL Creatinine 1.8 mg/dL Aspartate aminotransferase (AST, GOT) 210 Alanine aminotransferase (ALT, GPT) 250 Creatine kinase 86,000 U/mL Which of the following is the most appropriate next step in patient management?

A. Dantrolene
B. Acetaminophen therapy
C. Hemodialysis
D. Ice water immersion (Correct Answer)
E. Evaporative cooling

Explanation: ***Ice water immersion*** - This patient presents with signs and symptoms consistent with **heat stroke**, including high body temperature (41°C), altered mental status, and a history of working in a hot environment (boiler room). **Rapid aggressive cooling** is the most critical immediate intervention to prevent organ damage. - **Ice water immersion** is the fastest and most effective cooling method for heat stroke, aiming to reduce core body temperature to less than 39°C (102.2°F) within 30 minutes. *Dantrolene* - **Dantrolene** is primarily used to treat **malignant hyperthermia** and **neuroleptic malignant syndrome**, conditions caused by abnormal calcium release in muscle cells, not environmental heat exposure. - While both conditions involve hyperthermia, the underlying pathophysiology and triggers are different from heat stroke. *Acetaminophen therapy* - **Acetaminophen** is an antipyretic that works by inhibiting prostaglandin synthesis in the central nervous system, affecting the hypothalamic thermoregulatory center. - It is **ineffective** for the hyperthermia seen in heat stroke, which is due to a failure of thermoregulation rather than an altered hypothalamic set point, and could potentially worsen liver injury. *Hemodialysis* - **Hemodialysis** is indicated for severe **renal failure**, drug overdose, or certain electrolyte imbalances. Although this patient has acute kidney injury (elevated BUN and creatinine, dark urine suggestive of rhabdomyolysis), aggressive cooling is the immediate life-saving intervention for heat stroke. - While renal support might be necessary later if kidney injury progresses, it is not the most appropriate *initial* next step for hyperthermia and altered mental status. *Evaporative cooling* - **Evaporative cooling** (e.g., spraying with lukewarm water and using fans) is a cooling method that can be effective, particularly in environments with low humidity. - However, for severe heat stroke with a temperature as high as 41°C, **ice water immersion** provides a more rapid and aggressive temperature reduction, which is crucial for improving outcomes.

Question 1043: A 55-year-old woman presents to her primary care provider with a 2-month history of insidious onset of left shoulder pain. It only occurs at the extremes of her range of motion and has made it difficult to sleep on the affected side. She has noticed increasing difficulty with activities of daily living, including brushing her hair and putting on or taking off her blouse and bra. She denies a history of shoulder trauma, neck pain, arm/hand weakness, numbness, or paresthesias. Her medical history is remarkable for type 2 diabetes mellitus, for which she takes metformin and glipizide. Her physical examination reveals a marked decrease in both active and passive range of motion of the left shoulder, with forwarding flexion to 75°, abduction to 75°, external rotation to 45°, and internal rotation to 15° with significant pain. Rotator cuff strength is normal. AP, scapular Y, and axillary plain film radiographs are reported as normal. Which of the following is the most likely diagnosis?

A. Degenerative cervical spine disease
B. Glenohumeral arthritis
C. Subacromial impingement syndrome
D. Rotator cuff injury
E. Adhesive capsulitis (Correct Answer)

Explanation: **Adhesive capsulitis** - The patient's presentation of **insidious onset of shoulder pain**, progressive loss of both **active and passive range of motion**, difficulty with activities of daily living, and a history of **diabetes mellitus** are classic for adhesive capsulitis, also known as **frozen shoulder**. - **Normal rotator cuff strength** and **normal plain film radiographs** further support this diagnosis by ruling out other common shoulder pathologies. *Degenerative cervical spine disease* - While cervical spine issues can cause referred shoulder pain, they typically present with **neurological symptoms** like numbness, tingling, or weakness in the arm/hand, which are absent here. - Cervical spine disease would not typically cause such a **marked restriction in both active and passive glenohumeral range of motion**. *Glenohumeral arthritis* - Although glenohumeral arthritis can cause stiffness and pain, it would likely show **degenerative changes on plain film radiographs**, which were reported as normal in this case. - The **insidious, progressive loss of all ranges of motion** in a diabetic patient is more characteristic of adhesive capsulitis than primary arthritis. *Subacromial impingement syndrome* - This condition typically causes pain with overhead activities and specific movements, but usually spares **full passive range of motion** and doesn't result in the global, severe stiffness seen here. - Impingement syndrome is also commonly associated with rotator cuff tendinopathy, but this patient has **normal rotator cuff strength**. *Rotator cuff injury* - A rotator cuff injury would primarily affect **active range of motion** and strength, often with specific weakness on examination, but usually would not cause the significant loss of **passive range of motion** described. - The patient's **normal rotator cuff strength** directly contradicts a significant rotator cuff injury.

Question 1044: A 48-year-old female presents to the emergency room with mental status changes. Laboratory analysis of the patient's serum shows: Na 122 mEq/L K 3.9 mEq/L HCO3 24 mEq/L BUN 21 mg/dL Cr 0.9 mg/dL Ca 8.5 mg/dL Glu 105 mg/dL Urinalysis shows: Osmolality 334 mOsm/kg Na 45 mEq/L Glu 0 mg/dL Which of the following is the most likely diagnosis?

A. Diabetes insipidus
B. Aspirin overdose
C. Primary polydipsia
D. Diarrhea
E. Lung cancer (Correct Answer)

Explanation: ***Lung cancer*** - The patient presents with **hyponatremia** (Na 122 mEq/L) and **mental status changes**, along with a **euvolemic state** (normal BUN, creatinine, and potassium), which are characteristic of **Syndrome of Inappropriate Antidiuretic Hormone (SIADH)**. - **Small cell lung cancer** is a common cause of **ectopic ADH production**, leading to SIADH. *Diabetes insipidus* - Characterized by **hypernatremia** and the excretion of **large volumes of dilute urine** (low urine osmolality), which contradicts the patient's hyponatremia and relatively concentrated urine (334 mOsm/kg). - This condition involves insufficient ADH or renal unresponsiveness to ADH, leading to free water loss, not retention. *Aspirin overdose* - Typically causes an **acid-base disturbance**, often a mixed respiratory alkalosis and metabolic acidosis, and may lead to **tinnitus** and **hyperthermia**. - While it can affect mental status, it does not directly explain the specific pattern of **hyponatremia** and urine osmolality observed. *Primary polydipsia* - Usually results in **hyponatremia** due to excessive water intake, but the urine would be **maximally dilute** (urine osmolality < 100 mOsm/kg) as the kidneys try to excrete the excess water. - The patient's urine osmolality of 334 mOsm/kg indicates that the kidneys are still able to concentrate urine somewhat, making primary polydipsia less likely. *Diarrhea* - Causes **volume depletion** and can lead to various electrolyte abnormalities, but typically results in **hypernatremia** or isotonic hyponatremia with signs of dehydration. - The patient's lab values do not show signs of dehydration or a primary gastrointestinal disturbance.

Question 1045: A 52-year-old woman presents to her primary care physician with a chief complaint of diarrhea. She states that it has been going on for the past month and started after she ate a burger cooked over a campfire. She endorses having lost 10 pounds during this time. The patient has no other complaints other than hoarseness which has persisted during this time. The patient has a past medical history of obesity, hypothyroidism, diabetes, and anxiety. Her current medications include insulin, metformin, levothyroxine, and fluoxetine. She currently drinks 4 to 5 alcoholic beverages per day. Her temperature is 99.5°F (37.5°C), blood pressure is 157/98 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. On physical exam, you note a healthy obese woman. Cardiopulmonary exam is within normal limits. HEENT exam is notable for a mass on the thyroid. Abdominal exam is notable for a candida infection underneath the patient's pannus. Pelvic exam is notable for a white, fish-odored discharge. Laboratory values are as follows: Hemoglobin: 12 g/dL Hematocrit: 36% Leukocyte count: 4,500 cells/mm^3 with normal differential Platelet count: 190,000/mm^3 Serum: Na+: 141 mEq/L Cl-: 102 mEq/L K+: 5.5 mEq/L HCO3-: 24 mEq/L Glucose: 122 mg/dL Ca2+: 7.1 mg/dL Which of the following could also be found in this patient?

A. Bitemporal hemianopsia
B. Acute liver failure
C. Schistocytes
D. Acute renal failure
E. Episodic hypertension and headaches (Correct Answer)

Explanation: ***Episodic hypertension and headaches*** - The patient presents with a **palpable thyroid mass**, **hoarseness**, and **chronic diarrhea**, which are classic signs of **medullary thyroid cancer (MTC)**. MTC secretes **calcitonin** and can produce other peptides causing secretory diarrhea. - MTC can occur as part of **MEN 2 syndromes (MEN 2A or 2B)**, which are associated with **pheochromocytoma** in approximately 50% of cases. - Pheochromocytoma causes **episodic catecholamine release**, leading to **paroxysmal hypertension and headaches**. - Her current blood pressure is elevated (157/98 mmHg), and the clinical context strongly supports screening for pheochromocytoma. - The **hypocalcemia (7.1 mg/dL)** may be related to hypoparathyroidism (part of MEN 2A) or other metabolic factors, though calcitonin itself typically does not cause significant hypocalcemia. *Bitemporal hemianopsia* - This visual field defect is typically associated with **pituitary adenomas** pressing on the optic chiasm. - Pituitary adenomas are part of **MEN 1 syndrome** (along with parathyroid adenomas and pancreatic tumors), not MEN 2. - The patient's presentation with a thyroid mass and diarrhea points to **medullary thyroid cancer**, which is characteristic of **MEN 2**, not MEN 1. *Schistocytes* - **Schistocytes** are fragmented red blood cells seen in **microangiopathic hemolytic anemia (MAHA)**, such as in **thrombotic thrombocytopenic purpura (TTP)** or **hemolytic uremic syndrome (HUS)**. - The patient's blood counts show **normal hemoglobin (12 g/dL), hematocrit (36%), and platelet count (190,000/mm³)**, making MAHA unlikely. *Acute liver failure* - The patient reports significant alcohol consumption (4-5 drinks/day), which could predispose to alcoholic liver disease. - However, there are **no clinical signs** (jaundice, encephalopathy, coagulopathy) or **laboratory findings** (elevated AST/ALT, prolonged PT/INR) to suggest acute liver failure in this presentation. *Acute renal failure* - The patient's **potassium is mildly elevated (5.5 mEq/L)**, which can be seen in renal failure. - However, there are **no other indicators** of acute renal failure, such as elevated creatinine, oliguria, or uremic symptoms provided in the clinical scenario.

Question 1046: A 28-year-old male presents with sharp, stabbing chest pain that worsens when lying flat and improves when sitting forward. He reports a recent viral upper respiratory infection 2 weeks ago. On examination, a friction rub is heard on auscultation. His vital signs are stable. An ECG is most likely to show which of the following findings in this patient?

A. Diffuse, concave ST-segment elevations (Correct Answer)
B. Peaked T waves and ST-segment elevations in leads V1-V6
C. Sawtooth-appearance of P waves
D. S waves in lead I, Q waves in lead III, and inverted T waves in lead III
E. Alternating high and low amplitude QRS complexes

Explanation: ***Diffuse, concave ST-segment elevations*** - This is a hallmark ECG finding in **acute pericarditis**, along with **PR segment depression**, due to widespread inflammation of the epicardium. - The chest pain described here (sharp, stabbing, worse when lying flat, improved by sitting forward) paired with a recent viral infection and a pericardial friction rub, is highly characteristic of **pericarditis**. *Peaked T waves and ST-segment elevations in leads V1-V6* - **Peaked T waves** are typically seen in early stages of hyperkalemia or myocardial ischemia, while **ST-segment elevations in specific leads (V1-V6)** are more indicative of an **ST-elevation myocardial infarction (STEMI)** involving the anterior wall. - The diffuse nature of ST elevation in pericarditis, as opposed to regional changes, along with **PR depression**, differentiates it from STEMI. *Sawtooth-appearance of P waves* - A **sawtooth appearance of P waves** (often referred to as 'f waves') is characteristic of **atrial flutter**, a type of supraventricular tachycardia. - This finding is unrelated to pericarditis, which primarily affects the pericardium and not the atrial electrical activity in this specific manner. *S waves in lead I, Q waves in lead III, and inverted T waves in lead III* - This pattern, known as the **S1Q3T3 pattern**, is a classic (though not always present) ECG finding suggestive of **acute pulmonary embolism**. - While pulmonary embolism can cause chest pain, its presentation differs significantly from the positional relief and friction rub seen in pericarditis. *Alternating high and low amplitude QRS complexes* - This ECG finding, known as **electrical alternans**, is highly specific for a large **pericardial effusion** or **cardiac tamponade**, where the heart swings within the fluid-filled pericardial sac. - Although pericarditis can lead to effusion, the presence of a friction rub and stable vital signs suggests acute pericarditis without significant tamponade at this stage, making diffuse ST elevation a more likely initial finding.

Question 1047: An 82-year-old woman is brought to the emergency department after losing consciousness at her nursing home. She had been watching TV for several hours and while getting up to use the bathroom, she fell and was unconscious for several seconds. She felt dizzy shortly before the fall. She does not have a headache or any other pain. She has a history of hypertension, intermittent atrial fibrillation, and stable angina pectoris. Current medications include warfarin, aspirin, hydrochlorothiazide, and a nitroglycerin spray as needed. Her temperature is 36.7°C (98.1°F), pulse is 100/min and regular, and blood pressure is 102/56 mm Hg. Physical exam shows a dry tongue. A fold of skin that is pinched on the back of her hand unfolds after 2 seconds. Cardiopulmonary examination shows no abnormalities. Further evaluation of this patient is most likely to show which of the following findings?

A. Elevated serum concentration of cardiac enzymes
B. Elevated serum creatine kinase concentration
C. Absent P waves on ECG
D. Elevated blood urea nitrogen concentration (Correct Answer)
E. Hypodense lesions on CT scan of the head

Explanation: ***Elevated blood urea nitrogen concentration*** - The patient presents with symptoms of **dehydration**, including a dry tongue, decreased skin turgor (skin fold taking 2 seconds to unfold), and **orthostatic hypotension** (dizziness upon standing, low blood pressure). - Dehydration leads to **prerenal acute kidney injury**, characterized by an elevated blood urea nitrogen (BUN) concentration, often with an elevated BUN:creatinine ratio. *Elevated serum concentration of cardiac enzymes* - While the patient has a history of angina, there are no classic symptoms of an acute coronary syndrome such as **chest pain**, radiation, or ECG changes that would suggest myocardial injury warranting elevated cardiac enzymes. - The syncope is more consistent with a **hemodynamic cause** (dehydration/hypotension) rather than a primary cardiac event like an MI. *Elevated serum creatine kinase concentration* - This is a non-specific marker for muscle damage and would be elevated if the patient experienced significant muscle injury from the fall. - However, there is no mention of **trauma** or prolonged immobilization that would lead to rhabdomyolysis or significant muscle breakdown. *Absent P waves on ECG* - The patient has a history of **intermittent atrial fibrillation**, but her pulse is currently 100/min and **regular**, which indicates her current rhythm is likely not atrial fibrillation. - Absence of P waves would specifically indicate **atrial fibrillation** or another atrial arrhythmia, but her regular pulse suggests a more sinus or junctional rhythm. *Hypodense lesions on CT scan of the head* - A CT scan of the head would be indicated to rule out **intracranial hemorrhage** or other structural brain lesions, especially given the fall and syncope. - However, there are no focal neurological deficits, severe headache, or other signs strongly suggestive of a new stroke or hemorrhage, and the primary cause of syncope appears to be orthostatic hypotension due to hypovolemia.

Question 1048: A 24-year-old man presents to his primary care physician for a persistent and low grade headache as well as trouble focusing. The patient was seen in the emergency department 3 days ago after hitting his head on a branch while biking under the influence of alcohol. His head CT at the time was normal, and the patient was sent home with follow up instructions. Since the event, he has experienced trouble focusing on his school work and feels confused at times while listening to lectures. He states that he can’t remember the lectures and also says he has experienced a sensation of vertigo at times. On review of systems, he states that he has felt depressed lately and has had trouble sleeping, though he denies any suicidal or homicidal ideation. His temperature is 98.2°F (36.8°C), blood pressure is 122/65 mmHg, pulse is 70/min, respirations are 12/min, and oxygen saturation is 98% on room air. The patient’s neurological and cardiopulmonary exam are within normal limits. Which of the following is the best next step in management?

A. Thiamine
B. Cognitive behavioral therapy
C. Rest and primary care follow up (Correct Answer)
D. CT scan of the head without contrast
E. Fluoxetine

Explanation: ***Rest and primary care follow up*** - The patient's symptoms of **headache**, **confusion**, **vertigo**, **difficulty concentrating**, and **sleep disturbances** following a minor head injury are highly suggestive of a **concussion** or **post-concussive syndrome**. - For concussion, the primary management involves **physical and cognitive rest** to allow the brain to heal, along with close follow-up to monitor symptom resolution or worsening. *Thiamine* - **Thiamine** (vitamin B1) is primarily indicated for conditions such as **Wernicke encephalopathy** or **Korsakoff syndrome**, often associated with chronic alcohol abuse and malnutrition. - While the patient had a history of alcohol use, his acute symptoms are more consistent with head trauma, and there's no indication of a **thiamine deficiency**-related neurological syndrome. *Cognitive behavioral therapy* - **Cognitive Behavioral Therapy (CBT)** is a psychotherapeutic intervention used for conditions like **depression**, **anxiety disorders**, and **insomnia**. - While the patient reports feeling depressed and having trouble sleeping, these symptoms can be part of post-concussive syndrome, and initial management should prioritize brain rest before focusing solely on CBT for mood and sleep. *CT scan of the head without contrast* - A **CT scan of the head without contrast** was already performed 3 days ago and was normal, effectively ruling out acute intracranial hemorrhage or major structural damage immediately after the injury. - Given the normal initial CT and the constellation of symptoms consistent with **concussion**, a repeat CT scan is unlikely to provide additional useful information and is not the best immediate next step. *Fluoxetine* - **Fluoxetine** is a Selective Serotonin Reuptake Inhibitor (SSRI) used to treat **depression** and **anxiety disorders**. - While the patient reports feeling depressed, initiating an antidepressant is not the immediate best step for a suspected concussion; depression and sleep issues can be sequelae of a concussion, and management should initially focus on concussion recovery.

Question 1049: A 29-year-old African American female presents to your office with extreme fatigue and bilateral joint pain. Serologies demonstrate the presence of rheumatoid factor along with anti-Smith and anti-dsDNA antibodies. A VDRL syphilis test is positive. You order a coagulation profile, which reveals normal bleeding time, normal PT, and prolonged PTT as well as normal platelet count. Further evaluation is most likely to reveal which of the following?

A. Immune thrombocytopenia
B. HLA-B27 positivity
C. Factor VIII deficiency
D. Palmar rash
E. History of multiple spontaneous abortions (Correct Answer)

Explanation: ***History of multiple spontaneous abortions*** - The patient's presentation with **fatigue**, **bilateral joint pain**, positive **anti-Smith** and **anti-dsDNA antibodies**, **prolonged PTT** (without bleeding), and a positive **VDRL syphilis test** (a false positive often seen in SLE) strongly suggests **Systemic Lupus Erythematosus (SLE)**. - The combination of lupus and a prolonged PTT (suggesting a **lupus anticoagulant**) points to **Antiphospholipid Syndrome (APS)**, which frequently manifests with recurrent **thrombosis** and **recurrent spontaneous abortions** as a common complication. *Immune thrombocytopenia* - While **thrombocytopenia** can be associated with SLE, the patient's **platelet count is stated as normal**, making immune thrombocytopenia an unlikely further finding in this scenario. - Immune thrombocytopenia would typically present with a **low platelet count**, which is not found here. *HLA-B27 positivity* - **HLA-B27** is primarily associated with **seronegative spondyloarthropathies** like ankylosing spondylitis, reactive arthritis, and psoriatic arthritis. - It is **not typically associated** with Systemic Lupus Erythematosus or Antiphospholipid Syndrome. *Factor VIII deficiency* - **Factor VIII deficiency (hemophilia A)** would cause a **prolonged PTT** but would also typically present with **bleeding tendencies**, which are absent here (normal bleeding time). - Furthermore, the presence of **lupus anticoagulant** as part of Antiphospholipid Syndrome in SLE is a more fitting explanation for the isolated prolonged PTT without significant bleeding, as lupus anticoagulant *in vitro* prolongs PTT but *in vivo* is **prothrombotic**. *Palmar rash* - While a **rash (e.g., malar rash)** is a common finding in SLE, a **palmar rash** is more characteristic of **syphilis**, which this patient has a false positive VDRL for. - The combination of other serologies points away from actual syphilis and towards SLE, making a palmar rash less specific or likely in the context of additional findings of APS.

Question 1050: A 52-year-old woman comes to the physician because of a 4-month history of progressive pain and stiffness of the fingers of her right hand that is worse at the end of the day. She works as a hair dresser and has to take frequent breaks to rest her hand. She has hypertension, for which she takes hydrochlorothiazide. Two weeks ago, she completed a course of oral antibiotics for a urinary tract infection. Her sister has systemic lupus erythematosus. She drinks one to two beers daily and occasionally more on weekends. Over the past 2 weeks, she has been taking ibuprofen as needed for the joint pain. Her vital signs are within normal limits. Physical examination shows swelling, joint-line tenderness, and decreased range of motion of the right first metacarpophalangeal joint as well as the 2nd and 4th distal interphalangeal joints of the right hand. Discrete, hard, mildly tender swellings are palpated over the 2nd and 4th distal interphalangeal joints of the right hand. Which of the following is the most likely underlying mechanism for these findings?

A. Bacterial infection of the joint space
B. Autoimmune-mediated cartilage erosion
C. Monosodium urate crystal precipitation in the joints
D. Degenerative disease of the joints (Correct Answer)
E. Calcium pyrophosphate dihydrate crystal precipitation in the joints

Explanation: ***Degenerative disease of the joints*** - The patient's symptoms are characteristic of **osteoarthritis (degenerative joint disease)**: chronic, progressive joint pain and stiffness, worse with activity and at the end of the day. - The presence of **Heberden's nodes** (hard, discrete swellings over the DIP joints) is a hallmark of osteoarthritis. - The involvement of the **1st MCP joint and DIP joints** with mechanical pain (worse with use) strongly supports this diagnosis. *Bacterial infection of the joint space* - **Septic arthritis** typically presents with acute, severe pain, marked swelling, erythema, and fever, none of which are prominent in this patient's 4-month history of progressive symptoms. - While she had a recent UTI, the presentation is chronic and localized to multiple small joints, not a single acutely inflamed joint. *Autoimmune-mediated cartilage erosion* - **Rheumatoid arthritis** usually involves symmetric small joint disease, especially the MCP and PIP joints, but typically **spares the DIP joints**. - The presence of **hard, discrete swellings (Heberden's nodes)** and pain worse at the end of the day is less typical for rheumatoid arthritis, which typically causes morning stiffness that improves with activity. *Monosodium urate crystal precipitation in the joints* - This describes **gout**, which typically causes acute, severe, intermittent attacks of exquisitely painful arthritis, often in a single joint (e.g., great toe). - The chronic, progressive nature and the location of involvement (DIPs with hard nodes) are not characteristic of gout. *Calcium pyrophosphate dihydrate crystal precipitation in the joints* - This describes **pseudogout (CPPD disease)**, which can affect multiple joints (often knees, wrists, shoulders) and present with acute attacks similar to gout, but may also have a more chronic presentation. - While CPPD can affect the DIPs, the description of **hard, discrete swellings (Heberden's nodes)** points more strongly to osteoarthritis.

Question 1051: A 72-year-old man presents to his primary care provider complaining of fatigue, mild headache, and discomfort with chewing for roughly 1 week. Before this, he felt well overall, but now he is quite bothered by these symptoms. His medical history is notable for hypertension and hyperlipidemia, both controlled. On examination, he is uncomfortable but nontoxic-appearing. There is mild tenderness to palpation over his right temporal artery, but otherwise the exam is not revealing. Prompt recognition and treatment can prevent which of the following feared complications:

A. Renal failure
B. Cognitive impairment
C. Blindness (Correct Answer)
D. Pulmonary fibrosis
E. Pericarditis

Explanation: ***Blindness*** - **Giant cell arteritis (GCA)**, suggested by the patient's symptoms (fatigue, headache, jaw claudication, tender temporal artery), can lead to irreversible **vision loss** if not treated promptly with high-dose steroids. - The most feared complication is **ischemic optic neuropathy** due to inflammation of the ophthalmic artery or its branches, supplying the optic nerve. *Renal failure* - While some vasculitides can affect the kidneys, **renal failure** is not a characteristic or feared complication directly associated with untreated giant cell arteritis. - Other systemic vasculitides like **ANCA-associated vasculitis** are more commonly linked to kidney involvement. *Cognitive impairment* - Although GCA can cause headache and general malaise, it does not typically lead to **progressive cognitive impairment** as a direct or feared complication. - **Stroke** can occur but is less common than visual loss, and a stroke would be a cause of acute cognitive deficits. *Pulmonary fibrosis* - **Pulmonary fibrosis** is not a known complication of giant cell arteritis. - It is more commonly associated with conditions like **systemic sclerosis**, certain autoimmune diseases, or environmental exposures. *Pericarditis* - **Pericarditis** (inflammation of the sac surrounding the heart) is not a typical or feared complication of giant cell arteritis. - While GCA can affect large vessels, it does not commonly target the pericardium.

Question 1052: A 29-year-old female presents to her primary care provider complaining of pain and stiffness in her hands and knees. She reports that the stiffness is worse in the morning and appears to get better throughout the day. She is otherwise healthy and denies any recent illness. She does not play sports. On examination, her metacarpal-phalangeal (MCP) and proximal interphalangeal (PIP) joints are swollen and erythematous. Her distal interphalangeal (DIP) joints appear normal. She exhibits pain with both passive and active range of motion in her knees bilaterally. Serological analysis reveals high titers of anti-cyclic citrullinated peptide antibodies. Which of the following processes underlies this patient’s condition?

A. Post-infectious inflammation of the articular surfaces
B. Degenerative deterioration of articular cartilage
C. Synovial hypertrophy and pannus formation (Correct Answer)
D. Precipitation of monosodium urate crystals in the intra-articular space
E. Aseptic necrosis of articular cartilage and subchondral bone

Explanation: ***Synovial hypertrophy and pannus formation*** - The patient's symptoms (morning stiffness, symmetrical polyarthritis of **MCP/PIP joints**, sparing **DIP joints**) and high titers of **anti-cyclic citrullinated peptide (anti-CCP) antibodies** are classic for **rheumatoid arthritis (RA)**. - The hallmark of RA pathology is chronic inflammation of the synovium, leading to **synovial hypertrophy** and the formation of a **pannus**, which invades and destroys cartilage and bone. *Post-infectious inflammation of the articular surfaces* - This describes **reactive arthritis** or **post-streptococcal arthritis**, which typically follows an infection elsewhere in the body. - While it can manifest as arthritis, the presence of high **anti-CCP antibodies** and the chronic, progressive nature of the symptoms presented are not typical for a post-infectious process. *Degenerative deterioration of articular cartilage* - This refers to **osteoarthritis**, which is characterized by **wear-and-tear** of cartilage, often affecting weight-bearing joints and **DIP joints**, with pain typically worsening with activity. - **Osteoarthritis** is not associated with significant systemic inflammation, morning stiffness that improves with activity, or positive **anti-CCP antibodies**. *Precipitation of monosodium urate crystals in the intra-articular space* - This describes **gout**, which typically presents as acute, severe, intermittent arthritis, often affecting a single joint (most commonly the **first metatarsophalangeal joint**). - The patient's presentation of chronic, symmetrical polyarthritis and positive **anti-CCP antibodies** does not align with gout. *Aseptic necrosis of articular cartilage and subchondral bone* - This refers to **osteonecrosis** or **avirulent necrosis**, a condition where bone tissue dies due to a lack of blood supply, often leading to collapse of the bone and overlying cartilage. - While it causes pain and joint dysfunction, it does not typically present with symmetrical polyarthritis, morning stiffness, or elevated **anti-CCP antibodies** as primary features.

Question 1053: A 49-year-old man comes to the physician because of a 6-month history of increasing fatigue and reduced libido. He also complains of joint pain in both of his hands. His vital signs are within normal limits. Physical examination shows tanned skin and small testes. The second and third metacarpophalangeal joints of both hands are tender to palpation and range of motion is limited. The liver is palpated 2 to 3 cm below the right costal margin. Histopathologic examination of a liver biopsy specimen shows intracellular material that stains with Prussian blue. This patient is at greatest risk for developing which of the following complications?

A. Rheumatoid arthritis
B. Restrictive cardiomyopathy (Correct Answer)
C. Non-Hodgkin lymphoma
D. Colorectal carcinoma
E. Pancreatic adenocarcinoma

Explanation: ***Restrictive cardiomyopathy*** - The patient's symptoms (fatigue, reduced libido, tanned skin, small testes, joint pain, hepatomegaly) and **Prussian blue-positive intracellular material** in the liver biopsy are classic for **hemochromatosis**. - **Cardiac iron deposition** is a serious and common complication leading to cardiomyopathy with symptoms like **fatigue** and heart failure. - While hemochromatosis most commonly causes **dilated cardiomyopathy** or a mixed pattern, **restrictive features** can occur, and cardiac involvement is the **leading cause of death** in untreated patients. *Rheumatoid arthritis* - While joint pain is present, the specific involvement of the **second and third MCP joints** and the overall clinical picture are more consistent with **hemochromatosis-associated arthropathy**, not rheumatoid arthritis. - Absence of typical RA features like **symmetric polyarthritis**, **morning stiffness lasting over 30 minutes**, and positive RF/anti-CCP antibodies make RA less likely. *Non-Hodgkin lymphoma* - **Non-Hodgkin lymphoma** is not a complication of hemochromatosis. - While chronic immune stimulation in some conditions can increase lymphoma risk, there is no established association with **iron overload**. *Colorectal carcinoma* - There is no established increased risk of **colorectal carcinoma** due to hemochromatosis. - **Hereditary hemochromatosis** primarily increases the risk of **hepatocellular carcinoma** (up to 200-fold increased risk in cirrhotic patients). *Pancreatic adenocarcinoma* - While **hemochromatosis** can lead to iron deposition in the pancreas, causing **diabetes mellitus** (bronze diabetes), it does not significantly increase the risk of **pancreatic adenocarcinoma**. - Pancreatic involvement typically manifests as endocrine dysfunction, specifically **insulin deficiency** from beta-cell damage.

Question 1054: A 6-year-old boy is brought to the emergency room by ambulance, accompanied by his kindergarten teacher. Emergency department staff attempt to call his parents, but they cannot be reached. The boy’s medical history is unknown. According to his teacher, the boy was eating in the cafeteria with friends when he suddenly complained of itching and developed a widespread rash. Physical exam is notable for diffuse hives and tongue edema. His pulse is 100/min and blood pressure is 90/60 mmHg. The boy appears frightened and tells you that he does not want any treatment until his parents arrive. Which of the following is the next best step in the management of this patient?

A. Immediately administer epinephrine and provide supportive care (Correct Answer)
B. Continue calling the patient’s parents and do not intubate until verbal consent is obtained over the phone
C. Obtain written consent to intubate from the patient’s teacher
D. Wait for the patient's parents to arrive, calm the patient, and provide written consent before intubating
E. Obtain written consent to intubate from the patient

Explanation: ***Immediately administer epinephrine and provide supportive care*** - This patient is experiencing **anaphylaxis**, characterized by diffuse hives, tongue edema, and hypotension (BP 90/60 mmHg in a 6-year-old). **Epinephrine** is the first-line treatment for anaphylaxis and should be administered immediately. - In an emergency where a child's life is at risk and parents are unreachable, **implied consent** allows for life-saving treatment without explicit parental permission. Delaying treatment for consent would put the child's life at severe risk. *Continue calling the patient’s parents and do not intubate until verbal consent is obtained over the phone* - Delaying life-saving treatment like **epinephrine** or potential intubation for anaphylaxis while waiting for parental consent over the phone is unethical and could lead to irreversible harm or death. - Anaphylaxis with tongue edema and hypotension is a **medical emergency** requiring immediate intervention, irrespective of consent if the patient is a minor and parents are unavailable. *Obtain written consent to intubate from the patient’s teacher* - A kindergarten teacher typically **does not have legal authority** to provide consent for invasive medical procedures like intubation for a student. - The immediate priority is to treat the anaphylaxis with **epinephrine**, not to focus on intubation consent from an unauthorized party. *Wait for the patient's parents to arrive, calm the patient, and provide written consent before intubating* - Waiting for parents to arrive for written consent in a rapidly progressing anaphylactic reaction with **airway compromise** (tongue edema) and **hypotension** is extremely dangerous and potentially fatal. - The patient's expressed wishes or fear do not supersede the immediate need for **life-saving intervention** when a minor's life is at risk and they lack the capacity to make such decisions. *Obtain written consent to intubate from the patient* - A 6-year-old child is considered a **minor** and does not have the legal capacity to give informed consent for complex medical procedures like intubation. - While a child's assent is important, in a life-threatening emergency, the medical team is obligated to provide necessary treatment under the principle of **implied consent**.

Question 1055: A 23-year-old woman is brought to the emergency department 8 hours after the sudden onset of shortness of breath and pleuritic chest pain. She has cystic fibrosis and, during the past year, has had 4 respiratory exacerbations that have required hospitalization. Current medications include an inhaled bronchodilator, an inhaled corticosteroid, inhaled N-acetylcysteine, and azithromycin. The patient appears chronically ill. Her temperature is 37.9°C (100.2°F), pulse is 96/min, respirations are 22/min and labored, and blood pressure is 106/64 mm Hg. Pulse oximetry on 2 L/min of oxygen via nasal cannula shows an oxygen saturation of 96%. Examination shows an increased anteroposterior chest diameter. There is digital clubbing. Chest excursions and tactile fremitus are decreased on the right side. On auscultation of the chest, breath sounds are significantly diminished over the right lung field and diffuse wheezing is heard over the left lung field. Which of the following is the most likely underlying cause of this patient's current symptoms?

A. Infection with gram-negative coccobacilli
B. Inflammation of costal cartilage
C. Bronchial hyperresponsiveness
D. Increased pulmonary capillary permeability
E. Apical subpleural cyst (Correct Answer)

Explanation: ***Apical subpleural cyst*** - The sudden onset of **shortness of breath** and **pleuritic chest pain** in a patient with advanced **cystic fibrosis (CF)** and previous frequent pulmonary exacerbations strongly suggests **spontaneous pneumothorax**. - In CF, chronic inflammation and recurrent infections can lead to the formation of **apical subpleural blebs or cysts**, which can rupture, causing air to leak into the pleural space. This is supported by decreased breath sounds and tactile fremitus on one side, indicating a pneumothorax. *Infection with gram-negative coccobacilli* - While **gram-negative bacteria** like *Pseudomonas aeruginosa* are common in CF and can cause respiratory exacerbations, an infection would typically present with increasing productive cough, fever, and leukocytosis, not sudden pleuritic chest pain and diminished breath sounds indicative of pneumothorax. - The patient's current presentation is more acute and localized to a mechanical issue in the chest rather than a widespread infectious process, especially with normal temperature and relatively stable vitals for an infection. *Inflammation of costal cartilage* - **Costochondritis** causes localized chest wall pain that is typically reproducible with palpation and does not cause **shortness of breath** or changes in breath sounds and tactile fremitus like a pneumothorax. - It is a musculoskeletal issue, not a pulmonary emergency that would explain the acute respiratory distress and physical exam findings. *Bronchial hyperresponsiveness* - **Bronchial hyperresponsiveness** is underlying asthma or reactive airway disease, characterized by widespread bronchoconstriction and wheezing. While **wheezing** is present, the unilateral diminished breath sounds and tactile fremitus, coupled with pleuritic chest pain, point away from a primary exacerbation of hyperresponsive airways alone. - An asthma exacerbation typically presents with more diffuse wheezing and air trapping, rather than a unilateral absence of breath sounds caused by air in the pleural space. *Increased pulmonary capillary permeability* - **Increased pulmonary capillary permeability** leads to **pulmonary edema**, which would manifest as diffuse crackles, hypoxemia, and possibly pink frothy sputum, not localized diminished breath sounds and tactile fremitus. - This condition is more commonly seen in conditions like **ARDS** or **heart failure**, not typically as an acute complication of CF in this manner.

Question 1056: A 60-year-old male presents for a routine health check-up. The patient complains of reduced exercise tolerance for the past 2 years. Also, in the past year, he has noticed chest pain after climbing the stairs in his home. He has no significant past medical history or current medications. The patient reports a 45-pack-year smoking history. The vital signs include temperature 37.0°C (98.6°F), blood pressure 160/100 mm Hg, pulse 72/min, respiratory rate 15/min, and oxygen saturation 99% on room air. His body mass index (BMI) is 34 kg/m2. Physical examination is unremarkable. Laboratory studies show: Serum total cholesterol 265 mg/dL HDL 22 mg/dL LDL 130 mg/dL Triglycerides 175 mg/dL HDL: high-density lipoprotein; LDL: low-density lipoprotein Which of the following vascular pathologies is most likely present in this patient?

A. Medial calcific sclerosis
B. Deep venous thrombosis
C. Lymphedema
D. Atherosclerosis (Correct Answer)
E. Hyperplastic arteriosclerosis

Explanation: ***Atherosclerosis*** - This patient presents with multiple **risk factors for atherosclerosis**, including **hyperlipidemia** (elevated total cholesterol, LDL, and triglycerides with low HDL), **hypertension**, **obesity**, and a significant **smoking history**. - His symptoms of **reduced exercise tolerance** and **exertional chest pain** are classic manifestations of **angina pectoris**, which is caused by narrowed coronary arteries due to atherosclerosis. *Medial calcific sclerosis* - Also known as **Mönckeberg arteriosclerosis**, involves calcification of the **tunica media** of muscular arteries, without significant luminal narrowing. - While it can lead to **artery hardening**, it typically does not obstruct blood flow or cause angina, and is more common in **elderly** and **diabetic** individuals. *Deep venous thrombosis* - This condition involves the formation of a **blood clot in a deep vein**, usually in the legs, leading to symptoms like **leg swelling, pain, and redness**. - The patient's symptoms of chest pain and reduced exercise tolerance are not characteristic of DVT. *Lymphedema* - Characterized by **swelling** in one or more limbs due to an impaired **lymphatic drainage system**. - It does not present with chest pain or reduced exercise tolerance and is distinct from vascular pathologies affecting blood flow. *Hyperplastic arteriosclerosis* - This is a form of **arteriolar sclerosis** primarily seen in severe **hypertension**, characterized by **concentric thickening of arteriolar walls** due to smooth muscle cell proliferation and basement membrane duplication. - While the patient has hypertension, his symptoms point towards obstruction of larger coronary arteries rather than widespread arteriolar changes, and his lipid profile is more indicative of atherosclerosis.

Question 1057: A 58-year-old man presents to the emergency department for evaluation of intermittent chest pain over the past 6 months. His history reveals that he has had moderate exertional dyspnea and 2 episodes of syncope while working at his factory job. These episodes of syncope were witnessed by others and lasted roughly 30 seconds. The patient states that he did not have any seizure activity. His vital signs include: blood pressure 121/89 mm Hg, heart rate 89/min, temperature 37.0°C (98.6°F), and respiratory rate 16/min. Physical examination reveals a crescendo-decrescendo systolic murmur in the right second intercostal area. An electrocardiogram is performed, which shows left ventricular hypertrophy. Which of the following is the best next step for this patient?

A. Transthoracic echocardiography (Correct Answer)
B. Chest radiograph
C. Computed tomography (CT) chest scan without contrast
D. Cardiac chamber catheterization
E. Transesophageal echocardiography

Explanation: ***Transthoracic echocardiography*** - The patient's symptoms (chest pain, exertional dyspnea, syncope) and physical exam findings (**crescendo-decrescendo systolic murmur at the right second intercostal space**, ECG showing **left ventricular hypertrophy**) are highly suggestive of **aortic stenosis**. - **Transthoracic echocardiography** is the gold standard for diagnosing and assessing the severity of valvular heart diseases like aortic stenosis, quantifying valve area, pressure gradients, and ventricular function. *Chest radiograph* - A chest radiograph provides information about lung fields, cardiac size, and aortic calcification, but it cannot directly visualize or assess the function of heart valves. - While it may show signs of heart failure (e.g., **pulmonary congestion**) or **cardiomegaly**, it is insufficient for a definitive diagnosis or severity assessment of valvular lesions. *Computed tomography (CT) chest scan without contrast* - A CT scan can detect calcification of the aortic valve, but it is not the primary imaging modality for assessing valvular function or the severity of stenotic lesions. - CT is more useful for evaluating the **aorta for aneurysm** or dissection, or for **pulmonary pathology**, neither of which is the most likely diagnosis given the presenting symptoms. *Cardiac chamber catheterization* - Cardiac catheterization is an **invasive procedure** that is typically reserved for cases where non-invasive imaging is inconclusive or when planning for intervention (e.g., prior to valve replacement). - It involves risks and is not the initial best step for diagnosis when a less invasive and highly informative test like echocardiography is available. *Transesophageal echocardiography* - **Transesophageal echocardiography (TEE)** provides more detailed images of the heart and valves compared to TTE because it avoids acoustic shadowing from the ribs and lungs. - However, TEE is more invasive than TTE and is usually reserved for situations where TTE is inadequate or when a higher resolution view is needed, such as for infective endocarditis, prosthetic valve dysfunction, or before/during surgical procedures.

Question 1058: An 82-year-old comes to the physician for a routine checkup. He feels well. He has a history of hypertension, peripheral vascular disease, carotid stenosis, and mild dementia. His father had Parkinson's disease and died of a stroke at the age of 74 years. He has smoked one-half pack of cigarettes daily for 30 years but quit at the age of 50 years. He drinks alcohol in moderation. Current medications include aspirin and lisinopril. He appears healthy. His temperature is 36.9°C (98.4°F), pulse is 73/min, respirations are 12/min, and blood pressure is 142/92 mmHg. Examination shows decreased pedal pulses bilaterally. Ankle jerk and patellar reflexes are absent bilaterally. Sensation to light touch, pinprick, and proprioception is intact bilaterally. Muscle strength is 5/5 bilaterally. He describes the town he grew up in with detail but only recalls one of three words after 5 minutes. Which of the following is the most appropriate next step in management for these findings?

A. Lumbar puncture
B. Prescribe thiamine supplementation
C. CT scan of the head
D. Carbidopa-levodopa
E. No further workup required (Correct Answer)

Explanation: ***No further workup required*** - The patient's **depressed ankle and patellar reflexes** are common in **elderly patients** and can be part of normal aging, especially given his history of **peripheral vascular disease**. - His memory impairment, specifically the inability to recall three words after 5 minutes while retaining detailed long-term memories, is consistent with his **known mild dementia** and represents expected age-related cognitive changes that do not require additional workup in an otherwise stable, well-functioning individual. *Lumbar puncture* - A lumbar puncture is an **invasive procedure** typically reserved for investigating suspected **meningitis**, **encephalitis**, **subarachnoid hemorrhage**, or certain **neurological disorders** not suggested by this patient's presentation. - There are no signs of acute infection, inflammation, or rapidly progressing neurological decline to warrant an immediate lumbar puncture. *Prescribe thiamine supplementation* - **Thiamine supplementation** is primarily indicated for patients with suspected **Wernicke-Korsakoff syndrome** due to chronic alcohol abuse or severe malnutrition. - This patient reports moderate alcohol use and shows no other signs of thiamine deficiency, such as **ataxia**, **ophthalmoplegia**, or **confusion** typical of Wernicke encephalopathy. *CT scan of the head* - A CT scan of the head is typically indicated for acute neurological changes like **stroke symptoms**, **severe headaches with focal deficits**, or to evaluate for **hydrocephalus** or **brain tumors**. - While the patient has a history of mild dementia, his current cognitive findings are mild and stable, making an immediate CT scan unnecessary for routine follow-up in the absence of acute changes. *Carbidopa-levodopa* - **Carbidopa-levodopa** is a treatment for **Parkinson's disease**, characterized by specific motor symptoms like **bradykinesia**, **rigidity**, **tremor**, and **postural instability**. - This patient does not exhibit any signs of Parkinson's disease, and his father's history of the disease does not automatically warrant treatment in an asymptomatic individual.

Question 1059: A 48-year-old female complains of tingling sensation in her fingertips as well as the skin around her mouth which woke her up from sleep. She is in the postoperative floor as she just underwent a complete thyroidectomy for papillary thyroid cancer. Her temperature is 37° C (98.6° F), respirations are 15/min, pulse is 67/min, and blood pressure is 122/88 mm Hg. While recording the blood pressure, spasm of the muscles of the hand and forearm is seen. What is the next best step in the management of this patient?

A. No treatment is necessary, this is expected following surgery
B. Magnesium replacement
C. Albumin infusion
D. Calcium replacement (Correct Answer)
E. Propylthiouracil

Explanation: ***Calcium replacement*** - The patient's symptoms of **perioral tingling**, **fingertip paresthesias**, and **carpopedal spasm** (Chvostek's or Trousseau's sign when blood pressure cuff is inflated) are classic signs of **hypocalcemia**, a common complication following total thyroidectomy due to inadvertent parathyroid gland removal or damage. - **Immediate calcium replacement** is crucial to prevent life-threatening complications such as laryngospasm and cardiac arrhythmias. *No treatment is necessary, this is expected following surgery* - While potential complications can arise after surgery, **symptomatic hypocalcemia** is not an expected or benign finding and requires prompt intervention. - Ignoring these symptoms could lead to severe consequences, including **respiratory distress** and **cardiac arrest**. *Magnesium replacement* - Although **hypomagnesemia** can sometimes cause symptoms similar to hypocalcemia or exacerbate it, the classic presentation described here points primarily to calcium deficiency. - While magnesium levels should be checked if calcium replacement is not fully effective, **calcium replacement** is the immediate priority for symptomatic hypocalcemia. *Albumin infusion* - **Albumin infusion** is primarily used to address low serum albumin levels, typically in states of significant fluid shifts, malnutrition, or ascites, to help maintain oncotic pressure. - There is no indication of hypoalbuminemia or related issues in this patient's presentation; it would not address the underlying hypocalcemia. *Propylthiouracil* - **Propylthiouracil (PTU)** is an antithyroid medication used to treat hyperthyroidism by inhibiting thyroid hormone synthesis. - The patient has just undergone a **total thyroidectomy** and has symptoms of **hypocalcemia**, not hyperthyroidism; therefore, PTU is completely inappropriate.

Question 1060: A 65-year-old man presents to his primary care physician for a pre-operative evaluation. He is scheduled for cataract surgery in 3 weeks. His past medical history is notable for diabetes, hypertension, and severe osteoarthritis of the right knee. His medications include metformin, hydrochlorothiazide, lisinopril, and aspirin. His surgeon ordered blood work 1 month ago, which showed a hemoglobin of 14.2 g/dL, INR of 1.2, and a hemoglobin A1c of 6.9%. His vital signs at the time of the visit show BP: 130/70 mmHg, Pulse: 80, RR: 12, and T: 37.2 C. He has no current complaints and is eager for his surgery. Which of the following is the most appropriate course of action for this patient at this time?

A. Tell the patient he will have to delay his surgery for at least 1 year
B. Medically clear the patient for surgery (Correct Answer)
C. Repeat the patient's CBC and coagulation studies
D. Schedule the patient for a stress test and ask him to delay surgery for at least 6 months
E. Perform an EKG

Explanation: **Medically clear the patient for surgery** - The patient's **blood pressure is well-controlled** (130/70 mmHg), and his **hemoglobin A1c of 6.9%** indicates good glycemic control, both of which are favorable for elective surgery. - He is currently on **aspirin**, which, for cataract surgery (a low-risk bleeding procedure), can generally be continued, and his **INR of 1.2 is within a safe range** for surgery. *Tell the patient he will have to delay his surgery for at least 1 year* - There are **no indications for such a prolonged delay** based on the provided clinical information. - His chronic conditions (diabetes, hypertension) are **adequately managed**, and his lab values are acceptable. *Repeat the patient's CBC and coagulation studies* - The **existing blood work from 1 month ago is recent enough** for a pre-operative evaluation for cataract surgery, especially with no new symptoms. - Repeating these tests without a clinical indication would be **unnecessary and inefficient**. *Schedule the patient for a stress test and ask him to delay surgery for at least 6 months* - The patient has **no active cardiac symptoms** (e.g., chest pain, shortness of breath), and his well-controlled hypertension does not automatically warrant a stress test for low-risk surgery. - A stress test and a **6-month delay are not indicated** for a low-risk procedure like cataract surgery in an asymptomatic patient. *Perform an EKG* - While an EKG might be considered in some pre-operative evaluations for patients with cardiac risk factors, there are **no specific symptoms or significant new risk factors** presented that necessitate an EKG for this low-risk cataract surgery. - Given his stable condition and controlled hypertension, an EKG is **not a mandatory part of medical clearance** for this procedure.

Question 1061: A 34-year-old Caucasian female presents at the ER with fever and sharp pain in her chest upon coughing and inhalation. Three weeks earlier she presented to her rheumatologist with a butterfly rash, joint pain and fatigue and was given a diagnosis of systemic lupus erythematosus. A friction rub is present upon physical exam. Which of the following do you most suspect in this patient?

A. Pericardial tamponade
B. Pericarditis (Correct Answer)
C. Acute myocardial infarction
D. Pulmonary hypertension
E. Interstitial lung disease

Explanation: ***Pericarditis*** - The patient's symptoms of **sharp chest pain** worsened by coughing and inhalation, along with a **friction rub** upon examination, are classic signs of pericarditis. - Her recent diagnosis of **systemic lupus erythematosus (SLE)** makes pericarditis a highly suspect complication, as SLE can affect the pericardium. *Pericardial tamponade* - While pericarditis can lead to tamponade, the clinical presentation here (chest pain, friction rub) more strongly points to **inflammation of the pericardium** rather than the signs of **hemodynamic compromise** seen in tamponade (e.g., muffled heart sounds, hypotension, jugular venous distention). - There are no specific signs of **Beck's triad** (hypotension, muffled heart sounds, JVD) which would indicate tamponade. *Acute myocardial infarction* - The described **sharp chest pain worsened by inspiration and coughing** is atypical for myocardial infarction, which usually involves crushing or pressure-like pain. - The presence of a **friction rub** is highly characteristic of pericarditis, not an MI. *Pulmonary hypertension* - Pulmonary hypertension typically presents with **dyspnea, fatigue, and signs of right-sided heart failure**, none of which are highlighted in this patient's acute presentation. - **Chest pain** in pulmonary hypertension is usually exertion-related or due to right ventricular ischemia, not pleuritic. *Interstitial lung disease* - Interstitial lung disease primarily causes **progressive dyspnea and cough**, often with crackles on auscultation. - The acute, pleuritic chest pain and **friction rub** are not characteristic findings of interstitial lung disease.

Question 1062: A 52-year-old man presents to the emergency department because of pain and swelling in his left leg over the past few hours. He traveled from Sydney to Los Angeles 2 days ago. He has had type 2 diabetes mellitus for 10 years and takes metformin for it. He has smoked a pack of cigarettes daily for 25 years. His temperature is 36.9°C (98.4°F), the blood pressure is 140/90 mm Hg, and the pulse is 90/min. On examination, the left calf is 5 cm greater in circumference than the right. The left leg appears more erythematous than the right with dilated superficial veins. Venous duplex ultrasound shows non-compressibility. Which of the following best represents the mechanism of this patient’s illness?

A. Impaired venous blood flow (Correct Answer)
B. Subcutaneous soft-tissue infection that may extend to the deep fascia
C. Infection of the dermis and subcutaneous tissues
D. Impaired arterial blood flow
E. Impaired lymphatic flow

Explanation: ***Impaired venous blood flow*** - The patient's symptoms (unilateral leg pain and swelling, erythema, dilated superficial veins, recent long-haul travel) and the **venous duplex ultrasound** finding of **non-compressibility** are highly indicative of **deep vein thrombosis (DVT)**, which results from impaired venous outflow. - Risk factors such as **long-haul travel** (venous stasis), **smoking** (endothelial damage), and potentially **diabetes** contribute to a hypercoagulable state. *Impaired lymphatic flow* - This typically presents as **lymphedema**, characterized by chronic, often pitting edema, and skin changes like thickening (peau d'orange), but usually without acute erythema or dilated superficial veins in this context. - **Venous duplex ultrasound** would not show non-compressibility in cases of impaired lymphatic flow, as veins themselves would be clear. *Subcutaneous soft-tissue infection that may extend to the deep fascia* - This describes **necrotizing fasciitis**, a severe infection often characterized by rapid progression, severe pain disproportionate to examination findings, blistering, and systemic toxicity, which are not clearly evident here. - While there is erythema, the key diagnostic finding is the **non-compressible vein**, not signs of crepitus or rapidly spreading infection. *Infection of the dermis and subcutaneous tissues* - This describes **cellulitis**, which presents with localized redness, warmth, swelling, and tenderness, often with an entry point. - While some symptoms overlap (erythema, swelling), the **venous duplex ultrasound finding of non-compressibility** definitively points away from a simple skin infection and towards a vascular obstruction. *Impaired arterial blood flow* - This presents as **acute limb ischemia**, characterized by the "6 Ps": pain, pallor, pulselessness, paresthesias, poikilothermia (coldness), and paralysis. - The patient's leg is swollen and erythematous, not pale and cold, and the ultrasound directly implicates venous rather than arterial occlusion.

Question 1063: A 53-year-old man is brought to the emergency department following an episode of loss of consciousness 1 hour ago. He had just finished micturating, when he fell down. His wife heard the noise and found him unconscious on the floor. He regained consciousness after 30 seconds and was able to talk normally with his wife immediately. There was no urinary incontinence. On arrival, he is alert and oriented. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. Serum concentrations of glucose, creatinine, and electrolytes are within the reference range. An electrocardiogram shows no abnormalities. Which of the following is the most likely diagnosis?

A. Emotional syncope
B. Situational syncope (Correct Answer)
C. Cardiovascular syncope
D. Arrhythmogenic syncope
E. Neurocardiogenic syncope

Explanation: ***Situational syncope*** - The episode of **loss of consciousness** occurred immediately after **micturition**, which is a classic trigger for situational syncope. - The rapid recovery, absence of focal neurological deficits, and normal workup findings support a **vasovagal reflex** triggered by specific physiological stresses. *Emotional syncope* - This typically occurs in response to **fear, pain, or emotional distress**, none of which are explicitly mentioned as triggers in this case. - While emotional factors can sometimes contribute to vasovagal responses, the direct temporal association with micturition points more specifically to situational syncope. *Cardiovascular syncope* - **Cardiac syncope** is often associated with underlying structural heart disease (e.g., valvular stenosis, cardiomyopathy) or significant arrhythmias. - The patient's normal **cardiopulmonary examination** and **normal electrocardiogram** make a primary cardiac cause less likely. *Arrhythmogenic syncope* - This type of syncope is caused by **cardiac arrhythmias**, leading to transient cerebral hypoperfusion. - The normal **electrocardiogram** and absence of any reported palpitations or pre-syncopal symptoms suggesting an arrhythmia make this diagnosis less probable. *Neurocardiogenic syncope* - While **situational syncope** is a subtype of **neurocardiogenic syncope** (also known as vasovagal syncope), situational syncope (like micturition syncope) describes the specific triggering event. - **Neurocardiogenic syncope** is a broader category, and since a specific trigger is identified, the more precise term is situational (micturition) syncope.

Question 1064: A 35-year-old woman with type 1 diabetes mellitus comes to the emergency department for evaluation of a 1-month history of fever, fatigue, loss of appetite, and a 3.6-kg (8-lb) weight loss. She has also had a cough for the last 2 months. She reports recent loss of pubic hair. The patient immigrated from the Philippines 7 weeks ago. Her mother has systemic lupus erythematosus. She has never smoked and does not drink alcohol. Her only medication is insulin, but she sometimes misses doses. She is 165 cm (5 ft 5 in) tall and weighs 49 kg (108 lb); BMI is 18 kg/m2. She appears lethargic. Her temperature is 38.9°C (102°F), pulse is 58/min, and blood pressure is 90/60 mm Hg. Examination shows decreased sensation to touch and vibration over both feet. The remainder of the examination shows no abnormalities. Serum studies show: Na+ 122 mEq/L Cl- 100 mEq/L K+ 5.8 mEq/L Glucose 172 mg/dL Albumin 2.8 g/dL Cortisol 2.5 μg/dL ACTH 531.2 pg/mL (N=5–27 pg/mL) CT scan of the abdomen with contrast shows bilateral adrenal enlargement. Which of the following is the most likely underlying mechanism of this patient's symptoms?

A. Infection with acid-fast bacilli (Correct Answer)
B. Adrenal infarction
C. Pituitary tumor
D. Autoimmune adrenalitis
E. Adrenal hemorrhage

Explanation: ***Infection with acid-fast bacilli*** - The patient's symptoms (fever, weight loss, cough, fatigue, low blood pressure, hyponatremia, hyperkalemia, low cortisol, elevated ACTH, and **bilateral adrenal enlargement**) are highly suggestive of **primary adrenal insufficiency** with an infectious etiology. - Given her recent immigration from the **Philippines** (an endemic area for tuberculosis), the prolonged cough (2 months), and **bilateral adrenal enlargement**, **adrenal tuberculosis caused by acid-fast bacilli** is the most likely diagnosis. - Adrenal TB is the most common cause of adrenal insufficiency in developing countries and causes adrenal enlargement (unlike autoimmune causes which cause atrophy). *Adrenal infarction* - Adrenal infarction typically presents with **acute, severe flank pain** and rapid onset of adrenal insufficiency, which does not match the patient's **subacute presentation over 1-2 months**. - While it can cause bilateral adrenal damage, it is not associated with a prolonged cough, fever, or history from a TB-endemic area. *Pituitary tumor* - A pituitary tumor causing adrenal insufficiency (secondary adrenal insufficiency) would lead to **low ACTH levels**, whereas this patient has markedly **elevated ACTH (531.2 pg/mL)**, indicating a primary adrenal problem. - A pituitary tumor would not explain the bilateral adrenal enlargement or the constitutional symptoms like cough, fever, and weight loss. *Autoimmune adrenalitis* - While autoimmune adrenalitis is the most common cause of **primary adrenal insufficiency** in developed countries, it typically causes **adrenal atrophy rather than enlargement**. - The patient's country of origin, prolonged cough, fever, and **adrenal enlargement** point more strongly towards an infectious cause like tuberculosis. *Adrenal hemorrhage* - Adrenal hemorrhage usually presents as an **acute, life-threatening event** with sudden onset of severe abdominal or flank pain and rapid hemodynamic collapse. - It often occurs in settings of **sepsis, anticoagulant use, trauma, or stress**, none of which are described in this patient's subacute presentation over months.

Question 1065: A 47-year-old female with a history of hypertension presents to your outpatient clinic for numbness, tingling in her right hand that has been slowly worsening over the last several months. She has tried using a splint but receives minimal relief. She is an analyst for a large consulting firm and spends most of her workday in front of a computer. Upon examination, you noticed that the patient has a prominent jaw and her hands appear disproportionately large. Her temperature is 99 deg F (37.2 deg C), blood pressure is 154/72 mmHg, pulse is 87/min, respirations are 12/min. A fasting basic metabolic panel shows: Na: 138 mEq/L, K: 4.1 mEq/L, Cl: 103 mEq/L, CO2: 24 mEq/L, BUN: 12 mg/dL, Cr: 0.8 mg/dL, Glucose: 163 mg/dL. Which of the following tests would be most helpful in identifying the underlying diagnosis?

A. Measurement of insulin-like growth factor 1 and growth hormone levels after oral glucose (Correct Answer)
B. Measurement of serum morning cortisol levels and dexamethasone suppression test
C. Measurement of thyroid stimulating hormone
D. Measurement of insulin-like growth factor 1 levels alone
E. Measurement of serum growth hormone alone

Explanation: ***Measurement of insulin-like growth factor 1 and growth hormone levels after oral glucose*** - This combination is the **most definitive diagnostic test for acromegaly**, as it assesses both the baseline levels of IGF-1 (a stable indicator of GH activity) and the failure of GH to suppress after glucose administration. - The patient's symptoms of **prominent jaw (prognathism)**, **disproportionately large hands**, **numbness/tingling in the hand (carpal tunnel syndrome)**, **hypertension**, and **elevated fasting glucose** are highly suggestive of acromegaly. *Measurement of serum morning cortisol levels and dexamethasone suppression test* - This is used to diagnose **Cushing's syndrome**, which involves cortisol excess. While Cushing's can present with hypertension and glucose intolerance, the physical exam findings of a prominent jaw and large hands are not typical. - The patient shows no other classic signs of Cushing's like central obesity, striae, or facial plethora. *Measurement of thyroid stimulating hormone* - This test is used to assess **thyroid function (e.g., hypothyroidism or hyperthyroidism)**. While thyroid dysfunction can cause some non-specific symptoms, it does not explain the characteristic physical findings of acromegaly such as a prominent jaw and large hands. - Carpal tunnel syndrome can be seen in hypothyroidism but without the other classic features of acromegaly. *Measurement of insulin-like growth factor 1 levels alone* - While **elevated IGF-1 is a key diagnostic indicator for acromegaly**, it is not as definitive as combining it with the oral glucose tolerance test. - IGF-1 can be influenced by other factors (e.g., liver disease, malnutrition), and a confirmatory test using GH suppression is crucial. *Measurement of serum growth hormone alone* - A single measurement of **serum GH is generally not sufficient for diagnosing acromegaly** due to its pulsatile secretion, which can lead to fluctuating levels even in healthy individuals. - The **oral glucose tolerance test (OGTT)** is essential to confirm the lack of GH suppression, which is pathognomonic for acromegaly.

Question 1066: A 71-year-old man comes to the emergency department because of a 2-month history of severe muscle cramps and back pain. He says that he is homeless and has not visited a physician in the past 20 years. He is 183 cm (6 ft 0 in) tall and weighs 62 kg (137 lb); BMI is 18.5 kg/m2. His blood pressure is 154/88 mm Hg. Physical examination shows pallor, multiple cutaneous excoriations, and decreased sensation over the lower extremities. Serum studies show: Calcium 7.2 mg/dL Phosphorus 5.1 mg/dL Glucose 221 mg/dL Creatinine 4.5 mg/dL An x-ray of the spine shows alternating sclerotic and radiolucent bands in the lumbar and thoracic vertebral bodies. Which of the following is the most likely explanation for these findings?

A. Primary hypoparathyroidism
B. Secondary hyperparathyroidism (Correct Answer)
C. Multiple myeloma
D. Pseudohypoparathyroidism
E. Tertiary hyperparathyroidism

Explanation: ***Secondary hyperparathyroidism*** - This patient presents with **hypocalcemia** (7.2 mg/dL) and **hyperphosphatemia** (5.1 mg/dL) in the context of **renal insufficiency** (creatinine 4.5 mg/dL), which are hallmarks of chronic kidney disease (CKD). - **Secondary hyperparathyroidism** is a common complication of CKD, where the parathyroid glands overproduce PTH in response to low serum calcium and impaired phosphate excretion, leading to characteristic bone changes like **osteomalacia** and **osteitis fibrosa**, which can manifest as alternating sclerotic and radiolucent bands on X-ray (rugger-jersey spine). *Primary hypoparathyroidism* - This condition is characterized by **low PTH**, leading to both **hypocalcemia** and **hyperphosphatemia**. - However, it would not typically present with the severe **renal insufficiency** seen in this patient, and the bone changes would differ. *Multiple myeloma* - Multiple myeloma is a plasma cell malignancy that often causes **hypercalcemia** due to bone destruction. - It would not typically present with **hypocalcemia** and hyperphosphatemia, nor would it cause the specific rugger-jersey spine appearance (alternating sclerotic and radiolucent bands). *Pseudohypoparathyroidism* - This is a rare genetic disorder where target tissues are resistant to PTH, resulting in **hypocalcemia** and **hyperphosphatemia** despite **high PTH levels**. - While it shares some lab findings, it is typically diagnosed in childhood and often associated with specific physical features (e.g., short stature, brachydactyly), which are not mentioned. *Tertiary hyperparathyroidism* - This condition develops in patients with long-standing **secondary hyperparathyroidism** where the parathyroid glands become autonomous, leading to **hypercalcemia** and **hyperphosphatemia** or normal phosphate levels. - The patient's **hypocalcemia** makes tertiary hyperparathyroidism unlikely, as it typically involves elevated calcium levels due to uncontrolled PTH secretion.

Question 1067: A 40-year-old woman comes to the physician because of a 1-week history of fatigue, dark urine, and a feeling of heaviness in her legs. Two weeks ago, she returned from a vacation to Brazil, where she spent most of her days exploring the city of Rio de Janeiro on foot. She also gained 3 kg (7 lb) during her vacation. She has systemic lupus erythematosus. Her only medication is hydroxychloroquine. Her temperature is 37.5°C (99.5°F), pulse is 78/min, and blood pressure is 162/98 mm Hg. Physical examination shows 2+ pretibial edema bilaterally. Urinalysis shows: Blood 3+ Protein 1+ RBC 6–8/hpf with dysmorphic features RBC casts numerous WBC 8/hpf WBC casts rare Bacteria negative Which of the following is the most likely cause of this patient's leg findings?

A. Venous insufficiency
B. Increased capillary permeability
C. Renal protein loss
D. Lymphatic obstruction
E. Salt retention (Correct Answer)

Explanation: ***Salt retention*** - The patient's presentation with **dark urine**, **fatigue**, new-onset **hypertension**, **pretibial edema**, **weight gain**, and a **urinalysis** consistent with **glomerulonephritis** (RBC casts, dysmorphic RBCs, proteinuria) points to **acute nephritic syndrome**. - In acute nephritic syndrome, inflammation of the glomeruli leads to reduced glomerular filtration rate (GFR). This impaired GFR results in **decreased sodium and water excretion**, causing **volume overload**, which manifests as edema (e.g., pretibial edema) and hypertension. *Venous insufficiency* - While **venous insufficiency** can cause **bilateral lower extremity edema**, it typically does not present with **dark urine**, **hypertension**, or the specific **urinalysis findings** (RBC casts, proteinuria) seen in this patient. - The edema from venous insufficiency is primarily due to **increased hydrostatic pressure** in the venous system, often accompanied by skin changes like hyperpigmentation or varicosities, which are not mentioned. *Increased capillary permeability* - **Increased capillary permeability** can lead to edema by allowing more fluid and protein to leak into the interstitial space. However, this is typically associated with conditions like **sepsis**, **allergic reactions**, or **severe inflammation** and would not explain the specific kidney findings like **RBC casts** and **hypertension** in this context. - While inflammation in glomerulonephritis does involve capillary damage, the primary mechanism for significant edema and hypertension is **fluid retention due to impaired renal excretion**, not just localized permeability increase. *Renal protein loss* - Significant **renal protein loss** (e.g., in nephrotic syndrome) leads to **hypoalbuminemia**, which reduces plasma oncotic pressure and causes **edema**. - However, this patient's urinalysis shows only **1+ protein**, which is not indicative of the massive proteinuria typically seen in nephrotic syndrome that causes edema primarily through hypoalbuminemia. Her primary renal pathology is consistent with **nephritic syndrome**, not nephrotic syndrome. *Lymphatic obstruction* - **Lymphatic obstruction** causes **lymphedema**, which is typically **non-pitting**, often unilateral (though bilateral can occur), and does not improve significantly with elevation. - It would not explain the systemic symptoms (fatigue, hypertension), dark urine, or the characteristic **glomerular findings** like **RBC casts** and **hypertension** associated with acute nephritic syndrome.

Question 1068: A 32-year-old woman presents to her primary care physician for a general wellness appointment. The patient has no complaints currently and just wants to be sure that she is in good health. The patient has a past medical history of asthma, hypertension, and anxiety. Her current medications include albuterol, fluticasone, hydrochlorothiazide, lisinopril, and fexofenadine. Her temperature is 99.5°F (37.5°C), blood pressure is 165/95 mmHg, pulse is 70/min, respirations are 15/min, and oxygen saturation is 98% on room air. On exam, you note a healthy young woman with a lean habitus. Cardiac exam reveals a S1 and S2 heart sound with a normal rate. Pulmonary exam is clear to auscultation bilaterally with good air movement. Abdominal exam reveals a bruit, normoactive bowel sounds, and an audible borborygmus. Neurological exam reveals cranial nerves II-XII as grossly intact with normal strength and reflexes in the upper and lower extremities. Which of the following is the best next step in management?

A. CT of the abdomen
B. No additional management needed
C. Ultrasound with Doppler (Correct Answer)
D. Raise lisinopril dose
E. Add furosemide

Explanation: ***Ultrasound with Doppler*** - The presence of an **abdominal bruit** in a young woman with **hypertension refractory to multiple medications** (lisinopril, HCTZ), suggests **renal artery stenosis** as a potential cause of secondary hypertension. - An ultrasound with Doppler is a non-invasive, initial diagnostic study to evaluate for renal artery stenosis by assessing blood flow and velocity in the renal arteries. *CT of the abdomen* - While a CT angiography can diagnose renal artery stenosis, it involves **radiation exposure** and **contrast dye**, which should ideally be avoided as a first-line diagnostic in a young patient, especially when a less invasive option is available. - A standard CT of the abdomen without contrast may not adequately visualize renal artery stenosis. *No additional management needed* - The patient has **uncontrolled hypertension** (165/95 mmHg) despite being on two antihypertensive medications, and presents with an **abdominal bruit**, which is a significant physical exam finding indicating a potential underlying pathology. - Ignoring these findings would be poor medical practice as it leaves the cause of hypertension unaddressed and potentially reversible conditions undiagnosed. *Raise lisinopril dose* - Raising the dose of an ACE inhibitor like lisinopril without investigating the cause of uncontrolled hypertension, especially in the presence of a **bruit**, could worsen renal function if **bilateral renal artery stenosis** is present. - The priority should be to *diagnose the underlying cause* of resistant hypertension, not just empirically increase medication dosage. *Add furosemide* - Furosemide is a loop diuretic primarily used for volume overload and edema, or sometimes as an add-on for severe hypertension, but it does **not address the underlying cause** of resistant hypertension suggested by the abdominal bruit. - Adding another medication without evaluating for secondary causes would be inappropriate and potentially mask the diagnosis.

Question 1069: A 37-year-old woman presents to the emergency department complaining of generalized malaise, weakness, headache, nausea, vomiting, and diarrhea; she last felt well roughly two days ago. She is otherwise healthy, and takes no medications. Her vital signs are: T 38.0, HR 96 beats per minute, BP 110/73, and O2 sat 96% on room air. Examination reveals a somewhat ill-appearing woman; she is drowsy but arousable and has no focal neurological deficits. Initial laboratory studies are notable for hematocrit 26%, platelets of 80,000/mL, and serum creatinine of 1.5 mg/dL. Which of the following is the most appropriate treatment at this time?

A. Cyclophosphamide and rituximab
B. Vancomycin and cefepime
C. High-dose glucocorticoids
D. Plasma exchange therapy (Correct Answer)
E. Urgent laparoscopic splenectomy

Explanation: ***Plasma exchange therapy*** - This patient presents with symptoms suggestive of **Thrombotic Thrombocytopenic Purpura (TTP)**, characterized by the pentad of microangiopathic hemolytic anemia, thrombocytopenia, neurological symptoms, renal impairment, and fever. - **Plasma exchange therapy** is the cornerstone of treatment for TTP, as it removes antibodies against **ADAMTS13** and replaces depleted ADAMTS13 enzyme. *Cyclophosphamide and rituximab* - These are **immunosuppressive agents** typically used in autoimmune conditions or certain vasculitides, but they are not first-line for acute TTP. - While TTP has an autoimmune basis, these agents are usually reserved for refractory cases or given as adjuncts after initial plasma exchange. *Vancomycin and cefepime* - These are **broad-spectrum antibiotics** used to treat bacterial infections. - While the patient has a low-grade fever, her symptoms and lab findings (anemia, thrombocytopenia, renal failure, neurological changes) are more characteristic of TTP than a primary bacterial sepsis. *High-dose glucocorticoids* - **Glucocorticoids** can be used as an adjunct in TTP, but they are not the primary treatment. - They alone are insufficient to address the underlying mechanism of TTP, which requires prompt removal of inhibitory antibodies and replacement of ADAMTS13 via plasma exchange. *Urgent laparoscopic splenectomy* - **Splenectomy** is generally considered a treatment option for **refractory immune thrombocytopenia (ITP)** that does not respond to medical management. - It is not indicated for acute TTP, where the pathology is related to ADAMTS13 deficiency and microthrombi formation, not splenic platelet destruction.

Question 1070: A 60-year-old man seeks evaluation at a medical office due to leg pain while walking. He says the pain starts in his buttocks and extends to his thighs and down to his calves. Previously, the pain resolved with rest, but the pain now persists in his feet, even during rest. His past medical history is significant for diabetes mellitus, hypertension, and cigarette smoking. The vital signs are within normal limits. The physical examination shows an atrophied leg with bilateral loss of hair. Which of the following is the most likely cause of this patient’s condition?

A. Thrombus formation
B. Weakening of vessel wall
C. Narrowing and calcification of vessels (Correct Answer)
D. Decreased permeability of endothelium
E. Peripheral emboli formation

Explanation: ***Narrowing and calcification of vessels*** - This describes **atherosclerosis**, the most common cause of **peripheral artery disease (PAD)**, which presents with **intermittent claudication** (leg pain with walking, improving with rest) progressing to **rest pain**, especially in the feet. - The patient's risk factors (**diabetes, hypertension, smoking**) and physical findings (**atrophied leg, hair loss**) are highly consistent with chronic ischemia due to atherosclerosis. *Thrombus formation* - While thrombus formation can cause acute limb ischemia, the patient's symptoms are chronic and progressive, evolving over time from claudication to rest pain, which is more characteristic of gradual **atherosclerotic narrowing**. - Acute thrombosis typically leads to a sudden onset of severe pain, pallor, pulselessness, paresthesias, and paralysis, which are not described here. *Weakening of vessel wall* - Weakening of the vessel wall is associated with conditions like **aneurysms** or dissections, which typically present with different symptoms (e.g., pulsatile masses, sudden severe chest/back pain). - It does not directly explain the progressive ischemic symptoms described, such as claudication and rest pain from inadequate blood flow. *Decreased permeability of endothelium* - Decreased permeability of the endothelium generally implies difficulty in substances passing through the vessel wall, which is not directly linked to the pathophysiology of ischemic pain and tissue atrophy observed in this patient. - Conditions affecting endothelial permeability often relate to inflammation, edema, or microvascular dysfunction, but not the macrovascular obstruction causing PAD. *Peripheral emboli formation* - Emboli can cause acute peripheral artery occlusion, leading to sudden onset severe limb pain and signs of ischemia. - However, the patient's symptoms have progressed chronically over time, starting with intermittent claudication and worsening to rest pain, which is more indicative of a gradual atherosclerotic process rather than an acute embolic event.

Question 1071: A 35-year-old woman comes to the physician because of a 1-month history of double vision, difficulty climbing stairs, and weakness when trying to brush her hair. She reports that these symptoms are worse after she exercises and disappear after she rests for a few hours. Physical examination shows drooping of her right upper eyelid that worsens when the patient is asked to gaze at the ceiling for 2 minutes. There is diminished motor strength in the upper extremities. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?

A. Amyotrophic lateral sclerosis
B. Myasthenia gravis (Correct Answer)
C. Polymyositis
D. Guillain-Barré syndrome
E. Multiple sclerosis

Explanation: ***Myasthenia gravis*** - The patient's symptoms of **double vision (diplopia)**, **difficulty climbing stairs**, **weakness exacerbated by activity**, and **ptosis (drooping eyelid)** are classic presentations of myasthenia gravis, a disorder of the **neuromuscular junction**. - The improvement of symptoms after rest and worsening after activity (**fatigability**) is a hallmark feature, as is the positive **Cogan's lid twitch sign** (worsening ptosis on sustained upward gaze). *Amyotrophic lateral sclerosis* - This is a disease of both **upper and lower motor neurons**, leading to progressive muscle weakness, atrophy, and spasticity. - ALS typically does not present with fluctuating weakness or ocular symptoms like **diplopia and ptosis**, and sensory function is usually spared. *Polymyositis* - Polymyositis is an **inflammatory myopathy** characterized by **proximal muscle weakness** (e.g., difficulty climbing stairs, brushing hair) that is typically progressive and constant, not fluctuating with activity and rest. - It does not involve ocular muscles or present with **fatigability** of symptoms. *Guillain-Barré syndrome* - This is an **acute demyelinating polyradiculoneuropathy** characterized by **ascending paralysis**, often following an infection. - Symptoms are usually rapid in onset and progressive, not fluctuating or limited primarily to specific muscle groups that worsen with exertion. *Multiple sclerosis* - MS is a **demyelinating disease** of the central nervous system, which can cause varied neurological symptoms depending on the location of lesions. - While it can cause **diplopia** and **fatigue**, the characteristic fluctuating weakness that improves with rest and specific ocular motor findings like **ptosis** that worsen with sustained gaze are not typical primary features of MS.

Question 1072: A 53-year-old man comes to the emergency department because of severe right-sided flank pain for 3 hours. The pain is colicky, radiates towards his right groin, and he describes it as 8/10 in intensity. He has vomited once. He has no history of similar episodes in the past. Last year, he was treated with naproxen for swelling and pain of his right toe. He has a history of hypertension. He drinks one to two beers on the weekends. Current medications include amlodipine. He appears uncomfortable. His temperature is 37.1°C (99.3°F), pulse is 101/min, and blood pressure is 130/90 mm Hg. Examination shows a soft, nontender abdomen and right costovertebral angle tenderness. An upright x-ray of the abdomen shows no abnormalities. A CT scan of the abdomen and pelvis shows a 7-mm stone in the proximal ureter and grade I hydronephrosis on the right. Which of the following is most likely to be seen on urinalysis?

A. Urinary pH: 4.7 (Correct Answer)
B. Positive nitrites test
C. Hexagon shaped crystals
D. Urinary pH: 7.3
E. Largely positive urinary protein

Explanation: ***Urinary pH: 4.7*** - The patient's history of right toe pain and swelling treated with naproxen, despite no confirmed gout diagnosis, suggests a predisposition to **hyperuricemia** and uric acid stone formation. - **Uric acid stones** are the only common kidney stone type that is radiolucent (explaining the normal X-ray) and characteristically form in acidic urine (pH < 5.5). *Positive nitrites test* - A positive nitrites test indicates the presence of **nitrate-reducing bacteria**, suggesting a **urinary tract infection (UTI)**. - While UTIs can complicate kidney stones, the patient's presentation with acute, severe pain and no fever makes a primary UTI with positive nitrites less likely as the most prominent finding. *Hexagon shaped crystals* - **Hexagonal crystals** in urine are pathognomonic for **cystine stones**. - Cystine stones are rare, inherited metabolic disorders, and there is nothing in this patient's history to suggest cystinuria. *Urinary pH: 7.3* - An alkaline urinary pH (e.g., 7.3) is typically associated with **struvite stones** (magnesium ammonium phosphate), which form in the presence of urease-producing bacteria (often causing UTIs), or sometimes with calcium phosphate stones. - This is inconsistent with the patient's likely uric acid stone, which forms in acidic urine. *Largely positive urinary protein* - Significant proteinuria (largely positive urinary protein) usually indicates **glomerular or severe renal parenchymal disease**. - While microscopic hematuria is common with kidney stones, gross proteinuria is not a typical finding in simple nephrolithiasis and implies a different underlying renal pathology.

Question 1073: A 69-year-old male presents to the emergency room with back pain. He has a history of personality disorder and metastatic prostate cancer and was not a candidate for surgical resection. He began chemotherapy but discontinued due to unremitting nausea. He denies any bowel or bladder incontinence. He has never had pain like this before and is demanding morphine. The nurse administers IV morphine and he feels more comfortable. Vital signs are stable. On physical examination you note tenderness to palpation along the lower spine, weakness in the bilateral lower extremities, left greater than right. Neurological examination is also notable for hyporeflexia in the knee and ankle jerks bilaterally. You conduct a rectal examination, which reveals saddle anesthesia. Regarding this patient, what is the most likely diagnosis and the appropriate next step in management?

A. The most likely diagnosis is cauda equina syndrome and the patient should be rushed to radiation
B. The most likely diagnosis is conus medullaris syndrome and steroids should be started prior to MRI
C. The most likely diagnosis is cauda equina syndrome and steroids should be started prior to MRI (Correct Answer)
D. The most likely diagnosis is conus medullaris syndrome and steroids should be started after MRI
E. The most likely diagnosis is cauda equina syndrome and steroids should be started after MRI

Explanation: ***The most likely diagnosis is cauda equina syndrome and steroids should be started prior to MRI*** - The patient's presentation with **back pain**, **bilateral lower extremity weakness** (left > right), **hyporeflexia**, and **saddle anesthesia** are classic signs of **cauda equina syndrome**. This is often caused by compression of the nerve roots below the spinal cord, commonly from metastasis in patients with a history of prostate cancer. - Given the suspected **spinal cord compression** due to metastatic disease, initiating **high-dose corticosteroids** (like dexamethasone) before imaging is crucial to reduce edema around the spinal cord and preserve neurological function. An **urgent MRI** is the next step to confirm the diagnosis and localize the compression. *The most likely diagnosis is cauda equina syndrome and the patient should be rushed to radiation* - While **cauda equina syndrome** is the correct diagnosis, **radiation** is typically a definitive treatment modality for metastatic compression, not an immediate next step before confirming the extent and location of compression with imaging. - **Corticosteroids** are the immediate priority to reduce swelling and improve neurological outcomes while awaiting definitive imaging and treatment planning. *The most likely diagnosis is conus medullaris syndrome and steroids should be started prior to MRI* - **Conus medullaris syndrome** typically presents with more symmetrical symptoms, often including early-onset **bladder and bowel dysfunction** and **hyperreflexia** (or mixed reflexes), which are not fully consistent with this patient's presentation of hyporeflexia and lack of incontinence. - Although steroids would be appropriate for suspected compression before MRI for either syndrome, the specific symptom profile strongly favors cauda equina over conus. *The most likely diagnosis is conus medullaris syndrome and steroids should be started after MRI* - The patient's symptoms (weakness, hyporeflexia, saddle anesthesia) are more indicative of **cauda equina syndrome** rather than **conus medullaris syndrome** (which often involves hyperreflexia and earlier bowel/bladder dysfunction). - Delaying **corticosteroids** until after the MRI in suspected spinal cord compression can lead to irreversible neurological damage, as they help reduce edema immediately. *The most likely diagnosis is cauda equina syndrome and steroids should be started after MRI* - While **cauda equina syndrome** is the correct diagnosis, waiting for an **MRI** before initiating **corticosteroids** would be a critical delay. - **Early administration of steroids** is vital in cases of suspected spinal cord compression to reduce inflammation and preserve neurological function, even before definitive imaging.

Question 1074: A 68-year-old man comes to the physician because of recurrent episodes of nausea and abdominal discomfort for the past 4 months. The discomfort is located in the upper abdomen and sometimes occurs after eating, especially after a big meal. He has tried to go for a walk after dinner to help with digestion, but his complaints have only increased. For the past 3 weeks he has also had symptoms while climbing the stairs to his apartment. He has type 2 diabetes mellitus, hypertension, and stage 2 peripheral arterial disease. He has smoked one pack of cigarettes daily for the past 45 years. He drinks one to two beers daily and occasionally more on weekends. His current medications include metformin, enalapril, and aspirin. He is 168 cm (5 ft 6 in) tall and weighs 126 kg (278 lb); BMI is 45 kg/m2. His temperature is 36.4°C (97.5°F), pulse is 78/min, and blood pressure is 148/86 mm Hg. On physical examination, the abdomen is soft and nontender with no organomegaly. Foot pulses are absent bilaterally. An ECG shows no abnormalities. Which of the following is the most appropriate next step in diagnosis?

A. CT scan of the abdomen
B. Abdominal ultrasonography of the right upper quadrant
C. Esophagogastroduodenoscopy
D. Hydrogen breath test
E. Cardiac stress test (Correct Answer)

Explanation: ***Cardiac stress test*** - The patient's **epigastric discomfort** that is exacerbated by exertion (walking, climbing stairs) and presents with several **cardiovascular risk factors** (obesity, type 2 diabetes mellitus, hypertension, smoking, peripheral arterial disease) strongly suggests **ischemic heart disease** as the cause of his abdominal symptoms. - A **cardiac stress test** is the most appropriate next step to evaluate for **exercise-induced myocardial ischemia**, which can manifest as referred pain to the epigastrium (angina equivalent). - This patient has a high pretest probability of coronary artery disease, making functional cardiac testing essential before pursuing other diagnostic workup. *CT scan of the abdomen* - A CT scan of the abdomen would be indicated for evaluating structural abnormalities of abdominal organs, but the **exertional nature** of the patient's symptoms makes **cardiac ischemia** a more pressing concern. - While it could rule out other abdominal pathologies, it would not address the likely cardiac origin of his symptoms. *Abdominal ultrasonography of the right upper quadrant* - Abdominal ultrasonography is used to evaluate organs like the **gallbladder, liver, and pancreas** for conditions such as **cholelithiasis or cholecystitis**. - The patient's symptoms are more consistent with **exertional pain** rather than typical biliary colic, making cardiac evaluation a higher priority. *Esophagogastroduodenoscopy* - An **EGD** is used to visualize the **esophagus, stomach, and duodenum** to diagnose conditions like **peptic ulcer disease, esophagitis, or gastritis**. - While **upper GI symptoms** are present, the exacerbation with exertion shifts the focus away from primary gastrointestinal pathology toward cardiac causes. *Hydrogen breath test* - A **hydrogen breath test** is primarily used to diagnose **small intestinal bacterial overgrowth (SIBO)** or **carbohydrate malabsorption** (e.g., lactose intolerance). - The patient's symptoms are not classic for SIBO or malabsorption, and the **exertional component** makes this a less probable diagnosis.

Question 1075: A 46-year-old woman comes to the physician because of a 2-week history of diplopia and ocular pain when reading the newspaper. She also has a 3-month history of amenorrhea, hot flashes, and increased sweating. She reports that she has been overweight all her adult life and is happy to have lost 6.8-kg (15-lb) of weight in the past 2 months. Her pulse is 110/min, and blood pressure is 148/98 mm Hg. Physical examination shows moist palms and a nontender thyroid gland that is enlarged to two times its normal size. Ophthalmologic examination shows prominence of the globes of the eyes, bilateral lid retraction, conjunctival injection, and an inability to converge the eyes. There is no pain on movement of the extraocular muscles. Visual acuity is 20/20 bilaterally. Neurologic examination shows a fine resting tremor of the hands. Deep tendon reflexes are 3+ with a shortened relaxation phase. Which of the following is the most likely cause of this patient's ocular complaints?

A. Sympathetic hyperactivity of levator palpebrae superioris
B. Abnormal communication between the cavernous sinus and the internal carotid artery
C. Granulomatous inflammation of the cavernous sinus
D. Glycosaminoglycan accumulation in the orbit (Correct Answer)
E. Bacterial infection of the orbital contents

Explanation: ***Glycosaminoglycan accumulation in the orbit*** - The patient exhibits classic signs of **Graves' ophthalmopathy (exophthalmos, lid retraction, conjunctival injection, inability to converge)**, which is caused by the accumulation of **glycosaminoglycans** and fibrous tissue in the retro-orbital space due to autoimmune stimulation of fibroblasts. - This accumulation leads to increased orbital pressure, fat and muscle enlargement, causing the described ocular symptoms like **diplopia and ocular pain, especially with eye movement** (though not painful in this case, the other orbital signs are prominent). *Sympathetic hyperactivity of levator palpebrae superioris* - **Sympathetic hyperactivity** can cause **lid retraction (Darlmple's sign)** and a "staring" appearance (lid lag, von Graefe's sign), which are part of Graves' ophthalmopathy. - However, it does not explain the other prominent symptoms like **proptosis (prominence of globes), conjunctival injection, diplopia**, or the more severe orbital changes. *Abnormal communication between the cavernous sinus and the internal carotid artery* - An **arteriovenous fistula** (e.g., carotid-cavernous fistula) can lead to **pulsatile exophthalmos, chemosis, bruits, and visual impairment**. - While it can cause some ocular signs, it typically presents with a **bruit** and often more acute onset or traumatic etiology, which are not described. *Granulomatous inflammation of the cavernous sinus* - **Tolosa-Hunt syndrome**, a form of granulomatous inflammation of the cavernous sinus, typically causes **painful ophthalmoplegia** (paralysis of eye muscles) and can affect specific cranial nerves (III, IV, VI). - This condition does not explain the **proptosis, lid retraction, or systemic features of hyperthyroidism** seen in the patient. *Bacterial infection of the orbital contents* - **Orbital cellulitis** would present with **acute onset, severe pain, fever, erythema, edema, and often vision loss**, along with signs of infection. - The patient's chronic symptoms spanning months, lack of infectious signs, and systemic hyperthyroid features make bacterial infection highly unlikely.

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Cardiology — MCQs

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