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?
Q432
A previously healthy 26-year-old man is brought to the emergency department 30 minutes after collapsing during soccer practice. The patient appears well. His pulse is 73/min and blood pressure is 125/78 mm Hg. Cardiac examination is shown. Rapid squatting decreases the intensity of the patient's auscultation finding. Which of the following is the most likely cause of this patient's condition?
Q433
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?
Q434
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?
Q435
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?
Q436
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?
Q437
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?
Q438
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?
Q439
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?
Q440
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?
Cardiology US Medical PG Practice Questions and MCQs
Question 431: 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 432: A previously healthy 26-year-old man is brought to the emergency department 30 minutes after collapsing during soccer practice. The patient appears well. His pulse is 73/min and blood pressure is 125/78 mm Hg. Cardiac examination is shown. Rapid squatting decreases the intensity of the patient's auscultation finding. Which of the following is the most likely cause of this patient's condition?
A. Calcification of the aortic valve
B. Dilation of the aortic root
C. Fibrinoid necrosis of the mitral valve
D. Eccentric dilatation of the left ventricle
E. Asymmetric hypertrophy of the septum (Correct Answer)
Explanation: ***Asymmetric hypertrophy of the septum***
- The patient's collapse during soccer practice, normal vitals, and the auscultation finding that decreases with rapid squatting are classic signs of **Hypertrophic Obstructive Cardiomyopathy (HOCM)**.
- HOCM is characterized by **asymmetric hypertrophy of the interventricular septum**, leading to left ventricular outflow tract obstruction and dynamic murmur changes with maneuvers.
*Calcification of the aortic valve*
- **Aortic valve calcification** is a slow, progressive process usually seen in older adults (degenerative) or with congenital bicuspid aortic valves, rarely causing sudden collapse in a young, healthy individual without prior symptoms.
- While it can cause aortic stenosis and a systolic murmur, the murmur would typically **increase with squatting** (due to increased preload and stroke volume), unlike the HOCM murmur which decreases.
*Dilation of the aortic root*
- **Aortic root dilation** is associated with conditions like Marfan syndrome or bicuspid aortic valve, which can lead to aortic regurgitation or dissection.
- Aortic root dilation itself does not directly explain a dynamic murmur that decreases with squatting or acute collapse during exercise in a healthy individual.
*Fibrinoid necrosis of the mitral valve*
- **Fibrinoid necrosis of the mitral valve** is characteristic of acute rheumatic fever or other inflammatory conditions; it would primarily cause mitral regurgitation and would present with systemic inflammatory symptoms.
- It is not typically associated with exercise-induced collapse in a young, otherwise healthy individual, nor would it explain the specific dynamic changes in a murmur with squatting.
*Eccentric dilatation of the left ventricle*
- **Eccentric left ventricular dilation** is seen in volume overload states, like chronic aortic or mitral regurgitation, or dilated cardiomyopathy.
- This condition would likely present with symptoms of heart failure (dyspnea, fatigue) rather than sudden collapse during exercise in an otherwise healthy young man, and would not typically produce a dynamic murmur that decreases with squatting.
Question 433: 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 434: 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 435: 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 436: 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 437: 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 438: 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 439: 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 440: 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.
