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?
Q62
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?
Q63
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?
Q64
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?
Q65
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?
Q66
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?
Q67
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?
Q68
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?
Q69
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?
Q70
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?
Cardiology US Medical PG Practice Questions and MCQs
Question 61: 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 62: 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 63: 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 64: 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 65: 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 66: 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 67: 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 68: 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 69: 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 70: 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.
