United States Medical Licensing Examination Step
Three: High-Yield Clinical Scenarios, Diagnostic
Dilemmas, Therapeutic Conundrums, and Patient Safety
Challenges for Independent Medical Practice – A
Comprehensive Question Bank V3.1
Question 1
A 72-year-old man with a history of hypertension, type 2 diabetes mellitus, and chronic kidney
disease stage 3b (eGFR 42 mL/min/1.73 m²) presents to the emergency department with a 3-
day history of progressive dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea.
He reports a 15-pound weight gain over the past 2 weeks. His medications include lisinopril 40
mg daily, metoprolol succinate 100 mg daily, furosemide 40 mg daily, metformin 1000 mg twice
daily, and atorvastatin 40 mg daily. On examination, temperature 37.0°C, heart rate 102 bpm
and irregularly irregular, blood pressure 165/95 mm Hg, respiratory rate 24/min, oxygen
saturation 91% on room air. He has jugular venous distension at 16 cm H₂O, crackles extending
to the mid-lung fields bilaterally, and 3+ pitting edema in the lower extremities. Laboratory
studies reveal sodium 132 mEq/L, potassium 5.1 mEq/L, BUN 38 mg/dL, creatinine 2.2 mg/dL
(baseline 1.8 mg/dL), hemoglobin 11.2 g/dL, and brain natriuretic peptide 1,800 pg/mL.
Electrocardiogram shows atrial fibrillation with rapid ventricular response at 120 bpm. Chest
radiograph shows cardiomegaly, pulmonary vascular congestion, and small bilateral pleural
effusions. Echocardiography reveals a left ventricular ejection fraction of 28% with severe
concentric left ventricular hypertrophy, moderate mitral regurgitation, and a dilated left atrium.
Which of the following is the most appropriate initial management strategy?
A) Increase furosemide to 80 mg intravenously twice daily, add spironolactone 25 mg daily, and
initiate digoxin 0.125 mg daily
B) Administer intravenous furosemide 80 mg, initiate continuous infusion of nicardipine for
blood pressure control, and schedule for urgent hemodialysis
C) Administer intravenous furosemide 80 mg, initiate dobutamine infusion, and transfer to the
cardiac intensive care unit for invasive hemodynamic monitoring
D) Administer intravenous furosemide 80 mg, initiate intravenous labetalol for rate control, and
adjust lisinopril dose based on renal function
E) Administer intravenous furosemide 80 mg, initiate intravenous diltiazem for rate control, and
prepare for emergent cardioversion
,Correct Answer: D
Rationale: This patient presents with acute decompensated heart failure with reduced ejection
fraction complicated by atrial fibrillation with rapid ventricular response, volume overload, and
worsening renal function. The most appropriate initial management is intravenous loop diuresis
for volume overload, rate control with a beta-blocker or calcium channel blocker (labetalol is
preferred given the reduced ejection fraction), and optimization of the ACE inhibitor with renal
function monitoring. While diltiazem is effective for rate control in atrial fibrillation, it is
relatively contraindicated in patients with HFrEF due to negative inotropic effects.
Spironolactone should be used cautiously in patients with renal dysfunction and hyperkalemia.
Dobutamine is reserved for cardiogenic shock. Hemodialysis is not indicated for this degree of
renal impairment. The approach should focus on decongestion, rate control, and optimization of
guideline-directed medical therapy.
Question 2
A 45-year-old woman with a 10-year history of systemic lupus erythematosus presents with a 6-
week history of progressive shortness of breath, nonproductive cough, and fatigue. She reports
that her symptoms have been gradually worsening despite adherence to her maintenance
medications (hydroxychloroquine 400 mg daily and prednisone 10 mg daily). She has no fevers,
night sweats, or weight loss. On examination, she has bibasilar crackles, digital clubbing, and
mild cyanosis. Pulse oximetry shows 89% on room air, which improves to 95% with 2 L/min of
supplemental oxygen. High-resolution CT of the chest reveals bilateral reticular opacities with
traction bronchiectasis and honeycombing predominantly in the lower lobes, with a peripheral
predominance. Pulmonary function testing shows a severe restrictive pattern with a forced vital
capacity of 45% predicted, diffusing capacity of the lung for carbon monoxide of 38% predicted,
and a normal FEV₁/FVC ratio. Laboratory studies reveal negative anti-dsDNA, normal
complement levels, and positive anti-SSA/Ro antibodies. Which of the following is the most
appropriate next step in management?
A) Increase prednisone to 60 mg daily and add cyclophosphamide
B) Initiate mycophenolate mofetil and begin a slow prednisone taper
C) Initiate rituximab and continue prednisone at the current dose
D) Start antifibrotic therapy with nintedanib and refer for lung transplantation evaluation
E) Perform surgical lung biopsy to confirm the diagnosis before initiating therapy
Correct Answer: D
Rationale: This patient has systemic lupus erythematosus-associated interstitial lung disease
with a fibrotic pattern (honeycombing, traction bronchiectasis). The presence of established
,fibrosis on HRCT with a restrictive pattern and reduced DLCO suggests that the disease is no
longer primarily inflammatory but has progressed to fibrosis. Antifibrotic therapy (nintedanib or
pirfenidone) has been shown to slow the decline in FVC in patients with progressive fibrosing
ILD, including those with connective tissue disease-associated ILD. Immunosuppression with
prednisone, mycophenolate, cyclophosphamide, or rituximab is more appropriate for
inflammatory ILD without established fibrosis. Lung transplantation evaluation is appropriate for
end-stage disease, but antifibrotic therapy should be initiated first. Surgical lung biopsy carries
significant risks and may not change management given the typical HRCT findings.
Question 3
A 62-year-old man with a 40-pack-year smoking history and known chronic obstructive
pulmonary disease (GOLD stage 3) presents with a 2-week history of worsening dyspnea,
increased sputum production that has changed from white to purulent, and subjective fevers.
He has had two similar exacerbations in the past 6 months, both requiring oral corticosteroids
and antibiotics. He is currently on tiotropium 18 mcg daily and fluticasone/salmeterol 250/50
twice daily. On examination, temperature 38.2°C, heart rate 110 bpm, respiratory rate 28/min,
oxygen saturation 86% on room air, which improves to 92% with 4 L/min via nasal cannula. He is
using accessory muscles of respiration and has diffuse expiratory wheezing. Arterial blood gas
on 4 L/min shows pH 7.32, PaCO₂ 58 mm Hg, PaO₂ 68 mm Hg, and bicarbonate 30 mEq/L. Chest
radiograph shows hyperinflation with no infiltrate. Which of the following is the most
appropriate initial management strategy?
A) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and noninvasive positive pressure ventilation
B) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and levofloxacin 750 mg intravenously
C) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and prepare for intubation and mechanical ventilation
D) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and piperacillin-tazobactam 4.5 g intravenously
E) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and doxycycline 100 mg intravenously
Correct Answer: A
Rationale: This patient presents with an acute exacerbation of COPD with acute hypercapnic
respiratory failure (pH 7.32, PaCO₂ 58 mm Hg). The most appropriate initial management
includes bronchodilators (nebulized albuterol and ipratropium), systemic corticosteroids, and
, noninvasive positive pressure ventilation (NIPPV). NIPPV has been shown to reduce the need for
intubation, decrease mortality, and shorten hospital length of stay in patients with acute
hypercapnic respiratory failure due to COPD exacerbation. While antibiotics are indicated for
purulent sputum, the immediate priority is ventilatory support. Intubation should be reserved
for patients who fail NIPPV or have contraindications to NIPPV. Levofloxacin or piperacillin-
tazobactam may be appropriate antibiotic choices but are not the immediate priority over
ventilatory support.
Question 4
A 55-year-old woman with a history of hypertension, hyperlipidemia, and obesity presents with
a 2-month history of progressive dysphagia to both solids and liquids, an involuntary 20-pound
weight loss, and hoarseness. She reports no heartburn or regurgitation. She has a 25-pack-year
smoking history. On examination, she has palpable left supraclavicular lymphadenopathy.
Esophagogastroduodenoscopy reveals a large, ulcerated, fungating mass in the mid-esophagus
at 30 cm from the incisors. Biopsy of the mass shows poorly differentiated adenocarcinoma
with signet ring cells. Her complete blood count shows hemoglobin 10.8 g/dL and mean
corpuscular volume 72 fL. Which of the following is the most appropriate next step in
management?
A) Endoscopic ultrasound for staging and CT scan of the chest, abdomen, and pelvis
B) PET/CT scan and referral for neoadjuvant chemoradiation
C) Surgical resection with esophagectomy and lymph node dissection
D) Endoscopic mucosal resection and palliative stenting
E) Initiation of palliative chemotherapy with FOLFOX
Correct Answer: A
Rationale: This patient has an esophageal adenocarcinoma with signet ring features and left
supraclavicular lymphadenopathy, which is concerning for metastatic disease. The most
appropriate next step is staging with endoscopic ultrasound (EUS) for local invasion (T stage)
and lymph node involvement (N stage), along with CT scan of the chest, abdomen, and pelvis to
evaluate for distant metastases (M stage). EUS provides critical information about the depth of
tumor invasion and involvement of adjacent structures, which guides treatment decisions.
PET/CT is also important for staging but should follow CT and EUS. Neoadjuvant chemoradiation
or surgical resection are treatment options that depend on staging results. Palliative
chemotherapy or stenting would be appropriate for metastatic disease but should not be
initiated without complete staging.
Three: High-Yield Clinical Scenarios, Diagnostic
Dilemmas, Therapeutic Conundrums, and Patient Safety
Challenges for Independent Medical Practice – A
Comprehensive Question Bank V3.1
Question 1
A 72-year-old man with a history of hypertension, type 2 diabetes mellitus, and chronic kidney
disease stage 3b (eGFR 42 mL/min/1.73 m²) presents to the emergency department with a 3-
day history of progressive dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea.
He reports a 15-pound weight gain over the past 2 weeks. His medications include lisinopril 40
mg daily, metoprolol succinate 100 mg daily, furosemide 40 mg daily, metformin 1000 mg twice
daily, and atorvastatin 40 mg daily. On examination, temperature 37.0°C, heart rate 102 bpm
and irregularly irregular, blood pressure 165/95 mm Hg, respiratory rate 24/min, oxygen
saturation 91% on room air. He has jugular venous distension at 16 cm H₂O, crackles extending
to the mid-lung fields bilaterally, and 3+ pitting edema in the lower extremities. Laboratory
studies reveal sodium 132 mEq/L, potassium 5.1 mEq/L, BUN 38 mg/dL, creatinine 2.2 mg/dL
(baseline 1.8 mg/dL), hemoglobin 11.2 g/dL, and brain natriuretic peptide 1,800 pg/mL.
Electrocardiogram shows atrial fibrillation with rapid ventricular response at 120 bpm. Chest
radiograph shows cardiomegaly, pulmonary vascular congestion, and small bilateral pleural
effusions. Echocardiography reveals a left ventricular ejection fraction of 28% with severe
concentric left ventricular hypertrophy, moderate mitral regurgitation, and a dilated left atrium.
Which of the following is the most appropriate initial management strategy?
A) Increase furosemide to 80 mg intravenously twice daily, add spironolactone 25 mg daily, and
initiate digoxin 0.125 mg daily
B) Administer intravenous furosemide 80 mg, initiate continuous infusion of nicardipine for
blood pressure control, and schedule for urgent hemodialysis
C) Administer intravenous furosemide 80 mg, initiate dobutamine infusion, and transfer to the
cardiac intensive care unit for invasive hemodynamic monitoring
D) Administer intravenous furosemide 80 mg, initiate intravenous labetalol for rate control, and
adjust lisinopril dose based on renal function
E) Administer intravenous furosemide 80 mg, initiate intravenous diltiazem for rate control, and
prepare for emergent cardioversion
,Correct Answer: D
Rationale: This patient presents with acute decompensated heart failure with reduced ejection
fraction complicated by atrial fibrillation with rapid ventricular response, volume overload, and
worsening renal function. The most appropriate initial management is intravenous loop diuresis
for volume overload, rate control with a beta-blocker or calcium channel blocker (labetalol is
preferred given the reduced ejection fraction), and optimization of the ACE inhibitor with renal
function monitoring. While diltiazem is effective for rate control in atrial fibrillation, it is
relatively contraindicated in patients with HFrEF due to negative inotropic effects.
Spironolactone should be used cautiously in patients with renal dysfunction and hyperkalemia.
Dobutamine is reserved for cardiogenic shock. Hemodialysis is not indicated for this degree of
renal impairment. The approach should focus on decongestion, rate control, and optimization of
guideline-directed medical therapy.
Question 2
A 45-year-old woman with a 10-year history of systemic lupus erythematosus presents with a 6-
week history of progressive shortness of breath, nonproductive cough, and fatigue. She reports
that her symptoms have been gradually worsening despite adherence to her maintenance
medications (hydroxychloroquine 400 mg daily and prednisone 10 mg daily). She has no fevers,
night sweats, or weight loss. On examination, she has bibasilar crackles, digital clubbing, and
mild cyanosis. Pulse oximetry shows 89% on room air, which improves to 95% with 2 L/min of
supplemental oxygen. High-resolution CT of the chest reveals bilateral reticular opacities with
traction bronchiectasis and honeycombing predominantly in the lower lobes, with a peripheral
predominance. Pulmonary function testing shows a severe restrictive pattern with a forced vital
capacity of 45% predicted, diffusing capacity of the lung for carbon monoxide of 38% predicted,
and a normal FEV₁/FVC ratio. Laboratory studies reveal negative anti-dsDNA, normal
complement levels, and positive anti-SSA/Ro antibodies. Which of the following is the most
appropriate next step in management?
A) Increase prednisone to 60 mg daily and add cyclophosphamide
B) Initiate mycophenolate mofetil and begin a slow prednisone taper
C) Initiate rituximab and continue prednisone at the current dose
D) Start antifibrotic therapy with nintedanib and refer for lung transplantation evaluation
E) Perform surgical lung biopsy to confirm the diagnosis before initiating therapy
Correct Answer: D
Rationale: This patient has systemic lupus erythematosus-associated interstitial lung disease
with a fibrotic pattern (honeycombing, traction bronchiectasis). The presence of established
,fibrosis on HRCT with a restrictive pattern and reduced DLCO suggests that the disease is no
longer primarily inflammatory but has progressed to fibrosis. Antifibrotic therapy (nintedanib or
pirfenidone) has been shown to slow the decline in FVC in patients with progressive fibrosing
ILD, including those with connective tissue disease-associated ILD. Immunosuppression with
prednisone, mycophenolate, cyclophosphamide, or rituximab is more appropriate for
inflammatory ILD without established fibrosis. Lung transplantation evaluation is appropriate for
end-stage disease, but antifibrotic therapy should be initiated first. Surgical lung biopsy carries
significant risks and may not change management given the typical HRCT findings.
Question 3
A 62-year-old man with a 40-pack-year smoking history and known chronic obstructive
pulmonary disease (GOLD stage 3) presents with a 2-week history of worsening dyspnea,
increased sputum production that has changed from white to purulent, and subjective fevers.
He has had two similar exacerbations in the past 6 months, both requiring oral corticosteroids
and antibiotics. He is currently on tiotropium 18 mcg daily and fluticasone/salmeterol 250/50
twice daily. On examination, temperature 38.2°C, heart rate 110 bpm, respiratory rate 28/min,
oxygen saturation 86% on room air, which improves to 92% with 4 L/min via nasal cannula. He is
using accessory muscles of respiration and has diffuse expiratory wheezing. Arterial blood gas
on 4 L/min shows pH 7.32, PaCO₂ 58 mm Hg, PaO₂ 68 mm Hg, and bicarbonate 30 mEq/L. Chest
radiograph shows hyperinflation with no infiltrate. Which of the following is the most
appropriate initial management strategy?
A) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and noninvasive positive pressure ventilation
B) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and levofloxacin 750 mg intravenously
C) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and prepare for intubation and mechanical ventilation
D) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and piperacillin-tazobactam 4.5 g intravenously
E) Administer inhaled albuterol and ipratropium via nebulizer, intravenous methylprednisolone
125 mg, and doxycycline 100 mg intravenously
Correct Answer: A
Rationale: This patient presents with an acute exacerbation of COPD with acute hypercapnic
respiratory failure (pH 7.32, PaCO₂ 58 mm Hg). The most appropriate initial management
includes bronchodilators (nebulized albuterol and ipratropium), systemic corticosteroids, and
, noninvasive positive pressure ventilation (NIPPV). NIPPV has been shown to reduce the need for
intubation, decrease mortality, and shorten hospital length of stay in patients with acute
hypercapnic respiratory failure due to COPD exacerbation. While antibiotics are indicated for
purulent sputum, the immediate priority is ventilatory support. Intubation should be reserved
for patients who fail NIPPV or have contraindications to NIPPV. Levofloxacin or piperacillin-
tazobactam may be appropriate antibiotic choices but are not the immediate priority over
ventilatory support.
Question 4
A 55-year-old woman with a history of hypertension, hyperlipidemia, and obesity presents with
a 2-month history of progressive dysphagia to both solids and liquids, an involuntary 20-pound
weight loss, and hoarseness. She reports no heartburn or regurgitation. She has a 25-pack-year
smoking history. On examination, she has palpable left supraclavicular lymphadenopathy.
Esophagogastroduodenoscopy reveals a large, ulcerated, fungating mass in the mid-esophagus
at 30 cm from the incisors. Biopsy of the mass shows poorly differentiated adenocarcinoma
with signet ring cells. Her complete blood count shows hemoglobin 10.8 g/dL and mean
corpuscular volume 72 fL. Which of the following is the most appropriate next step in
management?
A) Endoscopic ultrasound for staging and CT scan of the chest, abdomen, and pelvis
B) PET/CT scan and referral for neoadjuvant chemoradiation
C) Surgical resection with esophagectomy and lymph node dissection
D) Endoscopic mucosal resection and palliative stenting
E) Initiation of palliative chemotherapy with FOLFOX
Correct Answer: A
Rationale: This patient has an esophageal adenocarcinoma with signet ring features and left
supraclavicular lymphadenopathy, which is concerning for metastatic disease. The most
appropriate next step is staging with endoscopic ultrasound (EUS) for local invasion (T stage)
and lymph node involvement (N stage), along with CT scan of the chest, abdomen, and pelvis to
evaluate for distant metastases (M stage). EUS provides critical information about the depth of
tumor invasion and involvement of adjacent structures, which guides treatment decisions.
PET/CT is also important for staging but should follow CT and EUS. Neoadjuvant chemoradiation
or surgical resection are treatment options that depend on staging results. Palliative
chemotherapy or stenting would be appropriate for metastatic disease but should not be
initiated without complete staging.
