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NBME Comprehensive Basic Science Examination (CBSE)
| Newest 2025/2026 | Advanced/Hard Difficulty |
Graded A+
[1] A 58-year-old man with a 40-pack-year smoking history presents with a 3-month history of
progressive dysphagia and hoarseness. A biopsy of a mass in the upper esophagus reveals
squamous cell carcinoma. Which of the following is the most likely associated pre-existing
condition?
A. Barrett esophagus
B. Achalasia
C. Plummer-Vinson syndrome
D. Gastroesophageal reflux disease
☑ Correct Answer: C
☑ Explanation: Plummer-Vinson syndrome (esophageal webs, iron deficiency anemia, and
dysphagia) is a well-established risk factor for squamous cell carcinoma of the upper esophagus.
Barrett esophagus and GERD are associated with adenocarcinoma of the lower esophagus.
Achalasia increases risk for squamous cell carcinoma but is less directly linked to the upper
esophagus presentation in this scenario.
,2
[2] A 45-year-old woman with a history of systemic lupus erythematosus presents with
progressive shortness of breath and a dry cough. High-resolution CT shows bilateral interstitial
infiltrates with a "honeycombing" pattern in the lower lung zones. Which of the following is the
most likely underlying pulmonary pathology?
A. Usual interstitial pneumonia
B. Desquamative interstitial pneumonia
C. Acute interstitial pneumonia
D. Cryptogenic organizing pneumonia
☑ Correct Answer: A
☑ Explanation: Usual interstitial pneumonia (UIP) is the most common interstitial lung
disease associated with connective tissue diseases like SLE. The honeycombing pattern on HRCT
is characteristic of UIP. Desquamative interstitial pneumonia is associated with smoking; acute
interstitial pneumonia presents rapidly; cryptogenic organizing pneumonia shows patchy
consolidations.
,3
[3] A 67-year-old man with a history of hypertension and diabetes mellitus presents with
sudden-onset, painless vision loss in the right eye. Funduscopic examination reveals a pale,
swollen optic disc with blurred margins and splinter hemorrhages adjacent to the disc. Which of
the following is the most likely diagnosis?
A. Central retinal artery occlusion
B. Central retinal vein occlusion
C. Anterior ischemic optic neuropathy
D. Optic neuritis
☑ Correct Answer: C
☑ Explanation: Anterior ischemic optic neuropathy (AION) is caused by occlusion of the
posterior ciliary arteries, typically presenting as sudden, painless vision loss with a pale, swollen
optic disc. It is associated with vascular risk factors (hypertension, diabetes). Central retinal
artery occlusion causes a cherry-red spot; central retinal vein occlusion causes disc edema and
venous tortuosity; optic neuritis is painful and associated with multiple sclerosis.
[4] A 28-year-old woman who is 32 weeks pregnant develops pruritus, dark urine, and jaundice.
Laboratory studies reveal elevated serum bile acids and transaminases. Which of the following
, 4
is the most important immediate management step?
A. Immediate delivery
B. Ursodeoxycholic acid therapy
C. Corticosteroid administration
D. Plasmapheresis
☑ Correct Answer: A
☑ Explanation: Intrahepatic cholestasis of pregnancy presents with pruritus and elevated
bile acids. The condition is associated with significant fetal risks, including stillbirth. Immediate
delivery (induction) is the definitive management to prevent fetal complications.
Ursodeoxycholic acid can be used to alleviate symptoms but does not address the underlying
fetal risk.
[5] A 55-year-old man with a history of alcohol use disorder presents with confusion, ataxia,
and ophthalmoplegia. Which of the following is the most likely vitamin deficiency causing this
presentation?
A. Vitamin B1 (thiamine)
B. Vitamin B3 (niacin)
NBME Comprehensive Basic Science Examination (CBSE)
| Newest 2025/2026 | Advanced/Hard Difficulty |
Graded A+
[1] A 58-year-old man with a 40-pack-year smoking history presents with a 3-month history of
progressive dysphagia and hoarseness. A biopsy of a mass in the upper esophagus reveals
squamous cell carcinoma. Which of the following is the most likely associated pre-existing
condition?
A. Barrett esophagus
B. Achalasia
C. Plummer-Vinson syndrome
D. Gastroesophageal reflux disease
☑ Correct Answer: C
☑ Explanation: Plummer-Vinson syndrome (esophageal webs, iron deficiency anemia, and
dysphagia) is a well-established risk factor for squamous cell carcinoma of the upper esophagus.
Barrett esophagus and GERD are associated with adenocarcinoma of the lower esophagus.
Achalasia increases risk for squamous cell carcinoma but is less directly linked to the upper
esophagus presentation in this scenario.
,2
[2] A 45-year-old woman with a history of systemic lupus erythematosus presents with
progressive shortness of breath and a dry cough. High-resolution CT shows bilateral interstitial
infiltrates with a "honeycombing" pattern in the lower lung zones. Which of the following is the
most likely underlying pulmonary pathology?
A. Usual interstitial pneumonia
B. Desquamative interstitial pneumonia
C. Acute interstitial pneumonia
D. Cryptogenic organizing pneumonia
☑ Correct Answer: A
☑ Explanation: Usual interstitial pneumonia (UIP) is the most common interstitial lung
disease associated with connective tissue diseases like SLE. The honeycombing pattern on HRCT
is characteristic of UIP. Desquamative interstitial pneumonia is associated with smoking; acute
interstitial pneumonia presents rapidly; cryptogenic organizing pneumonia shows patchy
consolidations.
,3
[3] A 67-year-old man with a history of hypertension and diabetes mellitus presents with
sudden-onset, painless vision loss in the right eye. Funduscopic examination reveals a pale,
swollen optic disc with blurred margins and splinter hemorrhages adjacent to the disc. Which of
the following is the most likely diagnosis?
A. Central retinal artery occlusion
B. Central retinal vein occlusion
C. Anterior ischemic optic neuropathy
D. Optic neuritis
☑ Correct Answer: C
☑ Explanation: Anterior ischemic optic neuropathy (AION) is caused by occlusion of the
posterior ciliary arteries, typically presenting as sudden, painless vision loss with a pale, swollen
optic disc. It is associated with vascular risk factors (hypertension, diabetes). Central retinal
artery occlusion causes a cherry-red spot; central retinal vein occlusion causes disc edema and
venous tortuosity; optic neuritis is painful and associated with multiple sclerosis.
[4] A 28-year-old woman who is 32 weeks pregnant develops pruritus, dark urine, and jaundice.
Laboratory studies reveal elevated serum bile acids and transaminases. Which of the following
, 4
is the most important immediate management step?
A. Immediate delivery
B. Ursodeoxycholic acid therapy
C. Corticosteroid administration
D. Plasmapheresis
☑ Correct Answer: A
☑ Explanation: Intrahepatic cholestasis of pregnancy presents with pruritus and elevated
bile acids. The condition is associated with significant fetal risks, including stillbirth. Immediate
delivery (induction) is the definitive management to prevent fetal complications.
Ursodeoxycholic acid can be used to alleviate symptoms but does not address the underlying
fetal risk.
[5] A 55-year-old man with a history of alcohol use disorder presents with confusion, ataxia,
and ophthalmoplegia. Which of the following is the most likely vitamin deficiency causing this
presentation?
A. Vitamin B1 (thiamine)
B. Vitamin B3 (niacin)
