NBME CBSE 2026 EXAM BANK LATEST 2026
UPDATE 100+ QUESTIONS AND DETAILED VERIFIED
ANSWERS FROM ACTUAL EXAMS TEST GRADE A+
Question 1
A 45-year-old man presents with fatigue, weight loss, and a firm, non-tender mass
in the left upper quadrant of the abdomen. CT shows a large heterogeneous mass
arising from the tail of the pancreas. Which of the following is the most likely
diagnosis?
A) Pancreatic adenocarcinoma
B) Pancreatic neuroendocrine tumor
C) Pancreatic pseudocyst
D) Serous cystadenoma
Correct Answer: B
Explanation: Pancreatic neuroendocrine tumors (PNETs) often present as
hypervascular, heterogeneous masses, frequently in the tail; adenocarcinoma
typically arises in the head and is hypovascular. Pseudocysts follow pancreatitis.
Serous cystadenomas are benign and multilocular.
Question 2
A 23-year-old woman with no prior medical history develops acute-onset
shortness of breath and right-sided pleuritic chest pain one day after a long-haul
flight. Her oxygen saturation is 90% on room air. Which of the following is the
most appropriate initial diagnostic test?
A) D-dimer
B) CT pulmonary angiography
,C) Ventilation-perfusion scan
D) Chest X-ray
Correct Answer: B
Explanation: CT pulmonary angiography is the gold standard and most
appropriate initial test when PE is high probability (post-flight, hypoxia, pleuritic
pain). D-dimer is for low-risk patients. V/Q scan is used if CTPA contraindicated.
Question 3
A 67-year-old man with a 50-pack-year smoking history presents with hemoptysis
and weight loss. Chest CT shows a 4 cm cavitary lesion in the right upper lobe.
Which of the following is the most likely etiologic agent found on biopsy?
A) Adenocarcinoma
B) Squamous cell carcinoma
C) Small cell carcinoma
D) Carcinoid tumor
Correct Answer: B
Explanation: Squamous cell carcinoma is strongly linked to smoking, often
cavitates, and arises centrally. Adenocarcinoma is peripheral. Small cell is central
but rarely cavitates. Carcinoid tumors are indolent and not cavitary.
Question 4
A 32-year-old man presents with episodic palpitations, sweating, and headache.
His blood pressure is 200/110 mmHg during an episode. Which of the following
laboratory findings is most specific for the likely diagnosis?
A) Elevated serum metanephrines
B) Elevated plasma renin activity
C) Hypokalemia with metabolic alkalosis
D) Hypercalcemia
Correct Answer: A
Explanation: Elevated plasma or urinary metanephrines are highly specific for
,pheochromocytoma. Renin elevation suggests renovascular hypertension.
Hypokalemia/alkalosis suggests hyperaldosteronism. Hypercalcemia suggests
hyperparathyroidism.
Question 5
A 55-year-old woman with rheumatoid arthritis on methotrexate presents with a
2-week history of progressive dyspnea and dry cough. HRCT shows bilateral
ground-glass opacities. Which of the following is the most likely diagnosis?
A) Methotrexate-induced pneumonitis
B) Rheumatoid arthritis-associated interstitial lung disease
C) Opportunistic infection (PJP)
D) Pulmonary edema
Correct Answer: A
Explanation: Methotrexate can cause hypersensitivity pneumonitis with ground-
glass opacities, often subacute. RA-ILD is usually more chronic with fibrosis. PJP
occurs in significant immunosuppression. Pulmonary edema has
cardiomegaly/effusions.
Question 6
A 19-year-old college student reports 3 days of watery diarrhea, vomiting, and
low-grade fever. Several teammates have similar symptoms. Stool studies are
negative for ova and parasites. Which of the following is the most likely pathogen?
A) Norovirus
B) Giardia lamblia
C) Entamoeba histolytica
D) Cyclospora cayetanensis
Correct Answer: A
Explanation: Norovirus causes acute, self-limited gastroenteritis in outbreaks, no
blood or parasites. Giardia causes prolonged diarrhea with bloating. E. histolytica
causes bloody diarrhea (amebic dysentery). Cyclospora is associated with produce.
, Question 7
A 72-year-old man with hypertension and diabetes presents with sudden onset of
right-sided weakness and aphasia. CT head shows no hemorrhage. When should
aspirin be initiated?
A) Immediately
B) After 24 hours if no hemorrhage on repeat CT
C) After 48 hours
D) Aspirin is contraindicated
Correct Answer: B
*Explanation: For acute ischemic stroke, aspirin (325 mg) is given within 24-48
hours after ruling out hemorrhage. Immediate aspirin is given only for TIA or
minor stroke if no thrombolytics given. Delaying >48 hours increases recurrence
risk.*
Question 8
A 34-year-old woman with a history of bipolar disorder presents with polyuria,
polydipsia, and a serum sodium of 155 mEq/L. She takes lithium. Which of the
following is the most likely diagnosis?
A) Lithium-induced nephrogenic diabetes insipidus
B) Primary polydipsia
C) Central diabetes insipidus
D) Hyperglycemia-induced osmotic diuresis
Correct Answer: A
Explanation: Lithium inhibits ADH action at collecting duct, causing nephrogenic DI
(high Na, dilute urine). Primary polydipsia has low Na. Central DI has low ADH but
lithium does not cause it. Hyperglycemia would show high glucose.
Question 9
A 60-year-old woman with breast cancer treated with doxorubicin presents with
UPDATE 100+ QUESTIONS AND DETAILED VERIFIED
ANSWERS FROM ACTUAL EXAMS TEST GRADE A+
Question 1
A 45-year-old man presents with fatigue, weight loss, and a firm, non-tender mass
in the left upper quadrant of the abdomen. CT shows a large heterogeneous mass
arising from the tail of the pancreas. Which of the following is the most likely
diagnosis?
A) Pancreatic adenocarcinoma
B) Pancreatic neuroendocrine tumor
C) Pancreatic pseudocyst
D) Serous cystadenoma
Correct Answer: B
Explanation: Pancreatic neuroendocrine tumors (PNETs) often present as
hypervascular, heterogeneous masses, frequently in the tail; adenocarcinoma
typically arises in the head and is hypovascular. Pseudocysts follow pancreatitis.
Serous cystadenomas are benign and multilocular.
Question 2
A 23-year-old woman with no prior medical history develops acute-onset
shortness of breath and right-sided pleuritic chest pain one day after a long-haul
flight. Her oxygen saturation is 90% on room air. Which of the following is the
most appropriate initial diagnostic test?
A) D-dimer
B) CT pulmonary angiography
,C) Ventilation-perfusion scan
D) Chest X-ray
Correct Answer: B
Explanation: CT pulmonary angiography is the gold standard and most
appropriate initial test when PE is high probability (post-flight, hypoxia, pleuritic
pain). D-dimer is for low-risk patients. V/Q scan is used if CTPA contraindicated.
Question 3
A 67-year-old man with a 50-pack-year smoking history presents with hemoptysis
and weight loss. Chest CT shows a 4 cm cavitary lesion in the right upper lobe.
Which of the following is the most likely etiologic agent found on biopsy?
A) Adenocarcinoma
B) Squamous cell carcinoma
C) Small cell carcinoma
D) Carcinoid tumor
Correct Answer: B
Explanation: Squamous cell carcinoma is strongly linked to smoking, often
cavitates, and arises centrally. Adenocarcinoma is peripheral. Small cell is central
but rarely cavitates. Carcinoid tumors are indolent and not cavitary.
Question 4
A 32-year-old man presents with episodic palpitations, sweating, and headache.
His blood pressure is 200/110 mmHg during an episode. Which of the following
laboratory findings is most specific for the likely diagnosis?
A) Elevated serum metanephrines
B) Elevated plasma renin activity
C) Hypokalemia with metabolic alkalosis
D) Hypercalcemia
Correct Answer: A
Explanation: Elevated plasma or urinary metanephrines are highly specific for
,pheochromocytoma. Renin elevation suggests renovascular hypertension.
Hypokalemia/alkalosis suggests hyperaldosteronism. Hypercalcemia suggests
hyperparathyroidism.
Question 5
A 55-year-old woman with rheumatoid arthritis on methotrexate presents with a
2-week history of progressive dyspnea and dry cough. HRCT shows bilateral
ground-glass opacities. Which of the following is the most likely diagnosis?
A) Methotrexate-induced pneumonitis
B) Rheumatoid arthritis-associated interstitial lung disease
C) Opportunistic infection (PJP)
D) Pulmonary edema
Correct Answer: A
Explanation: Methotrexate can cause hypersensitivity pneumonitis with ground-
glass opacities, often subacute. RA-ILD is usually more chronic with fibrosis. PJP
occurs in significant immunosuppression. Pulmonary edema has
cardiomegaly/effusions.
Question 6
A 19-year-old college student reports 3 days of watery diarrhea, vomiting, and
low-grade fever. Several teammates have similar symptoms. Stool studies are
negative for ova and parasites. Which of the following is the most likely pathogen?
A) Norovirus
B) Giardia lamblia
C) Entamoeba histolytica
D) Cyclospora cayetanensis
Correct Answer: A
Explanation: Norovirus causes acute, self-limited gastroenteritis in outbreaks, no
blood or parasites. Giardia causes prolonged diarrhea with bloating. E. histolytica
causes bloody diarrhea (amebic dysentery). Cyclospora is associated with produce.
, Question 7
A 72-year-old man with hypertension and diabetes presents with sudden onset of
right-sided weakness and aphasia. CT head shows no hemorrhage. When should
aspirin be initiated?
A) Immediately
B) After 24 hours if no hemorrhage on repeat CT
C) After 48 hours
D) Aspirin is contraindicated
Correct Answer: B
*Explanation: For acute ischemic stroke, aspirin (325 mg) is given within 24-48
hours after ruling out hemorrhage. Immediate aspirin is given only for TIA or
minor stroke if no thrombolytics given. Delaying >48 hours increases recurrence
risk.*
Question 8
A 34-year-old woman with a history of bipolar disorder presents with polyuria,
polydipsia, and a serum sodium of 155 mEq/L. She takes lithium. Which of the
following is the most likely diagnosis?
A) Lithium-induced nephrogenic diabetes insipidus
B) Primary polydipsia
C) Central diabetes insipidus
D) Hyperglycemia-induced osmotic diuresis
Correct Answer: A
Explanation: Lithium inhibits ADH action at collecting duct, causing nephrogenic DI
(high Na, dilute urine). Primary polydipsia has low Na. Central DI has low ADH but
lithium does not cause it. Hyperglycemia would show high glucose.
Question 9
A 60-year-old woman with breast cancer treated with doxorubicin presents with
