1
NBME CBSE Actual Exam Practice
Test 2025 – 200 High-Level
Questions with 100% Verified
Answers & Expert Rationales | A+
Graded
Question 1
A 25-year-old man presents with a 2-day history of fever, sore throat, and cervical
lymphadenopathy. Physical examination shows pharyngeal erythema with a gray-white exudate.
A rapid streptococcal antigen test is negative. Which of the following is the most likely
diagnosis?
A) Streptococcal pharyngitis
B) Infectious mononucleosis
C) Diphtheria
D) Gonococcal pharyngitis
Correct Answer: B) Infectious mononucleosis
Rationale: The patient’s symptoms of fever, sore throat, cervical lymphadenopathy, and
pharyngeal exudate with a negative streptococcal antigen test suggest infectious mononucleosis,
commonly caused by Epstein-Barr virus. This condition often presents with a gray-white exudate
and lymphadenopathy, distinguishing it from streptococcal pharyngitis (positive rapid test),
diphtheria (rare, with a characteristic thick membrane), and gonococcal pharyngitis (less
common, typically associated with sexual history).
Question 2
A 60-year-old woman with a history of hypertension presents with chest pain radiating to her
jaw. The pain began while she was gardening. Her pulse is 90/min, and blood pressure is 140/80
mm Hg. An ECG shows ST-segment elevation in leads V1-V4. Which of the following is the
most appropriate immediate treatment?
A) Aspirin
B) Metoprolol
, 2
C) Nitroglycerin
D) Tissue plasminogen activator
Correct Answer: A) Aspirin
Rationale: The patient’s presentation and ECG findings indicate an acute ST-elevation
myocardial infarction (STEMI). Aspirin is the most appropriate immediate treatment as it
inhibits platelet aggregation, reducing thrombus progression. Nitroglycerin and metoprolol are
adjunctive therapies, while tissue plasminogen activator is considered for fibrinolysis if
percutaneous coronary intervention is unavailable.
Question 3
A 32-year-old man presents with a 3-week history of fatigue, night sweats, and weight loss.
Physical examination reveals painless cervical lymphadenopathy. A lymph node biopsy shows
Reed-Sternberg cells. Which of the following is the most likely diagnosis?
A) Non-Hodgkin lymphoma
B) Hodgkin lymphoma
C) Chronic lymphocytic leukemia
D) Acute lymphoblastic leukemia
Correct Answer: B) Hodgkin lymphoma
Rationale: The presence of Reed-Sternberg cells is pathognomonic for Hodgkin lymphoma. The
patient’s symptoms (B symptoms: fever, night sweats, weight loss) and painless
lymphadenopathy further support this diagnosis. Non-Hodgkin lymphoma lacks Reed-Sternberg
cells, and leukemias typically present with bone marrow involvement rather than lymph node
biopsies showing these cells.
Question 4
A 45-year-old woman with type 2 diabetes mellitus is prescribed metformin. Which of the
following is the primary mechanism of action of this drug?
A) Increases insulin secretion
B) Inhibits hepatic gluconeogenesis
C) Enhances peripheral glucose uptake
D) Blocks glucose absorption in the gut
Correct Answer: B) Inhibits hepatic gluconeogenesis
Rationale: Metformin primarily reduces blood glucose by inhibiting hepatic gluconeogenesis,
decreasing liver glucose output. It does not significantly increase insulin secretion
(sulfonylureas), enhance peripheral glucose uptake (thiazolidinediones), or block gut glucose
absorption (alpha-glucosidase inhibitors).
, 3
Question 5
A 19-year-old man presents with a 2-day history of painful genital ulcers and inguinal
lymphadenopathy. A swab of the ulcer reveals gram-negative rods in a "school of fish" pattern.
Which of the following is the most likely causative organism?
A) Herpes simplex virus
B) Haemophilus ducreyi
C) Treponema pallidum
D) Chlamydia trachomatis
Correct Answer: B) Haemophilus ducreyi
Rationale: The clinical presentation of painful genital ulcers with inguinal lymphadenopathy and
the "school of fish" pattern on Gram stain is characteristic of chancroid, caused by Haemophilus
ducreyi. Herpes simplex virus causes painful vesicles, Treponema pallidum causes painless
chancres, and Chlamydia trachomatis is associated with lymphogranuloma venereum.
Question 6
A 70-year-old man presents with a 3-month history of progressive dyspnea and dry cough. Chest
X-ray shows bilateral interstitial infiltrates. A lung biopsy reveals non-caseating granulomas.
Which of the following is the most likely diagnosis?
A) Tuberculosis
B) Sarcoidosis
C) Idiopathic pulmonary fibrosis
D) Pneumocystis pneumonia
Correct Answer: B) Sarcoidosis
Rationale: Non-caseating granulomas on lung biopsy, combined with bilateral interstitial
infiltrates, are highly suggestive of sarcoidosis. Tuberculosis typically shows caseating
granulomas, idiopathic pulmonary fibrosis shows fibrosis without granulomas, and Pneumocystis
pneumonia is associated with immunocompromised states and characteristic radiographic
findings.
Question 7
A 28-year-old woman presents with a 1-week history of watery diarrhea and abdominal
cramping after a camping trip. Stool microscopy reveals motile trophozoites. Which of the
following is the most likely causative organism?
A) Escherichia coli
, 4
B) Giardia lamblia
C) Clostridium difficile
D) Salmonella enterica
Correct Answer: B) Giardia lamblia
Rationale: Motile trophozoites in stool, especially after a camping trip (suggesting contaminated
water), are indicative of Giardia lamblia infection. Escherichia coli may cause diarrhea but not
trophozoites, Clostridium difficile is associated with antibiotic use, and Salmonella typically
causes inflammatory diarrhea.
Question 8
A 50-year-old man with a history of smoking presents with hemoptysis and weight loss. A chest
CT reveals a solitary pulmonary nodule. Biopsy shows squamous cell carcinoma. Which of the
following is the most likely associated paraneoplastic syndrome?
A) Hypercalcemia
B) Syndrome of inappropriate antidiuretic hormone (SIADH)
C) Cushing syndrome
D) Lambert-Eaton myasthenic syndrome
Correct Answer: A) Hypercalcemia
Rationale: Squamous cell carcinoma of the lung is commonly associated with hypercalcemia due
to the production of parathyroid hormone-related protein (PTHrP). SIADH and Cushing
syndrome are more commonly linked to small cell lung cancer, while Lambert-Eaton syndrome
is also associated with small cell carcinoma.
Question 9
A 35-year-old woman presents with fatigue, cold intolerance, and constipation. Physical
examination reveals dry skin and delayed deep tendon reflexes. Laboratory studies show
elevated thyroid-stimulating hormone (TSH) and low free T4. Which of the following is the most
likely diagnosis?
A) Hyperthyroidism
B) Hypothyroidism
C) Subclinical hyperthyroidism
D) Euthyroid sick syndrome
Correct Answer: B) Hypothyroidism
Rationale: Elevated TSH and low free T4, along with symptoms of fatigue, cold intolerance,
constipation, dry skin, and delayed reflexes, are classic for hypothyroidism. Hyperthyroidism
NBME CBSE Actual Exam Practice
Test 2025 – 200 High-Level
Questions with 100% Verified
Answers & Expert Rationales | A+
Graded
Question 1
A 25-year-old man presents with a 2-day history of fever, sore throat, and cervical
lymphadenopathy. Physical examination shows pharyngeal erythema with a gray-white exudate.
A rapid streptococcal antigen test is negative. Which of the following is the most likely
diagnosis?
A) Streptococcal pharyngitis
B) Infectious mononucleosis
C) Diphtheria
D) Gonococcal pharyngitis
Correct Answer: B) Infectious mononucleosis
Rationale: The patient’s symptoms of fever, sore throat, cervical lymphadenopathy, and
pharyngeal exudate with a negative streptococcal antigen test suggest infectious mononucleosis,
commonly caused by Epstein-Barr virus. This condition often presents with a gray-white exudate
and lymphadenopathy, distinguishing it from streptococcal pharyngitis (positive rapid test),
diphtheria (rare, with a characteristic thick membrane), and gonococcal pharyngitis (less
common, typically associated with sexual history).
Question 2
A 60-year-old woman with a history of hypertension presents with chest pain radiating to her
jaw. The pain began while she was gardening. Her pulse is 90/min, and blood pressure is 140/80
mm Hg. An ECG shows ST-segment elevation in leads V1-V4. Which of the following is the
most appropriate immediate treatment?
A) Aspirin
B) Metoprolol
, 2
C) Nitroglycerin
D) Tissue plasminogen activator
Correct Answer: A) Aspirin
Rationale: The patient’s presentation and ECG findings indicate an acute ST-elevation
myocardial infarction (STEMI). Aspirin is the most appropriate immediate treatment as it
inhibits platelet aggregation, reducing thrombus progression. Nitroglycerin and metoprolol are
adjunctive therapies, while tissue plasminogen activator is considered for fibrinolysis if
percutaneous coronary intervention is unavailable.
Question 3
A 32-year-old man presents with a 3-week history of fatigue, night sweats, and weight loss.
Physical examination reveals painless cervical lymphadenopathy. A lymph node biopsy shows
Reed-Sternberg cells. Which of the following is the most likely diagnosis?
A) Non-Hodgkin lymphoma
B) Hodgkin lymphoma
C) Chronic lymphocytic leukemia
D) Acute lymphoblastic leukemia
Correct Answer: B) Hodgkin lymphoma
Rationale: The presence of Reed-Sternberg cells is pathognomonic for Hodgkin lymphoma. The
patient’s symptoms (B symptoms: fever, night sweats, weight loss) and painless
lymphadenopathy further support this diagnosis. Non-Hodgkin lymphoma lacks Reed-Sternberg
cells, and leukemias typically present with bone marrow involvement rather than lymph node
biopsies showing these cells.
Question 4
A 45-year-old woman with type 2 diabetes mellitus is prescribed metformin. Which of the
following is the primary mechanism of action of this drug?
A) Increases insulin secretion
B) Inhibits hepatic gluconeogenesis
C) Enhances peripheral glucose uptake
D) Blocks glucose absorption in the gut
Correct Answer: B) Inhibits hepatic gluconeogenesis
Rationale: Metformin primarily reduces blood glucose by inhibiting hepatic gluconeogenesis,
decreasing liver glucose output. It does not significantly increase insulin secretion
(sulfonylureas), enhance peripheral glucose uptake (thiazolidinediones), or block gut glucose
absorption (alpha-glucosidase inhibitors).
, 3
Question 5
A 19-year-old man presents with a 2-day history of painful genital ulcers and inguinal
lymphadenopathy. A swab of the ulcer reveals gram-negative rods in a "school of fish" pattern.
Which of the following is the most likely causative organism?
A) Herpes simplex virus
B) Haemophilus ducreyi
C) Treponema pallidum
D) Chlamydia trachomatis
Correct Answer: B) Haemophilus ducreyi
Rationale: The clinical presentation of painful genital ulcers with inguinal lymphadenopathy and
the "school of fish" pattern on Gram stain is characteristic of chancroid, caused by Haemophilus
ducreyi. Herpes simplex virus causes painful vesicles, Treponema pallidum causes painless
chancres, and Chlamydia trachomatis is associated with lymphogranuloma venereum.
Question 6
A 70-year-old man presents with a 3-month history of progressive dyspnea and dry cough. Chest
X-ray shows bilateral interstitial infiltrates. A lung biopsy reveals non-caseating granulomas.
Which of the following is the most likely diagnosis?
A) Tuberculosis
B) Sarcoidosis
C) Idiopathic pulmonary fibrosis
D) Pneumocystis pneumonia
Correct Answer: B) Sarcoidosis
Rationale: Non-caseating granulomas on lung biopsy, combined with bilateral interstitial
infiltrates, are highly suggestive of sarcoidosis. Tuberculosis typically shows caseating
granulomas, idiopathic pulmonary fibrosis shows fibrosis without granulomas, and Pneumocystis
pneumonia is associated with immunocompromised states and characteristic radiographic
findings.
Question 7
A 28-year-old woman presents with a 1-week history of watery diarrhea and abdominal
cramping after a camping trip. Stool microscopy reveals motile trophozoites. Which of the
following is the most likely causative organism?
A) Escherichia coli
, 4
B) Giardia lamblia
C) Clostridium difficile
D) Salmonella enterica
Correct Answer: B) Giardia lamblia
Rationale: Motile trophozoites in stool, especially after a camping trip (suggesting contaminated
water), are indicative of Giardia lamblia infection. Escherichia coli may cause diarrhea but not
trophozoites, Clostridium difficile is associated with antibiotic use, and Salmonella typically
causes inflammatory diarrhea.
Question 8
A 50-year-old man with a history of smoking presents with hemoptysis and weight loss. A chest
CT reveals a solitary pulmonary nodule. Biopsy shows squamous cell carcinoma. Which of the
following is the most likely associated paraneoplastic syndrome?
A) Hypercalcemia
B) Syndrome of inappropriate antidiuretic hormone (SIADH)
C) Cushing syndrome
D) Lambert-Eaton myasthenic syndrome
Correct Answer: A) Hypercalcemia
Rationale: Squamous cell carcinoma of the lung is commonly associated with hypercalcemia due
to the production of parathyroid hormone-related protein (PTHrP). SIADH and Cushing
syndrome are more commonly linked to small cell lung cancer, while Lambert-Eaton syndrome
is also associated with small cell carcinoma.
Question 9
A 35-year-old woman presents with fatigue, cold intolerance, and constipation. Physical
examination reveals dry skin and delayed deep tendon reflexes. Laboratory studies show
elevated thyroid-stimulating hormone (TSH) and low free T4. Which of the following is the most
likely diagnosis?
A) Hyperthyroidism
B) Hypothyroidism
C) Subclinical hyperthyroidism
D) Euthyroid sick syndrome
Correct Answer: B) Hypothyroidism
Rationale: Elevated TSH and low free T4, along with symptoms of fatigue, cold intolerance,
constipation, dry skin, and delayed reflexes, are classic for hypothyroidism. Hyperthyroidism
