Update 2026
1. A patient with a history of hypertension and type 2 diabetes presents with acute onset of severe,
tearing chest pain radiating to the back, accompanied by a blood pressure difference of >20 mmHg
between arms. Which of the following diagnostic findings is most specific for the suspected
condition?
A. Widened mediastinum on chest X-ray
B. Elevated D-dimer >500 ng/mL
C. Pericardial effusion on echocardiogram
D. ST-segment elevation in leads II, III, aVF
Answer: A
Rationale: Acute aortic dissection presents with tearing chest pain and pulse deficits. A widened
mediastinum on chest X-ray is a classic and specific finding, though not pathognomonic. D-dimer is
sensitive but not specific. ST elevation suggests myocardial infarction, not dissection. Pericardial
effusion is more common in pericarditis.
2. Which of the following best explains the paradoxical bronchospasm observed with long-acting
beta-agonists (LABAs) in some patients with asthma?
A. Downregulation of beta-2 receptors leading to increased cholinergic tone
B. Genetic polymorphism in the beta-2 adrenergic receptor gene (ADRB2) causing receptor desensitization
C. Increased production of leukotrienes due to beta-agonist stimulation
D. Cross-reactivity with muscarinic receptors in the airway smooth muscle
Answer: B
Rationale: Paradoxical bronchospasm with LABAs is rare but associated with specific genetic variants in
ADRB2, particularly the Arg16Gly polymorphism, which increases susceptibility to receptor
desensitization. Downregulation of beta-2 receptors does occur but is not the primary mechanism of
paradoxical response. Leukotriene production is not directly increased by beta-agonists. LABAs do not
cross-react with muscarinic receptors.
3. A patient with a 30-pack-year smoking history presents with hemoptysis and a 3 cm solitary
pulmonary nodule on CT. PET-CT shows mild FDG uptake (SUVmax 2.5). Which of the following
is the most appropriate next step in management?
A. Repeat CT in 3 months
B. CT-guided needle biopsy
C. Bronchoscopy with endobronchial ultrasound (EBUS)
D. Positron emission tomography (PET) alone is sufficient for diagnosis
Answer: B
Page 1
,Rationale: For a solitary pulmonary nodule with low to intermediate probability of malignancy (SUVmax 2.5 is
indeterminate), tissue sampling is indicated. CT-guided biopsy is preferred for peripheral nodules. Repeat imaging is
appropriate only for low-risk nodules (<5% probability). EBUS is better for central lesions. PET alone cannot confirm
malignancy.
4. Which of the following laboratory abnormalities is most consistent with acute interstitial
nephritis (AIN) induced by a nonsteroidal anti-inflammatory drug (NSAID)?
A. Hyperkalemia, metabolic acidosis, and urine pH >7.5
B. Eosinophiluria, sterile pyuria, and low-grade proteinuria
C. Hematuria with dysmorphic red cells and red cell casts
D. Glycosuria, phosphaturia, and uricosuria with normal serum glucose
Answer: B
Rationale: AIN typically presents with eosinophiluria, sterile pyuria, and mild proteinuria. Hyperkalemia
and metabolic acidosis suggest type 4 renal tubular acidosis, more common in diabetic nephropathy or
hyporeninemic hypoaldosteronism. Hematuria with dysmorphic RBCs and casts is classic for
glomerulonephritis. Glycosuria, phosphaturia, and uricosuria indicate Fanconi syndrome, seen in
proximal tubular dysfunction.
5. A patient with chronic kidney disease stage 3b (eGFR 38 mL/min/1.73 m²) requires treatment
for acute gout flare. Which of the following agents is safest and most effective?
A. Colchicine 1.2 mg followed by 0.6 mg one hour later, then 0.6 mg twice daily
B. Indomethacin 50 mg three times daily with proton pump inhibitor
C. Prednisone 40 mg daily for 5 days, then taper
D. Allopurinol 300 mg daily as monotherapy
Answer: C
Rationale: In CKD stage 3b, NSAIDs are contraindicated due to risk of further renal impairment.
Colchicine requires dose adjustment; the standard regimen can cause toxicity. Allopurinol is for
prophylaxis, not acute flare. Corticosteroids (e.g., prednisone) are safe and effective for acute gout in
renal impairment, as they do not require renal dose adjustment and are not nephrotoxic.
6. A patient with recurrent urinary tract infections (UTIs) is found to have a post-void residual
volume of 250 mL. Which of the following mechanisms best explains the association between
increased post-void residual and recurrent UTIs?
A. Reduced urine flow rate decreases bacterial clearance from the bladder
B. Stagnant urine allows bacterial proliferation and biofilm formation
C. Increased intravesical pressure impairs mucosal immune response
D. Residual urine dilutes antimicrobial peptides in the bladder
Answer: B
Rationale: Elevated post-void residual volume creates a reservoir of stagnant urine that permits bacterial
multiplication and biofilm formation, increasing UTI risk. While reduced urine flow may contribute, the
primary mechanism is stasis. Increased pressure does not directly impair immunity. Antimicrobial
peptides are not significantly diluted by residual urine.
Page 2
, 7. A patient with HIV (CD4 count 180 cells/L, not on antiretroviral therapy) presents with fever,
headache, and neck stiffness. CSF analysis shows lymphocytic pleocytosis, elevated protein, and
low glucose. Which of the following diagnostic tests is most likely to confirm the etiology?
A. India ink stain of CSF
B. Cryptococcal antigen test in CSF
C. PCR for Mycobacterium tuberculosis in CSF
D. Viral culture for enterovirus
Answer: B
Rationale: In an HIV patient with low CD4 count, the classic presentation of lymphocytic meningitis with
low glucose suggests cryptococcal meningitis. Cryptococcal antigen test in CSF is highly sensitive and
specific. India ink stain is less sensitive. TB meningitis can present similarly but is less common.
Enterovirus typically causes aseptic meningitis with normal glucose.
8. Which of the following findings on a peripheral blood smear is most consistent with the
diagnosis of microangiopathic hemolytic anemia (MAHA) in a patient with thrombotic
thrombocytopenic purpura (TTP)?
A. Target cells and basophilic stippling
B. Spherocytes and agglutinated red cells
C. Schistocytes and decreased haptoglobin
D. Howell-Jolly bodies and nucleated red blood cells
Answer: C
Rationale: MAHA in TTP is characterized by schistocytes (fragmented red cells) due to microvascular
thrombosis, along with low haptoglobin from hemolysis. Target cells and basophilic stippling are seen in
thalassemia. Spherocytes and agglutination occur in autoimmune hemolytic anemia. Howell-Jolly bodies
and nucleated RBCs indicate hyposplenism or marrow stress, not MAHA.
9. A patient with cirrhosis and ascites develops spontaneous bacterial peritonitis (SBP). Which of
the following ascitic fluid parameters is most specific for the diagnosis?
A. White blood cell count >500 cells/L with >50% neutrophils
B. Protein concentration <1 g/dL
C. Serum-ascites albumin gradient (SAAG) >1.1 g/dL
D. Lactate dehydrogenase >225 IU/L
Answer: A
Rationale: SBP is diagnosed by ascitic fluid polymorphonuclear neutrophil (PMN) count "e250 cells/¼L. A
cutoff of >500 cells/L with >50% neutrophils is highly specific. Low protein concentration (<1 g/dL) is
a risk factor but not diagnostic. SAAG >1.1 indicates portal hypertension, not infection. LDH elevation
is nonspecific.
10. Which of the following best describes the mechanism of action of sodium-glucose
cotransporter-2 (SGLT2) inhibitors in reducing cardiovascular mortality in patients with heart
failure with reduced ejection fraction (HFrEF)?
A. Direct positive inotropic effect on cardiac myocytes
Page 3