Adrenal Disorders USMLE Step 1 Practice Question

A 50-year-old man with a history of hypertension presents to the emergency department with sudden-onset severe left flank pain radiating to the left groin, nausea, and diaphoresis. He reports no prior episodes of headache, palpitations, or perspiration at rest. Vital signs: BP 82/48 mmHg, HR 115 bpm, RR 22/min, T 37.2°C. Physical examination reveals left costovertebral angle tenderness and diminished breath sounds at the left base. Laboratory studies show hemoglobin 9.2 g/dL (previously 14.1 g/dL 6 months ago), WBC 13,200/μL, sodium 138 mEq/L, potassium 4.9 mEq/L, pH 7.32 with mild metabolic acidosis, and negative urine dipstick. Noncontrast CT abdomen demonstrates a 6 cm left adrenal mass with acute hemorrhage; no renal artery dissection or thrombosis is noted. Which of the following is the most likely diagnosis?