Adrenal Disorders USMLE Step 1 Practice Question
A 34-year-old woman with no prior medical history presents to clinic with fatigue and muscle weakness. She was found to be hypertensive (BP 162/98 mmHg) during a routine visit. Physical examination is notable for mild lower extremity edema but no other findings. Laboratory studies show: Serum sodium: 142 mEq/L
Serum potassium: 2.8 mEq/L
Serum chloride: 102 mEq/L
Serum bicarbonate: 32 mEq/L
Plasma renin activity: 0.2 ng/mL/hr (normal 0.5-4.0)
Plasma aldosterone: 28 ng/dL (normal <15)
Aldosterone-to-renin ratio: 140 Abdominal imaging shows a 1.2 cm left adrenal nodule with smooth margins and low lipid content. Which of the following is the most likely diagnosis?
Answer choices
- ASecondary hyperaldosteronism due to renal artery stenosis
- BHypokalemic periodic paralysis presenting with incidental hypertension
- CPrimary hyperaldosteronism due to an aldosterone-secreting adenomaCorrect answer
- DLicorice-induced apparent mineralocorticoid excess
- ECushing syndrome with secondary hypokalemia
- FCongenital adrenal hyperplasia with 11β-hydroxylase deficiency
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.