Adrenal Disorders USMLE Step 1 Practice Question
A 45-year-old woman presents to her primary care physician for evaluation of newly detected hypertension. Her blood pressure is 158/96 mmHg. She reports mild fatigue and ankle swelling but denies headaches, visual disturbances, or weight gain. Physical examination is unremarkable without striae or proximal muscle weakness. Laboratory studies show: Sodium: 145 mEq/L
Potassium: 3.0 mEq/L
Morning cortisol: 18 μg/dL (normal: 5-25)
ACTH: 2 pg/mL (normal: 10-50) Overnight dexamethasone suppression test (1 mg): cortisol 8 μg/dL (fails to suppress below 5 μg/dL) Which of the following is the most likely diagnosis?
Answer choices
- APituitary-dependent Cushing disease with secondary hyperaldosteronism
- BACTH-independent Cushing syndrome from adrenocortical adenomaCorrect answer
- CPrimary hyperaldosteronism with autonomous cortisol co-secretion
- DCushing syndrome from ectopic ACTH-secreting tumor
- EAdrenocortical carcinoma with mixed steroid production
- FSecondary hypertension from hypothyroidism with hypokalemia
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