Adrenal Disorders USMLE Step 1 Practice Question
A 42-year-old woman presents to clinic with a 6-month history of progressive fatigue, weight gain, and cold intolerance. She denies easy bruising, proximal weakness, or skin changes. Vital signs are BP 158/92 mmHg, HR 68/min, RR 14/min, temperature 36.8°C. Physical examination reveals central obesity without striae or hirsutism. Serum TSH is 2.1 mIU/L (normal). Morning cortisol is 16 μg/dL (normal range 10–20 μg/dL), and midnight cortisol is 11 μg/dL (normal <7.5 μg/dL). Low-dose dexamethasone suppression test shows cortisol suppression to 2 μg/dL. Abdominal CT shows a 1.3-cm left adrenal nodule with benign imaging features. Which of the following is the most likely diagnosis?
Answer choices
- AOvert Cushing syndrome
- BPrimary hypothyroidism
- CPseudo-Cushing syndrome
- DSubclinical Cushing syndromeCorrect answer
- EPrimary adrenal insufficiency
- FAdrenal metastasis from occult malignancy
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.