Pituitary Disorders USMLE Step 1 Practice Question
A 38-year-old woman reports weakness, polyuria, polydipsia, and hypertension. Laboratory evaluation shows hypokalemia (K+ 2.9 mEq/L), metabolic alkalosis, and elevated 24-hour urinary free cortisol (145 mcg/24 h). Low-dose dexamethasone suppression test shows no suppression of cortisol. High-dose dexamethasone suppression test suppresses cortisol to 8 mcg/dL. Which of the following is the most likely diagnosis?
Answer choices
- APrimary hyperaldosteronism
- BPrimary adrenal insufficiency
- CCushing syndrome from a pituitary adenomaCorrect answer
- DEctopic ACTH syndrome from lung cancer
- EAdrenocortical carcinoma
- FCushing syndrome from a benign adrenal adenoma
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