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?
- A)Pituitary-dependent Cushing disease with secondary hyperaldosteronism
- B)ACTH-independent Cushing syndrome from adrenocortical adenomaGABARITO
- C)Primary hyperaldosteronism with autonomous cortisol co-secretion
- D)Cushing syndrome from ectopic ACTH-secreting tumor
- E)Adrenocortical carcinoma with mixed steroid production
Explicação
The clinical presentation is diagnostic of ACTH-independent Cushing syndrome from an adrenocortical adenoma. The key findings are: (1) elevated morning cortisol with failed suppression on low-dose dexamethasone (confirming Cushing syndrome), (2) LOW-NORMAL ACT... Ver explicação completa e trilha adaptativa →