A 35-year-old woman presents to clinic with a 6-month history of progressive hypertension, central weight gain, and easy bruising. She denies exogenous corticosteroid use. Vital signs: BP 172/108 mmHg, HR 88/min, RR 16/min, T 37.2°C. On examination, she has central obesity with proximal muscle weakness, violaceous striae, and hypertrichosis. Laboratory studies: AM Cortisol: 95 µg/dL (normal 5–20) PM Cortisol: 92 µg/dL (normal 2.5–10) AM ACTH: 58 pg/mL (normal 10–46) Dexamethasone suppression test (1 mg overnight): Cortisol 78 µg/dL Dexamethasone suppression test (8 mg overnight): Cortisol 22 µg/dL (normal <5 µg/dL after 8 mg is still abnormal but shows partial suppression) What is the most likely diagnosis?
- A)Adrenocortical adenoma
- B)Ectopic corticotropin-releasing hormone (CRH)-secreting tumor
- C)Ectopic adrenocorticotropic hormone (ACTH)-secreting neoplasm
- D)Pituitary corticotroph adenoma (Cushing disease)GABARITO
- E)Iatrogenic Cushing syndrome from chronic glucocorticoid therapy
Explicação
The constellation of findings is diagnostic of Cushing disease (pituitary ACTH-secreting adenoma). The key diagnostic clues are: (1) elevated ACTH (58 pg/mL—inappropriately normal for elevated cortisol, ruling out adrenal source); (2) failure of suppression wi... Ver explicação completa e trilha adaptativa →