Pregnancy-induced Cushing syndrome: diagnosis and management of a rare endocrine disorder.

Pregnancy-induced Cushing syndrome (PICS) is an exceptionally rare form of adrenocorticotropin (ACTH)-independent Cushing syndrome (CS) caused by aberrant expression of luteinizing hormone (LH) and/or human chorionic gonadotropin (hCG) receptors in adrenal cortical cells. To date, only a small number of cases have been reported, most with adrenal abnormalities on imaging. We describe a 25-year-old pregnant woman who presented at 26 weeks' gestation with new-onset hypertension and overt features of hypercortisolism, including severe acne, hirsutism, dorsocervical fat pad, and extensive violaceous striae. Biochemical evaluation confirmed severe ACTH-independent CS with markedly elevated 24-hour urinary free cortisol, elevated serum cortisol with loss of diurnal variation, elevated midnight salivary cortisol, and suppressed ACTH levels. Pituitary, adrenal, and ovarian imaging were unremarkable. The patient was successfully managed with metyrapone until delivery, with favorable maternal and neonatal outcomes. Postpartum resolution of hypercortisolism and a positive hCG stimulation test confirmed the diagnosis of PICS. This case highlights the diagnostic complexity of PICS and underscores the role of timely medical therapy and multidisciplinary management.