Adrenocorticotropin-producing pituitary carcinoma with metastasis to the liver in a patient with Cushing's disease.

A 61-year-old woman who had a nonfunctioning pituitary tumor removed was later found to have a pituitary carcinoma with metastasis to the liver that produced adrenocorticotropic hormone (ACTH), causing Cushing's disease. Despite the second removal of the pituitary tumor, Cushing's disease persisted. Endocrinologic examination demonstrated marked elevation of plasma ACTH, beta-endorphin, and serum cortisol concentrations, which were not suppressed by low- or high-dose dexamethasone administration.