POMC and Cushing syndrome: Cushing's syndrome (CS) is a potentially lethal disease caused by the overproduction of cortisol, most commonly due to adrenocorticotropic hormone (ACTH)-producing pituitary adenomas [Cushing's disease (CD)], or less commonly by either ACTH-producing carcinoid tumors [ectopic ACTH secretion (EAS)] or primary adrenal gland disease (1).