Cushing’s syndrome reflects a constellation of clinical features that result from chronic exposure to excess glucocor- ticoids of any etiology. The disorder can be ACTH-dependent (e.g., pituitary corticotrope adenoma, ectopic secretion of ACTH by nonpi- tuitary tumor) or ACTH-independent (e.g., adrenocortical adenoma, adrenocortical carcinoma [ACC], nodular adrenal hyperplasia), as well as iatrogenic (e.g., administration of exogenous glucocorticoids to treat various inflammatory conditions). The term Cushing’s disease refers specifically to Cushing’s syndrome caused by a pituitary corticotrope adenoma.