ECTOPIC ACTH SYNDROME AND CRH-MEDIATED CUSHINGS-SYNDROME

The ectopic ACTH syndrome accounts for a substantial number of patient s with naturally occurring Cushing's syndrome. Patients with either ec topic ACTH syndrome or the rare CRH-mediated Cushing's syndrome may be indistinguishable from patients with pituitary ACTH Cushing's syndrom e, based on clinical grounds or simple biochemical and radiologic test ing. Because their therapies differ, accurate diagnosis is essential. While clinical researchers continue to develop more effective diagnost ic techniques and therapies, further advances in the molecular and cel l biology of ACTH and CRH-producing tumors will undoubtedly shed light on the pathogenesis of this perplexing, fascinating, and controversia l entity.