Cushing's disease: a review of pathogenesis, diagnostic methods, and treatment

Cushing's disease is a form of Cushing's syndrome that results from excessive ACTH secretion with consequent adrenal hyperplasia and increased cortisol secretion. Most patients have an ACTH-secreting tumor; in others, a hypothalamic defect may play an important role. Steroid determinations and the dexamethasone suppression test can confirm overproduction of cortisol. Measurement of basal plasma ACTH level is perhaps the most reliable way to determine the cause of overproduction. Transsphenoidal surgery seems to be the initial treatment of choice, if the necessary neurosurgical expertise is available. If it is not, bilateral adrenalectomy combined with conventional pituitary irradiation can be used. Other alternatives are cobalt 60 high-voltage or heavy-particle irradiation and drugs that interfere with cortisol biosynthesis.