An adrenocorticotropic hormone-producing pheochromocytoma: diagnostic and immunohistochemical studies.

A patient is described with Cushing's syndrome owing to a pheochromocytoma that was producing adrenocorticotropic hormone. Preoperative diagnosis was suggested by finding bilateral adrenocortical hyperplasia plus a separate unilateral adrenal medullary mass and was confirmed laboratory studies. Proper preoperative preparation was followed by a unilateral adrenalectomy and a clinical cure of both conditions. Immunohistochemical studies confirmed the ectopic production of adrenocorticotropic hormone and its related peptides more thoroughly than previous reports. The hormone production appeared clinically and immunocytochemically to resemble pituitary Cushing's disease more closely than ectopic production of adrenocorticotropic hormone by other tumors. The clinical aspects of this case illustrate the importance of proper preoperative recognition to reduce the high known percentage of morbidity and mortality.