Combined adrenal myelolipoma and adenoma associated with Cushing's syndrome

A case of Cushing's syndrome in a 31-year-old woman is presented. The resected left adrenal gland revealed a tumor consisting of cortical cells intermingled with myelolipomatous tissue comparable to that of normal bone marrow. The adjacent cortex was atrophic. Postoperative plasma cortisol concentrations have remained quite low. Previously, 28 cases of surgically removed adrenocortical tumors with a main diagnosis of myelolipoma have been published. Of these, three cases (two pituitary Cushing's disease, one steroid 21-hydroxylase deficiency) were associated with endocrine dysfunction. The combination of a myelolipoma and a true adenoma has only been described once before (in a case of virilization) and never in connection with Cushing's syndrome. The etiology of myelolipoma is discussed, and a local trigger mechanism related to adrenocortical growth disturbances is suggested.