17alpha-hydroxylase deficiency accompanied by adrenal myelolipoma.

A 45-year-old woman was admitted because of hypertension and hypokalemia. Primary amenorrhea from birth was noted. Plasma renin activity (PRA), 17alpha-hydroxyprogesterone and androgen levels were low, but progesterone, 11-deoxycorticosterone, corticosterone and adrenocorticotropic hormone (ACTH) were elevated, resulting in a diagnosis of 17alpha-hydroxylase deficiency. Abdominal magnetic resonance imaging revealed a round mass in the left adrenal region, the specimen of which was diagnosed as myelolipoma. After removal of the tumor, the blood pressure, serum potassium and hormone levels were unchanged, indicating an adrenal non-functioning tumor. Excessive ACTH secretion over a long period may stimulate the development of adrenal myelolipoma.