48,XXYY syndrome associated with acromegaloidism.

We report a case of double male syndrome, a type of Klinefelter's syndrome with 48,XXYY chromosome, associated with acromegaloidism. Although the patient presented acromegalic appearance, he did not show hypersecretion of growth hormone (GH). GH provocation tests revealed a rather low GH responses or no responses. After testosterone therapy, the GH responses were normalized except to Insulin tolerance test (ITT). On the other hand, the plasma corticotropin (ACTH) and cortisol levels were decreased paradoxically after hypoglycemia. Testosterone therapy did not restore this ACTH response. It was speculated that these abnormal GH and ACTH responses to hypoglycemia might indicate another congenital anomaly.