Isolated adrenocorticotrophin deficiency associated with anti-pituitary antibodies, pituitary cyst, sphenoidal cyst and pineal tumor.

This paper reports a rare case of isolated ACTH deficiency associated with anti-pituitary antibodies, pituitary cyst, sphenoidal cyst and pineal tumor. A 68-year-old man consulted our clinic for general fatigue. Laboratory data showed low plasma adrenocorticotrophin (ACTH) and cortisol levels with blunted responses to insulin-induced hypoglycemia and corticotrophin releasing factor (CRF). Urinary 17-OHCS was low but responded to ACTH-Z administration. No other pituitary functions were impaired. Antibodies to the cytoplasm of rat pituitary and the surface of GH3 cells were detected in the serum. The magnetic resonance imaging (MRI) showed a high signal intensity mass in the anterior pituitary and in the sphenoidal sinus in both T1 and T2 weighted images as well as a low signal intensity mass in a T1 weighted image of the pineal region. Transsphenoidal surgery was performed to resect the mass in the sphenoid sinus and in the pituitary. Pathological studies showed a benign cyst in the sphenoid sinus, and fibrous degeneration and decreased basophils in the pituitary. No infiltrative mononuclear cells were detected in the pituitary. Immunohistochemical studies revealed a decrease in the number of ACTH-producing cells in the pituitary. The patient was well maintained by glucocorticoid replacement without any growth of a possibly benign pineal tumor.