CUSHINGS-SYNDROME DUE TO ACTH-INDEPENDENT BILATERAL ADRENOCORTICAL MACRONODULAR HYPERPLASIA

ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) is a rare cause of Gushing's syndrome in which adrenal glands become very e nlarged, occupied and distorted by multiple cortical nodules. We repor t on such two patients, a 44-year-old man and a 40-year-old woman, Phy sical examination revealed in both cases a classic cushin-goid habit. Laboratory studies showed overt hypercortisolism with high urinary fre e cortisol excretion and elevated serum cortisol with loss of the circ adian rhythm, Serum cortisol levels were not modified after high dose dexamethasone, ACTH levels were undetectable both in baseline conditio ns and following CRH or metyrapone, In both cases, abdominal CT demons trated bilaterally enlarged adrenal glands which were distorted by mul tiple bumps. (131)-Nor-cholesterol scintiscan showed bilateral uptake of the radionuclide. Pituitary region was normal at neuroradiologic im aging, Bilateral adrenalectomy was performed in both cases, In patient I, adrenal glands weighted 77 and 90 g, respectively, while in patien t II they were of 90 and 55 g, respectively At histological examinatio n, the adrenal cortex was occupied by multiple nodular lesions compose d mostly of clear cells. In the internodular regions, no evidence of c ortical architecture was observed, At the immunohistochemical evaluati on, both cases displayed Ki-67 staining comparable with that of ACTH-d ependent diffuse hyperplasia, Postoperative course was uneventful and signs of Gushing's syndrome resolved in about three months. At the las t follow up, the patients are going well on glucocorticoid and mineral ocorticoid supplementation. Plasma ACTH levels are 65 and 107 pg/ml, r espectively. (C) 1997, Editrice Kurtis.