NELSONS SYNDROME - A REVIEW

Nelson's syndrome is the clinical progression of an ACTH secreting pit uitary adenoma that oc curs in patients adrenalectomized for Cushing's disease. These pituitary tumors differ from those before adrenalectom y by their sometimes aggressive growth potential. Additionally, their ACTH secretion is much less suppressible by administration of glucocor ticoids than in the stage of Cushing's disease. Nelson's tumor cells d iffer to some degree from those from Gushing's tumors. Recent research underscores the intriguing possibility that somatic mutations in the glucocorticoid receptor gene might contribute to its pathogenesis. The incidence of Nelson's syndrome after adrenalectomy is still a matter of dispute, in part explained by lack in uniformity of definition of t he syndrome. Because Nelson's tumors are often locally invasive, neuro surgery, either trans or suprasphenoidally, is the treatment of first choice. Postoperative radiotherapy is indicated in patients with resid ual tumor or extracellular extension. Recent reports claim benefit fro m long acting so matostatin analogues, although long-term success rema ins to be assessed. Notwithstanding improved treatment, Nelson's syndr ome shares with Gushing's disease the inevitable tendency to recur. Th erefore, life-long management of these patients is mandatory.