Multiple Endocrine Neoplasia Syndromes.

Multiple endocrine neoplasia (MEN) syndromes include several types of autosomal dominant inherited familial cancer syndromes, each characterized by a different pattern of endocrine gland tumors in affected individuals. The two major types are MEN1 (Wermer syndrome) and MEN2 (Sipple syndrome). MEN1 is an autosomal dominant disorder characterized by a high frequency of peptic ulcer disease and primary endocrine abnormalities involving the parathyroids (90-97% of patients), pancreatic islets (30-80% of patients; including adenoma, prolactinoma, insulinoma, glucagonoma, gastrinoma, etc.), and anterior pituitary (15-50% of patients).1 MEN2 includes subtypes MEN2A, MEN2B, and familial medullary thyroid carcinoma (FMTC, non-MEN), with the primary clinical features of medullary thyroid carcinoma (MTC; 95% of patients), pheochromocytoma (pheo; 50% of MEN2A and MEN2B), parathyroid hyperplasia (15-30% of MEN2A and rarely in MEN2B), plus mucosal neuromas (lips and tongue), ganglioneuromas of the gastrointestinal tract, and marfanoid habitus in MEN2B only.1 The MEN2A diagnostic category characterizes approximately 60% to 90% of patients with MEN2, FMTC accounts for 5% to 35%, and MEN2B for about 5%.2 In addition, MTC and pheo may be bilateral or multifocal with an earlier age of onset than sporadic occurrence of the same tumor type. [ABSTRACT FROM AUTHOR]