Mixed Multiple Endocrine Neoplasia Syndromes

ERDHEIM first reported the occurrence of multiple endocrine tumors in a single patient. Since that time, many such patients have been described, with the endocrine tumors most frequently occurring in one of two patterns. Type I, also known as Wermer's syndrome, consists of involvement of the pituitary gland, the pancreatic islets, and the parathyroid glands. Occurring less often, but still considered part of the multiple endocrine neoplasia (MEN) I syndrome, is involvement of the thyroid and adrenal cortex, bronchial and intestinal carcinoid tumors, lipomas, brown fat tumors, gastric polyps, schwannomas, and thymomas. Type II has been divided into type IIa, also known as Sipple's syndrome, which consists of pheochromocytoma, medullary carcinoma of the thyroid, and hyperparathyroidism, and into type IIb or type III,1which consists of medullary carcinoma of the thyroid, pheochromocytoma, mucosal neuromas, hyperplastic corneal nerves, Marfan-like appearance, and, rarely, parathyroid disorders.