Multiple Endocrine Neoplasia (MEN) type1

Abstract

MEN type 1 is an autosomal dominant syndrome associated with neoplasms in multiple endocrine organs （e.g., parathyroid, endocrine pancreas, and anterior pituitary）. Primary hyperparathyroidism is part of the phenotype with the highest frequency of MEN1, followed in order by pancreatic endocrine tumor and pituitary tumors. In addition, tumor of the adrenal cortex, thyroid tumor, and carcinoid have been reported. Treatment of MEN1 has a specific therapeutic method compared to that of the non-MEN neoplasms in each endocrine organ. Total parathyroidectomy with autoplantation is performed the patients with primary hyperparathyroidism associated with MEN1; for pancreatic tumor, nucleation, partial resection of the pancreas and total duodenalectomy with preserved pancreatic head is performed. Most pituitary tumors associated with MEN1 are followed and medicated without surgical treatment. There is a relationship with genotype and phenotype of RET in MEN2, but there is no correlation in MEN1. And prophylactic resection in the each organ involved by MEN1 is not performed based on the findings of MEN1 gene test, because cancer does not necessarily occur in MEN1, but total pancreatectomy would decreuse QOL. However, the MEN1 gene test also might contribute to early stage detection and allow the patient to avoid surgery such as the pituitary tumor. Although the most significant prognostic factor of MEN1 is the outcome of pancreatic tumor, it is controversial whether conservative treatment to preserve QOL or early aggressive resection of the pancreas should be performed. An increase in MEN1 cases will be expected in the future, and counseling for the long-term survivors will become important.