Endocrine Abstracts

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by variable combination of more than 20 types of endocrine and non-endocrine tumors: typically parathyroid glands, pancreatic islet cells and anterior pituitary gland are involved. We studied 20 patients (10M and 10F), affered to our Pituitary Unit in a period of 10 years. All patients had clinical diagnostic criteria suspected for MEN1 (presence of two endocrine tumors at least) and underwent genetic test (sequence analysis) for MEN1 mutations that were confirmed in five patients. Kindred of patients with MEN1 mutations were also tested and four people (in one family) were found to have MEN1 mutations. 18 patients had parathyroid tumors, 18 had pituitary tumors (9 GH-secreting adenomas, 5 prolactinomas and 6 non-functioning adenomas). One patient had colorectal carcinoid tumor and in three patients we found also gastric neuroendocrine cells hyperplasia. Five patients had pancreatic gastrinomas, four of them were MEN1 mutations carriers. One of them underwent total pancreatectomy while the others underwent excision of pancreatic gastrinomas or pancreaticoduodenectomy. After <10 years two of them (both carriers of MEN1 mutations) showed extensive disease recurrence (despite medical therapy and radiotherapy) and so underwent total pancreatectomy, maybe suggesting that these kinds of MEN1 mutations lead to a more aggressive type of pancreatic NET. Moreover, despite the data present in literature, we report a higher prevalence of GH-secreting pituitary adenomas, which appear to be more frequent than prolactinomas. Finally high proportion of MEN1 patients without detected MEN1 mutations suggests that unknown mutations of MEN1 gene may be involved in the occurrence of MEN1.