Endocrine Abstracts

Introduction: Multiple endocrine neoplasia (MEN) is a rare disease. Apart from the well recognised MEN2 syndrome the MEN1 is less common diagnosed. The MEN1 gene is localised on the 11q13 chromosome and encodes menin. There is no simple definition of MEN1 syndrome because of heterogenous combination over 20 different endocrine and non-endocrine tumours. According to the Gubbio consensus, MEN1 is diagnosed by the occurrence of two of the three main MEN1-related endocrine tumours: parathyroid adenomas, enteropancreatic tumours (GEP) and pituitary tumours (‘3P’) independently from different endocrine and non-endocrine tumours in the same patient. It seems to be over-simplified definition leads to MEN1 incidence being underestimated.

Materials and methods: Over the years 1994-2008, 42 cases (11 males and 31 females) of MEN (non MEN2) syndrome were diagnosed at our Department of Endocrinology. Hormone tests, and imaging (USG, CT, MRI, SRS) were carried out in all patients.

Results: The most common pathology was parathyroid adenoma or hyperplasia (26 patients) and pituitary adenoma (26 patients: 4 somatotropic, 4 lactotropic and 18 non-secretory). GEP tumours were diagnosed in 16 patients: in 2 patients glucagonoma, in 3 gastrinoma, in 2 somatostatinoma in 7 serotoninoma and in 2 patients non-secretory tumours. In 14 patients (4 males and10 females) of mean age 49.8±14 years ‘classic’ MEN1 was diagnosed. Three patients mean age 56±12 years had three tumours of the main glands. The others 16 patients (7 male and 22 females) mean age 52±9 years, had only one main MEN1-related tumour and other less essential, but connected with MEN1, abnormalities. The last group of 6 patients mean age 47.3±8 years had no main MEN1- related tumours but had adrenal tumours (pheochromocytoma, adenoma or adrenal carcinoma) and adenoma or thyroid carcinoma.

Conclusions: (1) Variability of the clinical presentation of MEN1 syndrome and variability of occurrence at different times, lead to underestimation of MEN1 incidence; (2) better specification of criteria for diagnosing the MEN1 syndrome need to be urgently established; (3) long-term observation of MEN1 patients may increase the number of cases established and decrease mortality due to tumour progression to malignancies.