Endocrine Abstracts

Introduction: Multiple Endocrine Neoplasia Type 1 (MEN1) is a rare disease inherited in an autosomal dominant pattern, caused by mutations in the MEN1 gene. The cardinal components of this syndrome are: primary hyperparathyroidism (PHPT), gastroenteropancreatic neuroendocrine tumors (NETs) and pituitary tumors.

Aim: The aim of the study was to evaluate clinical features of MEN1 patients under care of two teritiary centers in Warsaw, Poland with special focus on pituitary lesions.

Material and methods: We have used an authorial pre-prepared form in order to gain detailed data on the clinical course of the disease. Until the submission of this abstract (January 2022), study group consisted of 73 participants with diagnosed MEN1 syndrome, aged from 18 to 76 years old (mean 43 ±14 years) and followed-up from 2014 to 2022. As many as 47 of patients were women, 26 were men.

Results: In our group nearly 42% of subjects suffered from all three main components of MEN1 syndrome. Among them: 93% developed PHPT, 78% NETs, 60% pituitary tumors. In 77% of patients we have found other benign neoplasms of which the most common were adrenal adenomas (38%). What is more, 12% of subjects developed other malignant tumors. Out of 44 patients with pituitary tumors, in 26 imaging tests showed pituitary microadenomas, yet macroadenomas were present in next 18 cases. Most common type of tumor was prolactinoma (52%), with a predominance of microadenomas (32% of all pituitary tumors). Moreover, acromegaly was diagnosed in 6 patients what accounted for 14% of pituitary gland lesions cases. At least one pituitary surgery was performed in 11 subjects, 9 of them had hormonally active adenomas (4 prolactinomas, 3 cases of acromegaly, 2 non-functioning pituitary adenomas, 1 thyrotropinoma and 1 corticotropinoma). In two cases more than one operation was required. Dopamine agonists were administered to 18 patients. After PHPT, pituitary tumor was second most frequent first diagnosed component of MEN1 (26% of the group). In nearly 10% of all patients it manifested itself as menstrual disorders or decreased libido. Only in 9% patients NETs were diagnosed as the first component.

Conclusions: Despite the fact that pituitary tumors are the third most frequent tumors in MEN1, they are more likely to cause clinical manifestations than NETs. In our group there was relatively high prevalence of acromegaly. What is more, we observed frequent occurrence of other malignant tumors and noted a large number of adrenal gland adenomas.