Endocrine Abstracts

Background: Multiple endocrine neoplasia type 1 (MEN1), is an autosomal dominant inherited disorder with high penentrance, characterized by the onset of multiple tumors, mainly in parathyroid, pituitary gland and gastroenteropancreatic tract. During the course of the disease pituitary adenomas (PA) occur in 20-65%, rarely as first clinical manifestation, and are often described as larger, more aggressive, and more resistant to conventional therapy than their sporadic counterpart. The aim of this study is to analyse clinical characteristics of PA in a monocentric series of MEN1 patients.

Aim: The clinical charts of all patients with MEN1, referred to the Endocrinology Unit at the Federico II University of Naples from January 2000 to June 2021, were retrospectively evaluated, analyzing epidemiological and clinical data.

Results: We identified 91 MEN1 patients (F/M=50/41). The prevalence of PA was 49.5% (45 patients) with a slight female preponderance (F/M=1.36). PA was diagnosed in 92.2% of cases after the diagnosis of MEN1. The mean age at diagnosis of PA was 44.6y (13-75y), this was much lower when PA was identified as the first MEN1 manifestation (28y). PA were microadenoma in 60% (27 patients), and macroadenoma in 40% (18 patients). PA were non-secreting in 44.4% (20 patients), PRL-secreting in 42.2% (19 patients), GH-secreting in 2.2% (1 patients), PRL-GH secreting in 8.8% (4 patients), and ACTH-secreting in 2.2% (1 patients). Symptoms of hormonal hypersecretion and/or compression of adjacent structures were detected in 53.4% (24 patients). Among patients with prolactinomas the M:F ratio was 1/1.11 (11/12 patients), and all 12 affected females had associated symptoms (menstrual irregularities, galactorrhea); while only 2/11 male patients had hyperprolactinemia-related disorders (decreased libido, impotence). With regard to therapeutic treatment, cabergoline was used in 40% (18 patients) of PA, while octreotide was used only in 2.22% (1 patient). Transphenoidal surgery was performed in cases of refractoriness or macroadenoma-related symptoms in 15.5% of cases (7 patients), and radiotherapy subsequently was necessary in 2.22% of cases (1 patient).

Conclusion: PA within MEN1, are more common in women and are rarely the first clinical manifestation of the syndrome. Importantly, our data suggest that PA do not seem to be more aggressive than sporadic forms and show good response to medical and surgical therapy. A multidisciplinary approach in specialized centers may improve the clinical history of these patients allowing early diagnosis.