Endocrine Abstracts

Introduction: Clinically non-functioning pituitary adenomas (NFPA) are heterogeneous group. Some previous research has found that this type of pituitary adenomas may be smaller and have better prognostic in men. The aim of this study is to analyze if there are gender-related differences in NFPA.

Material and methods: Retrospective study of patients with NFPA followed up in regional hospitals (Community of Madrid, Spain). All NFPA had molecular analysis. The collected variables were: age, sex (women were divided according to premenopausal and menopausal status), diagnostic (NFPA were divided according to type of expression, classified as unihormonal, plurihormonal or null cell), initial tumor size, need of reintervention and radiotherapy. Concerning the molecular study we also included prolactin, GH, POMC, betaLH, betaFSH, betaTSH, alpha subunit, somatostatin receptors (SSTR 1–5), dopamine D1, D2 long, D4 and D5 receptor. Statistical analysis was made with SPSS version 22.0.0.0.

Results: 44 patients were included (age at diagnosis 61±14 years). 54.5% were women (17 menopausal women and 7 premenopausal). All of them were macroadenomas. 3 were silent corticotroph adenomas, 21 gonadotropinomas, 10 plurihormonal adenomas, 1 silent TSH adenomas, 2 silent prolactinomas and 10 were null cell. We found that dopamine receptor D1 expression was higher in silent prolactinomas and null cell adenomas, and was very low in gonadotropinomas (P=0.001). There were statistically significant differences in the type of adenoma according to gender and to menopausal and premenopausal status. Adenomas with hormonal expression were more frequent in premenopausal woman. The most frequent adenomas in men were gonadotropinomas and in menopausal women gonadotropinomas, plurihormonal and null cell adenomas. We observed that dopamine receptor D4 expression was higher in women than in men. There was a trend, although it was not statistically significant, in the need for reintervention (7/13 in men vs 3/21 in women; P=0.076). Gonadotropinomas had higher expression of prolactina and dopamine receptor D4 in women. No difference between tumor size and need of radiotherapy was found.

Conclusion: In our cohort, we found difference in the type of NFPA and dopamine receptor D4 expression between men and women. Also, the dopamine receptor D1 expression was higher in silent prolactinomas and null cell adenomas, and very low in gonadotropinomas.