Endocrine Abstracts

Background: It has been proposed that menopause has a beneficial effect on the natural history of hyperprolactinaemia attributed to prolactinoma. Nonetheless, series systematically assessing outcome in females with prolactinoma who have passed through menopause are very limited.

Aim: To investigate the impact of menopause on prolactinomas in patients not on dopamine agonist (DA) treatment.

Patients and Methods: Women with a prolactinoma diagnosed before the cessation of menses and who after menopause were off DA were identified from the Departmental database. Clinical, biochemical and imaging data were collected.

Results: Thirty-two patients were identified (median age at diagnosis 33.5 years, range 16-49, 24/8 micro-/macroadenomas). DA was stopped peri-/post-menopause in 28 and before menopause in 3; one patient diagnosed in the peri-menopausal period had not been offered DA treatment. Before stopping the DA, 23/31 (74%) women had normal PRL and in 11 there was no evidence of adenoma on imaging (for 4 patients imaging data close to DA discontinuation were not available and in the remaining ones there was visible adenoma). Median follow-up (from discontinuation of DA until last prolactin measurement) was 3 years (0.5–29). At latest assessment, prolactin was normal in 16/32 (50%) (13 had micro- and 3 macroadenoma at diagnosis). 7/23 (30%) women with normal prolactin at discontinuation of DA had hyperprolactinaemia at latest evaluation; 1/9 (11%) with hyperprolactinaemia at discontinuation of DA had normal prolactin at last assessment. Two patients (both with microadenoma) showed gradual increase in the prolactin values (43.3% and 73.6% increase of values of latest measurement in comparison to those one year after stopping DA), and in one of them, increase in the adenoma size was confirmed.

Conclusions: Following menopause, nearly half of women with prolactinoma will have hyperprolactinaemia after discontinuation of DA (median follow-up 3 years). Adenoma enlargement can occur rarely, necessitating monitoring of the serum prolactin.