Women with prolactinomas presented at the postmenopausal period

In women, prolactinomas (mainly microprolactinomas) are commonly diagnosed between 20–40-year old. In postmenopausal women, prolactinomas are rarely encountered and usually do not present with hyperprolactinemia-related symptoms as these are dependent on intact ovarian function. Therefore, the true incidence of prolactin (PRL)-secreting adenomas in postmenopausal woman is unknown. Our study objective was to characterize these rare and unique pituitary tumors. A retrospective study including a consecutive group of postmenopausal women followed and treated at 3 Endocrine academic clinics. Baseline clinical characteristics (PRL and gonadotropins levels, other pituitary hormones, adenoma size and invasiveness, visual fields) and response to treatment are reported. The cohort included 14 postmenopausal women with prolactinomas (mean age at diagnosis, 63.6 ± 7.1 years; range, 54–75 years). Mean adenoma size at presentation was 25.6 ± 12.4 mm (range, 8–50 mm). Six out of the 14 women had significant visual fields damage. Mean baseline PRL level was 1,783 ng/ml, and median PRL was 827 ng/ml (range, 85–6,732 ng/ml). Medical treatment with cabergoline was given to twelve of the patients. Cabergoline normalized/near-normalized PRL in eleven women; one woman was dopamine agonist-resistant. Five of the six subjects with visual disturbances normalized or improved their vision, and a pre-treatment diplopia in another patient disappeared. Two large pituitary tumors disappeared on MRI following long-term dopamine agonist therapy. All other treated prolactinomas, except the resistant adenoma, shrank following medical treatment. Prolactinomas are rarely diagnosed in postmenopausal women. These women usually harbor large and invasive macroadenomas, secreting high PRL levels, and usually respond to dopamine agonist treatment.