Hyperprolactinemia diagnosis in elderly men: a cohort of 28 patients over 65 years.

To characterize a cohort of elderly men with prolactinomas and their response to treatment. We have identified 28 elderly men diagnosed after the age of 65 with prolactinomas at seven different endocrine clinics in Israel. A retrospective electronic chart review identified a control group of 76 younger men with macroprolactinomas treated in one of the centers. Mean age at diagnosis was 71.3 ± 5.6 (range 65-86) years, and current age 76.6 ± 7.5 years. Initial complaints leading to diagnosis included sexual dysfunction in 17 males (61%), headaches in two patients (7%), and visual abnormalities in two (7%). Three men presented with osteoporosis. Ten patients (36%) were diagnosed incidentally following brain imaging for unrelated reasons. Seventeen patients (61%) had macroadenoma, while eleven (39%) presented with a microadenoma or no visible adenoma. Mean prolactin (PRL) at presentation was 1594 (median 382; range 50-18,329) ng/ml. Testosterone was low in 21 men. Patients were treated with cabergoline (max dose, 1.1 ± 0.5 mg/week), except for one given bromocriptine; none required pituitary surgery or radiotherapy. Treatment normalized PRL in 24 patients, and in three men PRL suppressed to <2 ULN. Fifteen men normalized testosterone, three improved without normalization, and in three the normal baseline level increased. After a mean follow-up of 5.3 years, 14/15 patients harboring a macroadenoma showed significant adenoma shrinkage. Most patients reported improvement of low libido/erectile dysfunction. In the control group 60 men (79%) achieved PRL normalization. Elderly men with prolactinomas are diagnosed incidentally in 36% of cases. Long-term medical therapy is successful, achieving biochemical remission, adenoma shrinkage, and clinical improvement in almost all patients.