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

Purpose: To characterize a cohort of elderly men with prolactinomas and their response to treatment.

Methods: 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.

Results: 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.

Conclusions: 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.