Ten-Year Clinical Follow-Up of a Cohort of 51 Patients with Macroprolactinemia Establishes It as a Benign Variant

Context: Macroprolactinemia is a common finding in patients with hyperprolactinemia. There are no published long-term follow-up studies. Objective: The aim of this study was to describe findings after prolonged follow-up in a previously published cohort of patients with macroprolactinemia. Study Population: We studied 51 patients identified as having macroprolactinemia after polyethylene glycol precipitation. Design: Clinical assessment and serum prolactin assay were repeated in 51 patients with macroprolactinemia after a median follow-up of 9.9 yr (range, 9–11 yr). Results: Median age at presentation was 41 yr (range, 18–55 yr). Mean serum prolactin concentration at presentation was 1885 mU/liter, and after follow-up 1370 mU/liter. At follow-up, headache had been experienced in 12 patients (24%) and oligomenorrhea in five (10%). Galactorrhea was present in only two patients (4%). No visual deterioration was noted in 50 patients. One had a transient bitemporal hemianopia. No patients developed an autoimmu...