Endocrine Abstracts

Background: Macroprolactinemia is a condition where more of 60% of circulating PRL is made up of macroprolactin. It may be observed in both sexes (although women represent about 90% of published cases), and at all ages. As macroprolactin has low biological active and low bioavailibility, most patients are asymptomatic. The Endocrine Society guidelines recommend screening for macroprolactin only in asymptomatic hyperprolactinemic patients. However, some data from the literature have challenged this recommendation.

Subjects and methods: The aim of this retrospective study was to evaluate clinical presentation and MRI findings among 220 patients with macroprolactinemia routinely followed at Division of Endocrinology, Hospital das Clinicas, Federal University of Pernambuco, and at Pernambuco Endocrine Research Center, Recife, Brazil.

Results: A total of 120 patients (100 women and 20 men; mean age, 32.5±6.5 yrs; age range, 19–46) were included. The great majority of female patients had been referred by gynecologists. Overall, 69 patients (57.5%) were asymptomatic, whereas 51 (42.5%) presented with symptoms related to hyperprolactinemia. Among the 100 female patients, 13% had galactorrhea, 26% menstrual disorders, and 3% both, whereas 58% were asymptomatic. Among the 20 male patients, 5 (30%) had erectile dysfunction, 3 (15%) had decreased libido and 1 (5%) both, whereas 11 (55%) subjects were asymptomatic. Abnormal MRI findings were found in 28 patients (23.3%): microadenomas in 16 (13.3%), empty sella in 8 (6.7%), and macroadenomas in 4 (3.3%).

Conclusion: Our findings demonstrated that abnormal MRI findings and particularly symptoms related to hyperprolactinemia are frequent features in patients with macroprolactinemia. Therefore, screening for macroprolactin only in asymptomatic patients seems to be an inappropriate approach.