Pituitary imaging is indicated for the evaluation of hyperprolactinemia

Abstract

To evaluate the signs and symptoms associated with hyperprolactinemia and establish guidelines for a minimal serum PRL level for which pituitary imaging is indicated. Retrospective study. Reproductive endocrinology clinic in a university hospital. One hundred four consecutive patients with hyperprolactinemia, mean age 30 +/- 6.5 (range 19-44) years. Classification of clinical symptoms, serum hormone measurements, and pituitary magnetic resonance imaging (MRI). Incidence of presenting symptoms, serum PRL levels, and pituitary tumor size. Median (range) PRL value was 82.6 ng/mL (25-1,342). Reported symptoms from most to least common were infertility (48%), headaches (39%), oligoamenorrhea (29%), galactorrhea (24%), and visual changes (13%). Hypothyroidism was diagnosed in 2 of 104 (1.9%) patients. Of 86 patients who had pituitary imaging, 23 (26%) had normal findings and 63 (74%) had pituitary tumor; of these, 47 (55% of total imaged) had microadenomas and 16 (19% of total imaged) had macroadenomas. There was a statistically significant association between the tumor size and the PRL level. However, 11% of the patients with microadenomas had PRL levels >200 ng/mL, and 44% of the patients with macroadenomas had PRL levels between 25 and 200 ng/mL. The most common symptoms in the population studied were infertility and headaches. Coexisting thyroid disease was an uncommon finding. Most patients had a pituitary tumor on MRI. Although tumor size correlated with the serum PRL level, some macroadenomas were detected in women with only moderately elevated PRL values. On the basis of these findings, pituitary imaging should be obtained to identify pituitary tumors in all patients with persistently elevated PRL levels.