Endocrine Abstracts

Background: Hyperprolactinaemia is common in patients presenting with polycystic ovary syndrome (PCOS). Recent studies suggest that each condition has an independent aetiology, hence appropriate investigation of hyperprolactinaemia in the context of PCOS is required, for which separate treatment may then be provided. Appropriate investigation includes a serum macroprolactin screen, a specific drug history for drug-induced hyperprolactinaemia (DIH), blood tests to exclude secondary causes and, when indicated, a magnetic resonance imaging (MRI) examination of the pituitary gland. However, there is no current algorithm for appropriate investigation of hyperprolactinaemia in the setting of PCOS.

Objectives: To determine in patients with PCOS: (i) the prevalence of hyperprolactinaemia and its causes, (ii) the sequence of investigations for hyperprolactinaemia, and (iii) their subsequent management plan.

Methods: A retrospective audit of 493 PCOS patients who attended an Endocrinology Outpatient clinic between June 2012 and April 2016. Data was collected on demographics, presenting signs and symptoms, further imaging investigations, biochemical results as well as treatment plans.

Results: Only 334 (67.7%) patients with PCOS had serum prolactin levels measured at presentation. Fifty-eight (17.4%) female patients with PCOS presented with coexisting hyperprolactinaemia. Twenty-five (43.1%) patients presented with macroprolactinaemia, 18 (31.0%) with a pituitary adenoma and the remaining 15 (25.9%) with DIH. Excluding macroprolactinaemia, 33 (9.9%) patients from the total PCOS cohort demonstrated true hyperprolactinaemia. Twenty (52.7%) MRI pituitary scans performed were not necessary since diagnoses of macroprolactinaemia and DIH had already been made. Elimination of these scans could have resulted in financial savings.

Conclusion: All patients being evaluated for PCOS should have serum prolactin measured. We propose a diagnostic algorithm for appropriate investigation of hyperprolactinaemia in PCOS, which ensures accurate diagnosis and prevents superfluous investigation.

Keywords: PCOS, Hyperprolactinaemia, macroprolactin, pituitary adenoma, drug-induced, MRI.