Endocrine Abstracts

Background: Hyperprolactinaemia is a common presentation in endocrine clinics. Current guidelines on BMJ best practice recommend evaluation with MRI only if levels are >2000 mU/l or absence of an identifiable secondary cause.

Aim: To identify if pituitary pathology would go undetected if pituitary imaging is not performed and determine a suitable threshold for performing pituitary imaging in the diagnosis of prolactinoma.

Methods: A retrospective study on 100 new patients with raised prolactin level below 1000 mU/l (17–75 years old) over 12 months (Jan–Dec 2017).

Result: 33 male and 67 female studied. 16% of patients had prolactin level of 350–500 mU/l, 54% with prolactin level of 500–700 mU/l and 30% between 750–1000 mU/l. Menstrual irregularities were the most common symptoms (22%) followed by Erectile dysfunction/Gynaecomastia (16%), headache (10%). Fatigue 8%, subfertility 6% and galactorrhoea 5%. 33% were asymptomatic. MRI pituitary was performed on 60 patients and CT head on 2. MRI pituitary gland identified 17 microadenoma, 3 pituitary cysts, and 2 empty Sella. 40 had normal MRI and CT finding.

Conclusion: 22 out of 62 (35%) patients had positive findings on MRI scan with mean initial prolactin level of 640 mU/l which based on current guidelines would not require pituitary imaging. With such a high pickup rate clinical as well as biochemical criterion should be applied to patient selection for imaging. The majority of lesions identified will be incidental but may benefit from followup.