Endocrine Abstracts

Background: Hyperprolactinemia is one of the most common endocrine disorders of the hypothalamic-pituitary axis. It is difficult to differentiate between stress induced hyperprolactinemia and true hyperprolactinaemia and may result in patients having unnecessary imaging.

Methods: We have collected data for 46 patients who had a cannulated prolactin test between January 2017 and June 2023 in the Royal United Hospital of Bath (RUH). After cannula insertion, prolactin was measured at 0, 30, 60 and 90 minutes.

Results: Prior to testing: 45 patients had raised prolactin. 1 patient had a normal prolactin. After cannulated prolactin testing: 67% results normal, no further action required 33% (13 patients) abnormal test suggestive of prolactinoma. Therefore, only 33% of patients had MRI pituitary: 12 were reported and 1 was pending. Of the 12 that had an MRI: • 2 identified pituitary pathology and were started on cabergoline • 10 no pituitary pathology identified:1. 1 was within 6 months of pregnancy so was followed up with biochemistry that settled.2. 1 without pituitary pathology present but symptomatic was started on cabergoline (nadir prolactin on test 1.4 x ULN)We have reviewed the costs for a cannulated prolactin test and an MRI pituitary in the NHS: Cost of completing a cannulated prolactin test (staff/blood test/equipment) £76.11 Cost of MRI £500 Total cost if all patients had an MRI: £23,000 Total cost of all patients having cannulated prolactin: £3,501.06 Total cost of cannulated prolactin tests completed + MRI for those with positive tests: £10,001.06 Savings to the Trust by completing cannulated prolactin prior to MRI: £12,998.94.

Conclusion: Cannulated prolactin is a very good cost-effective test which saved us £13000 in unnecessary MRI’s. We have saved 33 clinic consultations as patients with normal results get sent letters, no endocrine appointments.