Endocrine Abstracts

Introduction: Prolactin is assessed for a multitude of reasons in primary and secondary care. Wider testing with non-specific symptoms often yields ambiguous results requiring further confirmation of pathology. Defaulting to magnetic resonance imaging of the pituitary gland has the potential to increase demands on radiology services, waiting times and may result in the detection of incidental findings.

Methods: We organised cannulated prolactin levels for all patients referred with elevated prolactin up to 5000 mU/L without known cause (dopamine antagonist medication, known pituitary disease). We conducted a retrospective review of all data for 12 months on our day unit. All prolactin results, including community referral data, were carried out on the Roche platform with manufacturer reference ranges.

Results: 95 patients had cannulated prolactin during the study period (11 male, 84 female). 72 (75%) of these were tested from triage without clinical review. 72% patients were deemed to have a stress response and 62 patients (65%) were able to avoid imaging. Median time from referral to cannulation and diagnostic outcome was 21 days (6-452) and 27 days (12-459) respectively. The minimum prolactin level on cannulation associated with microadenoma was 537 mU/L affirming the need to avoid hard cut-offs at triage for a suspected stress response. Variance in cannulated levels was lower than in those deemed to have a stress response but there was little appreciable difference in variance from primary care referral prolactin data.

Conclusion: Cannulated prolactin levels used straight from referral without clinical review can improve clinic efficiency and reduce patient waiting times whilst also reducing overall cost. Variability of prolactin on repeated community testing may prove useful in future. Further studies looking at other reliable prognostic factors could help narrow testing criteria to ease service pressure.