Introduction Gynecomastia represents the most common reason for male attendances to breast clinics in the UK. This study aims to evaluate concordance of clinical practice to national guidelines at a tertiary breast unit.

Methods 2021 ABS Gynaecomastia guideline was utilised. Two cycles were conducted: Jun-Aug 2022, and Feb-May 2023. An educational intervention including development of a poster for clinical areas was implemented, with cycle 2 evaluating for improvements.

Results Cycle 1 and 2 had 62 and 97 patients respectively. Both cycles showed similar documentation rates of P stage (1-65%,2-70%), medication history (1-71%,2-75%), alcohol history (1-27%,2-27%), recreational drug use (1-24%,2-34%), steroid use (1-21%,2-32%) and family history (1-66%,2-73%). In both cycles the majority underwent imaging (1-94%,2-97%). Gynaecomastia was the most common diagnosis (1-68%,2-64%), with 1 cancer diagnosis across both cohorts. 6% of cycle 2 vs 24% of cycle 1 underwent further secondary care investigations. More discharges from clinics were observed in cycle 2 (2-90%,1-63%). 17% of cycle 1 discharge letters gave variable advice for further GP investigations, whilst 33% of cycle 2 letters gave explicit advice in accordance with guidelines.

Conclusion Post-intervention there was reduction in intra-departmental variability in investigation of gynaecomastia. Imaging rates remained high, with likely multi-factorial causality. Documentation rates did not significantly improve, which introduction of a proforma may address.