A longitudinal observational study of male referrals and adherence to imaging guidelines: a single centre experience in 148 patients

Introduction: Male breast cancer represents a rare clinical diagnosis, accounting for less than 1% of all breast cancers. The vast majority of male breast referrals are attributed to benign pathologies, most commonly gynaecomastia. Despite the low incidence of malignancy, variability in clinical acumen and a low threshold for concern frequently result in excessive imaging. To mitigate this, the Association of Breast Surgery (ABS) has issued national guidelines to standardise assessment and reduce unnecessary radiological exposure. This study aimed to evaluate male breast referrals to a high-volume UK breast unit over one year and assess adherence to ABS imaging recommendations. Methods: We conducted a retrospective analysis of all male patients referred to the symptomatic breast clinic at King George Hospital between January and December 2022. Clinical presentation, P-scores, radiological imaging (M and U scores), histopathological outcomes, and medication history were extracted from hospital records and multidisciplinary systems. Imaging pathways were critically appraised against 2021 ABS guidance, stratifying patients by age (<25 and ≥25 years). Results: A total of 148 male patients were assessed, with a mean age of 49.6 years (SD ± 22.3). The most frequent presentation was a unilateral breast lump (62.8%). Gynaecomastia was diagnosed in 97 patients (65.5%), with proton pump inhibitors implicated in over a quarter of these cases. Imaging was performed in 141 patients (95.3%), with 52.7% of all imaging deemed non-concordant with ABS guidance. Only 29.7% underwent imaging entirely in keeping with national recommendations. Eight patients (5.4%) were diagnosed with breast cancer, all over the age of 25. Notably, only one malignancy arose in a patient with a benign clinical examination (P1), flagged by indeterminate mammographic findings (M3). Advanced cross-sectional imaging (CT/MRI) was performed in 2% of the cohort. Conclusion: Despite clear national guidelines, our findings highlight a significant trend towards over-investigation in male breast referrals. The predominance of benign disease particularly drug-induced gynaecomastia underscores the need for judicious imaging. Adherence to ABS criteria must be reinforced, and closer collaboration between breast surgeons and radiologists is essential to optimise diagnostic yield, reduce patient anxiety, and conserve healthcare resources in the evaluation of the male breast.