Safety of Atypical Ductal Hyperplasia at the Nipple Margin in Nipple-Sparing Mastectomy

Purpose: Controversies persist regarding contraindications for nipple-sparing mastectomy (NSM). This study aimed to assess the accuracy of subareolar frozen section analysis and identify risk factors for nipple-areola complex (NAC) recurrence post NSM. Methods: Consecutive cases of primary invasive breast cancer undergoing NSM at our single center from January 2015 to December 2020 were retrospectively reviewed. Results: The nipples were retained in 126 patients (127 breasts), and the areola was retained with nipple excision for five breasts. Frozen section analysis demonstrated a sensitivity of 81.8% and specificity of 95.3%. The NAC recurrence rate was 4.3% over a median follow-up period of 48 (30-105) months. An atypical ductal hyperplasia (ADH) at the margin emerged as an independent factor for NAC recurrence in multivariate Cox regression analysis (hazard ratio, 25.464; 95% confidence interval, 1.841-352.145; p = 0.016). Kaplan-Meier survival analysis revealed no statistically significant reduction in overall survival rates (log-rank test, p = 0.660). Conclusion: Frozen sections of subareolar tissue are reliable and re-excision may be necessary when ADH is detected at the nipple margin in NSM. The NAC recurrence rate was low, and the outcome was favorable following wide local excision.