Nipple margin assessment at the time of nipple-sparing mastectomy

Documenting negative margins at the nipple-areolar complex (NAC) during nipple-sparing mastectomy (NSM) remains the standard, but how to achieve this and how to manage a positive margin is debated. We sought to review nipple margin assessments at our institution and to analyze the risk factors of a positive margin and rate of local recurrence.

Patients who underwent NSM between 2012 and 2018 were reviewed and divided into 3 groups based on indication - cancer, contralateral prophylactic mastectomy (CPM) and bilateral prophylactic mastectomy (BPM).

Nipple-sparing mastectomies were performed on 337 patients; 72% for cancer, 20% for CPMs and 8% for BPMs. Nipple margin assessments were performed in 87.8% of patients; 10 patients (3.4%) had a positive margin, 7 of whom underwent NAC excision and 3 were managed with observation.

As indications for NSM increase, assessment of nipple margin provides valuable information to manage the NAC in patients with cancer. The routine use of nipple margin biopsies in patients undergoing CPM and BPM may no longer be required, as rates of occult malignant disease are low with no positive biopsies. Further studies with larger sample sizes are needed.