Subareolar Tissue Biopsy Predicts Occult Nipple Involvement in Nipple-Sparing Mastectomies

Abstract Objectives Subareolar tissue is examined during nipple-sparing mastectomy (NSM) to minimize the risk of occult malignancy within the preserved nipple. A positive subareolar tissue biopsy typically warrants subsequent nipple excision. We study the factors associated with a positive subareolar tissue biopsy, the rate of residual malignancy in subsequent nipple excisions, and the value of subareolar tissue biopsy intraoperative frozen section (IOF). Methods We identified 1,026 consecutive NSMs with separately submitted subareolar tissue biopsies over a 5.5-year period. Clinicopathologic data were reviewed. We examined concordance rates between subareolar tissue biopsy and subsequent nipple excisions as well as IOF diagnosis and permanent control diagnosis. Results Among cases of therapeutic NSM, the rate of a positive subareolar tissue biopsy was 7.2%. Multifocal/multicentric disease (P = .0005), presence of lymphovascular invasion (P = .033), and nodal involvement (P = .006) were significantly associated with a positive subareolar tissue biopsy. Thirty-nine of 41 cases with positive subareolar biopsies underwent subsequent nipple excision, with 20 (51%) showing residual carcinoma. Among all IOF samples, 9 (3.3%) showed a discrepancy between the IOF and permanent diagnoses, mostly because of false-negatives. Conclusions A positive subareolar tissue biopsy predicts residual carcinoma in the excised nipples in 51% of cases. IOF is accurate and reliable.