Nipple-sparing Mastectomy and Sub-areolar Biopsy: To Freeze or not to Freeze? Evaluating the Role of Sub-areolar Intraoperative Frozen Section.

Use of nipple-sparing mastectomy (NSM) for risk-reduction and therapeutic breast cancer resection is growing. The role for intraoperative frozen section of the nipple-areolar complex remains controversial. Records of patients undergoing NSM at our institution from 2006 to 2013 were reviewed. Records from 501 nipple-sparing mastectomies were reviewed (216 therapeutic, 285 prophylactic). Of the 480 breasts with sub-areolar biopsies, 307 had intraoperative frozen sections and 173 were evaluated with permanent paraffin section only. Among the 307 intraoperative frozen sections, 12 biopsies were positive on permanent paraffin section (3.9% or 12/307). Of the 12 positive permanent biopsies, five were false negative and the remaining seven concordant intraoperatively. Sensitivity and specificity of sub-areolar frozen section were 0.58 and 1, respectively. Positive sub-areolar biopsies consisted primarily of ductal carcinoma in situ (62% or 13/21). The nipples or nipple-areolar complex were resected in a separate procedure following mastectomy (10/21), intraoperatively following frozen section results (7/21) or during second-stage breast reconstruction (3/21; 1 additional scheduled). Only 30% (6/20) of resected specimens had abnormal residual pathology. Intraoperative frozen section is highly specific and moderately sensitive for the detection of positive sub-areolar biopsies in NSM. Its use can help guide intraoperative reconstructive planning. The presence of positive sub-areolar biopsies in both contralateral and high-risk prophylactic mastectomy specimens emphasizes the need to perform sub-areolar biopsies in all nipple-sparing mastectomies.