Intraoperative frozen section of subareolar tissue in nipple-sparing mastectomy: Towards a less is more approach

Background: Nipple preservation contributes to aesthetic outcome and quality of life in women undergoing Skin-Sparing Mastectomy (SSM) with immediate breast reconstruction for the treatment of breast cancer. Intraoperative Frozen Section (IFS) has been advocated to facilitate conversion from Nipple-Sparing Mastectomy (NSM) to SSM in cases with positive subareolar margins. This study investigated the application of IFS at our comprehensive cancer centre. Methods: In this single-centre retrospective study, for all patients who underwent therapeutic NSM with IFS from 2000 to 2021 pathological reports, patient- and tumour characteristics were retrieved. Results: In total 640 women were included in whom 662 intended NSMs with IFS had been performed. Sensitivity and specificity of frozen section compared with definitive histopathology were 75.2% and 98.5% respectively. In six women with a false positive result, the nipple had been removed. In 16 out of 32 women with a false negative result, the nipple was excised in a second procedure. In total 115 nipples were resected. In 40% of these nipples, no residual disease was detected. Discussion: IFS is a moderately sensitive and highly specific diagnostic tool to detect positive subareolar margins. An alternative approach is to omit frozen section but take intraoperative biopsies of the sub areolar margin, which are postoperatively analysed with definitive formalin-fixed paraffin-embedded histopathology. This allows for shared decision making regarding nipple excision in cases where minimal disease is found in subareolar tissue or cases with an indication for post-mastectomy radiotherapy.