Frozen Section of Breast and Sentinel Lymph Node

Specimens submitted for intraoperative frozen sections from breast cancer patients most often include axillary sentinel lymph nodes and subareolar margins. Sentinel lymph node frozen section use has declined following the publication of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial. It is currently indicated for clinically node-negative patients undergoing mastectomy and for those that have received neoadjuvant chemotherapy. Nipple-sparing mastectomy has become increasingly popular as a procedure associated with superior aesthetic outcomes while being oncologically safe. Subareolar tissue biopsies from patients undergoing nipple-sparing mastectomy are often submitted for frozen section to exclude occult carcinoma. This chapter will provide a practical approach for evaluating frozen sections of sentinel lymph node and subareolar margin specimens. Pertinent data from clinical trials will provide context for the current use of frozen sections for breast carcinoma patients. Instructive examples of both routine and difficult cases will highlight challenges and pitfalls associated with frozen section interpretation.