Intraoperative Frozen Section Evaluation of Sentinel Lymph Nodes in Breast Carcinoma: Single-Institution Indian Experience

Abstract

Sentinel lymph node biopsy is an established way of predicting axillary nodal metastasis in early breast cancer. Intraoperative frozen sections (FS) of sentinel lymph nodes (SLNs) can be used to detect metastatic disease, allowing immediate axillary lymph node dissection. The purpose of this study was to evaluate the accuracy of intraoperative frozen sections in evaluation of sentinel lymph nodes in cases of breast cancer. Between March 2006 and August 2010, a total of 164 patients with clinically node-negative operable breast cancer were subjected to sentinel lymph node biopsy of axillary lymph nodes using preoperative peritumoral injection of radioactive colloid and methylene blue. Intraoperative identification of sentinel nodes was done using a handheld gamma probe and identification of blue-stained nodes. The nodes were sent for frozen section examination. The results of frozen section were compared with the final histopathology. Out of the 164 cases, metastases were detected in SLN by frozen section in 38 cases. There were three false-negative cases (all showing micrometastasis on final histopathology). FS had sensitivity of 92.6 %, specificity of 100 %, and overall accuracy of 98.1 %. The positive predictive value was 100 %, and the negative predictive value was 97.6 %. FS for diagnosis of metastasis of SLNs is reliable. Patients with negative SLNs by the FS diagnosis can avoid reoperation for axillary lymph node dissection. However, FS may fail to detect micrometastases, especially in cases with small tumors.

Keywords: Axillary clearance; Breast cancer; Frozen section; Sentinel node.

Fig. 1

Tumor characteristics in the patient population

Fig. 2

Pictures of pathological evaluation of SLN. a FS of SLN metastases; b subcapsular micrometastases missed by frozen section seen on final HPE (high-power view); c FS of sentinel node micrometastases