Intraoperative frozen section sentinel lymph node assessment in breast cancer: A tertiary institution experience

INTRODUCTION: Intraoperative frozen section lymph node assessment helps to predict axillary lymph node metastasis in breast cancer. However, the accuracy of this frozen section analysis may vary among institutions. This study describes our institution's experience in intraoperative analysis of sentinel lymph node and aims to determine the accuracy, sensitivity and specificity of our assessment.

MATERIALS AND METHODS: We retrospectively analysed the histopathological material and data from 82 breast cancer patients diagnosed over a period of four years who underwent intraoperative frozen section evaluation of sentinel lymph nodes.

RESULTS: Frozen section analysis detected metastasis in 13 out of 82 cases and definitive pathological examination on the paraffin section confirmed these positive findings. There was no false positive case (specificity of 100%). The true positive cases comprised seven macrometastases, five micrometastases and one isolated tumour cells. Sampling error was noted in two cases in which the malignant cells were only present in the deeper final paraffin sections (false negative rate of 13.3%). The test sensitivity was 86.7% and the accuracy rate was 97.5%. These findings are comparable to other published data.

CONCLUSION: Intraoperative frozen section analysis is a safe and reliable method for assessment of sentinel lymph node. Knowledge on limitation of frozen section analysis with diligent evaluation of frozen section specimen will be beneficial in reducing interpretation error.