INTRA OPERATIVE FROZEN EXAMINATION OF SENTINEL LYMPH NODE IN BREAST CANCER

Sentinel node (SN) biopsy is the standard of care for the assessment of axilla in early breast cancer patients with clinically node negative disease. Confirmed absence of tumour deposit in node on intra operative frozen section (FS) examination saves the patient from complete axillary dissection. However controversies arise when inconsistencies occur in results of frozen and permanent section. Reported sensitivity of frozen examination of sentinel node in literature ranges from 70-95%.The purpose of this study was to determine the sensitivity of frozen examination of sentinel node in breast cancer. The frozen section examination of sentinel node is not a reliable technique for accurate pathological assessment of node.

Data was collected prospectively on patients with sentinel node procedure from May to December 2013. All SNs removed at surgery were submitted for frozen section and the results were compared with permanent sections.

Of 50 patients 16 were true positive while 32 were true negative. Two patients reported negative on FS were confirmed to be positive on permanent section. The accuracy of frozen section was 96%, with sensitivity of 89%. In false negative cases the size of nodal metastasis was significantly smaller than that of true positive, i.e., 1-2 mm. The false negative cases were further classified for assessment into technical and interpretative error.

The intra operative frozen section examination is a reliable technique for the assessment of Sentinel node with a high accuracy rate to detect metastasis size of >2 mm. It spares the patient from complete axillary dissection and its subsequent morbidity of lymphedema and shoulder pain.