Role of intraoperative imprint cytology of axillary sentinel lymph nodes

OBJECTIVE: Sentinel lymph nodes (SLNs) predict the axillary’ s status and may allow lymphadenectomy on a selective basis. The purpose of this study was to evaluate the usefulness and accuracy of intraoperative imprint cytology (IIC) in comparison with definitive histological evaluation of SLN in early breast cancer patients. METHODS: From February 2003 to March 2006 total of 79 SLNs from 63 patients with T1 – T2 breast carcinoma were examined by IIC. SLNs were identified by technetium-labelled sulphur colloid and blue dye and bisected along the long axis. Intraoperative imprints were made of each cut surface, stained with Hemacolor and reviewed by a cytologist. The time taken for procedure was recorded. Histological analysis of SLN involved serial sectioning of the whole node with HE and immunostaining for cytokeratin. RESULTS: Definitive histology revealed metastases in 17/63 patients in 20/79 SLNs. IIC identified metastases in 11 patients (sensitivity 64.7%) in 14 SLNs (sensitivity 70%). All 6 false-negative cases were due to micrometastases in the SLN. In the group with negative SLN (59) in 46 patients, 3 cases were &laquo ; false positives&raquo ; (specificity 94.9% per sentinel and 93.5% per patient basis). The average time to perform intraoperative analysis was 10 min (range: 5 – 20 min). CONCLUSION: Intraoperative imprint cytology of SLN in breast carcinoma patients is a simple, quick and accurate method for detecting metastatic disease in the SLN and enables the surgeon to determine whether or not an axillary lymph node dissection is necessary at the time of the initial surgery