Intraoperative touch imprint of sentinel lymph nodes in breast carcinoma patients

BACKGROUND. Sentinel lymph node examination in patients with breast carcinoma has been gaining in popularity. Currently, there is no standard intraoperative assessment of sentinel lymph nodes. To assess the utility of an intraoperative touch imprint (TI) evaluation, the authors compared TI cytology with surface hematoxylin and eosin (H&E) histology in sentinel lymph nodes from patients with breast carcinoma. METHODS. Sixty five sentinel lymph node biopsy cases were identified. Diagnoses from TI and surface H&E histologic sections were compared. RESULTS. Touch imprint had a specificity of 100%, a negative predictive value of 88%, a sensitivity of 65%, and a false negative rate of 9% per sentinel lymph node biopsy case. Eighty three percent of the false negative TI cases were due to micrometastasis. Preoperative chemotherapy, primary tumor type, and primary tumor size did not significantly contribute to false negative events. Touch imprint identified 67% of the cases that required completion axillary dissection. CONCLUSIONS. Touch imprint is a reliable and accurate intraoperative technique, with the potential to save a significant number of patients morbidity and the cost of a second surgical procedure to remove axillary lymph nodes. The difficulty of identifying micrometastases appeared to be the major source of false negative events, a problem that is not unique to TI cytology.