Role of intra-operative touch imprint cytology in the treatment of breast cancer.

Objectives: A prospective study was carried out to evaluate the role of intra-operative touch imprint cytology (TIC) in the assessment of sentinel lymph node (SLN) involvement for staging and treatment of early-stage, clinically node-negative breast carcinoma.

Methods: Forty-five patients with early-stage, clinically node-negative breast cancer underwent a SLN biopsy with intra-operative TIC. The SLN was bisected if its width was less than 4 mm or sliced every 2 mm if it was more than 4 mm. The imprint specimens were stained with haematoxylin and eosin (H&E). Rapid immunochemistry (IH) was performed in case of equivocal cytological result. Permanent sections were evaluated with H&E and IH staining. The results of TIC were compared to histopathological results.

Results: The sensitivity, specificity and overall accuracy of TIC on a node basis were 65.5%, 96.3%, 85.5%, respectively. When calculated according to the size of SLN metastasis, the sensitivity of TIC for overt metastasis was 84.6%, while it was 62.5% for micrometastasis and 37.5% for sub-micrometastasis. The mean size of nodal metastasis was 5.08 mm and 1.25 mm for true positive and false negative results, respectively (P = 0.0236). Because of intra-operative TIC, 76.5% of the patients who needed further axillary lymph node dissection (ALND) could undergo this during the same operating time.

Conclusions: TIC is a rapid and reliable method for the intra-operative assessment of metastatic sentinel node involvement in patients with early-stage, clinically node-negative breast carcinoma. Despite a low sensitivity comparable to frozen section (FS) in detecting micro- and sub-micrometastases, the technique offers the advantage of full tissue preservation for subsequent histological analysis.