Background: Sentinel lymph nodes (SLNs) predict the axillary status and may allow lymphadenectomy on a selective basis. The aim of this study was to assess the accuracy of intraoperative imprint cytology (IC) analysis of sentinel nodes in patients with early breast cancer.
Methods: A total of 128 SLNs from 87 cases that had been identified with Patent blue dye were bisected for hematoxylin and eosin stained touch preparations. Intraoperative evaluation of sentinel node involvement by IC was compared with the final histopathological results of permanent sections. Tumour-negative nodes in standard paraffin sections were further studied using an anticytokeratin antibody (CK-IHC).
Results: Thirty-six of all SLNs contained metastases in paraffin sections, of which 32 were detected by IC procedure (sensitivity 88.8%). Three sentinel nodes were tumour-positive on imprint cytology and tumour-negative on stained paraffin sections. Comparison of the results of the imprints with the final histology (H&E and CK-IHC) showed a sensitivity of 83.3% and a negative predictive value of 92.5%. The specificity and positive predictive value were 100%.
Conclusion: Touch imprint cytology is a simple and quick method of intraoperative screening of SLNs for the presence of metastases in patients with breast cancer. Results may be improved by an appropriate enlargement of the surface sampled and the use of rapid CK-IHC on the touch preparations.