Usefulness of touch imprint cytology with immunocytochemistry of sentinel lymph node metastases in breast cancer

—Comparison with one-step nucleic acid amplification assay—

Abstract

Objective : To examine the superiority of immunocytochemistry (ICC) to Papanicolaou (Pap.) staining in touch imprint cytology for detecting sentinel lymph node metastases in patients with breast cancer.
Study Design : We analyzed 79 samples that were rated as positive by the One-step nucleic acid amplification (OSNA) assay. Each of the samples was sectioned serially and evaluated by touch imprint cytology with Pap. staining or ICC staining, and the results were compared with those of the OSNA assay.
Results : There was a statistically significant difference in the concordance rate of cytology between Pap. staining and ICC staining with the results of the OSNA assay for the detection of micrometastases (p<0.001), although there was no significant difference in the concordance rate of cytology between Pap. staining and ICC staining with the results of the OSNA assay for the detection of macrometastases.
Conclusion : Imprint cytology with ICC yields a significantly higher positivity rate than imprint cytology with Pap. staining. Imprint cytology with ICC is practicable for intraoperative evaluation of sentinel lymph node metastases and useful for institutions without facilities for the OSNA assay.