Comparison of frozen section and touch imprint cytology for evaluation of sentinel lymph node metastasis in breast cancer

Background: Sentinel lymph node metastasis of breast cancer is evaluated by frozen section (FS) or touch imprint cytology (TIC). However, which of the two methods is superior remains controversial. Here we directly compared the sensitivity of these methods prospectively. Methods: The study included 208 SNs harvested from 107 consecutive patients with breast cancer who underwent sentinel lymph node biopsy. SNs were serially sectioned at 2-mm intervals, and two sections were subjected to intraoperative evaluation of FS with hematoxylin and eosin staining. TIC specimens were prepared from all cut surfaces and analyzed by Papanicolaou (TIC) and cytokeratin (TIC with immunohistochemistry; TIHC) immunohistochemistry. Results: Thirty-five SNs from 27 patients were positive by final histopathology. The sensitivity per sentinel lymph node of FS was 89%; it was 86% for TIC and 89% for TIHC. Among 173 negative SNs, the results of FS were concordant with final histopathology, but TIC and TIHC were positive in 1 and 5 histopathology-negative SNs, respectively. The sensitivity per patient of FS was 85%; it was 85% for TIC and 89% for TIHC. Among 80 patients with node-negative disease, the results of FS and TIC were concordant with final histopathology, whereas TIHC was positive in 3 patients (3.8% were upstaged). A slight improvement of sensitivity per patient was achieved by the combination of FS and TIC (to 89%) or FS and TIHC (to 93%). Conclusions: The sensitivity of FS was almost equivalent to that of TIC. TIHC had a better sensitivity than FS and TIC, but it upstaged a few node-negative patients.