Intraoperative cytologic diagnosis of sentinel node metastases in breast cancer.

Objective: To clarify the usefulness of imprint cytology for intraoperative investigations of sentinel lymph nodes in breast cancer, comparing the results with those of examinations using frozen and permanent sections.

Methods: The material consisted of 303 sentinel lymph nodes from 124 cases of clinically node negative breast cancer. Touch imprint cytologic slides and frozen sections were obtained from the same cut surface of the sentinel nodes. Correlations with the final histopathologic results in paraffin sections were evaluated.

Results: The sensitivity, specificity and accuracy of imprint cytology were 70.3%, 99.6% and 96.0%, and those of frozen sections were 83.8%, 100%, 98.0%, respectively. The values were improved when the 2 methods were combined (89.2%, 99.6%, 98.3%), though the concordance between imprint cytology and frozen section was 91.9%.

Conclusions: Both imprint cytology and frozen section are useful for evaluating sentinel lymph node status in breast cancer. However, the 2 techniques should be combined to improve the diagnostic sensitivity.