Intraoperative sentinel lymph node examination by frozen section, immunohistochemistry and imprint cytology during breast surgery--a prospective study.

The aim of this study was to compare the sensitivity of intraoperative frozen section with hematoxyllin-eosin (H&E) staining, immunohistochemistry (IHC) or imprint cytology (IC) in the analysis of sentinel node (SN) in breast cancer. Towards this end, a prospective study of 102 patients undergoing mastectomy or sector resection with SN biopsy was conducted. Frozen sections of SN with H&E, IHC staining and IC had sensitivities of 73.5%, 75.5% and 51.0%, respectively. The combination of H&E and IHC raised the overall sensitivity to 83.7%. Macrometastases (>2 mm) were detected in 100% of the cases with H&E, 92.6% with IHC and 81.5% with IC; and micrometastases (2 mm) in 35.0%, 45.0% and 5.0%, respectively. The combination of H&E and IHC staining raised the sensitivity to 55.0%. Frozen-section analysis with H&E staining showed high sensitivity in detecting macrometastases but not micrometastases. The sensitivity for detection of micrometastases was not substantially increased by the use of intraoperative IHC. Imprint cytology did not provide any additional information.