Intraoperative diagnosis of cancer metastasis in sentinel lymph node of oral cancer patients

Sentinel lymph node (SLN) biopsy in the head and neck region is attracting attention. If intraoperative frozen section and/or cytology of SLN is available, one can select an appropriate patient who must undergo neck dissection in a one-stage procedure. We began intraoperative diagnosis of SLN biopsy in patients who underwent oral cancer surgery in 2003. From August 2003 to December 2006, 44 previously untreated patients were accumulated. All patients underwent SLN biopsy prior to the resection of primary cancer. Intraoperative diagnosis of SLN biopsy was performed by multislice frozen section analysis. Patients with positive SLN underwent immediate neck dissection in the same session. Imprint cytology specimen was prepared at the same time. The results of frozen section analysis and imprint cytology were compared with postoperative pathologic diagnosis of permanent specimens. The sensitivity, specificity, overall accuracy, positive and negative predictive value of intraoperative multislice frozen section analysis in lymph node basis were 90.9%, 100%, 99.1%, 100% and 99.0%, respectively. On the other hand, the indexes of imprint cytology were 27.3%, 99.0%, 92.0%, 75.0% and 92.6%, respectively. All indexes of intraoperative frozen section analysis were superior to imprint cytology. In our experience, multislice frozen section analysis surpasses imprint cytology in intraoperative diagnosis of SLN biopsy.