Use of Intraoperative Frozen Section during Mediastinoscopy

Introduction: Staging of mediastinal lymph nodes (MLN) by mediastinoscopy can be of critical importance in assessing candidacy for lung resection. Mediastinoscopy is often performed as a sole procedure, with permanent pathology results guiding subsequent intervention. Our practice has been to perform mediastinoscopy followed by immediate surgical resection, as indicated, based on intraoperative frozen section (FS) assessment. The goal of our review is to evaluate the reliability of FS when compared to permanent section (PS) and to investigate any discordant findings. Materials and methods: A retrospective review of patients with lung cancer that underwent mediastinoscopy from June 2006 to January 2011. All received clinical staging according to NCCN guidelines and were considered potential candidates for surgical resection. Results for FS and PS of MLN were assessed. Results: Staging mediastinoscopy was performed on 191 patients, with a total of 549 MLN undergoing FS and PS analysis. Concordance between FS and PS was found in 545 MLN (99.3%). Discordance was found in 4 MLN (0.7%), each in a different patient. All 4 discordant MLN were initially negative on FS and then found to be positive on PS. Overall accuracy of FS analysis for detecting all malignancy was 97.9%, with 94.3% sensitivity, 100% specificity, 96.7% negative predicted value, and 100% positive predicted value. Conclusion: Our data suggest that for lung cancer patients with potentially resectable tumors, immediate FS analysis of MLN followed by definitive surgery is a reliable and safe strategy. Discordance with final pathology was rare (0.7%) and resulted in improper staging in 1 (0.5%) patient. Advantages of this “fast-track” approach include less medical costs and hastening of time from diagnosis/staging to definitive treatment.