Intraoperative Frozen Section Analysis and an Audit of its Diagnostic Accuracy: A Cross-sectional Study from Maharashtra, India

Abstract

Introduction: Frozen Section (FS) is a diagnostic technique performed intraoperatively to obtain relevant information about the primary diagnosis, margin status, or sentinel lymph nodes, which helps guide the course of surgery. With the prevalent use of FS, it is imperative to recognise and scrutinise its diagnostic pitfalls and make efforts for rectification. Aim: To compare diagnostic results obtained on FS with final paraffin-embedded histopathology and calculate the Diagnostic Accuracy (DA) of FS. Materials and Methods: This cross-sectional study was conducted in the Department of Pathology at a tertiary care hospital, DVVPFs Medical College in Ahmednagar district, Maharashtra, India over a period of two years from January 1, 2020, to December 31, 2021. The diagnosis provided on specimens received for intraoperative FS was compared with the final histopathological diagnosis, considered as the gold standard for the same specimen. The results were categorised as concordant, discordant, and deferred cases. The diagnosis on FS and the final histopathological diagnosis, along with relevant clinical data, were entered into an excel sheet. Further, the DA of FS was calculated. All the discordant cases were analysed. Statistical analysis utilised simple percentage calculations from the excel sheet. Results: A total of 130 cases were analysed using FS, with the most common indication being sentinel lymph node analysis to detect metastatic deposits in 72 (55.4%) cases. Out of the total 130 cases, 119 (91.5%) were concordant, 10 (7.7%) were discordant, and 1 (0.8%) was deferred due to an insufficient specimen. Therefore, the overall DA rate was found to be 91.5% with an error rate of 8.5%. Upon analysis of the 10 discordant cases, the cause of inaccuracy was technical error in 7 (70%) cases and interpretation error in 3 (30%) cases. Conclusion: The DA obtained in the present study was somewhat lower than expected due to technical errors during FS sectioning, leading to artifacts, especially during lymph node processing. Analysis of the discordant cases unveiled this deficit. Therefore, such assessment studies should be performed periodically as they assist in highlighting the shortfalls and provide a plan to boost DA.