Concordance of Intra-Operative Frozen Section Consultation with Final Histopathology Interpretations of Surgical Specimens: A Retrospective Analysis.

Introduction: Intraoperative frozen section (IFS) consultation provides rapid histological assessment during surgery and can guide decisions regarding tumour diagnosis, margin status, metastasis, and other clinically relevant pathological findings. This retrospective study evaluated concordance between IFS consultation and final histopathology for surgical specimens at the University Malaya Medical Center (UMMC). Methods: A total of 109 IFS cases performed from January to December 2022 were reviewed. Concordance was defined as agreement between the IFS interpretation and final histopathology for the principal intraoperative diagnostic question, with final formalin-fixed paraffin-embedded histopathology used as the reference standard. Diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results: Of 109 cases, 106 (97.2%) were concordant, and three (2.8%) were discordant; all discordant cases were false negatives. Diagnostic accuracy was 97.2% (95% confidence interval [CI], 92.2%-99.4%), sensitivity was 89.7% (95% CI, 72.6%-97.8%), specificity was 100% (95% CI, 95.5%-100%), PPV was 100% (95% CI, 86.8%-100%), and NPV was 96.4% (95% CI, 89.8%-99.2%). Among the three discordant cases, two were attributed to interpretation errors and one to a technical error. Conclusions: IFS consultation demonstrated high concordance and diagnostic accuracy in this study. However, false-negative results remain possible, particularly in head-and-neck and lymph node specimens, emphasizing the importance of representative tissue sampling, optimal section quality, and cautious interpretation in minimizing discordant results. Continued institutional audit is recommended to support ongoing quality improvement.