An eight year review of intraoperative frozen section diagnoses and its limitations

Abstract

Background: Frozen section consultation (FS) is an integral part of surgical pathology to aid surgical colleagues in making an intraoperative management decision. This audit reviews the performance of FS diagnoses in a tertiary teaching hospital. Objective: To perform an 8-year retrospective review analysing the concordance rate of FS compared with the final diagnosis on paraffin-embedded sections. Methods: 2013 cases were received for FS from 1 January 2011 to 31 December 2018, comprising 3503 specimens. The patient’s age, sex, specimen type, indication of the FS and the year performed were recorded. The diagnoses between FS and paraffin section were compared, especially for the discrepant cases. Results: Of the 3503 specimens, 3288 results were concordant (93.86%). The major discordances occurred in 66 incidences (1.88%), the minor discordances in 68 specimens (1.94%) and the diagnoses were deferred in 81 cases (2.31%). Further analyses were performed on the major discordances. The true diagnostic error was seen in 26 specimens. Twenty-one incidences were due to undersampling, 17 specimens as a result of technical error and 2 specimens were difficult cases requiring specialist referral. Conclusion: This audit addresses the diagnostic performance of intraoperative consultation and explores ways to minimise error when utilising this method.