Surgical Pathology and Intraoperative Consultation: An Audit

Background: While intraoperative consultation has been used in Bangladesh for a long period of time, to date, there has been no published reporting on the performance of frozen sections. The current audit evaluates the performance of frozen sections in a well reputed medical center in Bangladesh, Anowara Medical Services.
Objective: This retrospective study has been designed to measure the accuracy of frozen section diagnosis in a medical center in a third-world country, where many surgical procedures rely on intraoperative consultation.
Methods: A series of 1379 intra- and peri-operative frozen section cases, from 2007 to 2014, was reviewed. Intraoperative tissue specimens received at Anowara Medical Services were processed for frozen sections. After examination of the frozen section that yielded the initial frozen section diagnoses, the frozen tissues were reprocessed for regular paraffin sectioning. These paraffin sections were examined by a second pathologist, and a final diagnosis was issued. The frozen section diagnosis and final diagnoses of all cases were retrospectively analysed to determine the accuracy of frozen section examination.
Results: Overall, accurate diagnosis was made on frozen sections in 98.2% of the cases. The discrepant diagnoses were all clinically significant, i.e., there were discrepancies between benign and malignant diagnoses on frozen and paraffin sections. In 1% of the cases, diagnosis was deferred. Fifty percent of the deferred cases were benign. Two cases, received in formalin, were excluded. In both cases, the diagnosis was positive for malignancy. The number of false negative results (4 false negatives) was slightly lower than that of false positives (5 false positives). Specificity and sensitivity of 99.3% and 99.4% were achieved, respectively. In this study, the positive predictive value was 99.2% and the negative predictive value was 99.5%. Over the years, the number of discrepant diagnoses remained fairly constant.
Conclusion: The present method has a satisfactory rate of accuracy of frozen section diagnosis, which is comparable to other remote and recent published series. The results of this study offer a testament to the reliability of frozen section diagnosis rendered by qualified pathologists in Bangladesh and may serve as evidence in building confidence among the surgeons who use this service for improved patient care.