The Accuracy of Intraoperative Pathological Consultation; A Five Years Experience (2006-2010) in Thammasat Hospital

Abstract

Objective: To evaluate the accuracy of frozen section and review the causes of discordance cases in various anatomical sites in Surgical Pathology Lab of Thammasat university hospital.

Method: We conducted a retrospective study from computerized database of all frozen section diagnoses, which performed between January 2006 and December 2010. These diagnoses were compared to final diagnoses obtained from permanent sections, the tests were divided into three groups: inconclusive (defer), concordance and discordance. The accuracy, sensitivity, specifi city, positive predictive value and negative predictive value were studied.

Results: The frozen sections were performed on 154 cases, of which 145 cases (94.16%) were concordance, 5 cases (3.24%) were discordance and 4 cases (2.6%) were inconclusive. The most frequent specimen submitted for frozen tests was breast tissue. The main indication was to evaluate the presence and categorization of neoplasm (66.23%).The reasons for discordance were due to freezing artifact, distorted/fi brotic lesion crush artifact and tissue sampling error. The overall accuracy of diagnosis was 96.67%. The sensitivity was 96.59%. The specifi citywas 96.77%. The positive predictive value was 97.7%. The negative predictive value was 95.23%.

Conclusion: The frozen section service of Thammasat university hospital is considerably comparable in accuracy to previous various type of tissues. The discordance of diagnoses when compared to permanent sections was due to various type of tissues and sampling errors. The awareness of these limitations among pathologist and surgeons with periodic monitoring should lead to the improvement of frozen sections service in our institute.

Key words: Frozen section, Intraoperative consultation, Accuracy