Rate of Diagnostic Change in Surgical Pathology Reports after Mandatory Intradepartmental Peer Review in a Tertiary Hospital in the Philippines: A Retrospective Study.

Objective: There is a mandatory intradepartmental peer review algorithm in the University of the Philippines - Philippine General Hospital (UP-PGH) Department of Laboratories wherein specific cases are required to be reviewed by another pathologist before the release of results. The main objective of this study was to determine the rate of diagnostic change in surgical pathology reports after undergoing the said review.

Methods: All surgical pathology cases which underwent the review from 2015 to 2018 were retrieved from the records of the Section of Surgical Pathology. The cases were classified as concordant or discordant. A case was considered concordant if the reviewing pathologist had agreed with the primary pathologist's diagnosis. A case was considered discordant if the reviewing pathologist had disagreed with the primary pathologist's diagnosis.

Results: Out of 5,377 cases included in this study, there were 5,209 concordant cases and 168 discordant cases, with the rate of discordance computed to be 3.1%. Out of the 168 discordant cases, 107 were revised for diagnostic change. Rate of diagnostic change was computed to be 2.0% (107 out of 5,377 cases for review). The most common criterion satisfied for meriting a mandatory review is being under the category of biopsies or cytology cases with malignant or borderline diagnoses (49.4%). The most common category of diagnostic change is change in immunohistochemistry recommendations (24.3%). Most of the discordant cases and cases revised for diagnostic change fall under the categories of gastrointestinal, gynecology, and head & neck pathology.

Conclusion: The low rate of diagnostic change in our institution might be attributed to good diagnostic accuracy. However, it is also possible that reviewing pathologists tended to agree with the diagnosis made by their colleagues because of the element of peer pressure. Data from the study may imply that special courses/ lectures or institutional standard practice guidelines on interpreting biopsy and cytology cases as well as on the utility of immunohistochemistry studies, especially those focused on gastrointestinal, gynecology, and head & neck pathology are needed by the pathologists and the doctors training to become pathologists in our institution.