Quality assurance of histopathologic diagnoses: a prospective audit of three thousand cases.

The purpose of this study was to examine a system of quality assurance in which microscopic slides from all surgical cases were subject to peer review before completion of the final pathology report. Three thousand surgical pathology cases were evaluated and the diagnoses entered on preliminary diagnosis sheets. Microscopic slides were reviewed and coded reviewer opinions entered on photostatic copies of preliminary diagnosis sheets. Reviewer comments were incorporated into the final pathology reports at the discretion of the responsible pathologist. Two hundred thirty-three (7.8%) cases were identified in which at least one reviewer disagreed with the preliminary diagnosis; in 67 of the 233 cases (2.2%) the final diagnosis was modified as a result of the review process. Changes in final diagnoses were judged to be significant in 29 (0.96%) cases. These results suggest that systematic review of surgical pathology diagnoses prior to preparation of final pathology reports may be a useful tool in assuring quality and consistency in diagnoses.