Objectives: Pathologists differ in their definition of "dysplasia." This study was done to test the hypothesis that experienced oral pathologists are consistent in diagnosing epithelial dysplasia.
Study design: Six board-certified oral pathologists examined 120 oral biopsies exhibiting simple hyperkeratosis to severe dysplasia. No clinical information was given, and presence of dysplasia was judged by histomorphology. Examiners' diagnoses were compared with sign-out diagnoses for each case. Months later, each examiner viewed 60 relabeled slides from the original 120. Each diagnosis was compared with the diagnosis in the first round.
Results: Exact agreement with the sign-out diagnosis averaged 50.5% (within one histologic grade 90.4%). Examiners agreed exactly with their own diagnoses 50.8% of the time (within one histologic grade 92.4%). Agreement distinguishing dysplasia from no dysplasia compared with original sign-out diagnosis was 81.5%. Agreement with themselves distinguishing dysplasia from no dysplasia was 80.3%.
Conclusions: Accurate reproducible agreement among experienced board-certified oral pathologists diagnosing oral epithelial dysplasia is difficult to achieve.