Identifying factors associated with diagnostic concordance/discordance in oral lichen planus.

PURPOSE To identify factors associated with concordance and discordance between clinical and histopathologic diagnoses of oral lichen planus lesions. MATERIALS AND METHODS A retrospective analysis was conducted on all study cases derived from archival oral pathology reports generated from all cases of oral lichen planus accessioned by the Faculty of Dentistry, University of Malaya. These study cases were diagnosed from January 1980 through December 2010. Predictor variables were diagnosis year, demographics, experience of the examiner, clinical appearance and diagnosis, and final histopathologic diagnosis; these were recorded for each study case. The outcome variable was agreement between the clinical and histopathologic diagnoses, and this was classified as concordant or discordant. Descriptive statistics and multiple linear regression analyses were computed to identify associations between predictors and outcomes. Statistical significance was set at P ≤ .05. RESULTS The sample was composed of 441 study cases with 593 oral mucosal lesions that met the inclusion criteria. The mean age of the sample was 47.5 ± 13.07 years (range, 12 to 82 yr) and 64.4% were female. The mean concordance was 83.2%. Diagnosis year and demographics showed no influence on concordance or discordance. The multiple linear regression model included experience of the examiner, clinical appearance and diagnosis, and final histopathologic diagnosis (R(2) = 0.82). Except for experience of the examiner (P = .12), clinical appearance and diagnosis and final histopathologic diagnosis were the variables statistically associated with concordance (P ≤ .01). CONCLUSIONS The present results suggest that concordance is governed primarily by the clinical appearance and diagnosis of the lesion and the final histopathologic diagnosis.