Clinico-pathological study to evaluate oral lichen planus for the establishment of clinical and histopathological diagnostic criteria.

OBJECTIVE Lichen planus and lichenoid lesions affecting the oral cavity show similar clinico-pathological features creating a diagnostic dilemma. Hence, the aim of the present study was to establish a clinical and histopathological correlation in the diagnosis of oral lichen planus, based on the modified WHO diagnostic criteria of oral lichen planus and oral lichenoid lesions proposed by Van der Meij and Van der Waal in 2003. MATERIAL AND METHOD In the present study, 100 cases of oral lichen planus were clinically and histopathologically analyzed. Out of the 100 cases, 50 were prospective and 50 were retrospective cases. Prospective cases were collected based on the clinical diagnosis of oral lichen planus and oral lichenoid lesion. Retrospective cases were collected based on the histopathological diagnosis of oral lichen planus. Both the clinical and histopathological analyses were performed based on a proposal for a set of modified diagnostic criteria of oral lichen planus and oral lichenoid lesion. A final diagnosis of oral lichen planus was made only after the correlation of the clinical diagnosis with the histopathological diagnosis. RESULTS The interobserver agreement among three observers for both prospective and retrospective cases in the final diagnosis of oral lichen planus was found to be "good" to "very good" indicating high reproducibility. However, the final diagnoses of true oral lichen planus after clinico-pathological correlation in prospective and retrospective study groups appeared to be 38.0% and 54.0% respectively. CONCLUSION The results of the present study revealed mild to moderate clinico-pathological correlation in the final diagnosis of oral lichen planus for the prospective and retrospective study groups respectively.