A histologic study of epithelial dysplasia in oral lichen planus.

One hundred cases of oral lichen planus were reviewed together with 100 nonspecific oral mucosal inflammatory lesions as a control group. The presence of dysplasia was noted, using well-established histologic criteria. Mild dysplasia was found in 57% of cases, moderate dysplasia in 9%, and severe dysplasia in 2% of cases. In the control group, mild dysplasia was observed in 32% of cases, moderate in 10%, and severe dysplasia was not present. It is suggested that, while mild or moderate dysplasia may not indicate precancerous potential, severe dysplasia in lichen planus may signify the development of a precancerous lesion.