Epithelial dysplasia in oral lichen planus. A preliminary report of a Dutch-Hungarian study of 100 cases.

In a combined study of the Free University, Amsterdam and the Semmelweis Medical University, Budapest, the presence of epithelial dysplasia was studied in 100 cases of oral lichen planus. The criteria of epithelial dysplasia which were used in this study correspond with those reported by the WHO Collaborating Centre for Oral Precancerous Lesions in 1978. In approximately 25% of all cases, moderate or at least mild dysplasia was observed. The number of dysplastic changes per section did not show any significant correlation with the clinical type, nor with age or sex. There were no marked differences between the Amsterdam and Budapest material. Long-term data on the follow-up were not available yet. No comment can therefore be given about the meaning of the finding of epithelial dysplasia in lichen planus being a sign of premalignancy or not.