Oral hairy leukoplakia: a light microscopic and immunohistochemical study.

We compared the light microscopic features and immunoperoxidase staining for human papillomavirus antigen of oral hairy leukoplakia (OHL) and flat condylomatous lesions of the cervix. Our findings support the conclusion that OHL and flat condylomatous lesions of the cervix are not similar morphologically or etiologically. Therefore the term koilocyte seems inappropriate to describe the swollen epithelial cells in OHL. The various diagnostic criteria for a diagnosis of OHL were reviewed. On the basis of the review of our cases of OHL and our review of the literature, we conclude that a definitive diagnosis of OHL requires either the biochemical evidence of Epstein-Barr virus or the ultrastructural demonstration of herpesviruses in suspected lesions.