Human papillomavirus in squamous cell carcinoma, leukoplakia, lichen planus, and clinically normal epithelium of the oral cavity.

Tissue specimens of carcinoma, leukoplakia, and clinically normal epithelium obtained at sites separate from the lesions were examined for the presence of human papillomavirus (HPV). Twenty-two paraffinized specimens of previously diagnosed oral lichen planus were also studied. The carcinoma and leukoplakia specimens were examined by Southern transfer hybridization and reverse blot hybridization; specimens HPV-positive by Southern hybridization were additionally examined by in situ hybridization and an immunoperoxidase technique. The lichen planus specimens were examined by in situ hybridization and immunoperoxidase techniques only. The HPV identification rates were in the range reported in previous studies, and the detection rates were similar for carcinoma, leukoplakia, histologically normal epithelium, and lichen planus. The clinical significance of HPV presence in carcinoma, leukoplakia, and lichen planus was not evaluable because of the short duration of follow-up.