Oral wart associated with human papillomavirus type 2.

More than 100 human papillomavirus (HPV) types have been identified to date. Of these, 24 types have been described as being associated with oral lesions. HPV-2 has been frequently associated with skin lesions, but the reports of oral lesions as features of mucosal infection are limited. A biopsy specimen of an oral wart on the right palate was taken from a 48-year-old man and examined for the presence of HPV The sections showed papillary growth of the epithelium with hyperkeratosis and parakeratosis, and koilocytotic changes of the cells located in the upper layers of the oral squamous cell epithelium. These histological features corresponded well to those of verruca vulgaris on the skin. Immunohistochemically, papillomavirus genus-specific capsid antigen was detected in most of the koilocytotic cells. In addition, Southern blot hybridization analysis revealed that the lesion harbored HPV-2 DNA. In situ hybridization with a biotinylated HPV-2 DNA probe clearly demonstrated viral DNA in the nuclei of squamous cells, which were located in a deeper layer of the epithelium than viral antigen-positive cells.