In situ hybridization and immunohistochemical study of human papillomavirus infection in adult laryngeal papillomas.

Routinely processed paraffin sections from 20 patients with adult laryngeal papillomas were examined for the presence of human papillomavirus type 11 (HPV-11) DNA and its specific mRNA by in situ hybridization methods using 35S-labeled RNA probes. Immunohistochemical techniques were also used to identify papillomavirus genus-specific common antigen (pgs-antigen). HPV-11 DNA signals and/or papillomavirus genus-specific common antigen were detected in all eight samples of multiple laryngeal papilloma. On the other hand, in 12 samples of single laryngeal papilloma, neither papillomavirus genus-specific common antigen nor HPV-11 DNA were detected. Four patients were positive for both HPV-11 DNA and pgs-antigen. In three of these four patients, HPV-11 mRNA signals were also detected. These results provided direct evidence of the association of HPV and adult multiple laryngeal papilloma.