Evaluation of formalin-fixed paraffin-embedded tissues from vaccine site-associated sarcomas of cats for papillomavirus DNA and antigen

Objective—To determine whether vaccine site-associated sarcomas (VSS) from cats contain papillomavirus antigen or DNA. Sample Population—50 formalin-fixed paraffinembedded tissue blocks of VSS from cats. Procedure—Sections from each tissue block were evaluated for papillomavirus antigen by use of an avidin-biotin-complex immunohistochemical staining method, using rabbit anti-bovine papillomavirus type-1 antibody. The DNA was extracted from sections of each tissue block, and polymerase chain reaction assays were performed, using primers designed to amplify regions of the E5 gene of bovine papillomavirus and consensus primers designed to amplify a region of the L1 gene of animal papillomaviruses. Sections from 20 of the tissue blocks were evaluated by use of nonradioactive in situ hybridization for bovine papillomavirus DNA. Results—Papillomavirus antigen and DNA were not detected in any of the VSS. Conclusions and Clinical Relevance—Results suggest that papillomaviruses likely do not have any direct involvement in the pathogenesis of VSS in cats.