Distinctive distribution of human papillomavirus type 16 and type 20 DNA in the tonsillar and the skin carcinomas of a patient with epidermodysplasia verruciformis

Background Epidermodysplasia verruciformis (EV) is a rare skin disease characterized by disseminated pityriasis versicolor-like or flat wart-like lesions and by the development of skin carcinomas. It is well established that specific cutaneous human papillomaviruses (EV-HPVs) are associated with both benign and malignant skin lesions in EV patients. However, little is known of the relationship between HPV and the mucosal lesions of EV patients. Objectives To detect and identify HPV types associated with skin and mucosal lesions of an EV patient. Patient/methods We investigated the skin carcinoma and the coexisting tonsillar carcinoma of a 41-year-old man with EV. Histopathologically, both lesions were squamous cell carcinomas. We analysed these two lesions by immunohistochemistry, in situ hybridization, and by molecular virology. Results Neither skin nor tonsillar lesions exhibited positivity for HPV capsid antigen by immunohistochemistry. By Southern blot hybridization, however, the skin carcinoma harboured 'EV-specific' HPV20 DNA, while the tonsillar carcinoma harboured 'genital' HPV16 DNA. In addition, in situ hybridization localized the respective viral DNA in the corresponding lesion. Conclusions The results indicate that EV-HPV could be responsible for the development of the skin carcinoma, but not the mucosal carcinoma in this patient.