[Demonstration of DNA tumor viruses in carcinomas of the upper respiratory tract].

In situ hybridization (ISH) using 35S-labeled probes was applied to the detection of viral DNAs in 115 epithelial tumours from various sites. Epstein-Barr virus (EBV) DNA was detected in 83% of undifferentiated nasopharyngeal carcinomas (NPC) while none of seven squamous cell NPC displayed an EBV-specific autoradiographic signal. Also, all other tumours investigated, including thymomas, thymic carcinomas, tonsillar carcinomas and medullary breast carcinomas were negative upon ISH to EBV-specific probes. These results suggest a unique association of undifferentiated NPC with EBV. 28 tonsillar carcinomas were further analyzed for the presence of human papillomavirus (HPV) DNA. Six carcinomas showed an HPV16-specific signal while hybridization to HPV6- and HPV11-specific probes yielded negative results. No HPV-DNA was detected in any of 30 tonsils with chronic inflammation, thus excluding that the finding of HPV16 in a proportion of tonsillar carcinomas is merely circumstantial. These results point to a possible etiologic role of HPV16 in the pathogenesis of some tonsillar carcinomas.