Cancers related to viral agents that have a direct role in carcinogenesis: pathological and diagnostic techniques.

The International Agency for Research on Cancer has recently reassessed the carcinogenicity of the biological agents classified as 'carcinogenic to humans'. Among the biological agents having a direct role in carcinogenesis, Epstein-Barr virus, Kaposi's sarcoma-associated herpes virus and human papillomavirus contribute to a variety of malignancies worldwide in humans including nasopharyngeal carcinoma, several types of lymphomas, genital tract carcinomas and Kaposi's sarcoma. The authors review the current knowledge on cancers that have been attributed to Epstein-Barr virus, Kaposi's sarcoma-associated herpes virus and human papillomavirus looking at the pathological classification of these cancers and description of the implicated viruses, highlighting a wide range of pathological and virological diagnostic techniques. This review also focuses on the new oncological scenario ahead, once strategies against carcinogenic infectious agents are found to be effective.