Demonstration of Epstein-Barr virus in carcinomas of various sites.

EBV is an etiological agent in infectious mononucleosis, is implicated in some malignant lymphomas and lymphoepithelioma-like carcinomas, and has been sporadically reported in carcinomas of the breast, lung, and other sites. We studied immunohistochemically benign and malignant tumors of the breast, lung, colon, and prostate and found EBV in some carcinomas of those sites. Also, EBV reactions were noted in hyperplasias and dysplasias, e.g., breast carcinomas in situ and prostatic intraepithelial neoplasia. Benign tumor counterparts were negative. PCR analysis of selected cases confirmed the presence of EBV. Our results suggest that EBV is not restricted to lymphoepithelioma-like carcinomas but may play an oncogenic role in frequent epithelial cancers and possibly also in hyperplasias and certain dysplasias preceding carcinomas.