Epstein-Barr virus infection and the pathogenesis of nasopharyngeal carcinoma: viral gene expression, tumour cell phenotype, and the role of the lymphoid stroma.

Nasopharyngeal carcinoma (NPC) is the human tumour showing the most consistent association with Epstein-Barr virus (EBV). The recent detection of EBV in in-situ NPC lesions has shed light on the sequence of events leading to the development of invasive NPC, and will be discussed in the context of what is known about EBV infection in non-neoplastic epithelial cells. The association of EBV with different histotypes of NPC will also be considered. EBV gene expression and NPC tumour cell phenotype will be discussed, and evidence will be presented suggesting that the lymphoid stroma characteristically found in undifferentiated NPC is a prerequisite for the development of this tumour.