Résumé
Purpose To investigate the relationship between Epstein-Barr virus (EBV) and lymphoepithelioma-like carcinoma (LELC) of the parotid gland and detect the gene expression products of EBV harbouring in LELC cells. Methods Thirty-two parotid LELCs were collected from the Departments of Pathology, Sun Yat-sen University of Medical Sciences, Guangzhou, China during the period of January 1986 and December 1995. All the 32 formalin-fixed paraffin-embedded blocks had been consecutively re-sectioned again. Immunohistochemical and in situ nucleic acid hybridization methods for detection of EBV gene encoded products were performed. Results (1) 32 LELCs were found out of 125 parotid gland carcinomas, the frequency was 25.6% (32/125). (2) All of the 32 specimens contained a variable number of EBNA-1 and EBERs positive neoplastic cells. (3) Twenty-seven out of 32 specimens (27/32, 84.4%) had a portion of carcinoma cells expressing LMP-1. (4) No ZEBRA positive cell could be found. (5) EA-D, VCA and MA positivity rates for these 32 parotid LELCs reached to 71.9%(23/32), 68.8%(22/32), and 12.5%(4/32), respectively. Conclusions (1) The parotid gland LELC is frequently to be seen in Guangzhou locale of China, where is a high-incidence area of nasopharyngeal carcinoma (NPC). The parotid gland LELC and NPC are co-prevalent in Guangzhou locale. (2) This disease is also consistently associated with EBV infection. (3) The EBV infection of the parotid gland LELCs is essentially the type of latency Ⅱ, expressing EBNA-1, EBERs and LMP-1. (4) The latent infected EBV harbouring in LELC cells could in part be switched over to lytic cycle, producing EA-D, VCA or/and MA.