Objective To detect whether Epstein Barr virus (EBV) harbors in nasopharyngeal lymphoid hyperplasia (NPLH) which is frequently to be seen in Guangzhou, a high incidence area of nasopharyngeal carcinoma (NPC), and to explore the relation between NPLH and development of NPC Methods Twenty four 10% formalin fixed, paraffin embedded biopsies oef patients with NPLH and elevated serum IgA antibody titer (≥1∶20) against viral capsid antigen of EB virus (IgA/VCA) were collected from the archives of the Department of Pathology, Sun Yat sen University of Medical Sciences during the period of January to June, 1993 PCR plus Southern blotting hybridization for detection of EBV DNA W fragment and in situ hybridization for detection of EB virus encoded small RNAs (EBERs) were performed All the patients were followed up more than 5 years Results Twenty two of 24 (91 7%) NPLH tissues contained EBV DNA A few definitely EBERs positive B lymphocytes could be found in 17 out of 24 specimens (70 8%) Neither NPC nor any EBV associated malignancies were developed in all of these 24 patients up to date Conclusion Most of the NPLH tissues taken from the patients with an elevated serum IgA/VCA titer carry EBV, which is harbouring in the nuclei of a few infiltrating and hyperplastic B lymphocytes The NPLH without epithelial dysplasia can not be recognized as a precancerous lesion, and EBV infection in these lesions is not an important event, having no substantial significance in development of NPC Objective To detect whether Epstein Barr virus (EBV) harbors in nasopharyngeal lymphoid hyperplasia (NPLH) which is frequently to be seen in Guangzhou, a high incidence area of ​​nasopharyngeal carcinoma (NPC), and to explore the relation between NPLH and development of NPC Methods Twenty four 10% formalin fixed, paraffin embedded biopsies oef patients with NPLH and elevated serum IgA antibody titer (≥1: 20) against viral capsid antigen of EB virus (IgA / VCA) were collected from the archives of the Department of Pathology, Sun Yat sen University of Medical Sciences during the period January to June, 1993 PCR plus Southern blotting hybridization for detection of EBV DNA W fragment and in situ hybridization for detection of EB virus encoded small RNAs (EBERs) were performed All the patients were followed up more than 5 years Results Twenty two of 24 (91 7%) NPLH tissues contained EBV DNA A few definitely EBERs positive B lymphocytes could b e found in 17 out of 24 specimens (70.8%) Neither NPC nor any EBV associated malignancies were developed in all of these 24 patients up to date Conclusion Most of the NPLH tissues taken from the patients with an elevated serum IgA / VCA titer carry EBV, which is harboring in the nuclei of a few infiltrating and hyperplastic B lymphocytes The NPLH without epithelial dysplasia can not be recognized as a precancerous lesion, and EBV infection in these lesions is not an important event, with no substantial significance in development of NPC