In the new World Health Organization (WHO) classification of malignant lymphoma, anaplastic large cell lymphoma of B-cell phenotype is classified either as the anaplastic large cell variant of diffuse large B-cell lymphoma or as Hodgkin's lymphoma. A 71-year-old Japanese man developed fever and generalized lymphadenopathy. Biopsy of the right axillary node revealed morphology of malignant lymphoma in which large cells with abundant cytoplasm and pleomorphic nuclei were scattered among small lymphocytes. Immunostaining with various monoclonal antibodies revealed the large cells to be CD79+, CD20/L26+, CD45RO/UCHL-(1-), CD3-, CD10-, CD30+, NPM/ALK-, EMA-, CD15-, and bcl-(2-). Amplification of the J region of the immunoglobulin heavy chain by polymerase chain reaction revealed a single rearranged band. Therefore the diagnosis of anaplastic large cell variant of diffuse large B-cell lymphoma, stage IIIB, was made from the standpoint of the new WHO classification of malignant lymphoma. Biopsy led to findings of Epstein-Barr virus (EBV)-associated lymphoma with positive in situ hybridization results for EBV small RNAs, positive results of immunostaining with EBV latent membrane 1 antibody, and negative results of immunostaining with Epstein-Barr nuclear antigen 2. Results of immunostaining of the mass with p53 antibody also were positive for lymphoma cells. The findings in this case may suggest a close relationship between p53 expression and latent EBV infection.