Persistent active Epstein-Barr virus infection and atypical lymphoproliferation. Report of two cases.

Two cases of what is apparently Epstein-Barr virus (EBV)-associated atypical lymphoproliferation which clinically suggested malignant lymphoma are discussed. Immunohistology revealed polyclonal T- and B-cell proliferation resembling progressive infectious mononucleosis. Giant cell formation and marked plasmacytosis was suggestive of Hodgkin's disease. EBV serology was initially not diagnostic, but during the course of the disease, elevated titers against early antigens and EBV-associated nuclear antigen suggested virus replication. EBV DNA was demonstrated in lymphoid cells of both cases by in situ hybridization. One case progressed to overt monoclonal B-cell malignant lymphoma. Atypical polyclonal lymphoproliferation in persistent active EBV infection may thus be considered a prelymphomatous condition.