EBV infection induced transformation of benign T lymphoproliferative statein patient with chronic active EBV infection into malignant lymphoma: implication of EBV infection as additive oncogenic factor in tumorigenesis

An 11-year-old girl with chronic EBV (Epstein-Barr virus) infection, who la ter developed malignant lymphoma in the lung, is reported. She had an incre ased number of V alpha 2, V beta 8, CD3, CD4, and HLADR positive activated lymphocytes (20-30% of total lymphocytes) in peripheral blood. One year lat er, she developed lymphoma in the lung, which was V alpha 2, V beta 8, CD3, CD4, HLADR and IL2R beta positive. At that time, the population in the per ipheral blood increased up to 40%, but there was no evidence of lymphoma in the bone marrow. In situ hybridization revealed lymphoma cells were EBER-1 positive but gp350/220 and LMP mRNA negative. The EBV genome was detected in the tumor, but not in the peripheral T cells. Clonal analysis of the lym phoma cells revealed monoclonal rearrangement of the TcR beta and gamma gen e, however, investigation of the terminal repeat of EBV gene did not show t he monoclonal pattern. These results indicate that infection of EBV into cl onally activated T cells was related with transformation from benign lympho proliferative disease to malignant lymphoma in this patient. (C) 1999 Elsev ier Science Ltd. All rights reserved.