[Follicular splenic lymphoid hyperplasia associated with EBV infection].

Massive splenomegaly is defined as a spleen weighing about 10 times normal weight. We describe a 36-year-old man who had huge splenomegaly and secondary pancytopenia simulating malignant lymphoma for about 3 months. Splenectomy was necessary because of the suspicion of hematologic malignancy, especially isolated lymphoma of the spleen, and pain and mechanical abdominal disturbances. On operation, the spleen was 25 cm long and weighted 250 g. There was florid, reactive follicular lymphoid hyperplasia. Immunohistochemical staining with CD-20(L26), CD-45Ro(UCHL), bcl-2 oncoprotein (Dakopatts), EBV (anti-EBV mol weight 60 KD, Dakopatts) was consistent with reaction to EBV infection and not with follicular lymphoma. Lack of PCR amplification using DNA extracted from paraffin-embedded splenic tissue indicated absence of a monoclonal B cell population carrying rearranged immunoglobulin genes. The lymphocytic population was proven polyclonal by the negative results of PCR for the bcl-2 gene rearrangement. EBV seroconversion from high titer antibodies of anti-EBV-VCA-IgM to negative, and from negative EBNA to positive was consistent with an apparent primary EBV infection. We have not found on computerized search a previous report of reactive follicular splenic hyperplasia to EBV infection causing huge splenomegaly, with or without EBV-induced infectious mononucleosis.