Post-transplant malignant lymphoma with monoclonal immunoglobulin gene rearrangement and polyclonal Epstein-Barr virus episomes

This report describes the case of an 8 year old boy who developed ileocecal B cell lymphoma after liver transplantation. The patient underwent orthotr opic liver transplantation for biliary atresia and had been given immunosup pressive drugs-cyclosporin A and tacrolimus hydrate. Six years after the li ver transplantation, the patient had a sudden onset of fever and abdominal pain. Necropsy revealed an ileocecal mass that was a B cell lymphoma. Epste in-Barr virus (EBV) encoded RNA I was demonstrated in lymphoma cells and hy perplastic follicular germinal centre cells in various tissues. Although mo noclonal immunoglobulin gene rearrangement was detected in the liver, EBV e pisomes were of polyclonal origin and lytic forms of EBV were also demonstr ated by Southern blotting. lmmunohistochemically, lymphoma cells were posit ive for p53 but negative for latent membrane protein 1 and EBV nuclear anti gen 2. These findings suggested that this B cell lymphoma might have occurr ed sporadically, regardless of EBV infection.