B cell Nearly 1 to 20% of people who receive a solid organ transplant develop a lymphoma. - Lymphomas have also been repoed (though less .frequently) after bone-marrow transplants .for other disorders. Why does it happen? - Post-transplant lymphomas are almost always related to infection by the Epstein Barr Virus (EBV). - Infection by the Epstein Barr Virus causes a transformation of B-cells which becomes cancerous. In normal individuals other cells of the immune system can tackle the EBV infection, but for organ transplants high doses of drugs that suppress the immune system must be administered. With nothing to control the infection, the chances of developing lymphomas increase. The two main factors that determine the chances of getting lymphoma are: How much immunosuppressive treatment is required - The more the immunosuppression, the more the chances of EBV infection. The status of EBV serology of the recipient of the transplant - If this individual has previously been infected by EBV the chances are that the body remembers the infection and the blood already has called antibodies that can identify and kill the virus. Clinical features Post-transplant lymphomas are usually different .from the usual Non-Hodgkin lymphomas. While most patients have involvement mainly of lymph nodes, other organs are very commonly affected as well. These include the brain, lungs and the intestines. The transplanted organ can also get involved. Treatment Whenever possible, immunosuppressive treatment has to be reduced or stopped. In those who have small and localized disease, surgery or radiation may be attempted. If not, the first line of treatment is usually Rituximab, a monoclonal antibody that specifically targets lymphoma cells. Only when this. fails is chemotherapy attempted. Chemotherapy is deferred until necessary as in paially immunosuppressed individuals, chemotherapy may fuher increase the risk of infections. In those who develop lymphomas after bone marrow transplants, donor leukocyte transfusions can be highly effective. Prognosis of Post transplant lymphomas In general, non-Hodgkin lymphomas occurring after organ transplants have a poorer outcome than other NHLs. Around 60-80% of the victims ultimately succumb to their lymphoma. Involvement of brain has poor prognosis