Posttransplant lymphoproliferative disorder （PTLD） is a well-known complication of both solid organ and bone marrow transplantation, with a prevalence estimated to be between 1% to 20% depending on the type of organ transplanted. PTLD includes a wide spectrum of proliferative changes ranging from reactive hyperplasia, borderline lesions, to malignant lymphomas. Several factors, such as the clinical immunosuppressive regimen, infection of the Epstein-Barr virus, and underlying disease in the patient are believed to contribute to the development of PTLD.