ABSTRACT
Posttransplant lymphoproliferative disorder (PTLD) is a proliferation of B-cells associated with Epstein-Barr virus (EBV) infection as a complication of immunosuppression, especially by FK506. We investigated four cases of PTLD which developed either in allografts or in other organs. Case 1 was a 38-year-old woman, who developed monomorphic PTLD in a kidney 7 years and 7 months after renal transplantation. Case 2 was a 37-year-old man, who developed monomorphic PTLD in the right submandibular lymph node 4 months after liver transplantation. Case 3 was a 60-year-old man, who developed monomorphic PTLD in the liver 8 months after liver transplantation. Case 4 was a 2-year-old female child, who developed polymorphic PTLD in the colon, liver, and mesenteric lymph node 10 months after liver transplantation. FK506 was administered to case 4. EBV was identified in the tissues of all cases by immunohistochemistry and/or in situ hybridization.