Abstract
An autopsy case of CD8+ T cell lymphoma after allogenic transplantation of peripheral blood stem cells (PBSC) is presented. A 57-year-old man was first diagnosed with diffuse large B cell lymphoma (DLBCL) based on a biopsy of an inguinal lymph node. The disease progressed with poor response to chemotherapy, and pathological diagnosis was reviewed. The revised diagnosis was angioimmunoblastic T-cell lymphoma (AITL) with secondary development of Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL). The patient died 114 days post-allogenic hematopoietic stem cell transplantation (allo-HSCT) and an autopsy was performed. EBV-positive CD8+ cells were systematically observed in organs, including the liver, spleen, gastrointestinal tracts, and lungs. Liver injury was also apparent with sinusoidal obstruction syndrome (SOS) / veno-occlusive disease (VOD), causing splenomegaly. Southern blot analysis of peripheral blood cells revealed the presence of monoclonal EBV DNA, indicating monoclonal expansion of EBV-positive CD8+ cells.
The present case uniquely displayed EBV-positive T-cell post-transplant lymphoproliferative disorder (PTLD), with monoclonal expansion of CD8+ cells. Although its pathophysiology is not fully understood, this is a typical and precious case of posttransplant EBV-positive T-cell lymphoma, designated in the upcoming WHO classification of haematolymphoid tumours, 5th edition.