Post-transplant lymphoproliferative disorder in view of the new WHO classification: a more rational approach to a protean disease?

Post-transplant lymphoproliferative disorders (PTLDs) are serious, life-threatening complications of solid-organ transplantation (SOT) and bone marrow transplantation leading to a high mortality (30-60%). PTLD represents a heterogeneous group of lymphoproliferative diseases. They become clinically relevant because of the expansion of transplantation medicine together with the development of potent immunosuppressive drugs. Although the diagnostic morphological criteria of different forms of PTLD are commonly known, rapid and correct diagnosis is not always easy. Because of the limited number of clinical trials, a consensus is lacking on the optimal treatment of PTLD. This review focuses on incidence, risk factors, clinical picture of the disease and diagnostic tools including histopathology relating to the new classification introduced in 2008 by the World Health Organisation (WHO) and treatment of PTLD.