Differentiation of EBV-induced post-transplant Hodgkin lymphoma from Hodgkin-like post-transplant lymphoproliferative disease.

The development of lymphomas after SOT is a well-known complication of the immunosuppressive therapy necessary to prevent graft rejection. Epstein-Barr virus plays a central role in the pathogenesis of lymphomas because of its ability to transform infected cells. Differentiating PTLD from malignant lymphomas, especially HL can be challenging. We report on two patients, who developed EBV-associated lymphomas several years after SOT. A histological examination of lymph nodes led to a diagnosis of HL in both patients, who were started on chemotherapy according to current treatment protocols. A rapid and complete remission in one patient prompted us to analyze the expression pattern of EBV-latency genes. In this patient, the EBV expression profile revealed a latency type III suggesting the diagnosis of Hodgkin-like PTLD. The other patient required six courses of chemotherapy plus radiotherapy to reach a complete remission. In his tumor cells, a restricted EBV-latency type II pattern was found, suggesting a diagnosis of classical HL. These two cases demonstrate that in post-transplant lymphomas with histological features of HL, an analysis of the expression pattern of EBV proteins might aid in the differentiation between PTLD and HL.