Isolated cerebral post-transplant lymphoproliferative disorder in a lymphoma recipient

Post-transplant lymphoproliferative disorder (PTLD) can occur after solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT). The majority of PTLDs are related to the reactivation of Epstein-Barr virus (EBV) in the lymphoid organs. PLTDs in HSCT recipients tend to present with systemic involvement, and isolated PTLD in these patients is rare. Only 14 isolated cerebral PTLDs have been reported in HSCT recipients, and none have been reported in lymphoma patients. When diagnosing PTLD in a lymphoma patient, it is challenging to discriminate between a PTLD that originated from previous disease and a newly developed clone and to distinguish between donor and recipient origin. In this report, we present the first case of a B-cell lymphoma patient who developed isolated PTLD in the CNS, and we confirmed that the PTLD originated in a distinct clone and from a different origin. Furthermore, the role of EBV-DNA monitoring in such patients is discussed.