Post-Transplantation Hairy Cell Leukemia with Hemophagocytic Lymphohistiocytosis in an Adult Kidney Transplant Recipient: A Case of Rare Occurrence.

Post-transplant lymphoproliferative disorder (PTLD) is a rare and severe complication that occurs after kidney transplantation. Most cases of PTLD are associated with reactivation of the Epstein-Barr virus (EBV), which often happens during the early phases following transplantation. Hemophagocytic lymphohistiocytosis (HLH) is an inflammatory syndrome characterized by a cytokine storm originating from activation of the reticuloendothelial system, leading to multi-organ failure (MOF). Herein, we present a case of late-onset EBV-positive hairy cell leukemia in a kidney transplant recipient who concurrently developed HLH. Diagnosing and managing HLH can be particularly challenging, as it can mimic sepsis. This is especially true for transplant recipients, where diagnosing and treating such conditions are difficult. Immunosuppressive therapy, malignancies like lymphoma, and EBV infection are recognized risk factors for developing HLH. However, very few cases have reported the simultaneous occurrence of HLH and PTLD.