Rare Presentation of Posttransplant Lymphoproliferative Disease in a Pediatric Liver Transplant Recipient: Plasmablastic Lymphoma Complicated With Hemophagocytic Lymphohistiocytosis.

A 3-year-old female patient, who had received a liver transplant from her father 1 year previously to treat biliary atresia, was admitted with fever and pancytopenia. History showed Epstein-Barr virus polymerase chain reaction positivity detected in the patient 3 months earlier; the patient received reduced immunosuppression in doses of tacrolimus, and valganciclovir was administered. Physical exa-mination showed lymphadenopathies at the cervical, axillary and inguinal regions with 2 × 2 cm at diameter, splenomegaly of 5 cm, and fever of 39 °C. Considering the clinical setting of immune suppression, the patient was diagnosed with monomorphic posttransplant lymphoproliferative disorder in the form of plasmablastic lymphoma. The pancytopenia of the patient could not be explained with plasmablastic lymphoma; therefore, a concomitant hemophagocytic lymphohistiocytosis was suspected. The patients was changed from tacrolimus to sirolimus followed by 6 days of induction therapy and received a combination regimen of cyclophosphamide, doxorubicin, prednisolone, and vincristine every 21 days for 4 to 6 cycles plus rituximab 375 mg/m2/wk for 4 weeks. For hemophagocytic lymphohistiocytosis, the patient received intravenous immunoglobulin 1 g/kg every week for 4 weeks, followed by monthly therapy during chemotherapy cycles. After 2 courses of chemotherapy and 4 doses of rituximab, lymph nodes and splenomegaly disappeared, blood tests returned to standard levels, and Epstein-Barr virus polymerase chain reaction results were negative. Positron emission tomography computed tomography after 2 cycles showed complete remission of disease. After 5 cycles of chemotherapy, the patient remained well without any complications.