Case report: Recipient-derived, late-onset post-transplant lymphoproliferative disorder involving a transplanted liver.

[INTRODUCTION] Post-transplant lymphoproliferative disorders (PTLD) are severe complications of transplantation associated with poor outcomes. Compared to early-onset PTLDs, late-onset PTLDs are much less associated with allograft localization. Herein, we report a case of Epstein-Barr virus (EBV)-negative lymphoma involving a graft 7 years after liver transplantation.

[CASE PRESENTATION] A 45-year-old man presented with hepatomegaly 7 years after liver transplantation. Liver puncture biopsy revealed B-cell lymphoma with a high proliferation index and a germinal center B-cell-like subtype. Tissue and other donor information were unavailable. Next-generation sequencing was performed on the tumor and recipient tissues, and the single nucleotide polymorphism (SNP) sites were identical, thereby confirming the recipient origin. The patient received a reduction in immunosuppression and six cycles of rituximab, reduced doses of cyclophosphamide, doxorubicin, vincristine, and prednisone, and achieved complete remission after the fourth cycle of treatment. The patient remained in good condition for 7 months after the last chemotherapy dose.

[CONCLUSION] This rare case report describes a late-onset EBV-negative recipient-derived PTLD involving a transplanted liver. SNP analysis is a useful method for determining tumor origin in situations where donor tissue is unavailable.