No abstract

To The Editor: We report an unusual case of metachronous T-cell post-transplant lymphoproliferative disease (PTLD) with clinicopathologic manifestations resembling chronic active Epstein-Barr virus (CAEBV) infection of T/NK subtype and hemophagocytic lymphohistiocytosis (HLH), more than 4 years following the occurrence of B-cell PTLD.A 15 year-old Chinese girl, in end-stage renal failure since 13 years of age from chronic glomerulonephritis, received a cadaveric donor Epstein-Barr virus (EBV)-unknown to recipient-seronegative renal transplant. She received EBV prophylaxis with oral valganciclovir.Five months post-transplant, she developed exudative tonsillitis and underwent tonsillectomy. Histology of the tonsils revealed a diffuse, destructive, and polymorphous lymphoid infiltrate composed of lymphoid cells showing a full range of B-cell maturation. The lymphoid cells were positive for CD20, CD79A, and showed kappa light chain restriction (Supporting Information Fig. 1). In situ hybridization for Epstein-Barr virusencoded small ribonucleic acid (EBER) was positive in B-cells but not T-cells. Features were consistent with EBV-positive PTLD, polymorphic type. Positron emission tomography-computed tomography (PET-CT) scan showed an intensely fluorodeoxyglucose (FDG)-avid soft tissue mass lesion in the nasopharynx and posterior nasal cavity associated with retropharyngeal and cervical adenopathy. Plasma EBV DNA by polymerase chain reaction (PCR) was 134 copies per lg DNA (reference <100 copies per lg DNA). Throat swab EBV DNA was 1,225 copies per lg DNA. She was treated with intravenous rituximab and immunoglobulin with continued antiviral therapy. Immunosuppression was reduced with tacrolimus weaned to minimal levels. Repeat PET-CT scan following tonsillectomy showed resolution of the FDG-avid lesions.In the ensuing period from 2 to 3 years post-transplant, the patient experienced recurrent episodes of pancytopenia which required treatment with granulocyte-colony stimulating factor. Throughout this period, her EBV viral load remained high (1,500-2,500 copies per lg DNA) while surveillance PET-CT scans were negative for metabolically active lesions. The cause of the pancytopenia was attributed to persistent EBV viremia with marrow suppression.Four years and 6 months post-transplant, the patient was treated for acute cellular rejection with intravenous pulse methylprednisolone. A month later, she developed high fevers, epistaxis, and spontaneous bruising. Physical examination revealed hepatosplenomegaly, cervical lymphadenopathy, and lower limb ecchymoses. Investigations showed pancytopenia with haemoglobin 7.1 g/dL, total white cell count 2.72 3 10