A rare case of EBV negative T-cell post renal transplant lymphoproliferative disorder

Case Report Post-transplant lympholproliferative disorders comprise a rare group of malignancies seen in solid-organ and hematopoetic transplantation. 90% of these malignancies are of B-cell origin while 10% are a heterogenrous group of T-cell lymphomas, described in rare case reports. T-cell variants are rapidly progressive with high a mortality incidence. Variables that increase the incidence include cumulative immunosuppression levels as well as EBV positivity. We present the case of a 35 year old male with a renal transplant at age 18 for focal segmental glomerulosclerosis. Complaints of fatigue, weight loss and petechiae resulted in a CBC showing WBC 23.4K, Hgb 9.0 g/dL, Plt 7k. Bone marrow biopsy and CT imaging showed no evidence of lymphoma. Clinical suspicion remained high and the patient was rescanned 3 months later for persistent symptoms and an accessible lymph node was biopsied. Histology revealed effaced nodal architecture by sheets of T-Lymphocytes surrounding small residual germinal centers. T-cells IHC staining was positive for CD 2,3,4,5, and bcl-2 but negative for EBV, CD7,8 by IHC. Ki-67 of 10% was noted on stains. Bone marrow flow cytometry corroborated the T-cell lineage with the same surface marker reportoire. T-cell beta and gamma receptor gene rearrangement clonality was confirmed by PCR. The patient completed a regimen including cyclophosphamide, liposomal doxorubicin, vincristine, and prednisone (CCOP) with only a partial PET scan response. The extremely low proliferation index, T-cell subtype, EBV negativity and time to diagnosis make this case unique. T-cell PTLD are a very rare subset of LPD with no randomized clinical trials determining the superiority of any one regimen. Oncogenic mechanisms have not been well elucidated, but murine Xenografts have now been developed. The Ki-67 of 10% is more than 2 standard deviations below reported averages for this subtype. Developing clinical trial will remain a formidable challenge given the tumor's rarity, histologic heterogeneity, and paucity in the pathophysiologic mechanisms of this disease. While we extrapolate therapeutic decision from other T-cell lymphomas, the future may change with next generation sequencing and immunotherapy.