T cell lymphoma involving the graft of a multivisceral organ recipient.

Posttransplant lymphoproliferative disorders are typically of B cell origin, whereas T cell lymphomas have been rarely documented. We present a case of a non-Hodgkin's T cell lymphoma involving the intestinal graft of a multivisceral transplant patient. The patient was a 7-year-old girl who underwent at age 5 a multivisceral transplant secondary to short gut syndrome. Baseline immunosuppressive therapy consisted of FK506, methylprednisone, and mycophenolate mofetil. At 2 years posttransplant she presented with fever, diarrhea, nausea, and vomiting. Multiple endoscopic biopsies revealed a severe intensity, diffuse and focally nodular lymphocytic infiltrate composed predominantly of small, monomorphic lymphoid cells with scattered plasma cells and abundant eosinophils. Immunohistochemically, the majority of the lymphoid cells expressed the pan T cell marker CD3. Southern blot analysis revealed rearrangement of the T cell receptor beta chain gene, with germline configuration of the heavy immunoglobulin chain gene, confirming a clonal T cell genotype. In situ hybridization for Epstein Barr virus revealed rare positive lymphoid cells, that were negative with CD3 by immunohistochemical staining. A detailed clinico-radiological work-up revealed no other sites of involvement by the lymphomatous process. After the diagnosis of posttransplant lymphoproliferative disorder, immunosuppression was reduced with a subsequent partial improvement in the endoscopic appearance of the graft and a focal decrease in the lymphocytic infiltrate seen in the follow-up biopsies. Repeat gene rearrangement studies demonstrated germline configuration of both the T cell receptor beta chain gene and the heavy chain immunoglobulin. gene. To our knowledge, this represents the first description of a T cell lymphoma affecting the intestinal allograft of a multivisceral transplant patient.