GAMMA DELTA T-CELL POSTTRANSPLANTATION LYMPHOPROLIFERATIVE DISORDER PRIMARILY IN THE SPLEEN/

A 31-year-old renal transplant recipient developed an unusual T-cell l ymphoproliferative disorder 3 years after transplantation. The neoplas m involved the spleen, without concomitant hepatomegaly, lymphadenopat hy, or obvious bone marrow involvement. Peripheral blood involvement d eveloped after splenectomy. Immunophenotypically, the neoplastic cells expressed CD2, CD3, CD7, CD16, CD45, CD56, and the gamma/delta T-cell receptor on the surface membrane. The neoplastic cells were negative for surface membrane CD4, CD5, and CD8. Serologic and/or DNA analyses for viruses, including Epstein-Barr virus, human T-cell lymphotropic v irus-1, human immunodeficiency virus, and human herpesvirus-6, were ne gative. Cytogenetic findings included a translocation breakpoint at ch romosome 7p15, consistent with involvement of the T-cell receptor gamm a-chain locus. Although gamma/delta T-cell lymphomas have been reporte d to have a predilection for hepatosplenic localization, this is the f irst,fell-documented case to be described in the setting of posttransp lantation immunosuppression.