Nasal natural killer cell lymphoma in a post-renal transplant patient

Posttransplant lymphoproliferative disorders in organ allograft recipients are most commonly of B cell origin and only occasionally of T-cell origin. We present here a case of nasal natural killer cell lymphoma associated with Epstein-Barr virus that occurred in a recipient of a renal transplant 4 years posttransplantation. Immunohistochemically, the lymphoma cells showed CD2(-), surface CD3(-), cytoplasmic CD3E(+), CD56(+), CD57(-), CD16(-), and CD43(+) phenotype, Analyses of T-cell receptor beta and gamma genes showed germ line configurations. EBER-1 was detectable in the lymphoma cells. The patient was diagnosed as having natural killer cell lymphoma and was treated with six courses of combination chemotherapy for non-Hodgkin's lymphoma. He has been in remission for more than 3 years thereafter. To the best of our knowledge, this is the first report of a posttransplant NK cell lymphoma associated with Epstein-Barr virus.