Successful treatment of refractory advanced nasal NK/T cell lymphoma with unrelated cord blood stem cell transplantation incorporating focal irradiation.

Nasal natural killer (NK)/T cell lymphoma is a rare disease with a poor prognosis. We report the case of a 52-year-old woman with progressive advanced nasal NK/T cell lymphoma, with local invasiveness and bone marrow involvement, who was successfully treated with unrelated cord blood transplantation (UCBT). The patient was initially refractory to conventional chemotherapy. She was therefore treated with local irradiation, which induced a partial response. The patient then underwent UCBT using a conditioning regimen consisting of cyclophosphamide and total body irradiation. Acute graft-versus-host disease involving the skin was observed, but it was well controlled without systemic administration of corticosteroids. The patient remained in complete remission for 18 months after UCBT. Although the observation period has been relatively short and longer follow-up is needed, our observations suggest that incorporating focal irradiation to conditioning regimen for local control might be an effective treatment option for advanced nasal NK/T cell lymphoma in the setting of UCBT.