Durable remission of Sézary syndrome after unrelated bone marrow transplantation by reduced-intensity conditioning.

A 22-year-old Japanese man was diagnosed with Sézary syndrome with large cell transformation. His skin lesions persisted after treatment with 7 cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone), psoralen and ultraviolet light A, and total skin electron beam irradiation. He subsequently underwent allogeneic bone marrow transplantation by reduced-intensity conditioning from a human leukocyte antigen-identical unrelated donor. He developed grade II of acute graft-versus-host disease and extensive-type chronic graft-versus-host disease. He has no signs of disease 36 months after the transplantation. The prognosis of patients with advanced stage of mycosis fungoides or Sézary syndrome is very poor. Allogeneic hematopoietic stem cell transplantation, especially by reduced-intensity conditioning, is expected to become a curative treatment option, and graft-versus-tumor effect might play a critical role for sustained remission.