[Successful treatment of myeloid/natural killer cell precursor acute leukemia with allogeneic peripheral blood stem cell transplantation].

We report a case of myeloid/NK cell precursor acute leukemia, which was successfully treated with allogeneic peripheral blood stem cell transplantation (allo PBSCT). A 31-year-old woman was admitted to our hospital with general fatigue, anorexia and leukocytosis. Bone marrow aspiration showed infiltration of many atypical blasts. She was diagnosed as having myeloid/NK cell precursor acute leukemia by morphological and immunohistochemical analysis. Complete remission was achieved by induction chemotherapy, but as myeloid/NK cell precursor acute leukemia is reported to have an extremely poor prognosis due to frequent relapse, the patient underwent allo PBSCT from her HLA-identical father, together with a myeloablative conditioning regimen. She suffered several transplantation-related complications including acute graft versus host disease (grade II) and ischemic enterocolitis associated with thrombotic microangiopathy, but these were overcome by supportive therapy. She was discharged on day 168 after allo PBSCT, and so far there has been no evidence of relapse during a follow-up period of 15 months.