[Inv(16)-type acute myeloid leukemia with repeated skin infiltration without bone marrow relapse before and after allogeneic hematopoietic stem cell transplantation].

We report a 40-year-old woman diagnosed as having acute myeloid leukemia with CBFB-MYH11. Before and after stem cell transplantation in the phase of molecular remission of the marrow, CBFB-MYH11-positive cells were detected by RT-PCR analysis in skin lesions. The former was pathologically diagnosed as leukemic infiltration, while the latter was considered to be graft-versus-host disease. We can speculate that a low level of leukemic stem cells not detectable by RT-PCR analysis remained in the bone marrow, at least prior to transplantation. This case may suggest interesting biological features of inv(16)-type acute myeloid leukemia.