Scanning electron microscopic observation of CFU-mix of normal adults and leukemic patients including two cases of myeloid-lymphoid bipotent leukemia.

We observed CFU-Mix of 4 normal adults and 11 cases of leukemia. The culture system used by us in this study represented a suitable model for studying differentiation of hemopoietic stem cells in vitro. The pathogenesis of myeloid-lymphoid bipotent leukemia were malignant changes in pluripotent hemopoietic progenitor cells. The leukemic clones showed proliferation, but did not mature in culture. It is suggested that differentiation of leukemic stem cell did not pass through CFU-Mix stage.