Abnormal differentiation of leukemic cells in vitro

Marrow or blood cells from 35 patients with uncontrolled acute myeloblastic leukemia or its varients were cultured in vitro. In 28 of the 35 there was sufficient growth to enable the cells to be examined morphologically after 9–12 days. In 4 of the 28 the cells which developed were indistinguishable from normal granulocytes, but in the remaining 24 the leukemic blasts developed into qualitatively abnormal cells showing a variable amount of somewhat disorganized differentiation. These results are in disagreement with previous reports and favor the clonal theory of the nature of leukemia.