Abstract
The technique of bone marrow cultures has been shown to be of value in childhood acute leukemia. It now appears that acute myelogenous leukemia may be due to defective maturation of normal progenitor cells. The pattern of growth of these cells has been demonstrated to be of prognostic value. In contrast, the growth of normal progenitor cells from the bone marrow cultures of children with acute lymphocytic leukemia (ALL) may be due to the few remaining normal cells. The cause of granulocytopenia in childhood ALL is still unclear.