title: A characteristic CFU-GM growth pattern in acute promyelocytic leukemia.
abstract: Bone marrow and/or peripheral blood cells from 12 patients with acute promyelocytic leukemia (APL) were cultured in soft agar or methylcellulose in the presence of 15% human placental conditioned medium as a source of colony stimulating factor. Buffy coat cells, taken from ten patients when APL was diagnosed, produced a growth pattern in soft agar that was characterized by a high incidence of small, relatively uniform clusters of promyelocytes, which, when stained in situ, reacted strongly with myeloperoxidase, Sudan black B and chloroacetate esterase. In six cases, the leukemic origin of the cluster forming cells was demonstrated by the presence of the t(15;17) in these cells. During periods of complete remission the small clusters were replaced by larger and more diverse aggregates which had a normal karyotype. At relapse the small cluster growth pattern returned. The growth pattern of small clusters is more commonly associated with APL than with other types of acute myeloid leukemia.
mesh_terms: D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006098:Granulocytes; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000473:pathology*; D008264:Macrophages; D008297:Male; D008875:Middle Aged; D011519:Proto-Oncogenes; D014178:Translocation, Genetic