Cytogenetically Unrelated Clones in Acute Myeloid Leukemia Showing Different Responses to Chemotherapy

Figure 1

(a) and (b) May-Giemsa staining of a bone marrow smear before and after induction therapy. (a) Monoblasts (left lower panel) consisted of 82.4% of bone marrow mononuclear cells at diagnosis. (b) Blast population significantly decreased after induction therapy, but there were background differentiated cells showing a dysplastic feature including hypogranular neutrophils (left lower panel) and discrete multinuclear megakaryocytes (right lower panel). (c) and (d) G-banding of bone marrow before and after induction therapy. Each panel showed a dominant karyotype at each point. (c) In the initial sample, all cells were abnormal, with a dominant clone showing multiple trisomies (red arrows). (d) The clone with multiple trisomies completely disappeared, but the monosomy 7 (blue arrow) clone was unmasked after induction therapy. All cells showed a pericentric inversion of chromosome 9 (green arrow), a known normal variant in the general population.

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