NCIt definition : A clonal expansion of myeloid blasts in the bone marrow, blood or other tissues. The
classification of acute myeloid leukemias (AMLs) encompasses four major categories:
1) AML with recurrent genetic abnormalities; 2) AML with multilineage dysplasia; 3)
Therapy-related AML; 4) AML not otherwise specified. The required bone marrow or peripheral
blood blast percentage for the diagnosis of AML is 20% (WHO classification).;
Alternative definition : NICHD: A rapidly progressive cancer of the blood and bone marrow consisting of the
proliferation of abnormal myeloblasts, which are immature, dysfunctional white blood
cells.; NCI-GLOSS: An aggressive (fast-growing) disease in which too many myeloblasts (immature
white blood cells that are not lymphoblasts) are found in the bone marrow and blood.;