Basic principles


Diagnosis of AML requires:

  • At least 20% myeloblasts in marrow or blood
  • Myeloid lineage should be established by multiparameter flow cytometry
  • AML can still be diagnosed (independently of blast percentage in the presence of the following:
    • CBF AML (cytogenetic abnormalities t([8;21], inv [16], or t[16;16]),
    • NPM1 mutated AML
    • Acute promyelocytic leukemia
  • Where myeloid blasts also express T- or B-cell markers, or where separate myeloid and lymphoid blast populations are detected, the diagnosis is “mixed phenotype acute leukaemia” (MPAL) (if specific criteria are met)
  • Where cases have >20% blasts, but lack any lineage-associated markers they are considered “acute undifferentiated leukaemia”