Acute Myeloid Leukemia With Myelodysplasia-Related Changes: A New Definition

Acute myeloid leukemia (AML) with multilineage dysplasia was introduced in the 2001 World Health Organization (WHO) classification to encompass cases of AML characterized by myelodysplastic syndrome-like features. The 2008 WHO classification revised this group into a new category, AML with myelodysplasia-related changes (AML-MRC). The category now includes patients with at least 20% blasts in peripheral blood or bone marrow and any of the following: (1) AML arising from a previous MDS or mixed MDS/myeloproliferative neoplasm, (2) AML with a specific MDS-associated cytogenetic abnormality and/or (3) AML with multilineage dysplasia. Up to 48% of all patients with AML are encompassed within the AML-MRC subgroup. AML-MRC patients have worse prognosis compared with patients with AML, not otherwise specified.