Atypical chronic myeloid leukemia (aCML) is a rare subtype of myelodysplastic/myeloproliferative neoplasm (MDS/MPN). It is characterized by leukocytosis, granulocytic dysplasia, and typically poor patient outcomes. aCML is dominated by mutations in SETBP1, granulocyte colony-stimulating factor 3 receptor (CSF3R), NRAS and KRAS. In addition to these mutations, other recurrent mutations in a variety of genes including NRAS, IDH2, and CBL have recently been described in aCML at lower frequencies.
