Acute Myeloid Leukemia with t(8;21)(q22;q22) (RUNX1-RUNX1T1)

• Translocation of RUNX1 (core binding factor-α or AML1) on 21q22 and RUNX1T1 (ETO) on 8q22

• Morphology:

  • Blasts:

    • Cytoplasmic hofs, occasional Auer rods

    • Characteristic large, salmon-colored granules

    • May resemble left shifted granulocytes with abundant granules and cytoplasm

  • Dysplastic maturing neutrophils with nuclear abnormalities

  • Background eosinophilia without morphologic abnormalities

• Immunoprofile:

  • CD34, MPO, variably CD13 and CD33

  • Weak CD19 in most cases

  • CD56, PAX5 and CD79a in some cases

• Favorable prognosis in the absence of KIT mutations

Reference: Hematopathology, 2010