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Case 263 - Discussion

Hematopathology Case


Acute Myeloid Leukemia

Auer rods:
  • Morphology: elongated needle shaped azurophilic intracytoplasmic inclusions, 0.1-2μ wide and 3-6μ long

  • Components: fused lysosomes, including lysosomal enzymes, peroxidase, acid phosphatase, peroxidase, and esterase

  • Seen in: acute leukemia (myeloblastic, promyelocytic, myelomonocytic and monocytic), myelodysplastic syndromes (RAEB-2) and chronic myelomonocytic leukemia

  • Significance:

    • Not present in acute lymphoblastic leukemia; helps to differentiate acute myeloid leukemia from ALL

    • MDS with <10% blast and Auer rods is classified as RAEB-2

    • Patients with Auer rods have a worse prognosis than similar patients without Auer rods