refractory anemia with excess blasts


Expand All | Collapse All
  • Clinical

    • age 50+
    • 40% of MDS
    • anemia, thrombocytopenia, neutropenia
    • progress to AML (25% RAEB1, 33% RAEB2)
    • CD7 = poorer prognosis
    • prognosis: RAEB1 > RAEB2 by Auer rod > RAEB2 by blast count
  • Types

    • RAEB1: 5-9% marrow blasts or 2-4% blood blasts
    • RAEB2: 10-19% marrow blasts, 5-19% blood blasts, or Auer rods in blast
    • RAEBF: myelofibrosis
  • Morphology

    • blood
  • - anisopoik

  • - giant plt, hypogranular plt

      • neutrophils: abnormal granularity, segmentation
      • 2-19% blasts
    • marrow
      • usually hypercellular, abnormal paratrabecular clustering of erythroids and megas
      • erythroid
        • can be increased
        • macrocytic
        • megaloblastoid
        • abnormal lobation, nuclear bridging
      • granulocytic
        • usually increased
        • small neuts
        • nuclear hypolobation, hypersegmentation
        • cytoplasmic hypogranularity, pseudo Chediak Higashi granules
      • megakaryocyte
        • normal to increased
        • paratrabecular clustering
        • micromegakaryocytes
        • multinucleation
      • 5-19% blasts, tend to localize away from trabeculae and vessels
  • Immunophenotype

    • precursor cells (CD34, CD117)
    • myeloid lineage: CD13, CD33
    • can have aberrant CD7 (worse prognosis), CD56
    • CD61 stains dysplasic megas