Refractory Anemia with Excess Blasts

Refractory Anemia with Excess Blasts

Carla S. Wilson, MD, PhD

This patient has pancytopenia with 13% circulating blasts image, consistent with RAEB-2. The neutrophil image has dysplastic features with hypogranular cytoplasm and atypical nuclear segmentation.

This 76-year-old man with RAEB-1 has macrocytic anemia, thrombocytopenia, and no circulating blasts. The bone marrow has 7% blasts image and dysplasia of the neutrophilic myeloid lineage image.



  • Refractory anemia with excess blasts (RAEB)


  • Myelodysplastic syndrome (MDS) with increased blasts or Auer rods

  • 2 categories based on prognosis

    • RAEB-1

      • 2-4% blasts in peripheral blood or

      • 5-9% blasts in bone marrow

    • RAEB-2

      • 5-19% blasts in peripheral blood or

      • 10-19% blasts in bone marrow

      • Auer rods, if present, advance MDS case to RAEB-2


Hematopoietic Stem Cell Disorder

  • Clonal hematopoietic stem cell disorder



  • Incidence

    • 35-40% of MDS

      • 15-20% RAEB-1

      • 20% RAEB-2

      • Associated reticulin fibrosis seen in ˜ 10% of MDS; most are RAEB-F (fibrosis)

  • Age

    • Older individuals, primarily > 50 years of age


  • Often seek medical attention for symptoms of anemia

    • Fatigue, dyspnea, palpitations, headache, dizziness

  • Other symptoms related to cytopenias

    • Exaggerated bleeding from thrombocytopenia with platelet dysfunction

    • Infection secondary to decreased neutrophils and neutrophil dysfunction

  • Occasional mild hepatomegaly or splenomegaly


  • High-risk MDS

    • May be treated similarly to acute myeloid leukemia (AML)

      • Depends partly on tempo of disease progression

    • Intensive chemotherapy with variety of regimens

    • RAEB-2 patients who are candidates for stem cell transplantation

      • Topotecan-cytarabine or idarubicin-cytarabine-based regimens

  • Hematopoietic stem cell transplantation

    • Patient must have low comorbidity scores

    • High upfront treatment-related mortality

      • May want to delay for low-risk or intermediate-risk patients

    • Risk of relapse increases if cytogenetics classified as poor risk


  • 25% 5-year survival rate

    • Patients have progressive bone marrow failure with increasing cytopenias

      • Die from complications such as bleeding and infections

    • Subset progresses to AML

      • 25% of RAEB-1 cases at 5 years

      • 35% (to 50%) of RAEB-2 cases at 5 years

  • Predicted survival based on blast percentage, cytogenetic abnormalities, cytopenias

    • RAEB-1

      • Intermediate-risk prognostic group

      • Median survival is ˜ 16-40 months

    • RAEB-2

      • High-risk group

      • Median survival is ˜ 9-20 months


Cytologic Features

Jun 13, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Refractory Anemia with Excess Blasts
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