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Myelodysplastic Syndromes

Peter Hanna


  • MDS is a malignant clonal myeloid disorder resulting in ineffective (dysplastic) hematopoiesis leading to peripheral cytopenias and a risk of transformation to acute myeloid leukemia (AML)
  • Usually idiopathic, a disease of the elderly (median onset at age 70)
  • The WHO has several classification schemes for MDS
    • Most important for classification is the percent of blasts in the bone marrow
    • Note >20% blasts in marrow = AML. Thus MDS and AML are on a continuum


  • 50% asymptomatic; symptoms can include nonspecific but gradual fatigue, weakness
  • Dysplastic cells do not work properly à infections and bleeding are more likely
  • Macrocytic anemia is most common finding; followed by bicytopenia or pancytopenia
  • Isolated neutropenia or thrombocytopenia are unusual but possible
  • Ask about secondary causes
    • Exposure to chemicals (benzene, crude oil/gasoline industry, cigarette smoke), chemotherapy, radiation
    • Medications, alcohol use, chronic infections (HIV)


  • Goal is to rule out reversible causes of dysplasia and cytopenias
  • CBC w/differential, peripheral smear, B12, folate, HIV
    • Consider copper and zinc
  • Dysplastic changes on peripheral smear: hypogranulated/hyposegmented neutrophils, hypogranulated platelets and macrocytosis of RBCs
    • Circulating myeloblasts can be seen
  • Final diagnosis made by bone marrow biopsy


  • Molecular characteristics define the “risk” of the disease and dictates treatments
  • Prognostic scoring tools: revised international prognostic staging system (R-IPSS)
  • Management general paradigm
    • Asymptomatic: with low-risk disease: monitoring
    • Low-risk disease + symptoms due to anemia only: transfusions, erythrocyte stimulating agents, and treatment with Luspatercept
    • MDS with isolated del(5q): treated with lenalidomide
    • High-risk pts: treated with hypomethylating agents
    • Only curative intervention: hematopoietic stem cell transplant (HSCT)