Myelodysplastic Syndromes

Myelodysplastic Syndromes – Peter Hanna

Background

  • MDS is a malignant clonal myeloid disorder resulting in ineffective hematopoiesis leading to peripheral cytopenia’s and a risk of transformation to acute myeloid leukemia (AML)
  • The bone marrow is hypercellular and dysplastic usually
  • 20% of cases have hypocellular marrow and look like aplastic anemia
  • 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 & AML are on a continuum

Presentation

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

 

Evaluation

  • Goal is to rule out reversible causes of dysplasia and cytopenias
  • CBC w/differential, Peripheral Smear, B12, Folate, HIV
    • May consider Copper & Zinc (send out labs, are expensive and rare)
  • 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

 

Management

  • Molecular characteristics define the “risk” of the disease 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 patients:  treated with hypomethylating agents
    • Only curative intervention = hematopoietic stem cell transplant (HSCT)