American Society of Hematology

Myelodysplastic Syndrome: Learning Objectives

Medical Importance

The myelodysplastic syndromes are clonal hematopoietic disorders that commonly cause macrocytic anemia in older patients. While the progeny of the mutant stem cells dominate the bone marrow, blood cell production rates are usually low because bone marrow cells do not mature normally and many of them undergo apoptosis in the bone marrow before reaching the peripheral blood. Thus myelodysplasia is characterized by ineffective hematopoiesis. The characteristic feature in the bone marrow is dysplastic and/or megaloblastic maturation. Although the differentiation process is less perturbed than in acute leukemia (where the leukemic cells are incapable of maturing beyond the blast stage), subtle differentiation abnormalities define myelodysplasia. Over time, the bone marrow cells of a substantial number of patients with myelodysplasia evolve to acute leukemia. Patients with myelodysplasia cannot be cured except by stem cell transplantation, and represent a considerable therapeutic challenge due to the limited effectiveness of most medical therapies.

Objectives

  1. Describe the typical age and classic peripheral blood findings of patients with myelodysplasia.
  2. Describe the bone marrow findings and cytogenetics seen in patients with myelodysplasia.
  3. Describe three laboratory determinants of prognosis in patients with myelodysplasia.
  4. Name three treatments used in patients with myelodysplasia, the goals of such therapy, and the results of each treatment in terms of response rate, cure, and/or impact on survival. 
back to top