C h r o n i c M y e l o p r o l i f e r a t i v e D i s o r d e r s
General
• Chronic myeloproliferative disorders are malignant clonal proliferations of a
pluripotent stem cell that lead to excessive proliferation of myeloid cells in
the blood and bone marrow.
• In contrast to acute myeloid leukemia (which is characterized by a
proliferation of myeloblasts, or very early myeloid precursors), chronic
myeloproliferative disorders are characterized by a proliferation of maturing myeloid cells (like mature neutrophils, red cells, or platelets) with only a few
cells at the blast stage.
• All myeloproliferative disorders have in common:
1. A high white blood cell count with a left shift.
2. A hypercellular marrow.
3. Splenomegaly.
Classification
• The classification of chronic myeloproliferative disorders is based on which
myeloid cell line is proliferating (red cell line, platelet line, or neutrophil line).
• There are four chronic myeloproliferative disorders:
