Disorders, myeloproliferative

Malignant diseases of certain bone marrow cells including those that give rise to the red blood cells, the granulocytes (types of white blood cells), and the platelets (crucial to blood clotting). The myeloproliferative disorders include myelophthisic anemia, erythroblastic leukemia, leukemoid reaction, myelofibrosis, myeloid metaplasia, polycythemia vera, and thrombocytosis. The myeloproliferative disorders are in contrast to the lymphoproliferative disorders which are malignancies of lymphoid cells and cells of the reticuloendothelial system (such as macrophages) which can take up inert particles and sequester them.