A group of neoplasms that originate in a primitive multipotential hematopoietic cell.. About half of the cases are mild to moderate anemias accompanied by mild to moderately reduced white cell and platelet counts. Often, these are not progressive but they have a heightened propensity to evolve into acute myelogenous leukemia. The other half of the cases are a type of low blast count leukemia that may be associated with severe white cell and platelet deficits. Many of the patients affected require transfusion therapy, have a propensity to infection or to bleeding, and frequently progress to more overt leukemia. These disorders can occur at any age but are most common after age 60 years.
Myelodysplastic syndromes a group of malignant hematologic disorders characterized by varying degrees of bone marrow failure. Referred to as "preleukemia" or "smoldering leukemia" though these are malignant, and are treated as separate diseases.
A group of bone marrow disorders characterized by the underproduction of one or more types of blood cells due to dysfuntion of the marrow . The myelodysplastic syndromes (MDS) may arise de novo (newly) or be secondary to treatment with chemotherapy or radiation therapy for another disease. De novo myelodysplasia usually has a better prognosis than does secondary myelodysplasia. See the entire definition of Myelodysplastic syndrome
The myelodysplastic syndromes (MDS, formerly known as "preleukemia") are a diverse collection of hematological conditions united by ineffective production of blood cells and varying risks of transformation to acute myelogenous leukemia. Anemia requiring chronic blood transfusion is frequently present. Although not a true malignant neoplasm, MDS is nevertheless classified within the hematological neoplasms.