Myelodysplasia

Myelodysplastic syndrome
Synonyms	preleukemia, myelodysplasia

Blood smear from a person with myelodysplastic syndrome. A hypogranular neutrophil with a pseudo-Pelger-Huet nucleus is shown. There are also abnormally shaped red blood cells, in part related to removal of the spleen.
Classification and external resources
Specialty	Haematology, oncology
ICD-10	D46
ICD-9-CM	238.7
ICD-O	9980/0-M 9989/3
DiseasesDB	8604
eMedicine	med/2695 ped/1527
MeSH	D009190
Orphanet	52688
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Myelodysplastic syndromes (MDS) are a group of cancers in which immature blood cells in the bone marrow do not mature and become healthy blood cells. Early on there are typically no symptoms. Later symptoms may include feeling tired, shortness of breath, easy bleeding, or frequent infections. Some types may develop into acute myeloid leukemia.

Risk factors include previous chemotherapy or radiation therapy, exposure to certain chemicals such as tobacco smoke, pesticides, and benzene, and exposure to heavy metals such as mercury or lead. Problems with blood cell formation result in some combination of low red blood cells, low platelets, and low white blood cells. Some types have an increase in immature blood cells, called blasts, in the bone marrow or blood. The types of MDS are based on specific changes in the blood cells and bone marrow.

Treatments may include supportive care, drug therapy, and stem cell transplantation. Supportive care may include blood transfusions, medications to increase the making of red blood cells, and antibiotics. Drug therapy may include the medication lenalidomide, antithymocyte globulin, and azacitidine, among others. Certain people can be cured with chemotherapy followed by a stem cell transplant from a donor.