Myelodysplastic syndrome refers to a group of related disorders in which abnormal blood-forming cells develop in the bone marrow. At first, these cells interfere with the production of normal blood cells. Later, these cells may become cancerous, turning into a form of leukemia.
(See also Overview of Leukemia.)
Symptoms depend on which type of cells is affected but may include tiredness, weakness, and paleness, or fever and infections, or bleeding and bruising.
Blood tests and examination of a bone marrow sample are needed for diagnosis.
Stem cell transplantation can cure the disease.
In myelodysplastic syndromes, a line of identical cells (clone) develops and occupies the bone marrow. These abnormal cells do not grow, mature, or function normally. The cells also interfere with normal bone marrow function, resulting in deficits of
Red blood cells (which carry oxygen in the bloodstream), causing anemia
White blood cells (which help defend the body against infection), causing infections
Platelets (small cell-like particles that help in the clotting process), causing bleeding and bruising
In some people, red blood cell production is predominantly affected.
Myelodysplastic syndromes occur most often in people older than 50 years, particularly those older than 65 years. Men are more likely than women to be affected.
The cause is usually not known. However, in some people, exposure of bone marrow to radiation therapy, certain types of chemotherapy drugs, or certain chemicals like benzene may play a role.
Symptoms of MDS
Symptoms may develop very slowly. Fatigue, weakness, and other symptoms of anemia are common. Fever due to infections may develop if the number of white blood cells decreases. Easy bruising and abnormal bleeding can result if the number of platelets drops (thrombocytopenia).
Diagnosis of MDS
Blood tests
Bone marrow examination
Molecular testing
A myelodysplastic syndrome may be suspected when people have unexplained persistent anemia, but diagnosis requires bone marrow evaluation.
At some centers, tests are done to look for gene or chromosome abnormalities usually present in myelodysplastic syndrome (sometimes called molecular testing). Experimental treatments are available that target some of these specific abnormalities.
Treatment of MDS
Chemotherapy
Sometimes stem cell transplantation
Stem cell transplantation is the only curative treatment and is usually done in young people.
If transformation to acute myeloid leukemia (AML) occurs, chemotherapy, such as that given for AML may be helpful, but this type of AML is unlikely to be curable with chemotherapy alone.
Treatment of complications of myelodysplastic syndrome
People with myelodysplastic syndromes often need transfusions of red blood cells
People who have very low numbers of neutrophils—the white blood cells that fight infection—may benefit from periodic injections of a special type of protein called granulocyte colony-stimulating factor. People may also benefit from the proteins erythropoietin, which may help in the production of red blood cells, and thrombopoietin, which stimulates the development of platelets.
Prognosis for MDS
Myelodysplastic syndromes are thought to be a type of preleukemia that can progress gradually over a period of several months to years. In 10 to 30% of people, a myelodysplastic syndrome transforms into acute myeloid leukemia.
More Information
The following English-language resources may be useful. Please note that the MANUAL is not responsible for the content of these resources.
Leukemia & Lymphoma Society: Myelodysplastic Syndromes: General information on many aspects of myelodysplastic syndromes, including diagnosis, treatment options, and research findings
MDS Foundation: What is MDS?: Provides information on causes of myelodysplastic syndrome, statistics on numbers of people affected, and treatment options
