Myelodysplastic Syndromes

Myelodysplastic syndromes (also called myelodysplastic neoplasms or myelodysplasia) are blood disorders that cause the immature blood stem cells (called blasts) in the bone marrow to die before they mature. As a result, the body doesn't have enough healthy red blood cells, white blood cells or platelets.

Myelodysplastic syndromes are precancerous conditions that carry the risk of progressing to leukemia.

Types of Myelodysplasia

The types of myelodysplasia identify which of the three types of blood cells is involved. The types of myelodysplastic syndromes include the following:

• Refractory anemia is a low red blood cell count that doesn't respond to conventional anemia treatment.
• Refractory anemia with ringed sideroblasts is different from refractory anemia because the existing red blood cells contain too much iron.
• Refractory anemia with excess blasts is a condition in which the number of any of the three types of blood cells may be low and appear abnormal under a microscope.
• Refractory anemia with excess blasts in transformation is different from other types of refractory anemia because in addition to low red cell count, white blood cell and platelet counts are low.
• Refractory cytopenia with unilineage dysplasia occurs when one or two blood cell types have low counts.
• Refractory cytopenia with multilineage dysplasia is a condition in which two of the three types of blood cells are abnormal.
• Unclassified myelodysplastic syndrome is diagnosed when reduced numbers of one of the three types of mature blood cells, and either the white blood cells or platelets look abnormal under a microscope.

Some myelodysplastic syndromes have no known cause, while others may be due to chemicals and radiation, from both the environment and other cancer treatments.

Symptoms of Myelodysplasia

The early stages of myelodysplastic syndromes rarely cause signs or symptoms. Sometimes, a routine blood test discovers myelodysplasia. When symptoms do occur, often they include:

• Easy bruising or bleeding
• Enlarged spleen
• Fatigue
• Frequent infections
• Pallor (pale skin)
• Pinpoint red spots just beneath the skin caused by bleeding (a condition called petechiae)
• Shortness of breath.

Myelodysplastic Syndrome Prognosis and Treatment

Myelodysplastic syndromes have no definite cure or treatment and a myelodysplastic syndrome prognosis depends on:

• Changes in the chromosomes
• Number of blast cells in the bone marrow
• Types of blood cells affected
• Whether the condition occurred after chemotherapy or radiation therapy for another disease.

Treatment attempts to relieve symptoms, slow progression and improve quality of life. The three types of standard treatment for myelodysplastic syndromes are chemotherapy, supportive care and stem cell transplant. Supportive care includes:

• Blood transfusion: Patients receive blood transfusions to replace blood cells that have been damaged by the disease or by other treatments, like chemotherapy.
• Drug therapy: Patients receiving blood transfusions may receive deferoxamine to treat iron build-up. Lenalidomide or antithymocyte globulin (ATG) may lessen the need for transfusions if you have certain types of myelodysplastic syndrome.
• Growth factor therapy: Erythropoietin can increase the number of red blood cells, decreasing the effects of anemia.

Resources

City of Hope. (2009). Myelodysplasia, Retrieved October 12, 2010, from http://www.cityofhope.org/patient_care/treatments/myelodysplasia/Pages/default.aspx.

Mayo Clinic. (2009). Myelodysplastic syndromes. Retrieved October 12, 2010, from http://www.mayoclinic.com/health/myelodysplastic-syndromes/DS00596.

Masonic Cancer Center. (2005). Myelodysplastic syndromes treatment. Retrieved October 12, 2010, from http://www.cancer.umn.edu/cancerinfo/NCI/CDR378089.html.