Under the name of Síndomes Myelodysplastic include a number of diseases characterized by defective maturation of stem cells from the bone marrow to produce blood cells, unable to perform their usual functions and lesser amounts than normal. This alteration can affect either a single line or hematologic three production lines of blood (red cells, white cells and platelets). Sometimes it can be caused by a genetic disorder, as in Fanconi Anemia, or due to a secondary acquired disorder treatment radio quimioterápic or, and evolve after years of acute leukemia (acute leukemia postmielodisplásica) being, in this case a poor prognostic factor for the development of leukemia.
Incidence of Myelodysplastic Syndrome
The incidence of myelodysplastic syndrome increases with age, the average age being 70 years and only about 10% of patients are under 50 years. It is also more common in men than in women. They are diagnosed between 30 and 50 new cases per million population in a year in Spain.
Signs and symptoms that occur myelodysplastic syndromes
MDS may not show symptoms for years and when they appear are completely unspecific, as can be seen in many other diseases. The main manifestations are caused by deficiency of red blood cells (weakness, fatigue, dizziness, palpitations) or deficit or malfunction of platelets (bruising, bleeding from different locations) or leukocytes (fever and frequent infections). Sometimes the patient may notice abdominal discomfort as a result of enlargement of the spleen or liver.Consult your doctor if you have:• Difficulty breathing.• Weakness or feeling tired.• paler than normal skin.• Bruising or bleeding easily.• petechiae (flat spots located under the skin caused by bleeding).
Classification of Myelodysplastic Syndrome
The myelodysplastic syndrome has multiple variants, including:• Refractory anemia: the number of red blood cells is too low and the patient has anemia. The amount of white cells and platelets is normal.
• Refractory anemia with ringed sideroblasts: the number of red blood cells is too low and the patient has anemia. Red blood cells have too much iron inside. The amount of white cells and platelets is normal.
• Refractory anemia with excess blasts: the number of red blood cells is too low and the patient has anemia. Between 5 and 19% of bone marrow cells are blasts. You can also have changes in white blood cells and platelets. Refractory anemia with excess blasts may progress and become acute myeloid leukemia (AML).
• Refractory cytopenia with multilineage dysplasia: the number of at least two types of blood cells (red cells, platelets or white blood cells) is too low. Less than 5% of bone marrow cells are blasts and less than 1% of blood cells are blasts. If red blood cells are affected may have an additional amount of iron. Refractory cytopenia may evolve and become acute myeloid leukemia (AML).
• Refractory cytopenia with dysplasia unilineage: the number of a type of blood cells (red cells, platelets or white blood cells) is too low. There are changes in 10% or more of the other two types of blood cells. Less than 5% of bone marrow cells are blasts and less than 1% of blood cells are blasts.
• unclassifiable myelodysplastic syndrome: the number of blasts in the bone marrow and blood is normal, being different disease from other myelodysplastic syndromes.
• myelodysplastic syndrome associated with an isolated anomaly chromosome 5q in: the number of red blood cells is too low and the patient has anemia. Less than 5% of cells from the bone marrow and blood are blastocysts. There is a specific change in the chromosome.
• chronic myelomonocytic leukemia (CMML)
Edited by Patricia Crespo Pujante