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9 - Grade/differentiation unknown, not stated, or not applicable
Primary refractory anemia
Refractory anemia without sideroblasts
Refractory cytopenia with unilineage dysplasia
Refractory anemia (RA) is a specific type of myelodysplastic syndrome that is characterized mainly by unilineage dysplasia affecting erythroid series. (Diagnosis of exclusion) Myeloblasts < -1% in blood, <5% in marrow There should be a period of observation of six months followed by a re-evaluation before a definitive diagnosis of RA is established.
MDS is a group name for a number of specific diseases. As the MDS progresses, it may manifest as several subtypes. This is a part of the disease process. Abstracting each of the subtypes would result in over-counting these diseases. Code the first subtype that is diagnosed. Do not change the histology code or create a new abstract for any subsequent specific MDS subtypes.
RA is any of a group of anemic conditions not associated with another disease and is marked by a persistent, frequently advanced anemia that can only be successfully treated with blood transfusions. RA is only anemia. The early cells that develop into red blood cells have an abnormal appearance (called dysplasia). The number of very early cells (called blasts) is normal (less than 5%). About 5% to 10% of all MDS patients have refractory anemia. This type seldom, if ever, progresses to acute myeloid leukemia and patients with this type typically have long survivals. The peripheral blood smear usually shows normochromic, normocytic, or normochromic macrocytic. Blasts are rarely seen and, if present, account for <1% of the white blood cells. The erythroid precursors in the BM vary from decreased to markedly increased. The BM must show unequivocal evidence of dysplasia (dysplasia must be present in 10% or more erythroid precursors). Ring sideroblasts may be present. The BM biopsy is generally hypercellular.