Peripheral blood and bone marrow findings in myelodysplastic syndrome (MDS)
| Disease . | Blood findings . | BM findings . |
|---|---|---|
| Refractory cytopenia with unilineage dysplasia (RCUD): (refractory anemia [RA]; refractory neutropenia [RN]; refractory thrombocytopenia [RT]) | Unicytopenia or bicytopenia* No or rare blasts (< 1%)† | Unilineage dysplasia: ≥ 10% of the cells in one myeloid lineage < 5% blasts < 15% of erythroid precursors are ring sideroblasts |
| Refractory anemia with ring sideroblasts (RARS) | AnemiaNo blasts | ≥ 15% of erythroid precursors are ring sideroblasts Erythroid dysplasia only < 5% blasts |
| Refractory cytopenia with multilineage dysplasia (RCMD) | Cytopenia(s)No or rare blasts (< 1%)†No Auer rods< 1 × 109/L monocytes | Dysplasia in ≥ 10% of the cells in ≥ 2 myeloid lineages (neutrophil and/or erythroid precursors and/or megakaryocytes) < 5% blasts in marrow No Auer rods ± 15% ring sideroblasts |
| Refractory anemia with excess blasts-1 (RAEB-1) | Cytopenia(s)< 5% blasts†No Auer rods< 1 × 109/L monocytes | Unilineage or multilineage dysplasia 5%-9% blasts† No Auer rods |
| Refractory anemia with excess blasts-2 (RAEB-2) | Cytopenia(s)5%-19% blasts‡Auer rods ±‡< 1 × 109/L monocytes | Unilineage or multilineage dysplasia 10%-19% blasts‡ Auer rods ±‡ |
| Myelodysplastic syndrome—unclassified (MDS-U) | Cytopenias< 1% blasts† | Unequivocal dysplasia in < 10% of cells in one or more myeloid lineages when accompanied by a cytogenetic abnormality considered as presumptive evidence for a diagnosis of MDS (see Table 6) < 5% blasts |
| MDS associated with isolated del(5q) | AnemiaUsually normal or increased platelet countNo or rare blasts (< 1%) | Normal to increased megakaryocytes with hypolobated nuclei < 5% blasts Isolated del(5q) cytogenetic abnormality No Auer rods |
| Disease . | Blood findings . | BM findings . |
|---|---|---|
| Refractory cytopenia with unilineage dysplasia (RCUD): (refractory anemia [RA]; refractory neutropenia [RN]; refractory thrombocytopenia [RT]) | Unicytopenia or bicytopenia* No or rare blasts (< 1%)† | Unilineage dysplasia: ≥ 10% of the cells in one myeloid lineage < 5% blasts < 15% of erythroid precursors are ring sideroblasts |
| Refractory anemia with ring sideroblasts (RARS) | AnemiaNo blasts | ≥ 15% of erythroid precursors are ring sideroblasts Erythroid dysplasia only < 5% blasts |
| Refractory cytopenia with multilineage dysplasia (RCMD) | Cytopenia(s)No or rare blasts (< 1%)†No Auer rods< 1 × 109/L monocytes | Dysplasia in ≥ 10% of the cells in ≥ 2 myeloid lineages (neutrophil and/or erythroid precursors and/or megakaryocytes) < 5% blasts in marrow No Auer rods ± 15% ring sideroblasts |
| Refractory anemia with excess blasts-1 (RAEB-1) | Cytopenia(s)< 5% blasts†No Auer rods< 1 × 109/L monocytes | Unilineage or multilineage dysplasia 5%-9% blasts† No Auer rods |
| Refractory anemia with excess blasts-2 (RAEB-2) | Cytopenia(s)5%-19% blasts‡Auer rods ±‡< 1 × 109/L monocytes | Unilineage or multilineage dysplasia 10%-19% blasts‡ Auer rods ±‡ |
| Myelodysplastic syndrome—unclassified (MDS-U) | Cytopenias< 1% blasts† | Unequivocal dysplasia in < 10% of cells in one or more myeloid lineages when accompanied by a cytogenetic abnormality considered as presumptive evidence for a diagnosis of MDS (see Table 6) < 5% blasts |
| MDS associated with isolated del(5q) | AnemiaUsually normal or increased platelet countNo or rare blasts (< 1%) | Normal to increased megakaryocytes with hypolobated nuclei < 5% blasts Isolated del(5q) cytogenetic abnormality No Auer rods |
Bicytopenia may occasionally be observed. Cases with pancytopenia should be classified as MDS-U.
If the marrow myeloblast percentage is < 5% but there are 2% to 4% myeloblasts in the blood, the diagnostic classification is RAEB-1. Cases of RCUD and RCMD with 1% myeloblasts in the blood should be classified as MDS-U.
Cases with Auer rods and < 5% myeloblasts in the blood and less than 10% in the marrow should be classified as RAEB-2. Although the finding of 5% to 19% blasts in the blood is, in itself, diagnostic of RAEB-2, cases of RAEB-2 may have < 5% blasts in the blood if they have Auer rods or 10% to 19% blasts in the marrow or both. Similarly, cases of RAEB-2 may have < 10% blasts in the marrow but may be diagnosed by the other 2 findings, Auer rod+ and/or 5% to 19% blasts in the blood.