WHO classification and criteria for the myelodysplastic syndromes
| Disease . | Blood findings . | Bone marrow findings . |
|---|---|---|
| Refractory anemia (RA) | Anemia | Erythroid dysplasiaonly |
| No or rare blasts | < 5% blasts | |
| < 15% ringed sideroblasts | ||
| Refractory anemia with ringed sideroblasts (RARS) | Anemia | Erythroid dysplasiaonly |
| No blasts | ≥ 15% ringed sideroblasts | |
| < 5% blasts | ||
| Refractory cytopenia with multilineage dysplasia (RCMD) | Cytopenias (bicytopenia or pancytopenia) | Dysplasia in ≥ 10% of cells in 2 or more myeloid cell lines |
| No or rare blasts | < 5% blasts in marrow | |
| No Auer rods | No Auer rods | |
| < 1 × 109/L monocytes | < 15% ringed sideroblasts | |
| Refractory cytopenia with multilineage dysplasia and ringed | Cytopenias (bicytopenia or pancytopenia) | Dysplasia in ≥ 10% of cells in 2 or more myeloid cell lines |
| sideroblasts (RCMD-RS) | No or rare blasts | ≥ 15% ringed sideroblasts |
| No Auer rods | < 5% blasts | |
| < 1 × 109/L monocytes | No Auer rods | |
| Refractory anemia with excess blasts-1 (RAEB-1) | Cytopenias | Unilineage or multilineage dysplasia |
| < 5% blasts | 5% to 9% blasts | |
| No Auer rods | No Auer rods | |
| < 1 × 109/L monocytes | ||
| Refractory anemia with excess blasts-2 (RAEB-2) | Cytopenias | Unilineage or multilineage dysplasia |
| 5% to 19% blasts | 10% to 19% blasts | |
| Auer rods ± | Auer rods ± | |
| < 1 × 109/L monocytes | ||
| Myelodysplastic syndrome, unclassified (MDS-U) | Cytopenias | Unilineage dysplasia in granulocytes or megakaryocytes |
| No or rare blasts | < 5% blasts | |
| No Auer rods | No Auer rods | |
| MDS associated with isolated del(5q) | Anemia | Normal to increased megakaryocytes with hypolobated nuclei |
| < 5% blasts | < 5% blasts | |
| Platelets normal or increased | No Auer rods | |
| Isolated del(5q) |
| Disease . | Blood findings . | Bone marrow findings . |
|---|---|---|
| Refractory anemia (RA) | Anemia | Erythroid dysplasiaonly |
| No or rare blasts | < 5% blasts | |
| < 15% ringed sideroblasts | ||
| Refractory anemia with ringed sideroblasts (RARS) | Anemia | Erythroid dysplasiaonly |
| No blasts | ≥ 15% ringed sideroblasts | |
| < 5% blasts | ||
| Refractory cytopenia with multilineage dysplasia (RCMD) | Cytopenias (bicytopenia or pancytopenia) | Dysplasia in ≥ 10% of cells in 2 or more myeloid cell lines |
| No or rare blasts | < 5% blasts in marrow | |
| No Auer rods | No Auer rods | |
| < 1 × 109/L monocytes | < 15% ringed sideroblasts | |
| Refractory cytopenia with multilineage dysplasia and ringed | Cytopenias (bicytopenia or pancytopenia) | Dysplasia in ≥ 10% of cells in 2 or more myeloid cell lines |
| sideroblasts (RCMD-RS) | No or rare blasts | ≥ 15% ringed sideroblasts |
| No Auer rods | < 5% blasts | |
| < 1 × 109/L monocytes | No Auer rods | |
| Refractory anemia with excess blasts-1 (RAEB-1) | Cytopenias | Unilineage or multilineage dysplasia |
| < 5% blasts | 5% to 9% blasts | |
| No Auer rods | No Auer rods | |
| < 1 × 109/L monocytes | ||
| Refractory anemia with excess blasts-2 (RAEB-2) | Cytopenias | Unilineage or multilineage dysplasia |
| 5% to 19% blasts | 10% to 19% blasts | |
| Auer rods ± | Auer rods ± | |
| < 1 × 109/L monocytes | ||
| Myelodysplastic syndrome, unclassified (MDS-U) | Cytopenias | Unilineage dysplasia in granulocytes or megakaryocytes |
| No or rare blasts | < 5% blasts | |
| No Auer rods | No Auer rods | |
| MDS associated with isolated del(5q) | Anemia | Normal to increased megakaryocytes with hypolobated nuclei |
| < 5% blasts | < 5% blasts | |
| Platelets normal or increased | No Auer rods | |
| Isolated del(5q) |