Classifications of myelodysplastic syndrome (MDS).
| FAB1 . | WHO3,4 . |
|---|---|
| Abbreviations: MDS, myelodysplastic syndrome; FAB, French-American-British; WHO, World Health Organization; RA, refractory anemia; RCMD, refractory cytopenia with multilineage dysplasia; RARS, RA with ringed sideroblasts; RS, ringed sideroblasts; RAEB, RA with excess of blasts; RAEB-T, RAEB in transformation; AML, acute myeloid leukemia; CMML, chronic myelomonocytic leukemia; MPD, myeloproliferative disorder. | |
| †Requires ≥ 6 months of anemia unrelated to other causes. | |
| ‡< 5% marrow blasts, micromegakaryocytes, thrombocytosis. | |
| §MDS: WBC ≤13,000/mm3; MPD: WBC >13,000/mm3. | |
| RA | RA (unilineage)† 5q− syndrome‡ RCMD |
| RARS | RARS† (unilineage) RCMD (with RS) |
| RAEB | RAEB-I RAEB-II |
| RAEB-T | AML |
| CMML | MDS/MPD§ |
| — | Unclassified |
| FAB1 . | WHO3,4 . |
|---|---|
| Abbreviations: MDS, myelodysplastic syndrome; FAB, French-American-British; WHO, World Health Organization; RA, refractory anemia; RCMD, refractory cytopenia with multilineage dysplasia; RARS, RA with ringed sideroblasts; RS, ringed sideroblasts; RAEB, RA with excess of blasts; RAEB-T, RAEB in transformation; AML, acute myeloid leukemia; CMML, chronic myelomonocytic leukemia; MPD, myeloproliferative disorder. | |
| †Requires ≥ 6 months of anemia unrelated to other causes. | |
| ‡< 5% marrow blasts, micromegakaryocytes, thrombocytosis. | |
| §MDS: WBC ≤13,000/mm3; MPD: WBC >13,000/mm3. | |
| RA | RA (unilineage)† 5q− syndrome‡ RCMD |
| RARS | RARS† (unilineage) RCMD (with RS) |
| RAEB | RAEB-I RAEB-II |
| RAEB-T | AML |
| CMML | MDS/MPD§ |
| — | Unclassified |