WHO MDS
CLASSIFICATION SUBTYPES
World Health Organization (WHO) Classification Subtypes*
The WHO classification of MDS was updated in 2018. The WHO classification system has incorporated the key parts of the FAB classification system. The FAB Classification has been replaced by the WHO Classification System and is largely only used for historic reference and comparison. The WHO categories are largely based on morphology (how the cells look under the microscope), the presence of blasts (immature cells), how many cell lines are involved, and specific cytogenetic or molecular findings.
*The subtypes are based on the 2018 WHO Classification System. If you were classified under the 2008 WHO System (RA, RCUD, RARS, RCMD, RCMD-RS, RAEB-1, RAEB-2) your corresponding 2018 classification subtype is:
| 2008 Classification | 2018 Classification |
|---|---|
| RA | MDS |
| RCUD | MDS-SLD |
| RARS | MDS-SLD with ring sideroblasts |
| RCMD | MDS-MLD |
| RCMD-RS | MDS-MLD with ring sideroblasts |
| RAEB-1 | MDS-EB1 |
| RAEB-2 | MDS-EB2 |
| 5q- (5q minus) Syndrome | MDS with isolated del(5q) |
| Unclassified MDS | MDS-U (MDS, unclassifiable) |
