NEW CLASSIFICATION OF THE MYELODYSPLASTIC (PRELEUKAEMIAS) SYNDROMES

The myelodysplastic syndromes (MDS) is a group of clonal haematopoietic stem cells diseases, char- acterized by cytopenia, dysplasia in myeloid cell lines and increased risk of development of acute leukemias. The WHO classification system distignishes such subgroups of MDS: refractory cytopenias with unilineage displasia, re- fractory anemia with ring sideroblasts, refractory cytope- nia with multilineage dysplasia, refractory anemia with excess of blasts (RAEB-1 and RAEB-2), myelodysplas- tic syndrome unclassified, MDS associated with isolated del(5q) and refractory cytopenia of childhood.