[Myelodysplastic syndromes].

The myelodysplastic syndromes (MDS) are clonal disorders of hematopoietic stem cells. The transformation rate to acute myeloid leukemia reaches 30-40 %. In early phases of the disease, the clonal cells have a growth advantage but suffer from premature apoptosis, which explains the paradox of a cellular bone marrow coupled to peripheral blood cytopenias. At later stages, additional genetic aberrations accumulate and lead to proliferation with leukemic transformation. Patients with early MDS benefit from supportive therapy or growth factors. Sometimes, immunological or immunomodulatory treatments can suppress the malignant clone and strengthen normal hematopoiesis for sustained periods. Patients with advanced MDS are usually treated with cytotoxic therapy followed by allogeneic stem cell transplantation or with epigenetic therapy to initiate differentiation and slow down proliferation.