[Cytologic aspects and nosographic update of myelodysplastic syndromes].

A discussion is provided of the cytologic abnormalities in myelodysplastic syndromes (MDS), which remain central to the diagnosis and classification of these conditions. Accurate identification of the blast cells is essential since the proportion of these cells is of considerable prognostic significance. A description is given of the FAB classification scheme, which is both simple and reproducible. Prognostic scoring systems based on bone marrow blast proportion, cytopenias, and karyotypic abnormalities are also discussed.