The myelodysplastic syndromes: a personal recollection of four decades of classification and prognostic scoring systems.

In 1976 the French-American-British (FAB) Leukemia Working Group proposed the first definitions of patients with myelodysplastic syndromes (MDS), namely refractory anemia with excess blasts (RAEB) and chronic myelomonocytic leukemia (CMML). Subsequent publications resulted in additional subgroups that had prognostic significance. Incorporation of the subgroupings by the World Health Organization and additional fine tuning of the degrees of morphologic dysplasia and percentage of blasts have enhanced the classification. Several prognostic scoring systems have added degrees of cytopenia, cytogenetic aberrations and molecular genetic mutations that allow care providers to subdivide cases into lower, intermediate and higher grade categories.