[Histopathology and clinical aspects of primary myelodysplastic syndrome].

The histopathology of bone marrow in primary myelodysplastic syndromes (MDS) is described, with reference to the FAB classification. Variants such as hypoplastic, thrombocythemic and fibrotic MDS are recognized from their histopathology and must be incorporated in the FAB classification. The clinical significance of hypoplastic, thrombocythemic and fibrotic variants is illustrated by the survival rates and leukemic transformation in these patients. Histopathological classification according to the FAB system corresponds with cytological classification, as proven by the distribution of the subtypes, blood values, leukemic transformation rates and survival times. Finally it is even possible to elaborate a prognostic score for survival based on histological features of diagnostic biopsies, which emphasizes the importance of histopathological examination of bone marrow in MDS patients.