Proposal for refining the definition of dysgranulopoiesis in acute myeloid leukemia and myelodysplastic syndromes.

Studies of morphology of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) refer to the definitions produced by the French-American-British (FAB) group and by the World Health Organization expert group. To clarify some points regarding the dysgranulopoiesis that are still unclear we analyzed a series of 98 neutrophils from MDS patients with regard to granularity, nuclear segmentation, the appearance of the chromatin, the presence of giant neutrophils, and the presence of nuclear chromatin extensions. We found that cells with at least 2/3 reduction of the content of granules, Pelger-like neutrophils, dysplastic non-Pelger cells, neutrophils with abnormal clumping of the chromatin, and macropolycytes could be recognized as dysplastic and included in the 10% count recommended by these two classifications. In addition, we suggest that neutrophils with more than 4 nuclear projections could be recognized as a relevant dysplastic feature.