Myeloid malignancies: myelodysplastic syndromes, myeloproliferative disorders, and acute myeloid leukemia.

As hematopoietic cells proceed in differentiation from stem cells to committed progenitors to later stage mature forms, they undergo a sequence of morphologic, immunophenotypic, and functional changes that are a consequence of interaction between the underlying cellular genetic program and environmental cues, are linear for each cell lineage, and result in a pattern of antigenic expression related to lineage and stage of maturation. The antigenic patterns characteristic of normal maturation have been elucidated systematically and found invariant between individuals. Deviation from this pattern is a hallmark of hematopoietic neoplasia. Application of these principles to myelodysplastic syndromes, myeloproliferative disorders, and acute myeloid leukemia is presented and illustrated.