Hematologic, cytogenetic, and molecular studies demonstrated the heterogeneity of such cases, including the first example of clinically typical myelofibrosis (MF) associated with a bcr gene rearrangement characteristic of chronic myelogenous leukemia (CML).
Leukocytosis, mild anemia, thrombocytosis, and panhyperplasia in the marrow characterize the early stages of most of the CMPD, whereas extramedullary hematopoiesis (such as in the spleen or liver), peripheral cytopenias (anemia, leukopenia, or thrombocytopenia), and myelofibrosis, with or without osteosclerosis, reflect the changes seen in the later stages.