CMML

AKA Chronic MyeloMonocytic Leukemia is an abnormal Bone Marrow Stem cell disorder that has characteristic features of both a Myeloproliferative Neoplasm ("cytosis" specifically Monocytosis and splenomegaly) and a Myelodysplastic syndrome (dysplastic cells). Hence, per WHO 2008 criteria, it belongs to the category of Myeloproliferative/Myelodysplastic disorders. At the time of diagnosis, they usually present with leukocytosis and history of a "persistent Monocytosis" is typically required. As opposed to CML, there is no BCR-ABL1 fusion.