Chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a type of leukemia, which are cancers of the blood-forming cells of the bone marrow. In adults, blood cells are formed in the bone marrow, by a process that is known as haematopoiesis. In CMML, there are increased numbers of monocytes and immature blood cells (blasts) in the peripheral blood and bone marrow, as well as abnormal looking cells (dysplasia) in at least one type of blood cell. CMML shows characteristics of a myelodysplastic syndrome (MDS); a disorder that produces abnormal looking blood cells, and a myeloproliferative neoplasm (MPN); a disorder characterised by the overproduction of blood cells. For this reason, CMML was reclassified as a MDS/MPN overlap disorder in 2002. For a diagnosis of CMML, the World Health Organization (WHO) states that the blood monocyte count must be >1x109/L, no Philadelphia chromosome or mutations in the PDGFRA or PDGFRB gene should be present, the blast count must be 10% and