aggressive chronic leukemias 
limited therapeutic armamentarium compared with many other hematologic malignancies.
monocytosis should be especially evaluated in any patient with a pathologic diagnosis of MDS as it is the peripheral monocytosis that is the sole differentiator of CMML in many cases
in the absence of genetic abnormalities, a diagnosis of CMML should be established only after the patient has been followed for weeks to months with repeated laboratory testing rather than applying the diagnosis based upon the first abnormal peripheral blood count 
by definition do not exhibit evidence of BCR-ABL1 or the Philadelphia chromosome or rearrangements of the genes encoding the platelet derived growth factor receptor (PDGFRA or PDGFRB)
prognosis of patients with CMML is poor with an expected median survival of approximately 30 months
Global MD Anderson scoring system (MDACC) and Mayo scores (calculator 2) 
allogeneic hematopoietic cell transplantation (allo-HCT) is presently the only therapeutic maneuver that can substantively alter the natural history of CMML, resulting in cure in a small proportion of patients. Patients with low risk disease by both the MDACC and Mayo scoring systems can delay transplant until progression. 
outside of allo-HCT, there is no pharmacologic agent that has been proven to alter the natural history of this disease
transfusions
cytoreductive therapy (eg, hydroxyurea) bij dramatic proliferative symptoms
hypomethylating agents are preferred for patients with cytopenias and those with myeloproliferative symptoms in whom hydroxyurea is ineffective
 Xicoy, lage CPSS *Such et al" en EPO, Spaans/Deense studie, EPO
kleine studies:
?Oral etoposide [76]
?Low dose cytarabine [77]
?Thioguanine [78]
?Lenalidomide and melphalan [79]

CMML-1: <5% blasten perifeer bloed
CMML-2: 5-20% 
Persistent peripheral blood monocytosis >1x109/L No Philadelphia chromosome or BCR-ABL1 fusion gene No rearrangement of PDGFRA or PDGFRB (should be specifically excluded in cases with eosinophilia) Fewer than 20 percent blasts* in the blood and in the bone marrow Dysplasia in one or more myeloid lineages. If myelodysplasia is absent or minimal, the diagnosis of CMML may still be made if the other requirements are met, and:
An acquired, clonal cytogenetic or molecular genetic abnormality is present in the haemopoietic cells, or 
The monocytosis has persisted for at least three months and 
All other causes of monocytosis have been excluded