Chronic Myelomonocytic Leukemia (CMML)

Differential Diagnosis

	CML-CP	CMML-1	Myeloid Neoplasm with PDGFRB
Ph Chromosome and/or BCR-ABL1 Translocation	Almost 100%	Absent	Absent
WBC	Left shifted neutrophilia*	Monocytosis, may have left shifted neutrophilia	Variable, may have left shifted neutrophilia, monocytosis, eosinophilia
Blood eosinophils	Often increased	Not increased	Variable
Blood basophils	Increased	Not increased	Variable
Blood monocytes	Variable,** <1x10³/μL	Always >1x10³/μL	often <1x10³/μL
Blood immature granulocytes	>20%	Usually <10%	often <10%
Blood blasts	Usually <2%	<5%	Variable
Granulocytic dysplasia	Absent	+/-	Variable

*rare p230 BCR-ABL1 isoform may show mature neutrophilia, **rare p190 BCR-ABL1 isoform associated with monocytosis

Non-neoplastic Monocytosis