Chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia
ICD-O-2 Morphology
9868/3: Chronic myelomonocytic leukemia
Effective 1992 - 2000
ICD-O-3 Morphology
9945/3: Chronic myelomonocytic leukemia
Effective 2001 and later
for cases diagnosed 1992 and later
Primary Site(s)
Primary site must be bone marrow (C421)

9 - Grade/differentiation unknown, not stated, or not applicable
Module Rule
Alternate Names
Chronic myelomonocytic leukemia in transformation
Chronic myelomonocytic leukemia, NOS
Chronic myelomonocytic leukemia, Type I
Chronic myelomonocytic leukemia, Type II
Chronic myelomonocytic syndrome
CMML with eosinophilia
Subacute myelomonocytic leukemia
CMML is a clonal disorder of a bone marrow stem cell, in which monocytosis is a major defining feature. The clinical, hematologic and morphologic features of CMML are heterogeneous, and vary along a spectrum from predominantly myelodysplastic to mainly myeloproliferative in nature.

A slowly progressing type of myelodysplastic/myeloproliferative disease in which too many myelomonocytes (a type of white blood cell) are in the bone marrow, crowding out other normal blood cells, such as white blood cells, red blood cells and platelets. Also called chronic myelomonocytic leukemia.
Abstractor Notes
The peripheral blood and bone marrow are always involved. The spleen, liver, skin and lymph nodes are the most common sites of extramedullary infiltration. The peripheral blood has persistent monocytosis. There are fewer than 20% blasts in the peripheral blood and bone marrow.

The physician will run tests to exclude the BCR-ABL1 fusion gene, the rearrangement of PDGFRA or PDGFRB. The physician uses the information from these tests to do a diagnosis of exclusion (clinical diagnosis) of Chronic myelomonocytic leukemia.
Definitive Diagnostic Methods
Bone marrow biopsy
Clinical diagnosis
Genetic testing
Peripheral blood smear
Genetics Data
Structural abnormalities of 12p
Bone marrow transplant
Transformations from
Corresponding ICD-9 Codes
205.1 Chronic myeloid leukemia
Corresponding ICD-10 Codes
C92.1 Chronic myeloid leukemia
Corresponding ICD-10-CM Codes (U.S. only)
C93.1 Chronic myelomonocytic leukemia (effective October 01, 2015)
Signs and Symptoms
Increased white blood count (WBC) (in some cases)
Night sweats
Weight loss
Progression and Transformation
Transformation to AML occurs in ~15-30% of cases
Epidemiology and Mortality
Age: 65-75 years median age
Incidence: 12.8 cases per 100,000 persons per year
Sex: male predominance
Survival: 20-40 months median survival