Juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia
ICD-O-3 Morphology
9946/3: Juvenile myelomonocytic leukemia
Effective 2001 and later
for cases diagnosed 2001 and later
Primary Site(s)
Primary site must be bone marrow (C421)

Not Applicable
Module Rule
Alternate Names
Juvenile chronic myelomonocytic leukemia
A rare form of childhood leukemia in which cancer cells often spread into tissues such as the skin, lung and intestines.

JMML is a clonal hematopoietic disorder of childhood that is characterized by proliferation principally of the granulocytic and monocytic lineages. Erythroid and megakaryocytic abnormalities frequently present, in keeping with evidence that JMML arises from a BM stem cell with multilineage potential in the myeloid series.
Abstractor Notes
The peripheral blood and bone marrow are always involved; proliferation of the granulocytic and monocytic lineages. Blasts plus promonocytes account for <20% of PB and BM. Leukemic infiltrates are common in the skin.

The physician will test to confirm that the Philadelphia chromosome and the BCR-ABL1 fusion gene are absent.

Although JMML rarely transforms into acute leukemia, it is a rapidly-fatal disease for most children if left untreated.

In the absence of effective treatment most children die from organ failure, such as respiratory failure, due to leukemic infiltration. Stem cell transplant can cure about half of the patients.
Definitive Diagnostic Methods
Bone marrow biopsy
Genetic testing
Peripheral blood smear
Genetics Data
Stem cell 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)
C93.3 Juvenile myelomonocytic leukemia (effective October 01, 2015)
Signs and Symptoms
Easy bruising or bleeding
Enlarged tonsils
Frequent infections
Pain or a feeling of fullness below the ribs
Pale skin
Shortness of breath
Skin rashes
Progression and Transformation
Rarely transforms to acute myeloid leukemia
Epidemiology and Mortality
Age: 0-14 years (75% of cases <3 years of age)
Incidence: 1.3 per million children 0-14 years of age per year
Sex: male predominance
Survival: 1 year (without stem cell transplant). Cure is possible for patients who have a stem cell transplant