Juvenile Myelomonocytic Leukemia

**Semantic type:** Neoplastic Process

**Definition:** A clonal myeloid disorder of childhood previously classified as myelodysplastic/myeloproliferative neoplasm. It is characterized by the presence of monocytic proliferation in peripheral blood, less than 20% blasts in bone marrow and peripheral blood, splenomegaly, and the absence of BCR-ABL1 fusion. Almost all patients carry mutations of the RAS pathway.

**Synonyms:** - JCML - JMML - JMML - JMML - Juvenile Chronic Myelogenous Leukemia - Juvenile Chronic Myeloid Leukemia - Juvenile Chronic Myelomonocytic Leukemia - Juvenile myelomonocytic leukemia - Juvenile myelomonocytic leukemia - juvenile myelomonocytic leukemia