Skip to content

    Cancer Health Center

    Font Size
    A
    A
    A

    Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies Treatment (PDQ®): Treatment - Health Professional Information [NCI] - General Information

    continued...

    Myeloid Leukemias in Children

    Approximately 20% of childhood leukemias are of myeloid origin and they represent a spectrum of hematopoietic malignancies.[3] The majority of myeloid leukemias are acute, and the remainder include chronic and/or subacute myeloproliferative disorders such as chronic myelogenous leukemia (CML) and juvenile myelomonocytic leukemia (JMML). Myelodysplastic syndromes occur much less frequently in children than in adults and almost invariably represent clonal, preleukemic conditions.

    Acute myeloid leukemia (AML) is defined as a clonal disorder caused by malignant transformation of a bone marrow-derived, self-renewing stem cell or progenitor, which demonstrates a decreased rate of self-destruction as well as aberrant, and usually limited, differentiation capacity. These events lead to increased accumulation in the bone marrow and other organs by these malignant myeloid cells. To be called acute, the bone marrow usually must include greater than 20% leukemic blasts, with some exceptions as noted in subsequent sections.

    CML represents the most common of the chronic myeloproliferative disorders in childhood, although it accounts for only 10% to 15% of childhood myeloid leukemia.[3] Although CML has been diagnosed in very young children, most patients are aged 6 years and older. CML is a clonal panmyelopathy that involves all hematopoietic cell lineages. While the white blood cell (WBC) count can be extremely elevated, the bone marrow does not show increased numbers of leukemic blasts during the chronic phase of this disease. CML is nearly always characterized by the presence of the Philadelphia chromosome, a translocation between chromosomes 9 and 22 (i.e., t(9;22)) resulting in fusion of the BCR and ABL genes. Other chronic myeloproliferative syndromes, such as polycythemia vera and essential thrombocytosis, are extremely rare in children.

    JMML represents the most common myeloproliferative syndrome observed in young children. JMML occurs at a median age of 1.8 years and characteristically presents with hepatosplenomegaly, lymphadenopathy, fever, and skin rash along with an elevated WBC count and increased circulating monocytes.[4] In addition, patients often have an elevated hemoglobin F, hypersensitivity of the leukemic cells to granulocyte-macrophage colony-stimulating factor (GM-CSF), monosomy 7, and leukemia cell mutations in a gene involved in RAS pathway signaling (e.g., NF1, KRAS/NRAS, PTPN11, or CBL).[4,5]

    1 | 2 | 3 | 4
    Next Article:

    Today on WebMD

    Colorectal cancer cells
    New! I AM Not Cancer Facebook Group
    Lung cancer xray
    See it in pictures, plus read the facts.
     
    sauteed cherry tomatoes
    Fight cancer one plate at a time.
    Ovarian cancer illustration
    Real Cancer Perspectives
     
    Jennifer Goodman Linn self-portrait
    Blog
    what is your cancer risk
    HEALTH CHECK
     
    colorectal cancer treatment advances
    Video
    breast cancer overview slideshow
    SLIDESHOW
     
    prostate cancer overview
    SLIDESHOW
    lung cancer overview slideshow
    SLIDESHOW
     
    ovarian cancer overview slideshow
    SLIDESHOW
    Actor Michael Douglas
    Article