Childhood ependymoma is a cancer that forms in the ependymal cells that line the ventricles and passageways in the brain and the spinal cord. Ependymal cells make cerebrospinal fluid (CSF). Childhood ependymoma comprises approximately 9 percent of all childhood brain tumors, representing about 200 cases per year in the United States, according to the National Cancer Institute.
The World Health Organization (WHO) groups ependymal tumors into four main subtypes – subependymoma (WHO Grade I), myxopapillary ependymoma (WHO Grade I), ependymoma (WHO Grade II), and anaplastic ependymoma (WHO Grade III). The grade of a tumor describes how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Low-grade (Grade I) cancer cells look more like normal cells than high-grade cancer cells (Grade II and III). Low-grade cancers also tend to grow and spread more slowly than Grade II and III cancer cells.
Ependymomas can form anywhere in the fluid-filled ventricles and passageways in the brain and spinal cord. Most ependymomas form in the fourth ventricle and affect the cerebellum and the brain stem.Childhood Ependymoma Treatment (PDQ®)
Source: National Cancer Institute