Central nervous system (CNS) tumors include both non-malignant and malignant tumors of the brain and spinal cord. Primary malignant CNS tumors are the second most common childhood malignancies, after hematological malignancies, and are the most common pediatric solid organ tumor.Although progress has been made in the treatment of childhood tumors, significant mortality and morbidity are still associated with malignant brain tumors.In children, primary CNS tumors predominate, and about half are located in the posterior fossa In contrast, most CNS tumors in adults are metastatic lesions to the cerebral cortex. These differences translate to differences in clinical presentation between pediatric and adult malignant CNS tumors.Tumors of neuroepithelial tissue (incidence: 3.4 per 100,000 person-years) are also referred to as gliomas, which are tumors derived from glial cells (ie, astrocytes, oligodendrocytes, and ependymal cells). These tumors account for almost 75 percent of all primary childhood CNS tumors, and includeAstrocytic tumors.Embryonal CNS tumorsCNS primitive neuroectodermal tumors
