Cancer still represents one of the leading causes of death in children. Tumors of the CNS account for 17% of childhood malignancies, with the highest incidence during the first 5 years of life. Some types of tumors are more common in children than in adults. The most common childhood tumors are neuroblastoma, medulloblastoma, low-grade astrocytomas, ependymomas, craniophayngiomas, and brain stem gliomas. The incidence rate of primary tumors of children between the ages 0 to 19 years is approximately 4 cases/100,000. The most commonly occurring childhood cancer is leukemia. It is estimated that 43,050 new cases of leukemia were diagnosed in the United States in 2010 with 21,840 deaths.