Childhood brain tumors are a diverse group of diseases characterized by the abnormal growth of tissue contained within the skull. Brain tumors can be benign (without cancer cells) or malignant (contains cancer cells).The brain controls vital functions such as memory and learning, the senses (hearing, sight, smell, taste, and touch), and emotion.It also controls other parts of the body, including muscles, organs, and blood vessels. Other than leukemia and lymphoma, brain tumors are the most common type of cancer that occurs in children.The articles in this section refer only to tumors that originate in the brain (primary brain tumors). Metastatic brain tumors, which are secondary tumors formed by cancer cells that begin in other parts of the body and spread to the brain, are not included. Brain tumors can occur in both children and adults; however, treatment may be different for adults than for children.