The two most common types of brain tumors in children are astrocytoma and medulloblastoma. Astrocytoma is an aggressive, malignant tumor that can arise in any part of the brain or spinal cord. It is most common in children under 10 years of age. Medulloblastoma is the most common malignant brain tumor in children, accounting for approximately 20-30% of all pediatric brain tumors. It is a fast-growing cancer that typically starts in the cerebellum, the part of the brain located at the back of the head. Treatment for these types of tumors can include surgery, radiation, chemotherapy, and targeted drug therapy.