The document summarizes different types of primary and secondary brain tumors: - Primary brain tumors rarely metastasize outside the brain while secondary or metastatic tumors are more common. - Common primary brain tumors in adults include astrocytomas, meningiomas, and schwannomas. In children, common tumors are medulloblastoma and ependymoma. - Astrocytomas range from low to high grade and include glioblastoma multiforme, the most aggressive type. Medulloblastoma is a small, blue round cell tumor most common in children. Meningiomas form from meningiothelial cells and schwannomas originate from schwann cells.

1. CNS TUMORS