The cause of primary brain tumors is unknown. Primary brain tumors may be:
- Not cancerous (benign)
- Invasive (spread to nearby areas)
- Cancerous (malignant)
Brain tumors are classified based on:
- The exact site of the tumor
- The type of tissue involved
- Whether it is cancerous
Brain tumors can directly destroy brain cells. They can also indirectly damage cells by pushing on other parts of the brain. This leads to swelling and increased pressure inside the skull.
Tumors can occur at any age. Many tumors are more common at a certain age. In general, brain tumors in children are very rare.
COMMON TUMOR TYPES
Astrocytomas are usually noncancerous, slow-growing tumors. They commonly develop in children ages 5 through 8. Also called low-grade gliomas, these are the most common brain tumors in children.
Medulloblastomas are the most common type of childhood brain cancer. Most medulloblastomas occur before age 10.
Ependymomas are a type of childhood brain tumor that can be benign (non-cancerous) or malignant (cancerous). The location and type of ependymoma determine the type of therapy needed to control the tumor.
Brainstem gliomas are very rare tumors that occur almost only in children. The average age at which they develop is about 6. The tumor may grow very large before causing symptoms.