Adult Brain Tumors, Part 2

by National Cancer Institute

(Page 2 of 4)

Oligodendroglial Tumors

Oligodendroglial tumors begin in the brain cells called oligodendrocytes, which support and nourish nerve cells. Grades of oligodendroglial tumors include the following:

Oligodendroglioma (grade II): Oligodendrogliomas are slow-growing tumors with cells that look very much like normal cells. These tumors occur most often in patients between the ages of 40 and 60 years.

Anaplastic oligodendroglioma (grade III): Anaplastic oligodendrogliomas grow quickly and the cells look very different from normal cells.

Mixed Gliomas

Mixed gliomas are brain tumors that contain more than one type of cell. The prognosis is affected by the cell type with the highest grade present in the tumor.

Oligoastrocytoma (grade II): Oligoastrocytomas are slow-growing tumors composed of cells that look like astrocytes and oligodendrocytes.

Anaplastic oligoastrocytoma (grade III): These are higher-grade oligoastrocytomas. The average age of patients developing anaplastic oligoastrocytomas is 45 years.

Ependymal Tumors

Ependymal tumors usually begin in cells that line the spaces in the brain and around the spinal cord. These spaces contain cerebrospinal fluid, a liquid that cushions and protects the brain and spinal cord. Grades of ependymal tumors include the following:

Grade I and grade II ependymomas: These ependymomas grow slowly and have cells that look very much like normal cells. They can often be removed completely by surgery.

Anaplastic ependymoma (grade III): Anaplastic ependymomas grow very quickly.

Medulloblastoma (grade IV)

Medulloblastomas are brain tumors that begin in the lower back of the brain. They are formed from abnormal brain cells at a very early stage in development. Medulloblastomas are usually found in children or young adults between the ages of 21 and 40 years. This type of cancer may spread from the brain to the spine through the cerebrospinal fluid.

Pineal Parenchymal Tumors

Pineal parenchymal tumors form from parenchymal cells or pinocytes, the cells that make up most of the pineal gland. These differ from pineal astrocytic tumors, which are astrocytomas that form in tissue that supports the pineal gland. Grades of pineal parenchymal tumors include the following:

Pineocytomas (grade II): Pineocytomas are slow-growing pineal tumors that occur most often in adults aged 25 to 35.

Pineoblastomas (grade IV): Pineoblastomas are rare and highly malignant. They usually occur in children.

Meningeal Tumors

Meningeal tumors form in the meninges, thin layers of tissue that cover the brain and spinal cord. Types of meningeal tumors include the following:

Grade I meningioma: Meningiomas are the most common meningeal tumor. Grade I meningiomas are slow-growing and benign. They are found most often in women.

Grade II and III meningiomas and hemangiopericytomas: These are rare malignant meningeal tumors. They grow quickly and are likely to spread within the brain and spinal cord. Grade III meningiomas are more common in men. Hemangiopericytomas often recur after treatment and most of them spread to other parts of the body.

Germ Cell Tumor

Germ cell tumors arise from germ cells, cells that are meant to form sperm in the testicles or eggs in the ovaries. These cells may travel to other parts of the body and form tumors. Types of germ cell tumors include germinomas, embryonal cell carcinomas, choriocarcinomas, and teratomas. They can occur anywhere in the body and can be either benign or malignant. In the brain, they usually form in the center, near the pineal gland, and can spread to other parts of the brain and spinal cord. Most germ cell tumors occur in children.

Craniopharyngioma (grade II)

Craniopharyngiomas occur in the sellar region of the brain, near the pituitary gland. The pituitary gland is a small organ about the size of a pea, located at the base of the brain. This gland controls many of the body's functions, especially growth. In adults, these tumors occur most often after the age of 50 years. Craniopharyngiomas can press on vital brain tissue and cause symptoms to appear. The tumors can also block fluid in the brain and cause swelling. The prognosis is good for craniopharyngiomas that are completely removed in surgery.

Pituitary tumors also occur in this region.

Other Adult Brain Tumors

For information about other types of adult brain tumors, refer to the PDQ health professional summary on Adult Brain Tumors.

Recurrent Adult Brain Tumor

Recurrent adult brain tumor is a tumor that has recurred (come back) after it has been treated. Adult brain tumors often recur, sometimes many years after the first tumor. The tumor may come back in the brain or in other parts of the body.

Metastatic Brain Tumors

The types of cancer that commonly spread to the brain are cancers of the lung, breast, unknown primary site, melanoma, and colon. About half of metastatic spinal cord tumors are caused by lung cancer.

Prognosis depends on the following:

• Whether the patient is younger than 60 years.
• Whether there are fewer than 3 tumors in the brain and/or spinal cord.
• The location of the tumors in the brain and/or spinal cord.
• How well the tumor responds to treatment.
• Whether the primary tumor continues to grow or spread.

The prognosis is better for brain metastases from breast cancer than from other types of primary cancer. The prognosis is worse for brain metastases from colon cancer.

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