General Information About Adult Brain Tumors
(See the PDQ summary on Childhood Astrocytomas Treatment for more information about astrocytoma in children.)
An oligodendroglial tumor begins in brain cells called oligodendrocytes, which help keep nerve cells healthy. Oligodendrocytes are a type of glial cell and are sometimes called a glioma. Grades of oligodendroglial tumors include the following:
- Oligodendroglioma (grade II): An oligodendroglioma grows and spreads slowly and the tumor cells look very much like normal cells. This type of tumor most often forms in the cerebrum. An oligodendroglioma is most common in adults.
- Anaplastic oligodendroglioma (grade III): An anaplastic oligodendroglioma grows quickly and the tumor cells look very different from normal cells. It may grow in one place or in many places throughout the brain. This type of cancer most often forms in the cerebrum.
A mixed glioma is a brain tumor that has two types of tumor cells in it - oligodendrocytes and astrocytes. This type of tumor most often forms in the cerebrum.
- Oligoastrocytoma (grade II): An oligoastrocytoma is a slow-growing tumor and the tumor cells don't look very different from normal cells.
- Anaplastic oligoastrocytoma (grade III): The tumor cells in an anaplastic oligoastrocytoma look very different from normal cells.
An ependymal tumor usually begins in cells that line the fluid-filled spaces in the brain and around the spinal cord. Ependymal cells are a type of glial cell and are sometimes called a glioma. Grades of ependymal tumors include the following:
- Ependymoma (grade I or II): A grade I or II ependymoma grows slowly and has cells that look very much like normal cells. There are two types of grade I ependymoma - myxopapillary ependymoma and subependymoma. These tumors are most common in adults. A grade II ependymoma grows in the ventricle and its connecting paths or in the spinal cord. It is most common in children and young adults and in people with neurofibromatosis type 2 (NF2). (See the PDQ summary on Childhood Ependymoma Treatment for more information.)
- Anaplastic ependymoma (grade III): An anaplastic ependymoma grows very quickly and has a poor prognosis.
Embryonal Cell Tumors: Medulloblastoma (Grade IV)
A medulloblastoma is a type of embryonal tumor. The tumor forms in brain cells when the fetus is beginning to develop. This type of brain tumor often begins in the cerebellum. The tumor may spread from the brain to the spine through the cerebrospinal fluid (CSF). A medulloblastoma occurs most often in children or young adults and in people with Turcot syndrome type 2 or nevoid basal cell carcinoma syndrome.
See the following PDQ summaries for more information on embryonal tumors in children:
- Childhood Central Nervous System Embryonal Tumors Treatment
- Childhood Central Nervous System Atypical Teratoid/Rhabdoid Tumor Treatment
Pineal Parenchymal Tumors