Brain Cancer Types
The World Health Organization (WHO) has nine categories of primary brain tumors, which are based on the types of cells in which the tumors originate. Gliomas are primary brain tumors that are made up of glial cellscells that provide important structural support for the nerve cells in the brain.
Infiltrative astrocytoma and glioblastoma multiforme (GBM) account for nearly 85 percent of all brain tumors, with the remainder spread among the other seven types.
|Tumor Type||Cell Origin|
|Mixed oligoastrocytoma||Oligodendocytes and astrocytes|
|Glioblastoma multiforme (GBM)||Astrocytes and other brain cell types (astroblasts, spongioblasts)|
|Medulloblastoma||Primitive neural cell|
Tumor grade: All gliomas, except GBM, range from well-differentiated tumors (low grade) to anaplastic, that is, completely chaotic, undifferentiated (high grade). High-grade tumors are more aggressive and are associated with lower survival rates. In terms of surviving the disease, the grade of the tumor is the most important feature.
Primary Brain Tumors
A primary brain tumor usually develops through a complex series of molecular and cellular mutations and may take years to acquire enough mass to cause symptoms that bring the disease to a person's and/or a physician's attention.
Brain tumor types include the following:
- astrocytomamost common type of brain tumor in children; originates in the brainstem, cerebellum, white matter of the cerebrum, or spinal cord
- brainstem gliomaoriginates in the medulla, pons, or midbrain
- choroid plexus papillomaoriginates in the ventricles
- ependymomaoriginates in the membrane that lines the bentricles and central canal of the spine
- glioblastoma multiformemost common types in adults; originates in glial cells in the berebrum
- medulloblastomasecond most common type in children; originates in the fourth cerebral ventricle and the cerebellum; often invades the meninges
Other types of primary brain cancer include the following:
- acoustic neuromaoriginates in the vestibulocochlear nerve
- lymphomaoriginates in lymphocytes; common in HIV/AIDS patients
- meningiomaoriginates in the meninges
- pineal gland tumorrare; originates in the pineal gland
- pituitary adenomaoriginates in surface cells of the pituitary gland
- schwannomaoriginates in cells of the myelin sheath that covers neurons
Secondary (Metastatic) Brain Tumors
In adults, the most common types of cancer that spread to the brain are the following:
- breast cancer
- renal cell carcinoma
- lung cancer
- colorectal cancer
The prognosis for people who develop brain metastases is generally poor.