Brain Tumor

According to the American Cancer Society, brain tumors are classified based on several different factors. These factors often guide both the treatment path and prognosis.

Brain tumors are usually assigned what’s called a “grade.”

• Lower grade tumors (grades 1 and 2) aren’t as likely to invade other tissues and grow more slowly. Prognosis for lower-grade tumors is generally better
• Higher grade tumors (grades 3 and 4) grow more rapidly, and are more likely to spread into other parts of the brain. These tumors often require more invasive treatment efforts, and may have a worse long-term prognosis

There are many different types of brain tumors, each usually classified by where they start in the brain or the type of cells they started from. Types of brain tumors include:

• Craniopharyngiomas, which are tumors that begin between the bottom of the brain and the pituitary gland. These tumors often press on the hypothalamus or the pituitary gland, and can cause issues with hormone secretion. Because they often occur close to the optic nerves, they can also cause problems with vision.
• Glioblastomas (also called GBM) are grade 4 malignant (cancerous)  tumors predominantly made up of abnormal astrocytic cells, but also contains a mix of different cell types (including blood vessels) and areas of dead cells (necrosis). Glioblastomas can invade nearby regions of the brain and may also sometimes spread to the opposite side of the brain. It is exceedingly rare for glioblastomas to spread outside of the brain and spinal cord.
• Gliomas, which are tumors that start in specialized cells in the brain called glial cells. There are several subtypes of gliomas, including ependymomas, astrocytomas and oligodendrogliomas. According to the American Cancer Society, about 30% of brain tumors are gliomas.
• Meningiomas are tumors that start in meninges, which are the tissues that cover the outer part of the brain and spinal cord. According to the ACS, meningiomas are the most common non-metastatic brain tumors in adults.
• Gangliogliomas, which are rare, slow-growing tumors that include a mix of both abnormal glial cells and neurons.
• Medulloblastomas, which are tumors that develop in the cerebellum from immature nerve cells called neuroectodermal cells. Medulloblastomas are more common in children and adults.
• Schwannomas (AKA neurilemmomas), which are tumors that develop from specialized cells that protect and insulate nerves called Schwann cells. These tumors can begin in any nerve in the skull. When they occur on the nerve that controls balance and hearing, they are called “vestibular schwannomas.” Other forms of schwannomas can intrude on the upper spinal cord, causing issues with bowel/bladder control, muscle weakness and other effects.

Both cancerous and non-cancerous brain tumors cause symptoms that can severely impact a person’s health. These symptoms can be caused by malignant tumors spreading to other parts of the brain, or non-cancerous tumors pressing on nerves, the pituitary gland, spinal cord or brain tissue. Brain tumors can also increase what’s called intracranial pressure inside the skull, either through the growth of the tumor, causing the brain to swell, or blocking the movement of cerebrospinal fluid that the brain needs to function.

According to the American Cancer Society, symptoms caused by increased intracranial pressure due to a brain tumor can include:

• Headaches that grow in severity over time. While most headaches aren’t related to brain tumors, headaches are the most common symptom experienced by those with brain tumors, occurring in about half of those diagnosed according to the ACS.
• Unexplained drowsiness
• Sudden onset of coma
• Unexplained nausea or vomiting
• Blurred vision
• Seizures, though over 90% of first-time seizures are not related to brain tumors.
• Changes to a person’s behavior or personality

Issues with balance or walking

Other symptoms related to brain tumors can vary, depending on the part of the brain in which the tumor occurs. According to the American Cancer Society, these symptoms can include:

• Problems understanding words or speaking, which can be related to a tumor in the cerebellum near the part of the brain responsible for speech and language.
• Numbness or weakness, usually on only one side of the body, which can be related to a tumor in the part of the cerebellum that controls movement.
• Changes to personality or problems thinking, which can be related to tumors in the cerebellum.
• Trouble walking, issues with control of the hands and feet, problems swallowing and/or issues with controlling the eyes, which may be related to tumors in the lower-rear part of the cerebellum.
• Vision problems, which can be related to tumors near the optic nerve or other cranial nerves that control eye movement.
• Hearing loss, numbness or pain in the face, trouble swallowing and/or balance issues, which may be related to tumors pressing on or invading nerves in the head.
• Bladder/bowel control issues and/or numbness/weakness in the arms and legs, which can be related to tumors near the spinal cord.
• Over- or underproduction of certain hormones, which can be related to tumors in the skull base or near the pituitary gland. This can create hormone imbalances that seriously impact the normal function of the body. Learn more about skull base and pituitary tumors.