Brain Tumors in Adults

What is a Brain Tumor?

A brain tumor is a cluster of abnormal cells that grows out of control  in your brain. Some brain tumors are benign, which means the cells aren’t cancerous. Others are malignant, meaning they’re cancerous. Brain tumors are classified as primary if they start in your brain. They’re considered secondary if the cancer started somewhere else in your body and spread to your brain.

Types of Brain Tumors

Primary brain tumors emerge from the various cells that make up the brain and central nervous system and are named for the kind of cell in which they first form. There are more than 100 different kinds of brain tumors. The most common types in adults are:

  • Gliomas: These tumors start in the glial cells, which are cells that help keep nerves healthy. They are most often malignant. There are several categories of gliomas, based on which specific cells they target. Astrocytomas are most common in adults. A glioblastoma is the most aggressive type of glial tumor.
  • Meningiomas:These form in the meninges, the thin layer of tissue that covers the brain and spinal cord. They are not cancerous, but can cause complications by putting pressure on your brain. 
  • Schwannomas: These damage the protective coating of nerve cells. They’re not cancerous, but often cause hearing loss or problems with balance.
  • Pituitary adenomas: These form on the pituitary gland at the base of the brain that produces important hormones. They’re usually not cancerous and are slow growing.

Benign vs. Malignant Brain Tumors

Benign brain tumors are noncancerous. They aren’t aggressive and normally don’t spread to surrounding tissues, although they can be serious and even life-threatening. Benign brain tumors usually have clearly defined borders and usually aren’t deeply rooted in brain tissue. This makes them easier to surgically remove, assuming they’re in an area of the brain that can be safely operated on. But even after they've been removed, they can still come back. Benign tumors are less likely to come back than cancerous ones.

Even a benign brain tumor can be a serious health problem. Brain tumors can damage the cells around them by causing inflammation and putting increased pressure on the tissue under and around it, as well as inside the skull.


Malignant primary brain tumors are cancers that start in the brain, typically grow faster than benign tumors, and quickly invade surrounding tissue. Although brain cancer rarely spreads to other organs, it can spread to other parts of the brain and central nervous system.

Secondary brain tumors are cancerous. They come from cancer that started somewhere else in your body and spread, or metastasized, to the brain. About 1 in 4 people with cancer develops a secondary brain tumor.


Brain Tumor Symptoms

Symptoms of brain tumors vary according to the type of tumor and the location. Because different areas of the brain control different functions of the body, where the tumor lies affects the way symptoms are manifested.

Some tumors have no symptoms until they’re quite large and then cause a serious, rapid decline in health. Other tumors may have symptoms that develop slowly.

Common symptoms include: 

  • Headaches, which may not get better with the usual headache remedies. You may notice you’re getting them more often, or they’re worse than usual. 

  • Seizures, particularly in a person who doesn't have a history of seizures

  • Changes in speech or hearing

  • Changes in vision

  • Balance problems

  • Problems with walking

  • Numbness or tingling in the arms or legs

  • Problems with memory

  • Personality changes

  • Inability to concentrate

  • Weakness in one part of the body

  • Morning vomiting without nausea

It's important to keep in mind that these symptoms can be caused by a number of different conditions. Don't assume you have a brain tumor just because you have some of the symptoms. Check with your doctor.


Most of the time, doctors can’t determine what causes a brain tumor.There are only a few known risk factors for brain tumors in adults. 

  • Exposure to radiation: Children who receive radiation to the head have a higher risk of developing a brain tumor as adults.

  • Family history: Some brain tumors are linked to certain rare genetic conditions such as neurofibromatosis or Li-Fraumeni syndrome. 

  • Age: People between ages 65 and 79 make up the population most likely to be diagnosed with a brain tumor.

  • No history of chickenpox:One study has found people who had chickenpox are less likely to get gliomas.


Brain Tumor Diagnosis

To diagnose a brain tumor, the doctor starts by asking questions about your symptoms and taking a personal and family health history. Then they perform a physical exam, including a neurological exam. If there's reason to suspect a brain tumor, the doctor may request one or more of the following tests:

  • Imaging studies such as a CT (CAT) scan orMRI to see detailed images of the brain

  • Angiogram or MRA, which involve the use of dye and X-rays of blood vessels in the brain to look for signs of a tumor or abnormal blood vessels

The doctor may also ask for a biopsy to determine whether or not the tumor is cancer. A tissue sample is removed from the brain either during surgery to remove the tumor or with a needle inserted through a small hole drilled into the skull before treatment is started. The sample is then sent to a lab for testing.

Brain Tumor Treatment

Your doctor will consider several factors in deciding how to treat your brain tumor, including:

  • The location of the tumor

  • The size of the tumor

  • The type of tumor

  • Whether the tumor has spread

  • Your overall health

  • Potential complications

Surgery to remove the tumor is typically the first option once a brain tumor has been diagnosed. However, some tumors can't be surgically removed because of their location in the brain. In those cases, chemotherapy and radiation therapy may be options for killing and shrinking the tumor. Sometimes, chemotherapy or radiation is also used after surgery to kill any remaining cancer cells. Tumors that are deep in the brain or in areas that are difficult to reach may be treated with Gamma Knife therapy, which is a form of highly focused radiation therapy.

Because treatment for cancer also can damage healthy tissue, it's important to discuss possible side and long-term effects of whatever treatment is being used with your doctor. The doctor can explain the risk and the possibility of losing certain faculties. The doctor can also explain the importance of planning for rehabilitation following treatment. Rehabilitation could involve working with several different therapists, such as:

  • Physical therapist to regain strength and balance

  • Speech therapist to address problems with speaking, expressing thoughts, or swallowing

  • Occupational therapist to help manage daily activities such as using the bathroom, bathing, and dressing

WebMD Medical Reference Reviewed by Brunilda Nazario, MD on July 02, 2020



MedlinePlus Encyclopedia: "Brain tumor - primary - adults."

National Cancer Institute: "National Cancer Institute Brain Tumor Study in Adults: Fact Sheet."

National Cancer Institute: "What You Need to Know About Brain Tumors."

National Cancer Institute: "General Information About Brain Tumors."

American Brain Tumor Association: "Symptoms."

National Cancer Institute: "Adult Brain Tumors Treatment."

National Brain Tumor Society: "Quick Brain Tumor Facts." "Brain Tumor Education."

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