Brain Tumors

What is a brain tumor?

A brain tumor is an abnormal mass of tissue in which cells grow and multiply uncontrollably, seemingly unchecked by the mechanisms that control normal cells. A brain tumor is also known as an intracranial tumor.

Brain tumors are classified into two main groups:

More than 150 different brain tumors have been documented, but the two main groups of brain tumors are termed primary and metastatic.

  • Primary brain tumors originate from the tissues of the brain or the brain's immediate surroundings. Primary tumors are further categorized as either:
    • glial (composed of glial cells) or non-glial (developed on or in the structures of the brain, including nerves, blood vessels, and glands)
    • benign (harmless) or malignant (harmful, aggressively malicious)
  • Metastatic brain tumors begin somewhere else in the body (such as the breast or lungs) and migrate to the brain, usually through the bloodstream. Metastatic tumors are considered cancerous and are malignant. Metastatic brain tumors affect nearly one in four patients with cancer, or an estimated 150,000 people a year. Up to 40 percent of people with lung cancer will develop metastatic brain tumors.

Pediatric Brain Tumors

Some types of brain tumors are more common in children than in adults. The most common types of pediatric tumors are low-grade gliomas, medulloblastomas, ependymomas, choroid plexus tumors, pineal region tumors, and craniopharyngiomas.

The pediatric neurosurgeons at Semmes-Murphey are recognized as the leading experts in treating and operating on brain tumors in children.  Through our years of working with St. Jude Children’s Research Hospital, LeBonheur Children’s Hospital, and many others, the Semmes Murphey neurosurgeons are some of the most experienced in the world and have participated in ground-breaking treatment protocols to help improve the survival rate in children with this disease.

What are the causes of brain tumors?

Scientists believe brain tumors begin at the cellular level with genes which are responsible for regulating the rate at which the cell divides (if it divides at all), repairing genes that fix defects of other genes, as well as genes that should cause the cell to self-destruct if the damage is beyond repair.  

If those genes on a cell’s chromosomes are damaged and no longer function properly, the cell may begin dividing rapidly and can eventually grow into a tumor.   These genes may have been “born” with partial defects, damaged or changed by environmental factors.  Furthermore, it is not known why some people in a similar "environment" develop brain tumors, while others do not.

As a natural defense mechanism, the body's immune system would optimally detect the abnormal cell and kill it.   But tumors often produce substances that prevent the immune system from recognizing the abnormal tumor cells and eventually block all internal and external deterrents to its growth.

Tumors can produce substances called angiogenesis factors that promote the growth of blood vessels necessary to provide more oxygen and nutrients to aid its rapid growth.  New vessels grow to allow an increase of nutrients to the tumor, and, eventually, the tumor becomes dependent on these new vessels. Research is being done in this area, but more extensive and varied research is needed before this knowledge is translated into potential, viable therapies.

What are the symptoms or warning signs of a brain tumor?

Symptoms vary depending on the location of the brain tumor, but the following may accompany different types of brain tumors:

  • Headaches that may be more severe in the morning
  • Seizures or convulsions
  • Difficulty thinking, speaking, or articulating
  • Personality changes
  • Weakness or paralysis in one part or one side of the body
  • Loss of balance or dizziness
  • Vision changes
  • Hearing changes
  • Facial numbness or tingling
  • Nausea or vomiting
  • Confusion and disorientation

How are brain tumors diagnosed?

A variety of sophisticated imaging techniques are used in diagnosing and pinpointing brain tumors during surgery.

  • Diagnostic tools include computed tomography (CT or CAT scan) and magnetic resonance imaging (MRI).
  • Magnetic resonance spectroscopy (MRS) is used to examine the tumor's chemical profile and determine the nature of the lesions seen on the MRI.
  • Magnetic resonance perfusion can be used to assess the activity of the tumor cells.
  • Positron emission tomography (PET scan) can help detect recurring brain tumors.

What is the treatment for brain tumors?

Treatment options include surgery, radiation, and chemotherapy.  These can be used alone or in combinations, depending on the pathology of the tumor.  There are potential risks associated with each type of therapy.


It is generally accepted that complete, or nearly complete, surgical removal of a brain tumor is beneficial for a patient.   To do this, neurosurgeons traditionally open the skull through a craniotomy to help ensure they can access the tumor and remove as much of it as possible.  The neurosurgeon's goal is to remove as much tumor as possible without injuring brain tissue important to the patient's neurological function (such as the ability to speak, walk, etc.). 

Another operation commonly performed is a stereotactic biopsy.  This smaller operation sometimes is done before a craniotomy to obtain a small tissue sample which helps doctors make an accurate diagnosis. 


Radiation therapy is used with certain types of tumors.  There are many different types of radiation available.  Consultation with a Radiation Oncologist will be performed prior to proceeding with this mode of treatment.


Chemotherapy is a drug that is given either orally or intravenously.  In certain situations, chemotherapy is indicated.  Consultation with a Medical Oncologist will be performed prior to proceeding with this treatment option.


The neurosurgeons at Semmes-Murphey are renowned experts in the treatment of brain tumors.  You will receive world-class care as you undergo treatment.  Every effort is taken to ensure that your needs are met throughout the entire process.


This information was created by the specialists at Semmes Murphey Clinic.  Readers are encouraged to research trustworthy organizations for information.  Please talk with your physician for websites and sources that will enhance your knowledge and understanding of this issue and its treatment

Information courtesy of the American Association of Neurological Surgeons


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