Overview

The brain and spinal column make up the central nervous system (CNS), where all vital functions of the body, including thought, speech, and strength, are controlled.

Astrocytoma is a type of CNS tumor that forms in cells called astrocytes. Normal astrocytes provide the connecting network of the brain and spinal cord and form scar tissue when the CNS is damaged. Astrocytoma begins when normal astrocytes change and grow uncontrollably, forming a mass called a tumor.

Astrocytoma can occur throughout the CNS, including the following places:

• Cerebellum (the back part of the brain responsible for coordination and balance)
  
  
• Cerebrum (the top part of the brain that controls motor activities and talking)
  
  
• Diencephalon or central part of the brain (controls vision, hormone production, and arm and leg movement)
  
  
• Brain stem (controls eye and facial movements, arm and leg movement, and breathing)
  
  
• Spinal cord (controls sensation and arm and leg motor function)

A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). Astrocytoma is more commonly referred to by its grade (a measure of how much the tumor cells appear like normal cells), as either high grade or low grade, depending on the number and shape of the tumor cells and how quickly they grow and spread. A low-grade tumor is less likely to grow quickly or spread. Once a tumor is found in the CNS, the doctor will usually perform a biopsy (see Diagnosis) to see if the tumor is an astrocytoma and to determine the grade of the tumor. A biopsy is the removal of a small amount of tissue for examination under a microscope.

This section covers astrocytoma diagnosed in children; learn more about brain tumors in adults.

Find out more about basic cancer terms used in this section.

Looking for More of an Overview?

If you would like additional introductory information, explore these related items on Cancer.Net:

• ASCO Answers Fact Sheet: Read a one-page fact sheet (available in PDF) that offers an easy-to-print introduction for CNS tumors.
  
  
• Cancer.Net Patient Education Videos: View short videos led by ASCO experts in childhood cancers and brain tumors that provide basic information and areas of research.
  
  
• Cancer.Net En Español: Read about astrocytoma in Spanish. Infórmase sobre astrocitoma en español.

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