*
Brain Tumor  

Copyright © Nucleus Medical Media, Inc.

Definition  

A brain tumor occurs when cells grow uncontrollably in the brain. Cancer occurs when cells in the body divide without control or order. If cells divide uncontrollably, they form a mass of tissue. The mass is called a growth or tumor. The term cancer usually refers to malignant tumors. These can invade nearby tissue and spread to other parts of the body. A benign tumor does not spread. But, it can continue to grow and press structures near it, causing symptoms.

Malignant tumors can be fatal if not treated. The ability to cure a cancer depends on patient and tumor-related features. Patient-related features include:

  • Age
  • Overall health
  • Willingness to undergo treatment

Tumor-related features include:

  • Type of cancer
  • Site of the origin of the cancer
  • How advanced the disease is when it is detected
  • Tumor’s response to therapy

Brain tumors can be either primary or secondary.

Primary  

These are tumors which start in the brain or its coverings.

Secondary  

Secondary tumors begin in an organ other than the brain. They travel to the brain, usually through the blood. All secondary tumors are malignant.

Other

Other tumors, such as pituitary adenomas, neuromas, spinal cord tumors, and hydatid cysts, are not covered in this report.

Incidence  

Primary brain tumors are the second most common cancer in children and young adults, second only to leukemia. They are the third most common cancer in people between the ages of 15 and 34, fourth between the ages of 35 to 54, and much less common in older adults, where metastatic tumors are more common.

Causes  

Ionizing radiation and several hereditary diseases are the only known causes of brain tumors. The cause of the majority of primary brain cancers is unknown. Viruses and environmental factors may play a role. The causes of secondary brain cancers are the factors that caused the cancer at the site of origin.