Diagnosis of a Brain Tumor

These tests may be done:

• MRI scan (most common)
• CT scan
• MR angiography —shows blood vessels of the brain and blood supply to tumor
• CT angiography —shows blood vessels of the brain and blood supply to tumor
• PET scan

MRI Scan of the Head Copyright © Nucleus Medical Media, Inc.

Other Tests

Other tests may be done, such as:

• Blood and tissue tests—Blood tests may find tumor markers in the blood. Markers and certain blood proteins may be higher than normal. Blood and tissue tests look for chromosome changes or inherited disorders linked to certain types of brain tumors. This is not done for all tumors.
• Lumbar puncture—A needle is used to collect some cerebrospinal fluid (CSF) that surrounds and protects the brain and spinal cord. This test has limited use.
• Biopsy—A small piece of tissue is removed and looked at in a lab under a microscope or evaluated at the molecular level. A biopsy may be:
  • Stereotactic biopsy—A needle is used to remove tissue through a small hole in the skull. A computer version of a CT or MRI scan is used to find the tumor. This option may be used when a tumor cannot be taken out with surgery.
  • Open craniotomy —Tissue samples are looked at for cancer at the time of surgery. They are taken out through a hole in the skull.

Staging of a Brain Tumor

If a brain tumor is confirmed, the results from the tests will help determine the stage of the cancer. Staging is the evaluation of where a tumor has spread to. It is used with other information, such as molecular testing. Staging is not done for all types of brain tumors.

Grading

Tumor grades help predict the rate of growth, if it will spread, and outcomes that may happen. Brain tumors grades are:

• Grade 1 (low-grade) —Slow growing cells that rarely spread. They have the best chance to be cured if they can be surgically removed.
• Grade 2 —Has the potential to spread. Some may turn into a higher grade tumor. These may also return after treatment.
• Grade 3 —Likely to spread. They grow faster than lower grade tumors.
• Grade 4 (high-grade) —Spread quickly.