Brain Cancer Diagnosis & Tests

Exams & Tests

Findings of your medical interview and physical examination will probably suggest to your health care provider, whether your primary care provider or an emergency department physician, that you have a problem with the brain or brain stem.

• In most cases, you will have a CT scan of the brain.
• This test is like an x-ray but shows more detail in 3 dimensions.
• Usually, a harmless dye is injected into your bloodstream to highlight abnormalities on the scan.

People with brain cancer often have other medical problems; therefore, routine laboratory tests may be performed.

• These include analysis of blood, electrolytes, liver function tests, and a blood coagulation profile.
• If you have mental status change as the main symptom, blood or urine tests may be done to detect drug use.

More and more, the MRI scan is being used instead of CT scan for suspected brain tumors.

• This is because MRI has a higher sensitivity for detecting the presence of, or changes within, a tumor.
• Currently, however, most institutions still use the CT scan as the first diagnostic test.

Skull x-rays are not widely used any longer to diagnose brain cancer.

If your scans indicate the presence of a brain tumor, you will be referred to a specialist in cancer (oncologist). If one is available in your area, you should be referred to a specialist in brain tumors (neuro-oncologist).

The next step in diagnosis is confirmation that you have a cancer. A small sample of the mass (a biopsy) is taken to identify the type of tumor.

• The most widely used technique for obtaining a biopsy is surgery. The skull is opened, usually with the intention of removing the whole tumor if possible. A biopsy is then taken from the tumor.
• If the surgeon is unable to remove the entire tumor, a small piece of the tumor is removed.
• In some cases it is possible to collect a biopsy without opening the skull. The exact location of the tumor in the brain is determined stereotactically, that is, by using CT of MRI scan while the head is held still in a frame. A small hole is then made in the skull and a needle guided through the hole to the tumor. The needle collects the biopsy and is removed. This technique is called stereotaxis, or stereotactic biopsy.
• The biopsy is examined under a microscope by a pathologist (a physician who specializes in diagnosing diseases by looking at cells and tissues).