ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, a brain tumor. They also do tests to learn if a tumor has spread to other parts of the body. If the tumor has spread, it is called metastasis.

For most tumor types, a biopsy is the only sure way for the doctor to know if an area of the body has a tumor. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

How ependymoma is diagnosed

There are many tests used for diagnosing ependymoma. Not all tests described here will be used for every child. Your child’s doctor may consider these factors when choosing a diagnostic test:

• The type of tumor suspected

• Your child’s signs and symptoms

• Your child’s age and general health

• The results of earlier medical tests

In addition to a physical examination, the following tests may be used to diagnose ependymoma:

• Computed tomography (CT or CAT) scan. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called contrast medium is usually injected into a patient’s vein before the scan to provide better detail on the image.
  
  
• Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. MRI can be used to measure the tumor’s size. A contrast medium (or dye) is often injected into a patient’s vein during the scan to create a clearer picture. An MRI of the spine may be used to find out if the tumor has spread to the spine.
  
  
• Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that a tumor is present, but only a biopsy can make a definite diagnosis. A pathologist then analyzes the sample(s). A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. For ependymoma, surgery is needed to get a sample of tissue (see Types of Treatment).
  
  
• Lumbar puncture (spinal tap). A lumbar puncture is a procedure in which a needle is used to take a sample of cerebral spinal fluid (CSF) to look for cancer cells, blood, or tumor markers. Tumor markers are substances found in higher than normal amounts in the blood, urine, or body tissues of people with certain kinds of cancer. CSF is the fluid that flows around the brain and the spinal cord. Doctors generally give an anesthetic to numb the lower back before the procedure. This procedure is sometimes done after ependymoma is diagnosed and the tumor is removed.

After diagnostic tests are done, your child’s doctor will review the results with you. If the diagnosis is ependymoma, these results also help the doctor describe the tumor. This is called staging and grading.

The next section in this guide is Stages and Grades. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide.