Meningioma: Diagnosis

Approved by the Cancer.Net Editorial Board, 10/2022

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 tumor and learn if it is cancerous. They may also do tests to learn which treatments could work best.

For most tumor types, a biopsy or the removal of a tumor with surgery are the only sure ways 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 meningioma is diagnosed

There are different tests used for diagnosing meningioma. Not all tests described here will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of tumor suspected

  • Your signs and symptoms

  • Your age and general health

  • The results of earlier medical tests

Sometimes, meningioma is found accidentally while having a procedure for another reason. More commonly, meningioma is often diagnosed after a person starts having symptoms. A neuro-oncologist is a doctor who specializes in diagnosing and treating brain and nervous system tumors. The neuro-oncologist will use a patient’s symptoms as clues to the location of the tumor. In addition to a detailed medical history and physical examination, the following tests may help the doctor find and diagnose meningioma:

  • Neurological, vision, and hearing tests. These tests help find out how a possible tumor is affecting the brain. An eye examination can find changes to the optic nerve caused by pressure from a meningioma.

  • Stereotactic neurosurgery/biopsy. A biopsy can be performed during a procedure called a stereotactic technique. This technique uses a needle guided to the tumor with computers and imaging tests. A biopsy can also be done during surgery when the surgeon can look at the tumor directly. However, meningioma is usually removed rather than doing a separate biopsy. This means that surgery for meningioma is usually done by an open craniotomy instead of with stereotactic techniques. An open craniotomy is surgery where part of the skull is removed to provide access to the brain. The portion of skull removed during surgery is replaced after the tumor is removed. (More information on surgery can be found in the Types of Treatment section.)

  • Imaging tests. Sometimes, meningioma is diagnosed using only the imaging tests listed below because the location of the tumor may make a biopsy risky. Imaging tests show pictures of the inside of the body. Imaging tests are most useful when the results are combined with the patient’s medical history, physical examination, and neurological tests. This combination helps to more accurately find out where the tumor began and whether or where it has grown. The most common imaging tests used for diagnosing meningioma include:

    • Magnetic resonance imaging (MRI). An MRI produces detailed images of the inside of the body using magnetic fields, not x-rays. A special dye is injected into a patient’s vein before the scan to create a clearer picture. MRIs may create more detailed pictures than CT scans (see below) and often show changes in the brain caused by the tumor, such as swelling or areas where the tumor has grown. MRI is the preferred way to diagnose meningioma.

    • Computed tomography (CT or CAT) scan. A CT scan takes pictures of the brain by using x-rays of the head from many 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 a contrast medium is injected into a patient’s vein before the scan to provide better detail on the image. A CT scan is best for finding changes in the skull that can be caused by meningioma. These changes may include the hardening of the area near the tumor, which can mean that the tumor has been there for a long time.

    • X-ray. A general x-ray creates a picture of the structures inside of the body using a small amount of radiation. An x-ray of the head can sometimes help doctors find out where a tumor is, but it is not enough to diagnose meningioma.

    • Cerebral angiogram. A cerebral angiogram shows the arteries in the brain. It is a special type of x-ray, or series of x-rays, of the head. X-rays are taken after a special dye called a contrast medium is injected into the main arteries of the head. Because meningioma can block important veins that drain blood from the brain, it is sometimes important to get an angiogram to plan surgery. In addition, there may be abnormal blood vessels that feed the tumor, and these can be seen with the angiogram. Sometimes, material is injected into the tumor before surgery to reduce bleeding during surgery.

After diagnostic tests are done, your doctor will review the results with you. If the diagnosis is meningioma, 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.