To make a glioma diagnosis, Memorial Sloan Kettering doctors take several steps, which may include:

• A neurological exam. This test of a person’s vision, hearing, balance, coordination, strength, and reflexes can provide clues about which part of the brain is affected by a tumor.
• Imaging tests. CT, PET, and MRI scans can help doctors determine the location and size of a tumor.
• A tissue biopsy. A sample of tumor tissue can be taken before or during surgery. If before surgery, a small hole is drilled in the skull where the needle is inserted. This sample is then sent to a pathologist (a doctor who specializes in diagnosing disease) to determine the exact type of tumor.
• Genetic testing. A DNA sequencing test, such as MSK-IMPACT™, may identify genetic mutations that drive a tumor’s growth. This may help determine the care plan our experts recommend.