Part of diagnosing a brain tumor is determining the location of the tumor in the brain. If you have symptoms of a brain tumor, your doctor may perform some simple tests to check your motor skills and your vision and hearing. If a tumor is suspected, you may be referred to a specialist who will order further tests to diagnose the tumor.
Tests that allow the neurologist or neurosurgeon to see parts of the brain include MRIs or CT scans. These both provide a better look at the brain, sometimes using a special dye injected into your bloodstream to make the tumor easier to see. Once a tumor has been located, a biopsy may need to be performed, which would include removing a small piece of the tumor so it can be examined to further determine what kind of tumor it is, if it is cancerous or benign, and how it is to be treated. A spinal tap, or lumbar puncture, may be performed to see if any cancerous cells are present in the fluid around the brain.
Some brain tumors may be the result of other cancers elsewhere in the body, so your doctor may need to perform other tests to rule out that possibility.