Sometimes increased pressure in the brain can cause blurred, double or lost vision. If a patient has any of the above symptoms without any obvious explanation further work-up is warranted. Once a mass is confirmed by any of the imaging techniques available the diagnosis needs to be established by a biopsy of the mass. The biopsy will help differentiate tumor from other types of masses, such as infection. The microscopic structure of the tumor will be important in grading the tumor.
Tumor grading is important for prognosis and therapy.
Tumors are graded by microscopic examination of the tumor specimen. The specimen is scanned for the most malignant components and the maximum grade possible is given to the tumor. They are generally found in a younger population and have a more favorable prognosis. Low-grade astrocytomas are uncommon tumors. Their true incidence is difficult to determine because sampling and grading vary substantially.