Classifying brain tumors
After a biopsy or surgery to remove the tumor, a pathologist examines the cells of the brain tumor under a microscope and determines the tumor's grade. The tumor grade is an indication of the way the cells can grow. This information helps doctors plan the most suitable treatment.
Grades 1 and 2
These tumors are usually called low-grade or benign. They grow slowly.
Grades 3 and 4
These tumors are called high-grade or malignant. They grow more quickly.