| This
is the most common brain tumor which starts growing in the brain,
and there are roughly 12,000 new cases per year. Astrocytomas
are broken down in grading systems into either three or four
grades. On the four tier grading system, grade four is the most
agressive, and is called a glioblastoma multiforme. These tumors
arise from the "insulating cells" of the brain, known as
astrocytes, and generally exist without a discrete border. |
Glossary 
