What is the difference between a benign and malignant brain tumor?
The terms benign and malignant can be misleading when applied to brain tumors. These terms were first developed to apply to other cancers elsewhere in the body. “Benign” tumors remain localized and do not spread elsewhere in the body (“metastasize”), and can often be cured by complete surgical removal; “malignant” tumors characteristically spread to other organs and tissues, including the brain. By contrast, even the most aggressive primary brain tumors rarely metastasize outside of the brain and central nervous system. However, both high-grade, aggressive brain tumors and low-grade, indolent brain tumors can and often do invade normal brain tissue, and this invasiveness can produce a great deal of neurological disability or even death. Thus, even non-invasive brain tumors can have malignant consequences if they occur in an important part of the brain.
