What is brain cancer?

Benign brain tumors do not contain cancer cells, but they can press on sensitive areas in the brain and cause symptoms.

They are usually a collection of extra cells that cause a mass of tissue called a "tumor."

They typically have clear borders and do not invade surrounding areas.

They usually can be removed by surgery and are not likely to grow back.

Malignant brain tumors contain cancer cells that can grow like a plant and put out "roots" that grow into healthy brain tissue and interfere with vital functions.

They are often life threatening.

They may not have roots and then are called encapsulated.

Malignant tumors are likely to grow rapidly.

Doctors refer to brain tumors by grade, depending on what the cells look like under the microscope.

Grades are from low grade (I) to high grade (IV) that tell how abnormal the cells look and how fast they may grow.