What Is a Brain Tumor?

First, it’s helpful to understand the main functions of your brain. Your brain and spine make up the central nervous system — the body’s command center. It sends out and receives a constant stream of messages through other branches of the nervous system to regulate your breathing, heart rate, and other vital functions; to enable you to see, hear, feel, walk, and talk; to make it possible for you to acquire, organize, and remember new knowledge; to feel anger and fear and love, and to dream and imagine.

The brain has three main parts:

  • The cerebrum is the largest part of the brain. It controls thinking, learning, problem-solving, emotions, speech and voluntary movement.
  • The cerebellum controls movement, balance and posture.
  • The brain stem connects the brain to the spinal cord. It controls breathing, heart rate, nerves and muscles, and enables you to see, hear, walk, talk and eat.

    A brain tumor occurs when abnormal cells begin to grow in your brain. There are two main types of brain tumors: malignant (cancer) and benign (not cancer).

What’s the difference between malignant and benign brain tumors?

A malignant brain tumor contains cancer cells, grows rapidly, invades healthy brain tissue nearby, and may be life-threatening. There are two main types of malignant brain tumors: primary and secondary. Primary tumors begin in the brain. A secondary brain tumor, also called a metastatic tumor, begins in another part of the body (for example, the breast or lung) and spreads to the brain. Primary and metastatic brain tumors are usually treated differently.

Many malignant tumors can be treated successfully, and improvements in therapy are enabling patients to live longer while preserving their quality of life.

A benign brain tumor does not contain cancer cells, rarely invades nearby tissue or spreads to other parts of the body, and usually does not grow back after it is removed. However, even a benign brain tumor can press on sensitive areas of the brain and cause life-threatening health problems. Some benign tumors can become malignant in time.

Why treat a benign brain tumor? Robert Fenstermaker, MD, Chair of Neurosurgery at Roswell Park, explains: “Even a benign brain tumor can be fatal if left untreated. There isn’t much free space inside your skull, and your brain takes up most of it. When a tumor begins growing in that space, whether it’s benign or malignant, it starts to press on the brain and will cause serious neurologic symptoms — seizures, paralysis, speech problems or blindness — so it has to be treated quickly and effectively. Many noncancerous brain tumors are curable.”

Brain Tumors Info Sheet
Brain tumors info sheet

What you need to know about brain tumors.

Download our info sheet