Benign Tumors: Growths That Aren't Cancer

What they are

Tumors are abnormal growths in the body. They can be:

• benign — not cancer;
• malignant — cancer.

Benign tumors grow in one place only: they can't spread to or invade other parts of the body. Even so, they can be dangerous if they press on a vital organ, such as the brain.

How they form

Tumors are made of extra cells. Normally, cells grow and divide to make new cells as the body needs them, and old cells die and are replaced. Sometimes this goes wrong: new cells form when the body doesn't need them, and old cells don't die when they should. These extra cells can keep dividing and may form a tumor.

Treatment

Treatment often involves surgery. Benign tumors usually don't grow back.

Sources

Based on "Benign Tumors," MedlinePlus, National Library of Medicine, drawing on the National Cancer Institute (NIH); a work of the United States government in the public domain.