Question: how are non-cancerous tumours formed?

Sarah Martin answered on 18 Jun 2012:

Hi again gabiashby! Thanks for asking the question again outside the chat!

Non-cancerous tumors are also called benign, and cancerous ones malignant. Tumors are abnormal growths in the body. They are made up of extra cells. Normally, old cells die, and new ones take their place. Sometimes, however, this process goes wrong. New cells form even when you don’t need them, and old cells don’t die when they should. When these extra cells form a mass, it is called a tumor.

Tumors can be either benign or malignant. Benign tumors aren’t cancer. Malignant ones are. Benign tumors grow only in one place, and when they are removed in surgery they don’t tend to grow back. They cannot spread or invade other parts of your body. Even so, they can be dangerous if they press on vital organs, such as your brain.
My friend Ruth had a benign brain tumor when she was 20, and had brain surgery on it, because it was pressing on her brain and ear. She just had her brain day anniversary and her little girl baked her a cake with a brain design icing on it!
Do you know anyone with a tumor?