A benign tumor is a tumor that lacks all three of the malignant properties of a cancer. Thus, by definition, a benign tumor: # does not grow in an unlimited, aggressive manner # does not invade surrounding tissues # does not metastasize Common examples of benign tumors include moles and uterine fibroids. The term "benign" implies a mild and nonprogressive disease, and indeed, many kinds of benign tumor are harmless...