Most tumors develop slowly over a period of time and can present themselves in practically any part of the human body. A benign tumor, such as a mole or a cyst, is a noncancerous tumor that lacks the malignant properties of a cancer. Benign tumors do not grow aggressively, invade surrounding tissue nor do they have the ability to metastasize.  For the most part, benign tumors do not cause any harm. However, if a benign tumor is big enough and begins pressing on nearby tissue, blood vessels or organs, surgery may be necessary to remove the mass from the body.