If cells keep dividing when new cells are not needed a mass of tissue forms. This mass of extra tissue, called a growth or a tumor , can be benign or malignant . Benign tumors are not cancer . They do not invade nearby tissue or spread to other parts of the body. Benign tumors can usually be removed and are seldom life threatening.
Polyps are benign tumors that grow from the wall of the colon or rectum.
Polyps may be very small or very large. Colorectal polyps should be removed because they may bleed, cause blockage, or become cancerous. A malignant tumors is cancer. It can invade and damage nearby tissue and organs. Cancer cells can also spread from a malignant tumors and enter the bloodstream and lymphatic system .