A Answers (2)
Dr. Mehmet Oz, MD, Cardiology (Cardiovascular Disease), answered
There are two common types of colon polyps: hyperplastic polyp and adenoma. The hyperplastic polyp is typically not at risk for cancer. The adenoma, however, is thought to be the precursor (origin) for almost all colon cancers, although most adenomas never become cancers. Histology (examination of tissue under a microscope) is the best way to differentiate between hyperplastic and adenomatous polyps.
Although it's impossible to tell which adenomatous polyps will become cancers, larger polyps are more likely to become cancers and some of the largest ones (those larger than 1 inch) can already contain small areas of cancer. Because your doctor cannot usually be certain of the tissue type by the polyp's appearance, doctors generally recommend removing all polyps found during a colonoscopy.