Adenomatous Polyps


Polyps are growths that develop in the colon or the rectum. Colorectal polyps are common and may be found in approximately nine of every 10,000 persons. Polyps are usually classified into two types: adenomatous polyps (adenomas) and hyperplastic polyps. Hyperplastic polyps are generally considered to have a very low risk of becoming cancerous (mostly noncancerous); adenomatous polyps (adenomas) are considered to have a low, but increased risk, of becoming cancerous (possibly pre-cancerous). Adenomatous colorectal polyps are small, fleshy, mushroom-shaped growths that may turn cancerous if not removed. These polyps show abnormal cellular changes. It is estimated that during a yearís time, one out of every 400 adenomatous polyps will become cancerous. Although many people will develop colon polyps in their lifetime, most polyps will not develop into cancer.

Background Information

Colorectal cancer is the second leading cause of cancer deaths in the U.S. The risk of colorectal cancer tends to increase after the age of 50. Cancer of the colon and rectum usually begins as a polyp. Although most polyps never become cancerous, virtually all colon and rectal cancers start from these benign growths. Very rarely, colon cancers have been found that appear to have started without a preceding adjacent polyp.

Unless colon polyps are large and cause bleeding or pain, the only way to know if you have polyps is to have one or more tests that examine the surface of your colon. The most common test used for this examination is a colonoscopy procedure. Adenomas typically cause few symptoms; however, painless rectal bleeding and abdominal pain are the most common.

Risk Factors:
Most polyps are the result of a genetic mutation in the lining of the colon. The risk of developing polyps increases with age and some individuals may have more than one polyp. The likelihood of developing polyps is also higher in patients with a family history of colorectal polyps or colorectal cancer, including inherited disorders such as Gardnerís syndrome or familial adenomatous polyposis.

Follow-up and Treatment Options

Polyps are usually detected during a screening test for colon cancer or other abdominal conditions. The most common screening tests which can reveal a polyp are a colonoscopy (an examination of the large bowel with a telescope like device), a sigmoidoscopy (an examination of the lowest part of the bowel using a flexible telescope) or a barium enema (an X-ray taken after consuming a barium liquid). Only a physician can determine the most appropriate treatment.

A polypectomy involves the removal of the entire polyp during a colonoscopy. The tissue sample is reviewed by a pathologist to determine whether the tissue contains a cancer or other disease. A polyp that has been completely cut out will not grow back, however, some individuals tend to form multiple polyps, so there is the chance that new polyps could develop after polypectomy.

In some instances, although not frequently, a polyp may be too large to be removed during a colonoscopy. This generally occurs when the diameter is more than 4 cm and, particularly, if the base of the polyp is broad and not well defined. In these situations, endoscopic removal can carry an unacceptably high risk of bleeding or perforation. Such polyps are also more likely to already contain cancer and removal by surgery can be the safest option to ensure that the cancer is completely removed.

Follow-up Colonoscopy:
It is important to have follow up colonoscopies to monitor your condition and assure that new polyps have not developed.

Questions to Ask Your Healthcare Provider
  • Do you recommend the removal of my polyp(s)?
  • Does my polyp put me at increased risk for colorectal cancer?
  • Is there anything I should be doing or not doing during treatment?
  • Are there any other measures I can take to reduce my risk of future polyps?
  • What are the chances of recurrence after my treatment plan?
Sources for Additional Information

The content of this web page and corresponding downloadable handout is provided to you as general information and not intended as a diagnosis. Please consult with your personal physician regarding the essential details about your condition. Updated 12/2013.

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