What Is a Colon Polyp?
A colon polyp is a growth attached to the lining of the colon, or large intestine. Polyps are common, with as many as 50 percent of people age 60 and older having at least one, reports MedicineNet. Some polyps become large and develop into colon cancer, the second leading cause of cancer death in the United States.
Polyps found in the colon may be raised or flat. The flat growths are usually smaller and are more likely to become cancerous. In the majority of people, polyps develop with no symptoms. People over the age of 50 or with a family history of colon cancer should have a colonoscopy to look for the presence of polyps.
Detection and Treatment
A colonoscopy allows your doctor to visualize your entire colon for the presence of any abnormal growth or findings. You may be given a mild sedative to help you relax during the procedure. If any polyps are discovered during the colonoscopy, your doctor may remove them or obtain a biopsy to determine the type of growth.
Another diagnostic method is a virtual colonoscopy, which uses a computerized tomography scan (CT). A disadvantage of the virtual colonoscopy over the colonoscopy is the inability to remove tissue for pathological examination or to remove the polyps. A colonoscopy will still be required for removal of colon polyps.
Followup colonoscopies are encouraged to watch for new growth.
Non-cancerous Colon Polyps
Several types of nonadenomatous polyps, according to Merck Manuals, include: pseudopolyps, or false polyps; lipomas; leiomyomas; and inflammatory, which is a noncancerous polyp and the most common type found in patients with Crohn's disease or ulcerative colitis.
Hyperplastic is a benign (noncancerous) polyp found mostly on the left side of the colon and not associated with an increased risk of colon cancer, according to the College of American Pathologists. Most hyperplastic polyps are found during a colonoscopy and are removed during the procedure. If left undetected or not removed, hyperplastic polyps can develop into serrated adenomas, an aggressive cancerous growth.
The types of colon polyps causing the greatest concern are adenomatous. The larger the polyp is at the time of discovery increases the likelihood of the development of colon cancer.
Colon Cancer Resource reports on the following types of polyps most at risk for developing cancer:
- Tubular adenoma or adenomatous polyp is the most common accounting for about 70 percent of all polyps. This is a slow-growing polyp that may exist for years before becoming cancerous.
- Villous adenoma or tubulovillous adenoma, a more serious type, carries a high risk for developing cancer. This type can become quite large and attach to the inside wall of the colon instead of on a stalk, as with other types of polyps. Because of the size, removal of a villous adenoma may require a surgical resection of the colon.
MedicineNet: Colon Polyps https://www.medicinenet.com/colon_polyps/article.htm#1whatis
Merck Manuals: Polyps of the Colon and Rectum https://www.merckmanuals.com/professional/sec02/ch021/ch021g.html
College of American Pathologists: Hyperplastic Colon Polyps https://www.cap.org/apps/docs/reference/myBiopsy/hyperplastic_colon_polyps.html
Colon Cancer Resource: Types of Colon Polyps for Cancer Patients to Know About https://www.coloncancerresource.com/types-of-colon-polyps.html