What are the Different Types of Polyps?



You have most likely heard of colon polyps. Polyps are the precursor of colon cancer. Did you know that there are different types of polyps? Polyps can be knobby or flat, and some polyps tend to be benign while some polyps are at higher risk for cancer. Let’s go over the basic categories of polyps:

Hyperplastic polyps

> These polyps are small and circular, measuring less than ¼ -inch wide. Usually, hyperplastic polyps are benign. However, if hyperplastic polyps are discovered on the right side of the colon, they should be completely removed because they carry risk for cancer.



> Adenomas tend to be circular in shape as well. They account for about 75 percent of all colon polyps, so they are certainly the most common. These polyps are considered precancerous and should be removed. If adenomas are left to grow, they can turn into cancer. There are three types of adeonomas:


  • Villous—tend to be the largest and are most likely to become cancerous
  • Tubular—tend to be the least likely to become cancerous
  • Tubulovillous—considered to have a higher risk of malignant transformation than tubular adenoma

Flat Polyps

> Many polyps are easy to detect because they appear like a mushroom. Some polyps are flat, and these can be easily missed during a colonoscopy. Sometimes called lesions, flat polyps can be just as deadly as circular polyps. More studies are revealing the dangers of flat polyps, and gastroenterologists are taking special measures to look for flat polyps during colonoscopies. Flat polyps can be removed just like other types of polyps, but viewing them can be difficult because they appear level or like a small indentation.


Rely on the Expertise of Your Doctor


While round or circular polyps are much more common, a significant percentage of cancers are found in flat, depressed growths. In fact, researchers found that flat growths are nearly 10 times more likely to be cancerous than polyps. Because flat polyps can be so dangerous, it is important to have a thorough colonoscopy. A skilled gastroenterologist can identify and remove suspicious polyps during the procedure, and a trained pathologist can review specimens to examine for cancerous cells. Now that doctors know more about flat polyps, they know what to look for during the exam (Source: NBC News).

The patient has a responsibility as well. Your preparation for the procedure will make it easier or more difficult for the gastroenterologist to see. A complete colon cleanse is essential for maximum viewing, especially for flat polyps. If you have questions about how to effectively prepare for your colonoscopy, talk to your doctor or read “Your Guide to an Easy Prep."