Types of Colon Polyps
The two main kinds of colon polyps are adenomas and hyperplastic polyps. Adenomas are the most common and can lead to cancer if left in place. Hyperplastic polyps are smaller and not a risk for cancer. Other colon polyp types, such as inflammatory and hamartomatous polyps, are noncancerous.
Polyps can be found on the lining of the colon or rectum and vary from the size of a pinhead to a golf ball or larger. They are typically either noncancerous or precancerous (meaning they can turn into cancer if left in place). There are two main varieties of colon polyps: adenomas and hyperplastic polyps.
Because your doctor cannot easily tell the difference between the colon polyp types, he or she will take a tissue sample from the polyps during a sigmoidoscopy and either biopsy or remove large polyps during a colonoscopy.
Adenomas are the most common type of colon polyps, accounting for up to 75 percent of all colon polyps.
Adenomas are considered precancerous. If left in place, this type of colon polyp can turn into cancer.
Adenomas are divided into three sub-types:
Villous adenomas tend to be larger than the other types; they are the most likely to turn into cancer. Tubular adenomas are the least likely to turn into cancer.
Hyperplastic polyps tend to be smaller in size and not a risk for cancer.
Other kinds of colon polyps that have no potential to become cancerous include inflammatory and hamartomatous polyps.