Colonic polyps are extra fleshy growths that arise on the lining of the large intestine (colon). Colonic polyps are non-cancerous, but some polyps become cancerous.
There are 4 different types of polyps:
- Adenomatous polyps – These polyps have the potential to become cancerous. This process takes 5 – 10 years. Adenomatous polyps can be flat (sessile) or on a stalk (pedunculated).
- Hyperplastic polyps – These are benign and most of them cannot transform into cancer. A relatively newly described hyperplastic polyp called a sessile serrated adenoma does have malignant potential.
- Hamartomatous – These are rare and do not have malignant potential. They can cause local symptoms such as bleeding and obstruction.
- Inflammatory – These are associated with other conditions such as inflammatory bowel disease
Certain people may have a greater chance of getting polyps:
- Those 50 years of age or older
- Family history of polyps
- Previous history of polyps
- Family history of colon cancer
- History of uterine or ovarian cancer
The vast majority of polyps do not have symptoms. They are usually found incidentally at time of colonoscopy. Large polyps can bleed which is noticed in the stool.
High risk patients are screened by colonoscopy, a fibre-optic flexible telescope that can view the entire large bowel. The majority of polyps can be removed at the time of colonoscopy. Patients with adenomatous polyps require regular colonoscopic surveillance (every 3 years) to find and remove further polyps.