Gastrointestinal polyps are mucosal projections within the gastrointestinal tract. Grossly, they may be described as either sessile or pedunculated. They commonly occur in the colon and rectum but may also occur in the oesophagus, stomach and intestines.
Non-neoplastic polyps
| Non-neoplastic polyps | Description |
|---|---|
| Inflammatory polyps | Secondary to repeated bouts of intense inflammation. Seen in patients with inflammatory bowel disease, amebic colitis or schistosomal colitis. Have no malignant potential |
| Hamartomatous (juvenile) polyps | May be sporadic or acquired (syndromic). Includes peutz-jeghers polyps and juvenile polyps. Familial juvenile polyposis polyps may involve the entire colon and carry malignant potential. Peutz-Jeghers polyps have a very low potential for malignancy |
Neoplastic polyps
| Type of polyp | Description |
|---|---|
| Adenomatous polyps | These are either tubular, tubulovillous or villous polyps. They have malignant potential, with villous polyps having the highest risk (40%) |
| Hyperplastic polyps | Arise from decreased epithelial cell turnover and delayed shedding of surface epithelial cells. Common and relatively small polyps. Do not have significant malignant potential but polyps > 2 cm may carry some risk |
| Sessile serrated adenomas and polyps | Flat lesions with malignant potential. Characterised by disorganised and distorted crypt growth patterns on histology. Commonly occur in the right colon. |
