Definition
Polyps are abnormal projections of the mucosa in the digestive tract, usually in the colon. They can be solitary or multiple and are classified as adenomatous (precancerous) or non-neoplastic.
Pathogenesis
Polyps may arise from genetic mutations, chronic intestinal irritation, or inflammatory conditions. Adenomatous polyps carry an increased risk of malignancy, especially when they are larger than 1 cm or have high-risk histological features.
Diagnosis
Diagnosis is made through colonoscopy, which allows for direct visualization and removal of polyps for biopsy. Imaging methods like CT colonography can be used as alternatives.
Treatment
Treatment involves endoscopic removal of polyps, while high-risk cases may require surgical intervention. Regular follow-up with colonoscopies is essential to prevent progression to colorectal cancer. Dietary changes and smoking cessation may reduce the risk of recurrence.
How this works in practice is shown in the removal of multiple pedunculated polyps in a single session.
Removal takes place during colonoscopy and is the mechanism by which colorectal cancer is prevented. Larger or flat lesions are removed by endoscopic submucosal dissection.
- Adenoma under 10 mm with low grade dysplasia: no dedicated surveillance
- Adenoma of 10 mm or more, high grade dysplasia, or 5 or more adenomas: repeat at 3 years
- Normal screening at average risk: next colonoscopy at 10 years
- Screening starts at age 45
Removal of several pedunculated polyps in a single session is shown in this case, where each specimen was sent separately so that histology could be matched to its site.
Frequently asked questions
Do all polyps become cancer?
No. Hyperplastic polyps carry essentially no risk. Adenomas and sessile serrated lesions are the ones that can progress, and the sequence typically takes years. That slow timeline is precisely what makes screening effective: removing an adenoma interrupts the process before cancer develops.
How often is follow-up needed after removal?
One or two small tubular adenomas under 10 mm with low grade dysplasia require no dedicated surveillance. An adenoma of 10 mm or more, high grade dysplasia, or 5 or more adenomas prompt repeat colonoscopy at 3 years. After a normal screening examination at average risk, the interval is 10 years.
How are large or flat polyps removed?
With endoscopic mucosal resection for smaller confined lesions, or endoscopic submucosal dissection for extensive or flat ones, which removes them in a single piece. En bloc removal allows accurate assessment of margins and depth. Lesions once referred for surgery are now removed endoscopically in the great majority of cases.
Sources
- European Society of Gastrointestinal Endoscopy, Post-polypectomy colonoscopy surveillance: ESGE Guideline Update 2020. https://doi.org/10.1055/a-1185-3109
Content last updated: September 2026 (15/09/2026).
