Colonic polyp
Jump to navigation
Jump to search
In medicine, colonic polyps are "discrete tissue masses that protrude into the lumen of the colon. These polyps are connected to the wall of the colon either by a stalk, pedunculus, or by a broad base."[1]
High risk colonic polyps are either:[2]
- 3 or more synchronous adenomas
- adenomas ≥1 cm in diameter
- villous histology or high-grade dysplasia
The risk of dysplasia depends on the size of the polyp:[3]
| Polyp size | Cancer % |
Villous histology or high-grade dysplasia % |
Total % |
|---|---|---|---|
| < 4 mm | < 0.5 | < 2 | < 2 |
| 5–10 mm | < 1 | 9 | 10 |
Screening
A clinical practice guideline jointly written by the American Cancer Society and other groups recommends one of:[4]
- Flexible sigmoidoscopy every 5 years
- Barium enema every 5 years
- Virtual colonography (a noninvasive test based on computed tomography) every 5 years
- Colonoscopy every 10 years
When polyps are found, a clinical practice guideline jointly written by the American Cancer Society and other groups states:[2]
- High risk polyps are 1) 3 or more synchronous adenomas, 2) adenomas ≥1 cm in diameter, or 3) villous histology or high-grade dysplasia.
- High risk polyps should have follow-up colonoscopy in 3 years
- Low risk polyps should have repeat colonoscopy in 5 to 10 years
- If no adenomas are found, follow-up evaluation should be at 10 years
A validation of these guidelines found:[5]
- High risk adenomas - 9% of an advanced adenoma at 4 years of follow-up.
- Low risk adenomas - 5% of an advanced adenoma at 4 years of follow-up.
References
- ↑ Anonymous (2024), Colonic polyp (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ 2.0 2.1 Winawer SJ, Zauber AG, Fletcher RH, et al (May 2006). "Guidelines for colonoscopy surveillance after polypectomy: a consensus update by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society". Gastroenterology 130 (6): 1872–85. DOI:10.1053/j.gastro.2006.03.012. PMID 16697750. Research Blogging.
- ↑ 3.0 3.1 Butterly LF, Chase MP, Pohl H, Fiarman GS (March 2006). "Prevalence of clinically important histology in small adenomas". Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association 4 (3): 343–8. DOI:10.1016/j.cgh.2005.12.021. PMID 16527698. Research Blogging.
- ↑ Levin, B., Lieberman, D. A., McFarland, B., Smith, R. A., Brooks, D., Andrews, K. S., et al. (2008). Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi-society Task Force on Colorectal Cancer, and the American College of Radiology. CA Cancer J Clin, CA.2007.0018. DOI:10.3322/CA.2007.0018.
- ↑ Laiyemo AO, Murphy G, Albert PS, et al (March 2008). "Postpolypectomy colonoscopy surveillance guidelines: predictive accuracy for advanced adenoma at 4 years". Ann. Intern. Med. 148 (6): 419–26. PMID 18347350. [e]