Colonic polyp

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Colonic polyp
Colonic polyp.jpg

Colonic polyp
ICD-9 V12.72
OMIM 175100
MeSH D003111

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] Colonic polyps may become colorectal cancer.


In a study of 2531 volunteers 50 years of age or older:[2]

  • 1629 (64%) had no polyps
  • 902 (36%) had polyps
    • 512 (57% of the 902) had polyps with the largest being less than 5 mm in size
    • 258 (29% of the 902) had 392 polyps with the largest being 5 mm - 9 mm in size
      • 246 (63% of the 392 polyps) were adenomatous
      • 146 (27% of the 392 polyps) were non-adenomatous such as hyperplastic polyps and lipomas
    • 132 (15% of the 902) had 155 polyps with the largest being 10 mm or larger in size
      • 121 (78% of the 155 polyps) were adenomatous
      • 7 (5% of the 155 polyps) were carcinomas
      • 27 (17% of the 155 polyps) were non-adenomatous

Hyperplastic polpys

Adenomatous polyps

Adenomatous colonic polyps are common and are present in 25% of men and 15% of women undergoing screening colonoscopy.[3]

Tubular adenomas
Tubulovillous adenomas
Villous adenomas


CT scan may be used.[4][2][5][6]


Risk depends on polyp size (adapted from Table 2 in Butterly[7] and Johnson[2])
Polyp size Cancer
% (confidence interval)
Villous histology or
high-grade dysplasia
% (confidence interval)
% (confidence interval)
< 4 mm 0 (0–.36) 1.68 (.87–2.49) 1.68 (.87–2.49)
5–9 mm 0.87% (.26–1.48) 9.23 (7.32–11.14) 10.10 (8.11–12.08)
> 10 mm 5%    

Adenomatous colonic polyps may progress to colorectal cancer; however, less than 10% do so.[3] The rate of progression to invasive cancer among polyps of at least 10 mm size is about 1% per year.[8]

High risk colonic polyps are defined as either:[9]

  • 3 or more synchronous adenomas
  • Adenomas ≥1 cm in diameter
  • Villous histology or high-grade dysplasia

The risk of current dysplasia depends on the size of the polyp (see table).[7] Similar numbers have been reported by other studies.[10] The risk of recurrence of future high risk histology is also correlated with size.[11]


  1. Anonymous (2023), Colonic polyp (English). Medical Subject Headings. U.S. National Library of Medicine.
  2. 2.0 2.1 2.2 Johnson CD, Chen MH, Toledano AY, et al (September 2008). "Accuracy of CT colonography for detection of large adenomas and cancers". The New England journal of medicine 359 (12): 1207–17. DOI:10.1056/NEJMoa0800996. PMID 18799557. Research Blogging. Cite error: Invalid <ref> tag; name "pmid18799557" defined multiple times with different content Cite error: Invalid <ref> tag; name "pmid18799557" defined multiple times with different content
  3. 3.0 3.1 Levine JS, Ahnen DJ (December 2006). "Clinical practice. Adenomatous polyps of the colon". The New England journal of medicine 355 (24): 2551–7. DOI:10.1056/NEJMcp063038. PMID 17167138. Research Blogging.
  4. Regge D, Laudi C, Galatola G, Della Monica P, Bonelli L, Angelelli G et al. (2009). "Diagnostic accuracy of computed tomographic colonography for the detection of advanced neoplasia in individuals at increased risk of colorectal cancer.". JAMA 301 (23): 2453-61. DOI:10.1001/jama.2009.832. PMID 19531785. Research Blogging.
  5. Kim DH, Pickhardt PJ, Taylor AJ, Leung WK, Winter TC, Hinshaw JL et al. (2007). "CT colonography versus colonoscopy for the detection of advanced neoplasia.". N Engl J Med 357 (14): 1403-12. DOI:10.1056/NEJMoa070543. PMID 17914041. Research Blogging.
  6. Rockey DC, Paulson E, Niedzwiecki D, Davis W, Bosworth HB, Sanders L et al. (2005 Jan 22-28). "Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison.". Lancet 365 (9456): 305-11. DOI:10.1016/S0140-6736(05)17784-8. PMID 15664225. Research Blogging. Review in: ACP J Club. 2005 Jul-Aug;143(1):22
  7. 7.0 7.1 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.
  8. Stryker SJ, Wolff BG, Culp CE, Libbe SD, Ilstrup DM, MacCarty RL (November 1987). "Natural history of untreated colonic polyps". Gastroenterology 93 (5): 1009–13. PMID 3653628[e]
  9. 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.
  10. Pickhardt PJ, Hassan C, Laghi A, et al (November 2008). "Clinical management of small (6- to 9-mm) polyps detected at screening CT colonography: a cost-effectiveness analysis". AJR Am J Roentgenol 191 (5): 1509–16. DOI:10.2214/AJR.08.1010. PMID 18941093. Research Blogging.
  11. 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]