Colonic Polyps
Basics
Description
- Intraluminal colonic tissue growth; most commonly sporadic or part of polyposis syndromes
- Generally slow growing with low malignant potential; due to high prevalence in population; however, resection is generally recommended to eliminate risk.
- Size classification:
- Diminutive: ≤5 mm; small: 6 to 9 mm; large: ≥10 mm
- Morphologic classification:
- Depressed, flat, sessile, or pedunculated
- Clinical significance:
- >95% of colonic adenocarcinomas arise from polyps.
Epidemiology
Colorectal polyps are more common in non-Caucasian men in Western countries.
Incidence
Incidence increases with age.
Prevalence
- 15–20% of all adults
- 30% of U.S. population aged >50 years
- 6% of children
- 12% of children with lower GI bleed
Etiology and Pathophysiology
- Mucosal
- Neoplastic
- Adenomatous polyps (tubular >80%, villous 5–15%, tubulovillous 5–15%)
- Serrated polyps
- Sessile serrated polyps (SSPs) are common, more in proximal colon, with low malignant potential if no dysplasia and significant malignant potential if dysplastic.
- Traditional serrated adenoma is uncommon, more often noted in distal colon, with significant malignant potential.
- Nonneoplastic polyps (hyperplastic, juvenile polyps, hamartomas, inflammatory pseudopolyps)
- Hyperplastic polyps are very common, more in distal colon, with very low malignant potential.
- Juvenile polyps are common in childhood, benign hamartomas, more in rectosigmoid, and not premalignant.
- Neoplastic
- Submucosal (lipomas, lymphoid aggregates, carcinoids)
Genetics
- Inactivation of tumor suppressor genes as adenomatous polyposis coli (APC) or mismatch repair genes (MLH1) causes polyps to grow into cancer.
- Familial adenomatous polyposis (FAP) is autosomal dominant. By age 40 years, almost all patients develop colorectal cancer (CRC).
- MUTYH-associated polyposis (MAP) is autosomal recessive caused by biallelic mutations in MUTYH gene.
- Juvenile polyposis syndrome (JPS) is autosomal dominant. 50–60% of patients have a mutation in the SMAD4 or BMPR1A gene. By age 35 years, 20% of patients develop CRC.
Risk Factors
- Family history of intestinal polyposis, polyps, or CRC
- Advancing age; male
- High-fat, low-fiber diet; tobacco use
- Excessive alcohol intake: more than eight drinks a week
- Inflammatory bowel disease is associated with a decreased prevalence of colon polyps (but with higher risk of colon cancer).
General Prevention
- Low-fat, high-fiber diet
- Avoid smoking.
- Decrease alcohol intake.
- Use of NSAIDs and calcium is associated with decreased incidence and recurrence of polyps.
- No lower rates of CRC with azathioprine, 6-mercaptopurine, folate, calcium, multivitamins, or statins
Commonly Associated Conditions
Hereditary polyposis syndromes:
- Adenomatous
- FAP
- Classic (CFAP), attenuated (AFAP)
- MAP
- FAP variants:
- Gardner syndrome, Turcot syndrome
- FAP
- Hamartomatous
- Peutz-Jeghers syndrome (PJS), JPS, Cowden syndrome
ALERT
JPS imposes a higher risk of CRC, although juvenile polyps are not premalignant.
JPS imposes a higher risk of CRC, although juvenile polyps are not premalignant.
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Citation
Domino, Frank J., et al., editors. "Colonic Polyps." 5-Minute Clinical Consult, 33rd ed., Wolters Kluwer, 2025. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688568/all/Colonic_Polyps.
Colonic Polyps. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2025. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688568/all/Colonic_Polyps. Accessed November 12, 2024.
Colonic Polyps. (2025). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (33rd ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688568/all/Colonic_Polyps
Colonic Polyps [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2025. [cited 2024 November 12]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688568/all/Colonic_Polyps.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Colonic Polyps
ID - 1688568
ED - Domino,Frank J,
ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688568/all/Colonic_Polyps
PB - Wolters Kluwer
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DB - Medicine Central
DP - Unbound Medicine
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