Colonic polyps

Last updated: July 8, 2022

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Colonic polyps are abnormal colonic mucosal overgrowths. They are most common in people over 50 years of age but can also be found in younger patients who have hereditary polyposis syndromes. Affected individuals are typically asymptomatic but may present with gastrointestinal (GI) bleeding, iron deficiency anemia, and/or mechanical bowel obstruction (e.g., due to intussusception). Colonic polyps are classified macroscopically as either pedunculated (i.e., with a stalk) or sessile (i.e., without a stalk). They are classified histologically as adenomatous (most common), hyperplastic, inflammatory, serrated, or hamartomatous. Colonoscopy, which enables direct visualization biopsy and removal of the polyp, is the first-line diagnostic and therapeutic modality. Polyp removal is recommended because, although this condition is typically benign, it may transform to colorectal cancer. Adenomas (e.g., adenoma-carcinoma sequence) have the highest malignancy potential (∼ 5%). Patients with polyps that are concerning for malignancy and/or a history familial adenomatous polyposis syndrome often require surgical resection. Regular follow-up surveillance is required following the removal of the polyps.

References: [2]

Epidemiological data refers to the US, unless otherwise specified.

The exact etiology is unknown. Risk factors include the following: [1]

Macroscopic classification of colonic polyps

Histologic classification of colonic polyps

Histologic classification of colonic polyps [3][4][5]
Histological type Subtypes Characteristics Malignant potential
Inflammatory polyps (pseudopolyps)
  • Low malignant potential
Mucosal polyps
  • Benign (no clinical significance)
  • Typically small < 5 mm
  • Mostly appear like normal mucosa
Submucosal polyps

Hyperplastic polyps

  • Most common type of nonneoplastic polyp among those with low malignant potential
  • Small (< 5 mm)
  • Common in the distal colon (rectosigmoid)
  • Might transform to serrated polyps
  • Histology: hyperplasia of normal cellular components with a sawtooth/serrated pattern of crypt epithelium
Hamartomatous polyps [6]
  • Low for solitary polyps
  • Increased risk of colonic and extra-colonic malignancies when associated with syndromes
Serrated polyps

Sessile serrated polyps

  • Moderate malignant potential (∼ 5%) [7]

Traditional serrated adenoma

Adenomatous polyps

Tubular adenoma

  • Frequency: 65–80% [3]
  • Location: anywhere in the colon
  • Histology: proliferating cells forming tubules

Tubulovillous adenoma

  • Frequency: 10–25% [3]
  • Histology: a mixture of tubular and villous histological picture

Villous adenoma

The majority of colon carcinomas develop from adenomas (adenoma‑carcinoma sequence). However, only ∼ 5% of adenomas develop into colon cancers.

Villous adenomas are villains because they have the highest malignant potential.

Hereditary polyposis syndromes [8][9][10]

At-risk family members who decline genetic testing should undergo the same endoscopic surveillance as individuals with known mutations. [8]

Adenomatous polyposis syndromes [8][9][10]

Overview of adenomatous polyposis syndromes [8][9][10]
Syndrome Characteristic features Diagnostic findings Management [9]
Familial adenomatous polyposis (FAP) [9][10][12]
Attenuated FAP
  • Surveillance
    • Similar to FAP
    • Delayed onset of screening colonoscopies: every 1–2 years starting at 18–20 years of age [9]
  • Treatment

MUTYH-associated polyposis [10]

Colonoscopy, not sigmoidoscopy, is the first-line screening modality for individuals with attenuated FAP or MUTYH-associated polyposis because these conditions typically manifest with proximal colonic polyps. [8][9][10]

Counsel patients on the course of polyposis syndromes and the need for adherence to surveillance protocols. [8]

The Turban covers the head: Turcot syndrome is associated with malignant brain tumors.

Hamartomatous polyposis syndromes [9][10]

Hamartomatous polyposis syndromes [9][10]

Syndrome Characteristic features Diagnostic findings Management

Peutz-Jeghers syndrome (PJS)

Juvenile polyposis syndrome (JPS) [9]

Cowden syndrome (most common PTEN hamartoma tumor syndrome) [15]

  • Surveillance
    • Coloscopy and EGD: every 2 years starting at 15 years of age [9][10]
    • Screen for associated cancers. [9]
  • Treatment

25% of patients with hamartomatous polyposis syndromes have no family history (i.e., de novo mutation), and ≥ 10% of patients have negative genetic testing. [10]

Nonhereditary polyposis syndromes

Serrated polyposis syndrome [5][9][18]

Cronkhite-Canada syndrome [19][20]

Approach

Polyps are often identified as an incidental finding on workup for other conditions.

Patients with red flags for colon cancer or positive colorectal cancer screening tests (e.g., fecal occult blood testing) should undergo diagnostics for colorectal cancer.

Colonoscopy [24][25]

Colonoscopy facilitates simultaneous diagnosis and management of most polyps; suspected malignant colorectal polyps should be biopsied and referred to surgery.

Recommended removal techniques for low and high-risk colonic polyps [24][26][27]
Suspected polyp type Characteristic features Recommended excision technique
Low-risk
  • Sessile and < 10 mm
  • Penduculated at any size
High-risk
  • Sessile and ≥ 10 mm
  • Dominant nodule
  • Ulceration
  • No lifting with submucosal injection

Patients with hereditary polyposis syndromes with multiple polyps that cannot be managed endoscopically should also be referred for surgery.

Endoscopic colon polypectomy [24][25]

Surgical resection [24][25][28]

Refer patients with low-risk polyps that are difficult to remove (e.g., due to size and/or location) to an endoscopist with experience in advanced endoscopic removal techniques prior to referring to surgery. [24]

Follow-up [29][30]

The guidance in this section is for patients with no additional risk factors. For individuals at high risk of CRC, follow colorectal cancer screening in high-risk individuals. For individuals with hereditary polyposis syndromes, follow condition-specific screening procedures (see “Subtypes and variants”).

Surveillance after polypectomy [29][30]
Risk category Recommended interval to repeat colonoscopy

Very low risk

  • 10 years

Low-risk

  • 7–10 years
Intermediate risk
  • 3–5 years

High-risk

  • 3 years

Very high risk: > 10 adenomas

  • 1 year [9]

Follow-up should be tailored to the histology of the colonic polyp and the patient's risk factors for colorectal cancer.

  1. Grahn SW, Varma MG. Factors that increase risk of colon polyps. Clin Colon Rectal Surg. 2008; 21 (4): p.247-55. doi: 10.1055/s-0028-1089939 . | Open in Read by QxMD
  2. Liljegren A, Lindblom A, Rotstein S, Nilsson B, Rubio C, Jaramillo E.. Prevalence and incidence of hyperplastic polyps and adenomas in familial colorectal cancer: correlation between the two types of colon polyps. Gut. 2003; 52 (8): p.1140-1147. doi: 10.1136/gut.52.8.1140 . | Open in Read by QxMD
  3. Shussman N, Wexner SD. Colorectal polyps and polyposis syndromes. Gastroenterol Rep. 2014; 2 (1): p.1-15. doi: 10.1093/gastro/got041 . | Open in Read by QxMD
  4. Young B, O'Dowd G, Stewart W. Wheater's Basic Pathology: A Text, Atlas and Review of Histopathology E-Book. Elsevier Health Sciences ; 2009
  5. Ashburn JH, Plesec TP, Kalady MF. Serrated Polyps and Serrated Polyposis Syndrome. Clin Colon Rectal Surg. 2016; 29 (4): p.336-344. doi: 10.1055/s-0036-1584088 . | Open in Read by QxMD
  6. Jelsig AM, Qvist N, Brusgaard K, Nielsen CB, Hansen TP, Ousager LB. Hamartomatous polyposis syndromes: A review. Orphanet J Rare Dis. 2014 . doi: 10.1186/1750-1172-9-101 . | Open in Read by QxMD
  7. Update on Colorectal Cancer. http://www.aafp.org/afp/2000/0315/p1759.html. Updated: March 15, 2000. Accessed: February 8, 2017.
  8. Herzig D, Hardimann K, Weiser M, et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Inherited Polyposis Syndromes. Diseases of the Colon & Rectum. 2017; 60 (9): p.881-894. doi: 10.1097/dcr.0000000000000912 . | Open in Read by QxMD
  9. Syngal S, Brand RE, Church JM, Giardiello FM, Hampel HL, Burt RW. ACG Clinical Guideline: Genetic Testing and Management of Hereditary Gastrointestinal Cancer Syndromes. Am J Gastroenterol. 2015; 110 (2): p.223-262. doi: 10.1038/ajg.2014.435 . | Open in Read by QxMD
  10. Kidambi TD, Kohli DR, Samadder NJ, Singh A. Hereditary Polyposis Syndromes. Curr Treat Options Gastroenterol. 2019; 17 (4): p.650-665. doi: 10.1007/s11938-019-00251-4 . | Open in Read by QxMD
  11. Stoffel EM, Mangu PB, Gruber SB, et al. Hereditary Colorectal Cancer Syndromes: American Society of Clinical Oncology Clinical Practice Guideline Endorsement of the Familial Risk–Colorectal Cancer: European Society for Medical Oncology Clinical Practice Guidelines. J Clin Oncol. 2015; 33 (2): p.209-217. doi: 10.1200/jco.2014.58.1322 . | Open in Read by QxMD
  12. Aihara H, Kumar N, Thompson CC. Diagnosis, surveillance, and treatment strategies for familial adenomatous polyposis: rationale and update. Eur J Gastroenterol Hepatol. 2014; 26 (3): p.255-62. doi: 10.1097/MEG.0000000000000010 . | Open in Read by QxMD
  13. Basaran G, Erkan M. One of the rarest syndromes in dentistry: gardner syndrome.. Eur J Dent. 2008; 2 (3): p.208-12.
  14. Aelvoet AS, Buttitta F, Ricciardiello L, Dekker E. Management of familial adenomatous polyposis and MUTYH-associated polyposis; new insights. Best Pract Res Clin Gastroenterol. 2022 : p.101793. doi: 10.1016/j.bpg.2022.101793 . | Open in Read by QxMD
  15. Hobert JA, Eng C. PTEN hamartoma tumor syndrome: An overview. Genetics in Medicine. 2009; 11 (10): p.687-694. doi: 10.1097/gim.0b013e3181ac9aea . | Open in Read by QxMD
  16. Pilarski R, Burt R, Kohlman W, Pho L, Shannon KM, Swisher E. Cowden Syndrome and the PTEN Hamartoma Tumor Syndrome: Systematic Review and Revised Diagnostic Criteria. J Natl Cancer Inst. 2013; 105 (21): p.1607-1616. doi: 10.1093/jnci/djt277 . | Open in Read by QxMD
  17. Stanich PP, Owens VL, Sweetser S, et al. Colonic polyposis and neoplasia in Cowden syndrome. Mayo Clin Proc. 2011; 86 (6): p.489-92. doi: 10.4065/mcp.2010.0816 . | Open in Read by QxMD
  18. Mankaney G, Rouphael C, Burke CA. Serrated Polyposis Syndrome. Clin Gastroenterol Hepatol. 2020; 18 (4): p.777-779. doi: 10.1016/j.cgh.2019.09.006 . | Open in Read by QxMD
  19. Sweetser S, Boardman LA. Cronkhite-Canada Syndrome, An Acquired Condition of Gastrointestinal Polyposis and Dermatologic Abnormalities. Gastroenterol Hepatol. 2012; 8 (3): p.201-203.
  20. Kopáčová M, Urban O, Cyrany J, et al. Cronkhite-Canada syndrome: review of the literature. Gastroenterol Res Pract. 2013; 2013 : p.856873. doi: 10.1155/2013/856873 . | Open in Read by QxMD
  21. Wu ZY, Sang LX, Chang B. Cronkhite–Canada syndrome: from clinical features to treatment. Gastroenterol Rep. 2020; 8 (5): p.333-342. doi: 10.1093/gastro/goaa058 . | Open in Read by QxMD
  22. Moreno C, Kim DH, Bartel TB, et al. ACR Appropriateness Criteria ® Colorectal Cancer Screening. J Am Coll Radiol. 2018; 15 (5): p.S56-S68. doi: 10.1016/j.jacr.2018.03.014 . | Open in Read by QxMD
  23. Sovich JL, Sartor Z, Misra S. Developments in Screening Tests and Strategies for Colorectal Cancer. Biomed Res Int. 2015; 2015 : p.1-11. doi: 10.1155/2015/326728 . | Open in Read by QxMD
  24. Kaltenbach T, Anderson JC, Burke CA, et al. Endoscopic Removal of Colorectal Lesions—Recommendations by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2020; 158 (4): p.1095-1129. doi: 10.1053/j.gastro.2019.12.018 . | Open in Read by QxMD
  25. Ferlitsch M, Moss A, Hassan C, et al. Colorectal polypectomy and endoscopic mucosal resection (EMR): European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline. Endoscopy. 2017; 49 (03): p.270-297. doi: 10.1055/s-0043-102569 . | Open in Read by QxMD
  26. Herszényi L. The “Difficult” Colorectal Polyps and Adenomas: Practical Aspects. Digestive Diseases. 2018; 37 (5): p.394-399. doi: 10.1159/000495694 . | Open in Read by QxMD
  27. Hewett DG. Cold snare polypectomy: optimizing technique and technology (with videos). Gastrointest Endosc. 2015; 82 (4): p.693-696. doi: 10.1016/j.gie.2015.04.028 . | Open in Read by QxMD
  28. Rüth S, Spatz J, Anthuber M. Is There an Indication for Surgical Resection in Colorectal Adenoma?. Viszeralmedizin. 2014; 30 (1): p.5-5. doi: 10.1159/000358540 . | Open in Read by QxMD
  29. Lieberman DA, Rex DK, Winawer SJ, Giardiello FM, Johnson DA, Levin TR. Guidelines for colonoscopy surveillance after screening and polypectomy: A consensus update by the US Multi-Society Task Force on colorectal cancer. Gastroenterology. 2012; 143 (3): p.844-857. doi: 10.1053/j.gastro.2012.06.001 . | Open in Read by QxMD
  30. Gupta S, Lieberman D, Anderson JC, et al. Recommendations for Follow-Up After Colonoscopy and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2020; 158 (4): p.1131-1153.e5. doi: 10.1053/j.gastro.2019.10.026 . | Open in Read by QxMD

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