Polyps, Intestinal
Basics
Description
- Intestinal polyps are abnormal tissue growths protruding from the intestinal mucosa into the lumen.
- Most common in children are solitary juvenile polyps, but these may also be multiple in number.
- May be associated with various polyposis syndromes
- Classified by gross appearance
- Pedunculated: mushroom-like and attached to mucosa with a narrow stalk
- Sessile: elevated, flat lesions broadly attached to mucosa
- Types of polyps:
- Hamartomas
- Adenomatous
- Hamartomatous polyps
- Juvenile polyps: usually a solitary polyp
- Juvenile polyposis syndrome (>3 to 5 juvenile polyps or any number of juvenile polyps with a positive family history)
- Juvenile polyposis of infancy
- Juvenile polyposis coli (colonic involvement only)
- Generalized juvenile polyposis (small bowel and colonic involvement)
- Peutz-Jeghers syndrome
- Cowden syndrome
- Bannayan-Riley-Ruvalcaba syndrome (BRRS)
- Adenomatous polyps
- Familial adenomatous polyposis (FAP)
- Severe form and attenuated forms
- Gardner syndrome (colonic polyps with osteomas and epidermal inclusion cysts)
- Turcot syndrome (colonic polyps with brain tumors)
- Familial adenomatous polyposis (FAP)
- Other polyposis syndromes
- MUTYH-associated polyposis syndrome
- Serrated polyposis syndrome
Epidemiology
- Juvenile polyps are the most common childhood polyps:
- Account for >90% of polyps seen in children
- 1–2% of asymptomatic children are estimated to have juvenile polyps.
- Typically present between 2 and 5 years of age
- Twice as common in boys than girls
- >5 juvenile polyps should raise clinical suspicion for juvenile polyposis syndrome.
- Adenomatous polyps in FAP may present in early childhood or adolescence with an average age of onset of 16 years.
Prevalence
- Juvenile polyposis syndrome: 1 in 100,000 to 1 in 160,000
- Peutz-Jeghers syndrome: 1 in 25,000 to 1 in 300,000
- FAP: 1 in 5,000 to 1 in 17,000
Risk Factors
Family history of polyposis syndrome
Genetics
Different genes and inheritance patterns with various polyposis syndromes:
- Juvenile polyposis syndrome
- Autosomal dominant with variable penetrance
- Mutations in SMAD4 and BMPR1A genes, involved in transforming growth factor-β (TGF-β) signal transduction
- SMAD4 mutation also associated with hereditary hemorrhagic telangiectasia and arteriovenous malformations
- Peutz-Jeghers syndrome
- Autosomal dominant
- Mutations in STK11/LKB1 tumor suppressor gene are associated.
- Cowden syndrome and BRRS
- Autosomal dominant
- Associated with mutations in PTEN gene
- FAP
- Autosomal dominant
- Mutation in adenomatous polyposis coli (APC) tumor suppressor gene
Pathophysiology
Mutations in tumor suppressor genes likely lead to dysregulation of cell proliferation and apoptosis in polyposis syndromes.
Commonly Associated Conditions
- Juvenile polyposis syndrome, Cowden syndrome, and BRRS all have juvenile polyps as part of their manifestations.
- Cowden syndrome is associated with colonic and gastric polyps with extraintestinal symptoms including mucocutaneous lesions, thyroid adenomas and goiter, fibroadenomas and fibrocystic disease of the breast, uterine leiomyomas, and macrocephaly.
- BRRS is associated with colonic and ileal polyps.
- Peutz-Jeghers syndrome is characterized by multiple gastrointestinal (GI) pedunculated hamartomatous polyps.
- FAP, Gardner, and Turcot syndrome are characterized by multiple adenomatous polyps.
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Citation
Cabana, Michael D., editor. "Polyps, Intestinal." 5-Minute Pediatric Consult, 8th ed., Wolters Kluwer, 2019. Pediatrics Central, peds.unboundmedicine.com/pedscentral/view/5-Minute-Pediatric-Consult/617126/all/Polyps__Intestinal.
Polyps, Intestinal. In: Cabana MDM, ed. 5-Minute Pediatric Consult. Wolters Kluwer; 2019. https://peds.unboundmedicine.com/pedscentral/view/5-Minute-Pediatric-Consult/617126/all/Polyps__Intestinal. Accessed December 12, 2024.
Polyps, Intestinal. (2019). In Cabana, M. D. (Ed.), 5-Minute Pediatric Consult (8th ed.). Wolters Kluwer. https://peds.unboundmedicine.com/pedscentral/view/5-Minute-Pediatric-Consult/617126/all/Polyps__Intestinal
Polyps, Intestinal [Internet]. In: Cabana MDM, editors. 5-Minute Pediatric Consult. Wolters Kluwer; 2019. [cited 2024 December 12]. Available from: https://peds.unboundmedicine.com/pedscentral/view/5-Minute-Pediatric-Consult/617126/all/Polyps__Intestinal.
* Article titles in AMA citation format should be in sentence-case
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