Juvenile (retention) polyp

Topic Completed: 1 November 2017

Minor changes: 25 February 2021

Copyright: 2003-2021,, Inc.

PubMed Search: Juvenile polyp [title] colon

Nalini Bansal, M.D.
Page views in 2020: 19,751
Page views in 2021 to date: 7,498
Cite this page: Bansal N. Juvenile (retention) polyp. website. Accessed April 15th, 2021.
Definition / general
  • Most common type of intestinal polyp in children (> 90% of childhood colon polyps, Clin Colon Rectal Surg 2008;21:280)
  • "Juvenile polyp" was first used in 1957 by Horrilleno (Cancer 1957;10:1210)
  • "Juvenile" refers to the type of polyp (hamartomatous, usually limited to the colon), not the patient age
  • Solitary juvenile polyps have minimal malignant potential
  • Inflammatory / retention polyp
  • Juvenile polyposis syndrome: 5 or more juvenile polyps in the colorectum, juvenile polyps throughout the gastrointestinal tract or any number of juvenile polyps and a positive family history of juvenile polyposis
ICD coding
  • More common on left side of colon
  • Earliest morphologic lesions are focal areas of mucosal hyperplasia which seem to evolve into minute hyperplastic polyps
  • These become inflamed, frequently with ulceration and scarring of their surface, sealing over some of the crypts, with subsequent cystic dilatation of the crypts, accumulation of mucus within the cysts, enlargement of the structure to form a typical juvenile polyp and further inflammation and scarring
  • In some of the larger polyps, focal epithelial atypia develops (Cancer 1979;43:1906)
  • Second hypothesis: landscaper defect, in which an abnormal stromal environment leads to neoplastic transformation of adjacent epithelium (Science 1998;280:1036, World J Gastroenterol 2011 ;17:4839)
  • Juvenile polyposis syndrome is autosomal dominant
Clinical features
  • Lower endoscopy, preferably a colonoscopy rather than proctoscopy or flexible sigmoidoscopy, is increasingly the most common initial diagnostic study
Radiology description
  • Sessile or pedunculated polyp
Prognostic factors
  • Recent cancer risk analysis calculated a cumulative lifetime risk for colorectal cancer in juvenile polyposis syndrome (JPS) of 39% and a relative risk of 34.0 (Gut 2007;56:965)
Case reports
  • Many of these polyps simply outgrow their blood supply, become ischemic and autoamputate
  • For solitory juvenile polyp:
    • Colonoscopy / sigmoidoscopy and polypectomy
  • For juvenile polyposis syndrome:
    • Follow up: recommended every two to three years in patients with juvenile polyposis syndrome
    • Surgery: considered in patients with colorectal polyposis unmanageable by endoscopy (> 50 - 100 polyps), those with severe gastrointestinal bleeding or diarrhea, juvenile polyps with dysplasia and patients with a strong family history of colorectal cancer (Dis Colon Rectum 2005;48:49)
Clinical images

Images hosted on other servers:

Increase in vascularity surrounding the pits

Gross description
  • Sessile or pedunculated hamartomatous polyps
  • 5 mm to 50 mm, typically spherical, lobulated and pedunculated with surface erosion
Gross images

Contributed by Nalini Bansal, M.D.

Multiple polyps mainly in colon and rectum in 11 year old boy in a case of juvenile polyposis syndrome

Images hosted on other servers:

appearance of
juvenile polyposis

Microscopic (histologic) description
  • Characterized by an abundance of edematous lamina propria with inflammatory cells and cystically dilated glands lined by cuboidal to columnar epithelium with reactive changes (nonneoplastic, hamartomatous, epithelial retentions)
  • Dilated glands filled with mucus and inspissated inflammatory debris
  • Juvenile polyposis syndrome:
    • Polyps appear similar to sporadic solitary juvenile polyps, although syndromic polyps often have a frond-like growth pattern with less stroma, fewer dilated glands and more proliferative smaller glands
Microscopic (histologic) images

Contributed by Nalini Bansal, M.D.

Polyps showing mild frond like growth pattern in a case of juvenile polyposis syndrome

Contributed by Christopher Hartley, M.D.

Juvenile polyp

Images hosted on other servers:

Cystically dilated glands and inflammation

Juvenile polyp

Positive stains
  • TP53 mutations (p53 staining) in dysplastic epithelium can be seen in polyps of juvenile polyposis syndrome
Negative stains
  • p53 negative in benign solitary juvenile polyp as no dysplastic change
Molecular / cytogenetics description
  • A germline mutation in the SMAD4 or BMPR1A gene is found in 50 - 60% of patients with juvenile polyposis syndrome
Differential diagnosis
Board review style question #1
Juvenile polyps are a type of:

  1. Adenomatous polyp
  2. Hamartomatous polyp
  3. Neoplastic polyp
  4. None of the above
Board review style answer #1
Board review style question #2
The most common clinical presentation of juvenile polyp is:

  1. Abdominal pain
  2. Rectal bleeding
  3. Rectal prolapse
  4. None of the above
Board review style answer #2
Board review style question #3
In juvenile polyp, the term "juvenile" refers to the:

  1. Age of onset
  2. Type of polyp
  3. None of the above
Board review style answer #3
Back to top
Image 01 Image 02