Basics
Description
- Intestinal polyps are abnormal tissue growths protruding from the intestinal mucosa into the lumen.
- Most commonly solitary lesions (juvenile polyps) but 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:
- Polyposis syndromes
- Juvenile polyposis syndrome (>3 " 5 juvenile polyps)
- Juvenile polyposis of infancy
- Juvenile polyposis coli (colonic involvement only)
- Generalized juvenile polyposis
- Peutz-Jeghers syndrome
- Familial adenomatous polyposis (FAP)
- Other polyposis syndromes
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 a suspicion for juvenile polyposis syndrome.
- Average age at onset of adenomatous polyps in FAP is 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- ² (TGF- ²) signal transduction
- FAP
- Autosomal dominant
- Mutation in adenomatous polyposis coli (APC) tumor suppressor gene
- Peutz-Jeghers syndrome
- Autosomal dominant
- Mutations in STK11/LKB1 tumor suppressor gene are associated.
- Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome (BRRS)
- Autosomal dominant
- Associated with mutations in PTEN 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.
- Peutz-Jeghers syndrome is characterized by multiple GI pedunculated hamartomatous polyps.
- FAP and Turcot syndrome are characterized by multiple adenomatous polyps.
Diagnosis
History
- Family history of polyps or polyposis syndromes is essential to obtain.
- Presence and amount of blood in stool
- Signs and symptoms:
- Frequently asymptomatic
- Painless rectal bleeding is typical presentation.
- Iron deficiency anemia
- Prolapsing rectal lesion
- Abdominal pain or obstruction from intussusception
- Diarrhea
Physical Exam
- Digital rectal exam may identify rectal polyp.
- Pigmentation of skin and mucous membranes consistent with Peutz-Jeghers syndrome
- Mucocutaneous lesions such as facial trichilemmoma, oral fibromas, and acral keratosis are seen in Cowden syndrome.
- Mental retardation, macrocephaly, lipomatosis, hemangiomas, and genital pigmentation are seen in BRRS.
Diagnostic Tests & Interpretation
Lab
- Stool test for occult blood may be positive.
- CBC can assess degree of anemia and also for baseline hemoglobin before polypectomy.
- PT/PTT should be considered before polypectomy due to risk of bleeding.
- Genetic testing can be considered if a polyposis syndrome is suspected.
- Use of urine and tissue matrix metalloproteinases (MMPs) as biomarkers for the presence of polyps is being researched.
Imaging
Radiologic studies are not the most effective methods of identifying polyps but can be used:
- Barium enema may identify colonic polyps.
- Upper GI with small bowel study may locate presence of small bowel polyps.
- Use of CT and MR colonography has been studied mainly in adults.
Diagnostic Procedures/Other
- Full colonoscopy with polypectomy is the preferred test to perform.
- Flexible sigmoidoscopy may miss polyps in proximal colon:
- 32% of juvenile polyps are located proximal to splenic flexure.
- 12% of patients with juvenile polyps only have polyps located proximal to splenic flexure.
- Video capsule endoscopy and balloon enteroscopy may be useful to identify small bowel polyps.
Pathologic Findings
- Polyp pathology cannot be determined by gross visualization, hence polyps must be removed for histologic exam.
- Juvenile polyps
- Hamartomatous but occasionally capable of adenomatous changes
- Potential of malignancy in a solitary juvenile polyp is extremely low but is increased in juvenile polyposis syndrome.
- Peutz-Jeghers syndrome
- Hamartomatous
- Microscopically have hyperplasia of the smooth muscle layer, extending in an arborizing, tree-like manner
- Relatively low potential of GI malignancy but increased potential in other organs such as breast, pancreas, ovary, testicle, and uterus
- FAP
- Adenomatous polyps
- Lifetime risk for colorectal cancer is 100%.
- Increased association with hepatoblastoma, periampullary carcinoma, and desmoid tumors
Differential Diagnosis
- Because juvenile polyps often present with rectal bleeding, the differential diagnosis for lower GI bleeding should be considered:
- Anal fissure
- Meckel diverticulum
- Infectious enterocolitis
- Inflammatory bowel disease
- Intussusception
- Vascular malformation
- Hemorrhoids
- Hemolytic uremic syndrome
- Henoch-Sch Άnlein purpura
- Rectal trauma
- Neoplasm
Treatment
Medication
Administration of some NSAIDs (such as sulindac and celecoxib) may slow progression or reduce the number of adenomatous polyps.
Additional Treatment
General Measures
Full colonoscopy with polypectomy is an essential diagnostic and therapeutic tool. Removal of GI polyps can help to control symptoms and reduce the risk of malignancy.
Issues for Referral
Patients suspected of having a polyp or polyposis syndrome should be referred to a gastroenterologist for evaluation. Patients with polyposis syndromes should be referred to a tertiary care center for genetic counseling.
Surgery/Other Procedures
- When adenomatous polyps are identified in FAP, prophylactic colectomy should be considered.
- Colectomy should also be considered in other polyposis syndromes with innumerable polyps or polyps showing premalignant changes.
- The main surgical options include a subtotal colectomy with ileorectal anastomosis (IRA) or a proctocolectomy with ileal pouch " anal anastomosis (IPAA).
Ongoing Care
Follow-up Recommendations
- For solitary juvenile polyps, follow up with stool guaiac check and CBC 6 months after polypectomy. Repeat colonoscopy is indicated with any abnormalities.
- For polyposis syndromes, screening recommendations differ depending on the syndrome:
- Typically involve surveillance colonoscopies every 1 " 3 years depending on findings
- Asymptomatic children with an APC mutation for FAP should have annual colonoscopies starting at 10 " 12 years of age.
- Published guidelines for follow-up of patients with various polyposis syndromes are available.
Additional Reading
- Barnard J. Screening and surveillance recommendations for pediatric gastrointestinal polyposis syndromes. J Pediatr Gastroenterol Nutr. 2009;48(Suppl 2):S75 " S78. [View Abstract]
- Chow E, Macrae F. Review of juvenile polyposis syndrome. J Gastroenterol Hepatol. 2005;20(11):1634 " 1640. [View Abstract]
- Erdman SH, Barnard JA. Gastrointestinal polyps and polyposis syndromes in children. Curr Opin Pediatr. 2002;14(5):576 " 582. [View Abstract]
- Giardiello FM, Trimbath JD. Peutz-Jeghers syndrome and management recommendations. Clin Gastroenterol Hepatol. 2006;4(4):408 " 415. [View Abstract]
- Gupta SK, Fitzgerald JF, Croffie JM, et al. Experience with juvenile polyps in North American children: the need for pancolonoscopy. Am J Gastroenterol. 2001;96(6):1695 " 1697. [View Abstract]
- Merg A, Howe JR. Genetic conditions associated with intestinal juvenile polyps. Am J Med Genet C Semin Med Genet. 2004;129C(1):44 " 55. [View Abstract]
- Thakkar K, Fishman DS, Gilger MA. Colorectal polyps in childhood. Curr Opin Pediatr. 2012;24(5):632 " 637. [View Abstract]
Codes
ICD09
- 569.89 Other specified disorders of intestine
- 211.3 Benign neoplasm of colon
- 759.6 Other hamartoses, not elsewhere classified
ICD10
- K63.89 Other specified diseases of intestine
- D12.6 Benign neoplasm of colon, unspecified
- Q85.8 Other phakomatoses, not elsewhere classified
SNOMED
- 254588001 Polyp of intestine (disorder)
- 9273005 Juvenile polyposis syndrome (disorder)
- 254594009 Hamartoma of intestine
- 54411001 Peutz-Jeghers syndrome (disorder)
- 58037000 Cowden syndrome (disorder)
- 61665008 Turcot syndrome (disorder)
- 72900001 Familial multiple polyposis syndrome (disorder)
FAQ
- Q: What is the potential of developing cancer from a polyp?
- A: Risk of neoplasia depends on the type of polyp:
- Patients with solitary juvenile polyps have essentially no increased risk of colorectal carcinoma.
- Patients with juvenile polyposis syndrome have been reported to have up to a 65% chance of developing GI cancer, with the risk of malignancy commencing from age 20 years.
- Patients with Peutz-Jeghers syndrome have been reported to have almost a 50% chance of developing cancer in the intestinal tract or other organ systems.
- Patients with FAP have a 100% lifetime risk of developing colorectal cancer.
- Q: Is a flexible sigmoidoscopy sufficient for the detection of polyps?
- A: No. Approximately 37% of patients with juvenile polyps have polyps proximal to the splenic flexure, and 12% of patients have only proximal colon polyps. A flexible sigmoidoscopy would not identify these polyps, making it necessary to perform a full colonoscopy.
- Q: What is your management recommendation for a patient with painless rectal bleeding that stops on its own?
- A: It is widely believed that pedunculated polyps will autoamputate after outgrowing their blood supply, although there is no objective evidence supporting this. If there is no family history of a polyposis syndrome, the patient can be followed with stool guaiac checks and a CBC in 6 months. If there is a family history, then referral to a gastroenterologist for full colonoscopy is indicated.
- Q: How many polyps can patients have?
- A: Patients with juvenile polyposis syndrome often have 50 " 200 polyps distributed throughout the colon. Patients with FAP may have a few to over a thousand polyps in the colon.
- Q: When does endoscopic surveillance typically begin for children with FAP?
- A: It is generally recommended that annual endoscopic surveillance begin between 10 and 12 years of age in patients with an APC mutation.