eMedicine Specialties > Gastroenterology > Systemic Disease

Familial Adenomatous Polyposis: Differential Diagnoses & Workup

Author: Mohammad Wehbi, MD, Assistant Professor of Medicine, Associate Program Director, Department of Gastroenterology, Atlanta Veterans Affairs Medical Center, Emory University School of Medicine
Coauthor(s): Nicole M Griglione, MD, Staff Physician, Department of Medicine, Emory University School of Medicine; Vincent W Yang, MD, PhD, R Bruce Logue Professor, Director, Division of Digestive Diseases, Department of Medicine, Professor of Hematology and Oncology, Winship Cancer Institute, Emory University School of Medicine; Kamil Obideen, MD, Assistant Professor of Medicine, Division of Digestive Diseases, Emory University School of Medicine; Consulting Staff, Division of Gastrointestinal Endoscopy, Atlanta Veterans Affairs Medical Center; Jae W Nam, MD, Fellow in Gastroenterology, Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine; Consulting Staff, Department of Critical Care, Decatur Hospital; John M Carethers, MD, Professor of Medicine, Chief, Division of Gastroenterology, Department of Medicine, University of California at San Diego
Contributor Information and Disclosures

Updated: Jul 30, 2008

Differential Diagnoses

Peutz-Jeghers Syndrome

Other Problems to Be Considered

Bannayan-Riley-Ruvalcaba syndrome
Cowden disease
Juvenile polyposis syndrome
Cronkhite-Canada syndrome
Hereditary nonpolyposis colon cancer
Hyperplastic polyposis
Nodular lymphoid hyperplasia
Lymphomatous polyposis
Neurofibromatosis type 1 (NF-1)
Inflammatory polyposis
MYH-associated polyposis

Workup

Laboratory Studies

  • CBC count
  • Alpha-fetoprotein (AFP) blood test - For children with FAP until age 5 years as part of a screening program for hepatoblastoma

Imaging Studies

  • Flexible sigmoidoscopy: Visualization of more than 100 polyps usually establishes the diagnosis because of the diffuse nature of the polyposis.
  • Colonoscopy is usually reserved for patients thought to have AAPC because of the higher incidence of right-sided polyps (proximal colonic involvement).
  • Front- and side-viewing esophagogastroduodenoscopy is recommended if the sigmoidoscopy or the colonoscopy establishes the diagnosis of FAP. It is an essential component of the surveillance program in FAP, especially in that the second most common cancer involves the duodenum. This test helps to evaluate the presence of gastric, duodenal, and periampullary adenomas. It is recommended every 1-3 years. Benign gastric polyps are part of the spectrum of FAP. They are usually confined to the fundus.
  • Dental and skull x-ray films are recommended in patients thought to have a Gardner variant of FAP. The films help to detect osteomas and dental abnormalities.
  • Barium studies may be performed to visualize intestinal polyposis.
  • Periodic ultrasounds or abdominal computed tomography scans are used to check for intra-abdominal desmoid tumors and pancreatic cancer.
  • Periodic ultrasound of the thyroid: This imaging study is considered because of the increased risk of thyroid cancer. It can supplement the recommended annual physical examination of the thyroid.

Other Tests

  • Three genetic tests are available. Patients should receive genetic counseling from a trained individual prior to the performance of these tests.
  • In vitro protein synthesis assay
    • This is the genetic test of choice for the proband patient (patient with FAP). This test is commercially available.
    • DNA from peripheral blood is analyzed for a truncated APC gene product.
    • Because of the size of the APC protein, it is analyzed in 5 overlapping segments.
    • If the proband has a mutation, other family members can be tested (after genetic counseling) for the identical mutation. The test generally has 100% accuracy in detecting other gene carriers in the family.
  • APC gene sequencing is the most accurate test. However, it is hard logistically and, hence, is only reserved for research purposes.
  • Linkage testing
    • DNA markers near or in the APC locus are used to identify mutant gene carriers.
    • This test requires 2 affected family members to achieve an appropriate linkage relationship resulting in 90% accuracy. As a result, this is not appropriate logistically.

Procedures

  • Representative polyps should be removed by endoscopic polypectomy to confirm the diagnosis by histologic examination.

Histologic Findings

Characteristic pathology of a polyp from patients with FAP is a tubular adenoma.

More on Familial Adenomatous Polyposis

Overview: Familial Adenomatous Polyposis
Differential Diagnoses & Workup: Familial Adenomatous Polyposis
Treatment & Medication: Familial Adenomatous Polyposis
Follow-up: Familial Adenomatous Polyposis
Multimedia: Familial Adenomatous Polyposis
References
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References

  1. Nieuwenhuis MH, De Vos Tot Nederveen Cappel W, Botma A, et al. Desmoid tumors in a dutch cohort of patients with familial adenomatous polyposis. Clin Gastroenterol Hepatol. Feb 2008;6(2):215-9. [Medline].

  2. Ponti G, Losi L, Pellacani G, Rossi GB, Presutti L, Mattioli F, et al. Wnt pathway, angiogenetic and hormonal markers in sporadic and familial adenomatous polyposis-associated juvenile nasopharyngeal angiofibromas (JNA). Applied Immunohistochemistry & Molecular Morphology [serial online]. January 25, 2008;Available from: Pubmed. Accessed March 15, 2008. Available at http://www.appliedimmunohist.com/.

  3. Bianchi LK, Burke CA, Bennett AE, et al. Fundic gland polyp dysplasia is common in familial adenomatous polyposis. Clin Gastroenterol Hepatol. Feb 2008;6(2):180-5. [Medline].

  4. Friederich P, van Heumen BW, Nagtegaal ID, et al. Increased epithelial cell proliferation in the ileal pouch mucosa of patients with familial adenomatous polyposis. Virchows Arch. Sep 2007;451(3):659-67. [Medline]. [Full Text].

  5. Iaquinto G, Fornasarig M, Quaia M, et al. Capsule endoscopy is useful and safe for small-bowel surveillance in familial adenomatous polyposis. Gastrointest Endosc. Jan 2008;67(1):61-7. [Medline].

  6. Bresalier RS. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 2006;2759-2810.

  7. Brosens LA, Keller JJ, Offerhaus GJ, et al. Prevention and management of duodenal polyps in familial adenomatous polyposis. Gut. Jul 2005;54(7):1034-43. [Medline].

  8. Burke CA, Beck GJ, Church JM, et al. The natural history of untreated duodenal and ampullary adenomas in patients with familial adenomatous polyposis followed in an endoscopic surveillance program. Gastrointest Endosc. Mar 1999;49(3 Pt 1):358-64. [Medline].

  9. Burt R, Neklason DW. Genetic testing for inherited colon cancer. Gastroenterology. May 2005;128(6):1696-716. [Medline].

  10. Bussey HJR. Genetic and epidemiological features of familial polyposis coli. In: Bussey HJR, ed. Familial Polyposis Coli. Baltimore, Md: Johns Hopkins University Press; 1975:9-17.

  11. Doxey BW, Kuwada SK, Burt RW. Inherited polyposis syndromes: molecular mechanisms, clinicopathology, and genetic testing. Clin Gastroenterol Hepatol. Jul 2005;3(7):633-41. [Medline].

  12. Galiatsatos P, Foulkes WD. Familial adenomatous polyposis. Am J Gastroenterol. Feb 2006;101(2):385-98. [Medline].

  13. Giardiello FM, Brensinger JD, Petersen GM, et al. The use and interpretation of commercial APC gene testing for familial adenomatous polyposis. N Engl J Med. Mar 20 1997;336(12):823-7. [Medline].

  14. Giardiello FM, Hamilton SR, Krush AJ, et al. Treatment of colonic and rectal adenomas with sulindac in familial adenomatous polyposis. N Engl J Med. May 6 1993;328(18):1313-6. [Medline].

  15. Giardiello FM, Yang VW, Hylind LM, et al. Primary chemoprevention of familial adenomatous polyposis with sulindac. N Engl J Med. Apr 4 2002;346(14):1054-9. [Medline].

  16. Schulmann K, Pox C, Tannapfel A, Schmiegel W. The patient with multiple intestinal polyps. Best Practice & Research Clinical Gastroenterology [serial online]. June 2007;21(3):409-426. Available from: Science Direct. Accessed June 2, 2008. Available at http://www.sciencedirect.com.

  17. Thun MJ, Henley SJ, Patrono C. Nonsteroidal anti-inflammatory drugs as anticancer agents: mechanistic, pharmacologic, and clinical issues. J Natl Cancer Inst. Feb 20 2002;94(4):252-66. [Medline].

  18. Zhang J, Ahmad S, Mao Y. BubR1 and APC/EB1 cooperate to maintain metaphase chromosome alignment. J Cell Biol. Aug 27 2007;178(5):773-84. [Medline].

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Further Reading

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Keywords

familial adenomatous polyposis, FAP, adenomatous polyposis syndrome, adenomatous polyps, colon cancer, colorectal cancer, adenomatous polyposis coli, colorectal carcinoma, colonic polyps, colonic neoplasia, rectal bleeding, adenomatous polyposis coli gene, APC gene, Gardner syndrome, Turcot syndrome, attenuated adenomatous polyposis coli, AAPC, desmoid tumors, intestinal polyposis, colectomy, rectal resection, duodenal adenocarcinoma, periampullary adenocarcinoma, medulloblastoma, hepatoblastoma, thyroid cancers, adrenal cancers, upper gastrointestinal cancers

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Contributor Information and Disclosures

Author

Mohammad Wehbi, MD, Assistant Professor of Medicine, Associate Program Director, Department of Gastroenterology, Atlanta Veterans Affairs Medical Center, Emory University School of Medicine
Mohammad Wehbi, MD is a member of the following medical societies: American College of Physicians, American Gastroenterological Association, and American Medical Association
Disclosure: Nothing to disclose.

Coauthor(s)

Nicole M Griglione, MD, Staff Physician, Department of Medicine, Emory University School of Medicine
Nicole M Griglione, MD is a member of the following medical societies: American Medical Association and Illinois State Medical Society
Disclosure: Nothing to disclose.

Vincent W Yang, MD, PhD, R Bruce Logue Professor, Director, Division of Digestive Diseases, Department of Medicine, Professor of Hematology and Oncology, Winship Cancer Institute, Emory University School of Medicine
Vincent W Yang, MD, PhD is a member of the following medical societies: Alpha Omega Alpha, American Gastroenterological Association, American Society for Clinical Investigation, and Association of American Physicians
Disclosure: Nothing to disclose.

Kamil Obideen, MD, Assistant Professor of Medicine, Division of Digestive Diseases, Emory University School of Medicine; Consulting Staff, Division of Gastrointestinal Endoscopy, Atlanta Veterans Affairs Medical Center
Kamil Obideen, MD is a member of the following medical societies: American College of Gastroenterology, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy
Disclosure: Nothing to disclose.

Jae W Nam, MD, Fellow in Gastroenterology, Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine; Consulting Staff, Department of Critical Care, Decatur Hospital
Jae W Nam, MD is a member of the following medical societies: American College of Gastroenterology
Disclosure: Nothing to disclose.

John M Carethers, MD, Professor of Medicine, Chief, Division of Gastroenterology, Department of Medicine, University of California at San Diego
John M Carethers, MD is a member of the following medical societies: Alpha Omega Alpha, American Association for Cancer Research, American College of Gastroenterology, American College of Physicians, and American Gastroenterological Association
Disclosure: Nothing to disclose.

Medical Editor

John Gunn Lee, MD, Director of Pancreaticobiliary Service, Associate Professor, Department of Internal Medicine, Division of Gastroenterology, University of California at Irvine School of Medicine
John Gunn Lee, MD is a member of the following medical societies: American College of Gastroenterology, American College of Physicians, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Simmy Bank, MD, Chair, Professor, Department of Internal Medicine, Division of Gastroenterology, Long Island Jewish Hospital, Albert Einstein College of Medicine
Disclosure: Nothing to disclose.

CME Editor

Alex J Mechaber, MD, FACP, Assistant Dean for Medical Curriculum, Associate Professor of Medicine, Division of General Internal Medicine, University of Miami Miller School of Medicine
Alex J Mechaber, MD, FACP is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians-American Society of Internal Medicine, and Society of General Internal Medicine
Disclosure: Nothing to disclose.

Chief Editor

Julian Katz, MD, Clinical Professor of Medicine, Drexel University College of Medicine; Consulting Staff, Department of Medicine, Section of Gastroenterology and Hepatology, Hospital of the Medical College of Pennsylvania
Julian Katz, MD is a member of the following medical societies: American College of Gastroenterology, American College of Physicians, American Gastroenterological Association, American Geriatrics Society, American Medical Association, American Society for Gastrointestinal Endoscopy, American Society of Law Medicine and Ethics, American Trauma Society, Association of American Medical Colleges, and Physicians for Social Responsibility
Disclosure: Nothing to disclose.

 
 
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