GI POLYPOSIS - Classification

A GI polyp is defined as a mass of the mucosal surface protruding into the lumen of the bowel.
Polyps can be

• neoplastic,
• non-neoplastic, or submucosal.

GI polyposis is characterized by multiple polyps within the GI tract.
A variety of polyposis syndromes can affect the GI tract. These polyposis syndromes may be classified as

• familial inherited (autosomal dominant) or
• nonfamilial.

The inherited polyposis syndromes can be further subdivided into 2 groups depending on whether the polyps are

• adenomas or
• hamartomas.

The adenomatous polyposis syndromes include the classic

• familial adenomatous polyposis (FAP),
• Gardner syndrome,
• Turcot syndrome.

Hamartomatous familial polyposis syndromes include

• Peutz-Jeghers syndrome,
• juvenile polyposis syndrome,
• Cowden disease,
• Ruval-Caba-Myhre-Smith syndrome.

The non-inherited polyposis syndromes include

• Cronkhite-Canada syndrome,
• and a variety of miscellaneous non-familial polyposis.

• From a prognostic viewpoint, these syndromes must be recognized, because the adenomatous polyps are premalignant.
• These syndromes should be considered when
• an intestinal polyp is recognized in the young,
• when 2 or more polyps are seen in any patient,
• when colonic carcinoma is discovered in patients younger than 40 years, and
• when extraintestinal manifestations associated with these syndromes are discovered.
  
  
• GI polyps may be asymptomatic, but may also occur with rectal bleeding and diarrhea.

The urgency of case tracing and genetic counseling is related not so much to the symptoms of the disease but to the potential for the development of a colonic carcinoma. It is probable that patients with familial polyposis, if untreated, will develop a colonic carcinoma.