Intestinal polyposis syndrome

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 2, 2017
StartDiseasesIntestinal polyposis syndrome

Intestinal polyposis syndrome is a relatively rare condition. There are several different types of intestinal polyposis. They can be placed into different categories such as familial adenomatous polyposis (FAP) and hamartomatous polyposis.

Contents

Definition & Facts

A polyp is abnormal tissue growth from the surface of mucous membranes. Polyps can come in multiple different shapes though they are usually round, droplet-shaped, or irregular. Intestinal polyposis is characterized by the formation of multiple polyps in the lining of the intestinal mucosa. Patients with FAP typically have numerous polyps throughout the colon with 80 percent of them present in the left colon.

The condition has a five-year mortality rate with a 100 percent lifetime risk of developing colon cancer if the patient does not undergo a colectomy. Most people with intestinal polyposis are over the age of fifty. Inflammatory bowel disease like ulcerative colitis or Crohn's disease also increase the risk of polyp development.

Symptoms & Complaints

In many cases, intestinal polyposis causes no symptoms. In fact, the patient may not be aware that they have the condition until their doctor finds polyps when examining their bowel. When there are symptoms, they typically include:

Causes

FAP is the result of a mutated gene passed down from generation to generation within a family. It can be passed down via autosomal dominant inheritance pattern or autosomal recessive inheritance pattern. Mutations involve the APC gene and MUTYH gene. Peutz-Jeghers syndrome results from mutations of the STK11 gene which is located on chromosome 19.

Some of the mutations involved affect tumor suppressor genes. Loss of the function of this gene makes the development of polyps more likely. Under normal circumstances, cells of the intestinal lining grow and divide in an orderly manner but mutations in some genes may cause cells to keep dividing. They will continue to divide even when there is no need for new cells. This kind of unregulated growth is what causes intestinal polyps to form. A diet lacking in fiber and high alcohol intake may also contribute to polyp formation.

Diagnosis & Tests

Screening is important for the detection of polyps before they become cancerous. These tests also enable doctors to detect colon cancer while it is still in its earliest stages. As with other forms of cancer, early detection can significantly increase one's chance of recovery. Tests for intestinal polyps include:

  • Colonoscopy. When performing a colonoscopy, a doctor threads a colonoscope through the large intestine. This is considered the gold standard test since it is the only test that allows doctors to assess all of the colon lining for polyps. They can also take tissue samples for analysis and remove polyps all in the same procedure.
  • Virtual colonoscopy (CT colonography). This test involves the use of X-rays and computers to provide doctors with a two-or three-dimensional image of the colon. If one's doctor detects a polyp, a colonoscopy to have it removed.
  • Sigmoidoscopy. This is similar to the colonoscopy except that a shorter instrument called a sigmoidoscope is used. The instrument is inserted into the rectum so that the doctor can examine it. If the doctor finds a polyp, a colonoscopy to have it removed will be necessary.

Treatment & Therapy

Care for many of the different types of intestinal polyposis includes screening as well as steps to prevent the polyps from becoming malignant. In the case of FAP, screening of patients and their relatives has reduced the likelihood of cancer after a diagnosis of FAP by 55 percent. Options for polyp removal include:

  • During colonoscopy. In most cases, the doctor will be able to remove polyps using biopsy forceps or a wire loop for snipping off the polyp. They may also inject liquid under the polyp to lift it off the wall of the intestine. Larger polyps may also require the injection of a liquid so that the polyp can be isolated from tissue around it and removed.
  • Surgery. If a polyp is too large for it to be reached safely during screening, it may be removed via surgery. In some cases, this surgery can be minimally invasive. Endoscopic submucosal dissection involves removal of the polyp by placing it onto a "pillow" to separate it from the intestine’s muscular layer. Once separated, it can be cut off with a special knife that is passed through the colonoscope.
  • Colectomy. A colectomy is a major surgical procedure that will require that the patient go under general anesthesia. A large portion of the intestine will be removed. The colectomy procedure may be essential for people with FAP.

Prevention & Prophylaxis

The combination of regular screenings and lifestyle changes can make a significant difference. Those lifestyle changes include:

  • Eating more dietary fiber and calcium. This means more fruits and vegetables along with whole grains. Studies have also shown that increased dietary calcium can help to prevent the recurrence of adenomatous polyps.
  • Reducing fat intake. Patients will want to consume less fat in general and should make reducing in animal fats in their diet a priority.
  • Start exercising. Obesity is a factor in the development of intestinal polyps. This means that one should take steps to attain a healthy body weight.