A sessile polyp is a flat, wide, abnormal tissue growth that occurs on the lining (mucosa) of the large intestine, which includes the colon and rectum. Fixative polyps often have no symptoms. That means it doesn't cause any symptoms. Most cases are discovered through regular colon cancer screening, such as colonoscopy.
Most sessile polyps are benign (noncancerous), but some types have the potential to become cancerous over time. Treatment for sessile polyps depends on the size, type, and number of polyps found.
Between 15 and 40 percent of American adults have colon polyps, which are most common in people over 45 years of age. Although only a small percentage of all colon polyps become cancerous, certain types of sessile polyps account for up to 30% of colon cancers.
There are several types of sessile polyps and they are classified according to their growth pattern. Your healthcare provider can identify the type of sessile polyp by looking at a sample of polyp tissue under a microscope.
Identifying the type of sessile polyp a person has can help determine the likelihood that it will become cancerous (malignant), which can help health care providers assess cancer risk and make appropriate treatment decisions.
Types of sessile polyps include:
- Sedentary serrated adenoma: These polyps have serrated edges when viewed under a microscope. It is precancerous and requires immediate removal as it has the potential to progress to colon cancer.
- Tubular adenoma: These polyps can grow on the intestinal lining in a manner similar to mushrooms and their stems, but they can also be flat. Small tubular polyps are usually benign, but larger polyps are more likely to contain cancer cells.
- Villous adenoma: Under a microscope, these flat polyps have the appearance of bushy cauliflower or fingers. They are often larger than other polyp types. They are also more likely to contain cancer cells and require immediate removal.
- tubular Adenoma: Tubuloblastic adenomatous polyps have a combination of tubular and hairy growth patterns. Compared to tubular adenomas, these polyps generally have a higher risk of becoming cancerous, especially if they are larger than half an inch in size.
Fixative polyps usually do not cause symptoms. Larger sessile polyps may bleed and cause symptoms such as:
- Bloody stool: Blood in the stool (poop) may appear bright red or black, depending on where the bleeding is in the colon or rectum.
- Rectal bleeding: Blood on the toilet paper or toilet bowl after a bowel movement or blood on underwear are signs of rectal bleeding.
- fatigue: Blood loss can cause anemia (fewer red blood cells than usual), which can lead to fatigue.
- Changes in bowel habits: You may have fewer or more frequent bowel movements than usual.
- colic: Although less common, some people may experience abdominal pain.
Because the symptoms of sessile polyps are vague and similar to those of many gastrointestinal diseases, it is important to contact your health care provider to determine the cause, especially if you have bloody stools or rectal bleeding.
It is not known what causes sessile polyps to form in the lining of the colon and rectum, but research suggests that genetic and environmental factors likely play a role. Genetic mutations, either inherited (inherited) or acquired (caused by environmental factors), can contribute to the development of polyps by leading to uncontrolled cell growth.
Inherited genetic mutations can cause a rare inherited syndrome known as familial adenomatous polyposis. This causes hundreds or thousands of polyps to grow in the colon.
Meanwhile, some environmental factors, such as exposure to certain chemicals, can damage cellular DNA and cause acquired genetic mutations that can contribute to the development of polyps.
risk factors
Anyone can develop sessile polyps, but certain factors may increase your risk, including:
- age: Polyps are more common in people over 45 years of age.
- Family history: Having a family member with a history of polyps or colon cancer may increase your risk of developing polyps.
- Basic conditions: Inflammatory bowel diseases (IBD), such as ulcerative colitis (UC) and Crohn's disease, may increase your risk of developing polyps.
- diet: A diet low in fiber and high in red meat may contribute to the formation of polyps.
- Lifestyle habits: Smoking and excessive drinking are known risk factors for developing colon polyps.
Most people learn that they have one or more sessile polyps during a routine colon cancer screening. If you have concerning symptoms, such as bloody stool, or a family history or underlying medical condition that increases your risk of colon polyps, your health care provider may order screening tests to detect and diagnose sessile polyps.
Tests and procedures for diagnosing sessile polyps include:
- Colonoscopy: A flexible tube with a small camera (colonoscope) is inserted into the anus to view the colon and rectum and check for abnormalities, such as inflammation or polyps. Your health care provider may take a biopsy (a small sample of tissue) from a sessile polyp and examine it under a microscope to see if it contains cancer cells.
- Flexible sigmoidoscopy: This procedure involves inserting a flexible tube equipped with a light and a camera (sigmoidoscope) into the anus to help visualize the rectum and sigmoid (lower colon). If your health care provider finds a polyp, a biopsy may be taken and sent to a laboratory to test for cancer cells.
- Virtual Colonoscopy: A virtual colonoscopy, also known as a computed tomography (CT) colonoscopy, involves taking X-rays of the colon and rectum and using a computer to create detailed images and identify polyps and other abnormalities.
- Lower gastrointestinal (GI) series: Also known as a barium enema, this X-ray test involves filling the colon with a contrast agent (barium) to highlight and identify polyps and other abnormalities on the X-ray image.
The goal of treating sessile polyps is to remove them and prevent them from developing into colon cancer. The method of removal depends on the size, type, and number of sessile polyps found during imaging. Treatment for sessile polyps may include:
- Removal during colonoscopy or sigmoidoscopy: In many cases, a health care provider may remove sessile polyps during a colonoscopy or sigmoidoscopy using instruments that cut, cauterize (burn), or ablate (destroy) the abnormal tissue.
- Endoscopic mucosal resection (EMR): Your healthcare provider may use EMR to remove larger sessile polyps. EMR involves suctioning abnormal tissue or injecting a solution under the polyp to lift the polyp away from the surrounding tissue and then removing it using surgical tools.
- surgery: In some cases, surgery may be necessary to remove large sessile polyps or polyps that are difficult to reach with an endoscope.
After polyps are removed, regular follow-up colonoscopies or other screening tests are needed to monitor for new polyps. How often your health care provider recommends follow-up screenings depends on your risk factors and the type of sessile polyp that was removed.
There is no sure way to prevent sessile polyps, but a healthy lifestyle can lower your risk. These habits may include:
- Focus on a balanced diet: Maintaining a diet rich in fruits, vegetables, and whole grains while limiting red meat and processed foods can help prevent sessile polyps.
- Weight Management: Obesity is a risk factor for colon polyps. You can lower your risk by exercising regularly and eating a nutritious diet to maintain the weight you and your doctor have discussed.
- Alcohol Restrictions: Avoiding or limiting alcohol intake may help prevent colon polyps.
- Avoid smoking: Smoking increases the risk of colon polyps. Quitting smoking can help lower your risk and protect your overall health.
Regardless of whether sessile polyps are cancerous or not, complications can occur if they are not addressed. Undiagnosed and untreated sessile polyps can increase your risk of:
- Colon cancer: Some types of sessile polyps can progress to colon cancer when abnormal (cancerous) cells within the polyp continue to grow and multiply, forming a tumor.
- anemia: Chronic bleeding from the colon or rectum due to sessile polyps can cause blood loss and lead to iron deficiency anemia. This occurs when the body does not have enough iron to produce red blood cells. Symptoms include fatigue, headache, weakness, and heart palpitations.
- ileus: Large polyps in the colon can block the passage of stool through the colon and rectum, causing symptoms such as abdominal pain, bloating, constipation, gas, or difficulty passing stool.
Fixative polyps are flat growths that develop on the lining of the colon and rectum. Most sessile polyps are benign (noncancerous), but some can be malignant (cancerous). Most people with sessile polyps have no symptoms, but some sessile polyps may cause bloody stool, rectal bleeding, or abdominal pain.
Health care providers use imaging tests, such as colonoscopy and sigmoidoscopy, to diagnose sessile polyps. Removal of sessile polyps is necessary to lower the risk of colon cancer, and regular follow-up examinations are important to detect new polyps.
There is no sure way to prevent sessile polyps, but mindful lifestyle habits, including eating a balanced diet and not smoking, can help lower your risk. If you have a family history of colon polyps or colon cancer, or are experiencing concerning symptoms such as bloody stool, talk to your health care provider about screening.