What to Know About Tubular Adenoma

Medically Reviewed by Shruthi N, MD on June 23, 2024
Written by Hallie Levine
6 min read

If you’ve ever had a colonoscopy to screen for colon cancer, your doctor may have told you that they found polyps. These small clumps of cells that form on your colon lining are usually harmless. But they can sometimes lead to colon cancer.

The most common type of colon polyps doctors remove are a type called tubular adenoma. They get the name because their cells look like tubes under a microscope. Less than 10% of tubular adenomas will develop into cancer. If you have them – or any other type of colon polyps – your doctor will remove them to keep that from happening.

Sometimes, cells in your body grow out of control, a process called mutation. Some of the abnormal cells can turn into polyps and other types of tumors. Tubular adenomas are often small – less than 1/2 inch. 

Experts aren't sure what causes these mutations to happen, but it's thought to be a combination of your genes and things in your environment.

Some polyps in the colon develop as a response to long-term inflammation, such as that caused by ulcerative colitis or Crohn's disease. Polyps caused by inflammation aren't likely to turn cancerous. But these inflammatory bowel diseases still raise your risk of colon cancer. That's because the inflammation they cause damages your colon lining. Your body's efforts to heal this damage lead to increased cell turnover, which makes cancer more likely.

 

 

Colon adenomas have two main growth patterns:

  • Tubular adenomas grow in orderly, tube-shaped rows. About 70% of colon polyps are this type.
  • Villous adenomas grow in a shaggy, cauliflower-like pattern. 

Tubular adenomas are likely to be small, less than 1/2 inch. The spread-out growth pattern of villous adenomas means they tend to be larger. They also grow faster and are more likely to contain cancerous cells. 

What are tubulovillous adenomas?

Some polyps have a combination of the two growth patterns. They’re called tubulovillous adenomas. About 15% of colon polyps are villous or tubulovillous.

 

You’re more likely to get a tubular adenoma of the colon if you:

  • Are 50 or older
  • Have a high body mass index (BMI) or obesity
  • Are male (or were identified as male at birth)
  • Have a family history of colon polyps
  • Have diabetes
  • Smoke
  • Drink heavily
  • Aren't physically active

Some research has found that Black people have a higher risk of getting adenomas, but other studies had conflicting results.

Most polyps don't cause symptoms. So you may not know you have tubular adenomas until your doctor finds them during a colonoscopy. But you could notice:

 

Colonoscopy is the best way to detect and remove a tubular adenoma polyp. 

During a colonoscopy, your doctor inserts a long, flexible tube with a camera lens into your rectum and slowly threads it into your colon. They can see the images from inside your intestine on a video monitor. Any tubular adenomas will show up as lumps sticking out from the lining of your colon.

Your doctor will snip off the polyp or loop a wire around it and burn it off with electric current. You’ll be asleep during the procedure, so you won’t feel any pain.

Your doctor will send the polyp to a lab. A pathologist will check it under a microscope to see how much the sample looks like cancer. 

Some other screening tests can also find tubular adenomas, but you may still need a colonoscopy to remove them. These tests include:

  • CT colonography, sometimes called virtual colonoscopy
  • Flexible sigmoidoscopy
  • Fecal immunochemical test 
  • Fecal occult blood test
  • Stool DNA test

If you’ve had tubular or any other types of adenomas, you’ll need follow-up colonoscopies to make sure they don’t return. 

If you had only one or two small tubular adenomas removed, you'll likely need a procedure every 7-10 years. But you may need one sooner than that if you had three or more polyps, they were larger than 10 millimeters, or your doctor wasn't able to remove them completely. You also may need more frequent colonoscopies if you have a family history of polyps or colon cancer.

 

Almost all colon cancer starts out as polyps. They grow slowly, over a decade or more. 

Screening and removal of polyps is the best way to prevent colon cancer from developing. Doctors generally recommend getting your first colonoscopy at age 45. You may need to start at age 40 or earlier if:

  • Someone in your family has had colon cancer or questionable polyps.
  • You have inflammatory bowel disease (IBD).
  • You have a genetic condition that puts you at higher risk of getting polyps and colon cancer.

You also can take these steps to help avoid colon polyps and colon cancer:

  • Eat less fat and processed meat.
  • Eat more vegetables, fresh fruits, and other high-fiber foods.
  • Keep your weight in a range that's healthy for you.
  • Avoid smoking .
  • Drink alcohol in moderation if you drink at all.
  • Talk to your doctors about the pros and cons of regularly taking aspirin or another nonsteroidal anti-inflammatory drug (such as ibuprofen) regularly. It may help protect against colon cancer.

It's very rare for a colorectal polyp that was removed completely to come back. But about 30% of people who have polyps removed will go on to develop new ones. That's why it's important to have regular colonoscopies as often as your doctor recommends.

Some of the same things that make you more likely to get tubular adenomas in the first place also increase the risk that they'll return. You're more likely to get them again if you: 

  • Are male (or were identified as male at birth)
  • Are over 60 years old
  • Have a family history of colon polyps or colon cancer
  • Have a high BMI or obesity
  • Drink heavily or smoke

Tubular adenomas are the most common type of colon polyp, small clumps of cells that form on the lining of your intestine. They're usually harmless, but in some cases, they can turn into cancer. Regular colonoscopies are the best way for your doctor to detect and remove tubular adenomas before they can become harmful.

 

How serious is a tubular adenoma?

Tubular adenomas are very common, affecting about half the population. Most colon cancers start as tubular adenomas, but less than 10% of tubular adenomas turn into cancer.

How often should you repeat a colonoscopy if you have a tubular adenoma?

How soon you need another procedure depends on the number and size of tubular adenomas you had. Doctors recommend a repeat colonoscopy:

  • In 7-10 years if you had one to two tubular adenomas that were smaller than 10 millimeters and were completely removed
  • in 3-5 years if you had three to four adenomas smaller than 10 millimeters
  • In 3 years if you had five to 10 adenomas smaller than 10 millimeters or one or more larger than 10 millimeters

What is the normal size of a tubular adenoma?

Tubular adenomas are usually less than 1/2 inch, or 12.7 millimeters.

What is the difference between polyps and adenomas?

Adenomatous polyps, or adenomas, are a type of colon polyp.