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Exams and Tests for Cancer

Understanding Your Pathology Report: Colon Polyps (Sessile or Traditional Serrated Adenomas)

When your colon was biopsied, the samples taken were studied under the microscope by a specialized doctor with many years of training called a pathologist. The pathologist sends your doctor a report that gives a diagnosis for each sample taken. This report helps manage your care. The questions and answers that follow are meant to help you understand the medical language used in the pathology report you received for your biopsy.

What if my report mentions the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, or rectum?

These are all parts of the large intestine. The cecum is the beginning of the colon, where the small intestine empties into the large intestine. The ascending colon, transverse colon, descending colon, and sigmoid colon are other parts of the colon after the cecum. The colon ends at the rectum, where waste is stored until it exits through the anus.

What is a polyp in the colon?

A polyp is a projection (growth) of tissue from the inner lining of the colon into the lumen (hollow center) of the colon. Different types of polyps look different under the microscope. Polyps are benign (non-cancerous) growths, but cancer can start in some types of polyps. These polyps can be thought of as pre-cancers, which is why it is important to have them removed. 

What is an adenoma (adenomatous polyp)?

An adenoma is a polyp made up of tissue that looks much like the normal lining of your colon, although it is different in several important ways when it is looked at under the microscope. In some cases, a cancer can start in the adenoma.

What are tubular adenomas, tubulovillous adenomas, and villous adenomas?

Adenomas can have several different growth patterns that can be seen under the microscope by the pathologist. There are 2 major growth patterns: tubular and villous. Many adenomas have a mixture of both growth patterns, and are called tubulovillous adenomas. Most adenomas that are small (less than ½ inch) have a tubular growth pattern. Larger adenomas may have a villous growth pattern. Larger adenomas more often have cancers developing in them. Adenomas with a villous growth pattern are also more likely to have cancers develop in them.

The most important thing is that your polyp has been completely removed and does not show cancer. The growth pattern is only important because it helps determine when you will need your next colonoscopy to make sure you don’t develop colon cancer in the future.

What if my report uses the term sessile?

Polyps that tend to grow as slightly flattened, broad-based polyps are referred to as sessile.

What if my report uses the term serrated?

Serrated polyps (serrated adenomas) have a saw-tooth appearance under the microscope. There are 2 types, which look a little different under the microscope:

  • Sessile serrated adenomas (also called sessile serrated polyps)
  • Traditional serrated adenomas

Both types need to be removed from your colon.

What does it mean if I have an adenoma (adenomatous polyp), such as a sessile serrated adenoma or traditional serrated adenoma?

These types of polyps are not cancer, but they are pre-cancerous (meaning that they can turn into cancers). Someone who has had one of these types of polyps has an increased risk of later developing cancer of the colon. Most patients with these polyps, however, never develop colon cancer.

What if my report mentions dysplasia?

Dysplasia is a term that describes how much your polyp looks like cancer under the microscope:

  • Polyps that are only mildly abnormal (don’t look much like cancer) are said to have low-grade (mild or moderate) dysplasia.
  • Polyps that are more abnormal and look more like cancer are said to have high-grade (severe) dysplasia.

The most important thing is that your polyp has been completely removed and does not show cancer. If high-grade dysplasia is found in your polyp, it might mean you need to have a repeat (follow-up) colonoscopy sooner than if high-grade dysplasia wasn’t found, but otherwise you do not need to worry about dysplasia in your polyp.

How does having an adenoma affect my future follow-up care?

Since you had an adenoma, you will need to have another colonoscopy to make sure that you don’t develop any more adenomas. When your next colonoscopy should be scheduled depends on a number of things, like how many adenomas were found, if any were villous, and if any had high-grade dysplasia. The timing of your next colonoscopy should be discussed with your treating doctor who knows the details of your specific case.

What if my adenoma was not completely removed?

If your adenoma was biopsied but not completely removed, you will need to talk to your doctor about what other treatment you’ll need. Most of the time, adenomas are removed during a colonoscopy. Sometimes, though, the adenoma may be too large to remove during colonoscopy. In such cases you may need surgery to have the adenoma removed.

What if my report also mentions hyperplastic polyps?

Hyperplastic polyps are typically benign (they aren’t pre-cancers or cancers) and are not a cause for concern.


This series of Frequently Asked Questions (FAQs) was developed by the Association of Directors of Anatomic and Surgical Pathology to help patients and their families better understand what their pathology report means. These FAQs have been endorsed by the College of American Pathologists (CAP) and reviewed by the American Cancer Society.

Learn more about the FAQ Initiative


Last Revised: February 27, 2017