Hyperplastic polyp of the colon and rectum

by Jason Wasserman MD PhD FRCPC
July 23, 2025

A hyperplastic polyp is a common benign (non-cancerous) growth that develops on the inner surface of the colon or rectum. These polyps are made up of cells that look similar to the normal cells that line the colon but grow in a slightly disorganized. Hyperplastic polyps are not considered precancerous, and in most cases, they do not increase the risk of developing colorectal cancer.

What are the symptoms of a hyperplastic polyp?

Most people with a hyperplastic polyp do not experience any symptoms. These polyps are usually small and discovered incidentally during a colonoscopy performed for another reason, such as cancer screening or investigation of unrelated symptoms. Rarely, large hyperplastic polyps may cause rectal bleeding or a change in bowel habits, but this is uncommon.

Where are hyperplastic polyps found?

Hyperplastic polyps are most commonly found in the distal colon, especially the rectum and sigmoid colon. They may also appear in other parts of the colon but are much less common in those areas. In general, hyperplastic polyps are small (less than 5 mm in size) and sessile, meaning they sit flat against the lining of the colon.

What causes a hyperplastic polyp?

Hyperplastic polyps form when the cells that line the colon begin to grow and divide more rapidly than usual. This overgrowth is typically harmless and is not related to cancer. In most cases, the exact cause is unknown, but factors such as aging and chronic irritation of the colon may play a role. Hyperplastic polyps are also more common in people who undergo frequent colonoscopies or have a history of other benign polyps.

How is the diagnosis made?

The diagnosis of a hyperplastic polyp is made after a tissue sample is removed during a colonoscopy and examined under a microscope by a pathologist. These samples are usually taken using a procedure called a polypectomy or biopsy. The pathologist looks for characteristic features of a hyperplastic polyp, such as elongated, serrated (sawtooth-like) glands with cells that appear crowded but lack the abnormal features associated with precancerous polyps.

What does a hyperplastic polyp look like under the microscope?

When examined under the microscope, a hyperplastic polyp shows tightly packed glands with a serrated appearance near the surface. The cells lining the glands are typically mature and produce mucus, which helps lubricate the colon. The base of the glands looks normal, and there are no signs of dysplasia, a term used to describe abnormal cells that could lead to cancer.

There are two main subtypes of hyperplastic polyp based on their microscopic appearance:

• Microvesicular hyperplastic polyp – The most common subtype, with cells that have small mucin-filled bubbles (vesicles) and nuclei located at the base of the cells.

• Goblet cell-rich hyperplastic polyp – Contains a higher number of mucus-producing cells called goblet cells.

These differences do not affect treatment or follow-up and are mainly noted for classification purposes.

Is a hyperplastic polyp a type of cancer?

No. A hyperplastic polyp is a benign growth that is not cancerous and does not usually turn into cancer. Unlike other types of polyps, such as adenomas or sessile serrated lesions, hyperplastic polyps are not considered precancerous. However, in rare cases, very large hyperplastic polyps in the proximal (right-sided) colon may need closer follow-up because they can be difficult to distinguish from other serrated polyps with cancer potential.

Will I need more treatment or follow-up?

In most cases, no additional treatment is needed after a hyperplastic polyp is removed. Your doctor may recommend follow-up colonoscopy based on your overall risk of colorectal cancer, including the number and type of any other polyps found. If only one or a few small hyperplastic polyps are found in the rectum or sigmoid colon, the risk of future cancer is very low, and routine screening intervals are typically followed.

Questions to ask your doctor

• Was the polyp completely removed?

• Were any other types of polyps found during my colonoscopy?

• Do I need follow-up testing or another colonoscopy?

• How often should I be screened for colon cancer in the future?