What makes a polyp cancerous

Colorectal cancer often takes many years to grow, and nearly all cases of colon cancer and rectal cancer start off as a polyp.

A polyp is a group of cells that grow together, and a colon polyp occurs when these cells grow on the inside of the colon or rectum. There are a few different shapes of polyps. Some polyps grow on the end of a stalk and look similar to a mushroom this is called a pedunculated polyp. Adenomas are polyps that grow like a mushroom with a stalk. Sessile polyps grow without the narrow stalk and seem to lie flat against the wall of the colon. These polyps are also known as flat polyps. Both pedunculated and sessile polyps can turn into benign non-cancerous , precancerous and cancerous polyps.

This is why screening is important! Most polyps can be safely removed during a colonoscopy, thus removing the risk of the polyp growing into cancer. However, for some, polyps bleed. Bleeding may be intermittent. It is always important to notify your doctor if you notice blood in your stool. Talk to your doctor if you experience rectal bleeding, a change in bowel habits, pain, and anemia. This could mean you have a polyp and you need to be screened, or that you need additional surveillance.

Learn more about the symptoms of colorectal cancer. Some polyps grow into cancer, but others may not. Your cancer risk does increase with the size of the colon polyp, but there is no specific, generalized size that indicates a polyp is becoming cancerous. If you grow an advanced polyp, your doctor will likely ask you to return for a follow up sooner than normal.

Not all polyps will become cancerous, but it is important to remove them all to block the possibility. Although the polyps are generally non-cancerous, if you have IBD, you are at increased risk of colorectal cancer. Depending on their size and location in the colon, serrated polyps may become cancerous. Small, serrated polyps in the lower colon, also known as hyperplastic polyps, are rarely malignant. Larger serrated polyps, which are typically flat sessile , difficult to detect and located in the upper colon, are precancerous.

Inflammatory polyps most often occur in people who have inflammatory bowel disease IBD. These types of polyps are also known as pseudopolyps because they are not true polyps, but rather develop as a reaction to chronic inflammation in the colon. Inflammatory polyps are benign and generally do not carry the risk of developing into colon cancer.

Approximately 15 percent of polyps detected in colon cancer screening are villous or tubulovillous adenomas. This type of polyp carries a high risk of turning cancerous. They are commonly sessile, which makes them more difficult to remove.

Smaller villous adenoma polyps may be removed during a colonoscopy, while larger polyps of this type may require surgery for complete removal. Polyps can be detected and safely removed during a colonoscopy, preventing them from turning into cancer. Large polyps may require more than one treatment, and in some patients surgery could be required for complete removal.

If you have an increased risk for colon polyps, talk with your doctor about the types and frequency of tests that will be best for you. 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.

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.

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. 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. 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. Larger adenomas may have a villous growth pattern.