Villous Adenoma (Tubulovillous Adenoma) 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.
There are two main categories of polyps, nonneoplastic and neoplastic. Nonneoplastic polyps typically do not become cancerous. Neoplastic polyps include adenomas and serrated types. Adenomas are the most likely to turn into cancer if given enough time to grow.
It is well known that colorectal cancers arise from adenomatous polyps, which have three histologic variants: tubular, tubulovillous, and villous adenomas. Tubular adenomas represent ~75% to 85% of adenomatous polyps and have < 5% chance of harboring a malignancy.
The three different polyps are villous, tubular and tubulovillous. Adenomatous polyps will gradually show dysplastic changes, which differentiates them from hyperplastic polyps. In general, colonic polyps are benign but those that develop high-grade dysplasia will become malignant with time.
Approximately 1% of polyps with a diameter less than 1 centimeter (cm) are cancerous. More than one polyp or a polyp that is 1 cm or bigger places you at higher risk for colon cancer. Up to 50% of polyps greater than 2 cm (about the diameter of a nickel) are cancerous.
A gastroenterologist, the specialist who usually performs a colonoscopy, can't tell for certain if a colon polyp is precancerous or cancerous until it's removed and examined under a microscope.
If the colonoscopy finds one or two small polyps (5 mm in diameter or smaller), you are considered at relatively low risk. Most people will not have to return for a follow-up colonoscopy for at least five years, and possibly longer.
If your doctor finds precancerous polyps, there is no need for any additional treatment as long as they remove the entire polyp. Removing the tissue stops the development of cancer.
Right-sided polyps are more likely to develop into cancers — which often grow rapidly and have a higher risk for metastasis, spreading to distant body areas. Right-sided colon cancers also tend to develop from flat polyps rather than the usual mushroom-shaped ones, and are genetically atypical, too.
As the clinical importance of serrated lesions has been highlighted, serrated polyps ≥ 10 mm in size or with dysplasia are also considered high-risk colorectal neoplasms [4].
Hyperplastic polyps — Hyperplastic polyps are usually small, located in the end-portion of the colon (the rectum and sigmoid colon), have no potential to become malignant, and are not worrisome (figure 1).
If a polyp has cancerous cells, they will also biopsy nearby lymph nodes to determine if the cancer has spread or metastasized to other areas of the body. In this case radiation, chemotherapy or other therapies may be recommended. Colonoscopy screenings can be life saving!
ACPs are defined as any one of the following: (i) tubular adenoma ≥1 cm or any adenoma with villous features or high-grade dysplasia regardless of the size, (ii) sessile serrated polyp (SSP) ≥1 cm or SSP with cytologic dysplasia, or (iii) traditional serrated adenoma of any size.
A polyp is a growth inside of your body. Most aren't cancerous (benign), but a polyp contains abnormal cells or cells that may become abnormal (malignant). A polyp is usually a flat bump or shaped like a mushroom. Cancerous polyps can develop in many places in your body, such as your colon or uterus.
Research indicates that as many as 60 percent of polyps may grow back within three years. Also, about 30 percent of patients who've had polyps removed will develop new ones. This is why it is important to talk to the care team about follow-up screening within five years after the polyps are removed.
Precancerous polyps are those that can become cancerous over time if they aren't removed. The most common polyps are tubular adenomas, sessile serrated adenomas and hyperplastic polyps. These names are based on what the polyps' cells look like under a microscope.
Most polyps grow slowly and take from between 10 and 15 years to become cancerous. Due to this general time frame, most screenings are scheduled every 10 years which gives Colorectal Surgical Associates time to remove any polyps before they become cancerous.
Smoking, obesity, diabetes, and inadequate exercise are risk factors for polyps, but many people with none of these risk factors have precancerous polyps in the colon. There are genetic risk factors for developing polyps as well.
While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous. The size of a polyp typically does make a difference. The larger the polyp becomes, the bigger the risk of it developing into colon cancer.
Nearly all cases of colorectal cancer develop from polyps. They start in the inner lining of the colon and most often affect the left side of the colon and rectum.
Colorectal cancer can occur without polyps, but it is thought to be an uncommon event. Individuals with long-standing inflammatory bowel diseases, such as chronic ulcerative colitis and Crohn's colitis, are at increased risk for developing colorectal cancer that occurs in the absence of obvious polyps.
Polyps are benign, meaning that they're not cancer and they won't spread, but over time certain types can develop into cancer. One of these types is called adenomatous polyps. These are known as pre-cancerous polyps. Polyps bigger than 1 centimeter have a greater cancer risk than polyps under 1 centimeter.
Polyps of the colon and rectum are most often benign. This means they are not a cancer. You may have one or many polyps. They become more common with age.