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. Your healthcare provider may recommend a biopsy, surgery or active surveillance.
A polyp is a growth inside of your body that contains malignant (cancerous) or cells that may become malignant. It’s a clump of cells that are growing abnormally.
A polyp is usually shaped one of two ways. It can be a flat bump (sessile). Or it can be shaped like a mushroom, with a bulbous head projecting from a stalk (pedunculated). Polyps range in size, from about 5 millimeters (the size of a match head) to 3 centimeters (similar to the top of your thumb) or larger.
A growth may be a precancerous polyp (the cells are starting to change but have not yet become cancerous). Or the cells may be cancerous.
Polyps sometimes develop in other places. Although they may grow and cause symptoms, they don’t become cancerous:
Cancerous polyps may develop on several different surfaces inside of your body:
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If you have a polyp, your healthcare provider can determine whether it’s a cancerous tumor. This usually involves a biopsy. During a biopsy, your healthcare provider takes a small sample of tissue or removes the entire polyp. Then, an expert looks at the polyp’s cells under a microscope.
Polyps are common, but cancerous polyps aren’t. Most polyps are benign (not cancerous). Your doctor can tell if a colon polyp is cancerous during a colonoscopy by collecting tissue to biopsy. The results of the biopsy are typically sent to your doctor within a week.
Only 5% to 10% of all polyps become cancerous.
If a polyp becomes malignant (cancerous), it usually happens over the course of several years.
Cancerous polyps may cause no symptoms at all. But if you do have symptoms, they depend on where the polyp is located:
Scientists are still trying to understand what causes polyps, as well as what makes some polyps turn malignant. Most cancerous polyps are a result of genetic changes that are inherited or occur sporadically.
Some research suggests that certain types of cancerous polyps are related to hormones or other health conditions.
Treatment for a cancerous polyp varies widely, depending on:
Your healthcare provider may suggest surgery to remove cancerous polyps (polypectomy). But, sometimes, they recommend a “watch and wait” approach, or “active surveillance.” This means they’ll keep an eye on the polyp(s) until intervention is necessary.
Certain lifestyle choices can help decrease the chances of cancerous polyps:
Some research shows that certain medications may help prevent cancerous polyps:
If you have polyps or symptoms of polyps, talk to your healthcare provider. It’s especially important to report:
A note from Cleveland Clinic
Most polyps aren’t malignant, but some can become cancerous. Talk to your healthcare provider if you have a history of polyps or any symptoms. Your doctor can determine whether a polyp is cancerous and should be removed.
Last reviewed by a Cleveland Clinic medical professional on 02/25/2022.
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