Some stomach, or gastric, polyps are cancerous while others are not, according to Mayo Clinic. The majority of them do not become malignant. However, adenomas, the rarest kind, are most likely to become cancerous. These masses of glandular cells on the inside lining of the stomach are linked to inflammation and an inherited condition of polyps in the large and small intestines. A doctor often removes adenomas during endoscopy, an examination of the digestive tract.
Two common types of gastric polyps are hyperplastic polyps and fundic gland polyps, notes Mayo Clinic. Both form as a result of swelling in the stomach lining and have the potential to become cancerous. Hyperplastic polyps occur in people with gastritis or chronic stomach inflammation. There may also be a link to a potentially infectious bacteria called Helicobacter pylori. While the risk of cancer is low in hyperplastic polyps, it increases in polyps more than 3/4 inch in diameter.
Fundic gland polyps, on the other hand, consist of glandular cells in the stomach lining, explains Mayo Clinic. They occur in people with familial adenomatous polyposis syndrome and require removal because they can turn malignant. They are also common in people on proton pump inhibitors, which lessen stomach acid. If bigger than 2/5 inch in diameter, these fundic gland polyps pose a risk for cancer and require treatment by a doctor. Treatment may include stopping medication, removal of the polyp or a combination of the two.