Stomach Polyps

Stomach polyps are growths on the inside lining of your stomach. They’re also called gastric polyps. Polyps are a type of tumor that grows out of the mucous lining inside your hollow organs, like the ones in your gastrointestinal tract. Stomach polyps are usually benign, but some can become cancerous.

Are stomach polyps serious?

Many of the most common types of stomach polyps have little to no cancerous potential. Some types are precancerous, so they usually aren’t yet cancerous when a healthcare provider finds them. Polyps take a long time to turn into cancer. Healthcare providers remove them to prevent this from happening.

What are the different types of stomach polyps?

The most common types of stomach polyps are epithelial polyps, which means they grow out of the topmost layer of your stomach lining (epithelium.) Other, less common types can start in the deeper layers of your stomach lining and protrude through the upper layers. These are called mesenchymal polyps.

Epithelial stomach polyps include:

Fundic gland polyps. These are the most common stomach polyps, usually appearing sporadically through the upper part of your stomach (the fundus). They have little to no cancerous potential when they appear this way. However, they can sometimes occur in greater numbers with rare hereditary cancer syndromes, including familial adenomatous polyposis (FAP) and gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS). In these cases, they’re more likely to be precancerous.

Hyperplastic polyps. These are the second most common stomach polyps, and they also have little to no cancerous potential. They’re usually associated with inflammation in your stomach (gastritis). However, they can sometimes occur simultaneously with another cancer and can be considered a warning sign. When healthcare providers find them, they sample the surrounding mucosa to check for cancer.

Adenomatous polyps (adenomas). Around 10% of stomach polyps are adenomas, making them the most common precancerous type. They’re typically sporadic and solitary. But they can sometimes occur in greater numbers in association with familial adenomatous polyposis (FAP). Healthcare providers remove these polyps when they find them and examine them to determine their cancerous potential.

Gastric neuroendocrine tumors (carcinoid tumors). Carcinoid tumors grow out of neuroendocrine cells in your stomach lining. They represent 1% of all stomach tumors and can be cancerous or benign. There are four distinct types, and each has a slightly different prognosis (outlook). Healthcare providers identify the type in order to judge its cancerous potential.

Hamartomatous polyps (hamartomas). Hamartomas make up 1% of stomach polyps. They can appear sporadically or with certain rare hereditary syndromes, including Peutz-Jeghers syndrome, juvenile polyposis syndrome and PTEN hamartoma tumor syndrome. When they appear sporadically, they’re often solitary and benign. In syndromes, they appear in numbers and have cancerous potential.

Mesenchymal stomach polyps include:

Inflammatory fibroid polyps. Inflammatory fibroid polyps are rare, benign tumors whose origins are still in debate. They’ve sometimes been called granulomas, which are clusters of immune cells triggered by an inflammatory reaction. They’re usually solitary and small, but they can cause problems when they get big. In your stomach, a big one could potentially obstruct the outlet at the bottom (pylorus).

Gastrointestinal stromal tumors (GIST). GISTs are rare precancerous tumors that start in the deepest layer of your stomach lining (muscularis propria). Healthcare providers remove them when they find them. Removing these tumors usually requires a separate procedure, like endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD).

Leiomyomas. These rare smooth muscle tumors can develop in the muscularis propria and appear as lumps on the surface of your stomach lining. They can sometimes be cancerous (leiomyosarcomas). They may require a separate procedure to remove them.

How common are stomach polyps?

Stomach polyps overall are uncommon. They appear in approximately 4% of upper endoscopy exams (which go inside your stomach with a lighted camera). Around half of these are fundic gland polyps, 30% are hyperplastic polyps and 10% are adenomatous polyps, with rarer types making up the last 10%.