A polyp is an abnormal, localized growth of tissue that projects outward from the inner lining of an organ. In the stomach, these growths are called gastric polyps, developing on the mucous membrane lining the gastric wall. They occur in a small percentage of the population and are often discovered incidentally during examinations for other reasons. The vast majority of gastric polyps are benign and pose little threat. Their seriousness depends entirely on the specific cell type, which dictates the potential to develop into a cancerous lesion.
Defining Gastric Polyps and Their Primary Types
Gastric polyps are classified based on cell type and structure, with three main categories determining the level of risk. Fundic Gland Polyps (FGPs) are the most common type, frequently found in the upper body and dome of the stomach. These sporadic polyps are overwhelmingly benign and carry a negligible risk of malignant transformation. FGPs are often associated with the long-term use of Proton Pump Inhibitors (PPIs), medications used to reduce stomach acid.
The second most common category is the Hyperplastic Polyp, which usually arises in a stomach experiencing chronic inflammation. This inflammation is often the result of an infection with Helicobacter pylori (H. pylori) bacteria or long-standing gastritis. Hyperplastic polyps are considered low-risk, but they carry a small potential for developing cancer, especially if they grow larger than one centimeter. Complete removal of the H. pylori infection can sometimes lead to the regression or disappearance of these polyps.
The most significant type, despite being the rarest, is the Adenomatous Polyp or adenoma, accounting for approximately 6% to 10% of all gastric polyps. Adenomas are true neoplastic lesions, meaning they are composed of precancerous cells. These polyps have the highest risk of progression to invasive gastric cancer, with the risk increasing as the size of the adenoma grows. Due to their high malignant potential, adenomatous polyps require immediate and complete removal upon discovery.
How Gastric Polyps Are Identified
Gastric polyps are frequently asymptomatic, meaning most people are unaware they have them until they are found during a medical procedure. When symptoms occur, they are typically non-specific, often resulting from the polyp reaching a larger size or developing a superficial ulcer. These symptoms can include mild upper abdominal discomfort, nausea, or indigestion.
Gastrointestinal bleeding is a more concerning symptom, occurring if the polyp’s surface is eroded, leading to slow blood loss. This chronic blood loss may eventually manifest as iron deficiency anemia, causing fatigue and pallor. In rare instances, a large polyp near the stomach exit can cause a partial obstruction, leading to persistent vomiting, loss of appetite, and unexplained weight loss.
The definitive method for identifying and classifying gastric polyps is an upper endoscopy (EGD). During this procedure, a flexible tube with a camera is passed down the throat into the stomach to visualize the gastric lining. If a polyp is seen, a biopsy is performed using small forceps to remove a tissue sample for microscopic examination. This histological analysis by a pathologist is the only way to accurately determine the specific cell type and assess the risk of malignancy.
Treatment and Ongoing Monitoring
The management strategy for a gastric polyp is dictated by its histological classification, size, and the presence of cellular changes called dysplasia. Small, sporadic Fundic Gland Polyps (FGPs) are considered low-risk and may only require conservative management. If FGPs are linked to PPI use, a physician may recommend discontinuing the medication, which can sometimes cause the polyps to shrink or disappear.
For polyps with a higher risk, such as Hyperplastic Polyps larger than five millimeters or any Adenomatous Polyp, complete removal is recommended. This removal is typically performed endoscopically through a procedure called polypectomy. The most common technique involves using a wire loop, or snare, passed through the endoscope to encircle the base of the polyp. The snare is then tightened and uses an electrical current (hot polypectomy) or mechanical excision (cold polypectomy) to detach the growth from the stomach wall.
Following removal, a schedule for surveillance endoscopy is established to monitor for recurrence or the development of new polyps. For most adenomas, follow-up endoscopy is performed within one year to ensure complete resection and check the surrounding mucosa. The frequency of this monitoring is individualized, depending on the polyp type, size, the degree of dysplasia found, and whether the patient has any underlying genetic syndromes.