Fundic gland polyps (FGPs) are common growths on the inner lining of the stomach. While the term “polyp” might sound concerning, these growths are most often benign and generally do not pose a serious health threat. They are frequently discovered incidentally during routine medical examinations.
What is a Fundic Gland Polyp?
A fundic gland polyp originates from specialized cells lining the fundus and body of the stomach, where acid-producing fundic glands are located. These polyps are typically small, appearing as smooth, dome-shaped, and often translucent bumps on the stomach’s inner surface. Histologically, they are characterized by an overgrowth of normal fundic gland cells, which often appear cystic or dilated.
Fundic gland polyps are the most frequently encountered type of gastric polyp. While generally considered non-cancerous, their identification is important for differentiation from other gastric polyps that may have different implications. They rarely cause symptoms and are usually discovered during examinations for other digestive issues.
Causes and Formation
Fundic gland polyps can form due to several factors: sporadic, medication-induced, and syndromic origins. Most occur sporadically, arising without a clear identifiable cause or association with an inherited condition. These sporadic polyps often contain specific genetic changes, such as mutations in the β-catenin gene, which contribute to their formation.
A common cause is the long-term use of proton pump inhibitors (PPIs), medications widely used to reduce stomach acid. PPIs lead to increased levels of gastrin, which stimulates the growth of stomach lining cells. This prolonged stimulation can result in the formation of new polyps or an increase in their size and number.
In a rarer context, fundic gland polyps can be associated with inherited genetic conditions, such as Familial Adenomatous Polyposis (FAP) syndrome. In individuals with FAP, these polyps are often numerous. Unlike sporadic or PPI-induced polyps, FAP-associated fundic gland polyps carry a higher potential for developing abnormal cell changes, known as dysplasia, which can rarely progress to cancer.
Detection and Evaluation
Fundic gland polyps are typically discovered incidentally during an upper endoscopy, also known as an esophagogastroduodenoscopy (EGD). This procedure involves inserting a thin, flexible tube with a camera to visualize the esophagus, stomach, and the beginning of the small intestine. Often, endoscopy is performed to investigate other symptoms like acid reflux, abdominal pain, or difficulty swallowing, rather than specifically to look for polyps.
During the endoscopy, the physician observes the polyps’ appearance. Fundic gland polyps usually appear as small, sessile (flat or slightly raised) lesions that blend with the surrounding stomach lining. To confirm the diagnosis and distinguish them from other gastric polyps, a biopsy is typically performed. A small tissue sample is taken and examined under a microscope by a pathologist. This helps determine the specific type of polyp and whether any concerning cellular changes, such as dysplasia, are present.
Management and Outlook
For most sporadic fundic gland polyps, especially small ones without concerning cellular changes, no specific treatment is typically required. These polyps are generally considered benign and have a very low risk of becoming cancerous. They are often simply monitored.
When fundic gland polyps are linked to long-term proton pump inhibitor (PPI) use, discontinuing or reducing the PPI medication may be discussed if clinically appropriate. Discontinuing PPIs can sometimes lead to a reduction in the size or number of these polyps, though they may persist.
For polyps associated with Familial Adenomatous Polyposis (FAP), management is more proactive. Due to the increased risk of dysplasia and potential for cancer in this genetic syndrome, FAP-associated fundic gland polyps may require removal or more frequent endoscopic surveillance. The overall prognosis for most individuals with fundic gland polyps is excellent.