Abstract & Commentary
Synopsis: Despite their appearance, the significance of gastric fundic polyps in the setting of profound acid suppression is entirely trivial. However, in the absence of PPI therapy, they can be evidence of potentially life-threatening familial adenomatous polyposis (FAP).
Source: Burt R. Gastroenterology. 2003;125:1462-1469.
Gastric fundic gland polyps can be visually horrifying when seen on endoscopy, and they are now quite commonly present in patients taking chronic acid suppressive therapy with proton pump inhibitors (PPIs). Sporadic fundic gland polyps comprise 50% of all gastric polyps, and they may be seen in up to 2% of upper GI endoscopies (EGDs). They seem particularly common in middle-aged women, but they are also identified in men and even in pediatric patients (0.3%). More ominously, fundic gland polyps are present in 12.5-84% of patients with familial adenomatous polyposis. On histology, these polyps have irregular cystically dilated fundic glands, lined by flattened parietal cells and chief cells. These polyps have been considered to be benign hamartomas. Oddly enough, fundic gland polyps seem to have an inverse relationship with Helicobacter pylori. Fundic polyps present in FAP, a disease associated with mutational inactivation of the adenomatous polyp coli gene, can develop dysplasia and very rare gastric cancer (0.6%). Far more serious than rare gastric cancer, the real concern about fundic gland polyps in FAP is their association with multiple colonic polyposes and a very high risk of colon cancer.
With a mean of 32.5 months of PPI therapy, fundic polyposis has been seen in 7.3% of patients. This scenario of acid suppression will undoubtedly represent the great majority of fundic gland polyposis seen in clinical practice, and such polyps require absolutely no follow-up. However, it has been suggested in this paper that the presence of fundic gland polyps probably should lead to colonoscopy—since several syndromes that lead to such polyps (FAP, Cowden’s syndrome, and Peutz-Jeghers syndrome) all could be associated with colonic polyposis and high colon cancer risk. Familial colon polyposis involves multiple colon polyps, often innumerable. If several polyps are found in the colon of a patient with multiple fundic gland polyps, attenuated FAP could be the diagnosis (to be confirmed with genetic testing, also involving appropriate family screening if the genetic test is positive).
Comment by Malcolm Robinson, MD, FACP, FACG
This paper deals with an important issue. Many primary care physicians perform endoscopy. Due to the very wide use of PPIs, they are certain to see fundic gland polyps. Anyone who performs endoscopy or who cares for patients who undergo upper GI endoscopic evaluation needs to be aware of the issues surrounding fundic gland polyposis. A reasonable management protocol should exist for patients with this finding. Although Burt makes a cogent article for screening colonoscopy in all such patients, I am not convinced. It seems to me that huge numbers of patients will have fundic gland polyps from PPI treatment, and the overall risk of colon cancer may be quite low. Of course, there is the alternative argument that everyone older than age 50 should undergo screening colonoscopy. Therefore, a compromise position could be that fundic gland polyps in an unscreened person older than age 50 could warrant colonoscopy. Perhaps the presence of extremely numerous and large fundic gland polyps might raise more concern than a few apparently sporadic polyps, and some evidence-based findings suggest the appropriateness of this approach. In general, there is no reason to biopsy or excise obvious fundic gland polyps unless there is some other abnormality consistent with malignant degeneration.
Dr. Robinson, Medical Director, Oklahoma Foundation for Digestive Research; Clinical Professor of Medicine, University of Oklahoma College of Medicine, Oklahoma City, OK, is Associate Editor of Internal Medicine Alert.