Gastric and duodenal polyps in familial adenomatous polyposis: a prospective study of the nature and prevalence of upper gastrointestinal polyps.

One hundred patients with familial adenomatous polyposis have prospectively undergone gastroduodenoscopy to identify and characterise polyps found. Forty six patients had polyps in the stomach or duodenum. Thirty five patients had adenomas (33 in duodenum, two in stomach) and 26 patients had fundic gland polyps. Some of these patients had polyps in the stomach and the duodenum. Adenomas in the duodenum were present in 33% of patients studied with Gardner's syndrome variant (p = 0.04). Adenomas were also more common in older patients. As adenomas may be a precursor of adenocarcinoma, routine surveillance of the stomach and duodenum with gastroduodenoscopy is recommended in patients affected with familial adenomatous polyposis.