Importance of Gastroduodenal Endoscopic Findings in Patients with Classic Familial Adenomatous Polyposis Syndrome

Background:  Familial adenomatous polyposis (FAP) is an autosomal dominant disorder caused by a mutation in the adenomatous polyposis coli (APC) gene. FAP is characterized by development of multiple adenomatous polyps (>100) in the colon. The aim of this study was to evaluate the prevalence of gastroduodenal polyps in FAP patients referred to the Taleghani hospital, a teaching referral center in Tehran, Iran. Materials and Methods: Front-view and side-view endoscopies were performed in 33 FAP patients. Papillary biopsies were taken for all patients. Site of polyps, their number and size, histologic findings, patient general information (gender, age and family history of FAP/colorectal cancer/gastroduodenal polyps) were collected and reported. 28 patients of the study were evaluated using upper GI endoscopy again after 5 years for changes in characteristics and probable transformation of polyps into cancer. Results: Gastric polyps were seen in 42.4 % of patients. 76.45% of the patients had fundic gland polyps and hyperplastic polyps were noticed in 39.93% of them. Duodenal adenomas were found in 30.3% of patients which were reported to be tubular adenomas with low grade dysplasia and tubulovillous adenomas with low grade dysplasia in 60% and 45% of patients, respectively. Conclusions: Findings of this study bespeak the high prevalence of gastroduodenal polyps and the presence of dysplasia in duodenal polyps among FAP patients referred to the hospital. Therefore, it appears that routine gastroduodenal endoscopy in FAP patients is necessary.