High prevalence of adenomas and microadenomas of the duodenal papilla and periampullary region in patients with familial adenomatous polyposis

Background/Aims: Patients with familial adenomatous polyposis (FAP) are traditionally considered at high risk for duodenal papilla and periampullary neoplasms, duodenal malignancies representing the leading cause of death in prophylactically colectonuzed patients (1,2). We aimed at prospectically evaluate the prevalence, histology and clinical significance of papillary and periampullary macroscopic and microscopic abnormalities in a population of affected FAP patients. Patients and methods: Twenty-five affected patients afferent to three gastroentcrologic departments of normen Italy were carefully investigated over a 24-month period by means of end-viewing and side-viewing upper panendoscopy. Biopsies were performed of any representative macroscopic lesion and randomly on normal-appearing papillary and periampullary mucosa. Results: Seven patients showed macroscopic adenomas of the duodenal papilla (DP), 3 of the periampullary region (PR) and 5 in both sites (cumulative prevalence 40%). Six further patients showed macroadenomas in the rest of the duodenum (overall prevalence 64%). Microscopic adenomas were identified in 9 and 2 patients in the DP and PR respectively, and in 3 in both sites (overall prevalence 44%). Thus, a total of 17 (68%) patients showed macro- or microadenomas in these locations. The prevalence raised to 72% including a further patient with macroadenomas in the rest of the duodenum only. Malignancy was not encountered and severe dysplasia was observed only in an 8 mm adenoma of the third duodenal portion. A higher frequency of macroadenomas in the DP and PR was significantly correlated to the presence and number of such lesions in the rest of the duodenum (p=0.04). No other significant association was detected either between micro- or macroadenomas in different sites or with the considered demographic, clinical and pathological features Conclusions:This study confirms that DP and PR are high prevalence sites of macro- and microscopic adenomas in FAP patients. However, our data do not support a higher frequency and malignancy potential of such lesions when compared to polyps in the rest of the duodenum. Nevertheless, these findings warrant a periodic, careful examination of the duodenum either with end-viewing or side-viewing endoscopy, the necessity of random biopsies of the DP and PR and the removal of any larger or rapidly growing lesions detected.