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

BACKGROUND: Patients with familial adenomatous polyposis (FAP) are traditionally considered to be at high risk for duodenal-papillary and periampullary adenomas and cancer. AIM: To evaluate prospectively the prevalence, histology and clinical significance of ampullary and periampullary macroscopic and microscopic lesions in our population of affected patients.
SETTING: Three gastroenterological departments of northern Italian hospitals. PATIENT AND METHODS: Twenty-five affected patients were carefully investigated over a 24-month period by end-viewing and side-viewing upper panendoscopy. Biopsies were performed on representative macroscopic lesions and randomly on normal-appearing papillary and periampullary mucosa.
RESULTS: Seven patients had macroscopic adenomas of the duodenal papilla, three of the periampullary region and five at both sites (cumulative prevalence 40%). An additional six patients had macroadenomas in the rest of the duodenum (overall prevalence 64%). Microscopic adenomas were identified in nine and two patients in the papilla and periampullary region, respectively, and in three at both sites (overall prevalence 44%). Thus, a total of 17 (68%) patients presented macro- or microadenomas at these locations. The prevalence rose to 72%, when a further patient with macroadenomas in the rest of the duodenum only was included. Malignancy was not encountered and severe dysplasia was observed only in a macroadenoma of the second duodenal portion. A higher frequency of macroadenomas in the papilla and periampullary region was significantly correlated with 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 at different sites or with the demographic, clinical and pathological features.
CONCLUSION: This study confirms that the duodenal papilla and periampullary region are sites with high prevalence of macro- and microscopic adenomas in patients with FAP. However, our data do not seem to support a higher frequency and malignancy potential of such lesions as compared to polyps in the rest of the duodenum. Nevertheless, these findings warrant a periodic, careful examination of the duodenum with either end-viewing or side-viewing endoscopy, the need for random biopsies of the papilla and periampullary region and the removal of any larger or rapidly growing lesions detected.