Depressed adenoma sf the duodenum in patients with familial adenomatous polyposis - Endoscopic and immunohistochemical features

BACKGROUND. Depressed neoplastic lesions of the colorectum have been specif ied in patients with familial adenomatous polyposis (FAP). The aim of this study was to characterize endoscopic, histologic, and immunohistochemical f eatures of depressed adenoma of the duodenum in patients with FAP. METHODS. Duodenoscopy was performed on 25 patients with FAP, and the neopla stic nonampullary lesions were classified as polypoid or depressed adenomas . The grade of dysplasia, the proliferative activity determined by Ki-61 la beling index (LI), and the grade of p53 expression were compared between po lypoid and depressed neoplasia. RESULTS. Ten subjects had depressed nonampullary adenoma, whereas polypoid adenoma was found in the remaining 15 subjects. Moderate dysplasia was more frequent in depressed adenoma than in polypoid adenoma (70% vs. 27%, P = 0 .04). Whereas p53 expression was not different between the two adenoma grou ps, the LI was significantly higher in depressed adenoma than in polypoid a denoma (59.7 +/- 9.5 vs. 47.5 +/- 10.7, P < 0.01). CONCLUSIONS. Depressed adenoma of the duodenum is a distinctive phenotype o f duodenal neoplasm in patients with FAP. The high proliferative activity o f depressed adenoma suggests that there may be a need to survey FAP patient s with such lesions intensively. (C) 1999 American Cancer Society.