Carcinoma of the ampulla of vater associated with or without adenoma: A clinicopathologic analysis of 198 eases with reference to p53 and Ki-67 immunohistochemical expressions

Adenomatous areas are found frequently within or in the vicinity of carcino ma of the ampulla of Vater, This makes definite diagnosis difficult in the preoperative examination. The adenoma-carcinoma development hypothesis is g enerally accepted for colorectal tumors. Recently, a genetic alteration mod el during colorectal tumor development has attracted much attention, leadin g to various studies. We studied clinicopathologic features, prognostic fac tors, and the alteration of the p53 tumor suppressor gene using p53 immunoh istochemical staining in pure adenomas, pure carcinomas, and carcinomas wit h adenomatous areas. A proliferative activity of the tumors using Ki-67 was also evaluated. Nine cases of pure adenoma and 198 cases of carcinoma of t he ampulla of Vater were selected for this study. Among the 198 cases of th e carcinoma, 83 cases (42%) had adenomatous areas. Positivity of p53 immuno histochemical staining was 0% in pure adenomas, 36% in the adenomatous area s of carcinomas with adenomatous areas and 62% in the carcinomatous areas o f carcinomas with adenomatous areas, and 56% in pure carcinoma. Accumulatio n of p53 protein and the Ki-67 labeling index revealed no significant diffe rence In prognosis. The clinicopathological factors examined were as follow s: degree of invasion of the surrounding tissue, such as duodenal wall; pan creatic parenchyma; the presence or absence of lymphatic permeation; venous invasion; perineural invasion; the presence of regional lymph node metasta sis; and TNM stage. Each of the clinicopathological factors showed a signif icant difference. Multivariate analysis revealed strong predictors for a wo rse prognosis: presence of lymphatic permeation, invasion of the pancreas, and perineural invasion. In conclusion, our results are consistent with the adenoma-carcinoma development hypothesis. It would seem that the molecular events leading to p53 accumulation in neoplasms of the ampulla of Vater oc cur relatively late during the oncogenetic process. Moreover, we think it m ay be useful to refer to the p53 overexpression tn the diagnosis of ampulla ry tumors.