Background : The precise origin of a periampullary adenocarcinoma is often difficult to determine due to tumor destruction of normal periampullary anatomy, and presence of epithelial dysplasia. The aim of this study is to evaluate prognostic significance of histologic type in periampullary carcinoma.

Methods : Microscopic slides from 110 consecutive pancreatoduodenectomies were reviewed (40 pancreatic, 47 biliary, 17 ampullary, and 6 duodenal adenocarcinomas) and were classified into intestinal type or pancreatobiliry type. Clinicopathological factors were compared between 55 pancreatobiliary type, 15 intestinal type differentiation and 40 pancreatic cancer.

Results : Most distal CBD cancers (83.0% [39 of 47]) and ampulla of Vater cancers (64.7% [11 of 17]) were pancreatobiliary type. Intestinal type had significantly more patients with well-differentiated histology (33.3% vs. 14.3%, p=0.005) and less patients with perineural invasion (46.7% vs. 76.4%, p=0.025), advanced T stage (more than T3, 46.7% vs.74.5%, p=0.05), and systemic recurrence (50.0% vs. 93.8%, p=0.007) than pancreatobiliary type. The overall survival rate of intestinal type was better than that of pancreatobiliary type (75.8% vs. 52.7%) or that of pancreatic cancer (75.8% vs.39.4%) All patients with intestinal type in CBD cancer (n=6) survived more than 5 years.

Conclusions : Although there was no statistical significance because of small number of included patients, histologic phenotype including intestinal and pancreatobliary type showed the possibility as a prognostic factor in periampullary cancer excluding pancreatic cancer. Further large scale study is needed to demonstrate the prognostic significance of histologic phenotype.