Clinical, morphologic, and immunophenotypic characteristics of ampullary carcinomas with an emphasis on SMAD4 expression

Carcinomas of the ampulla of Vater (AOV) are malignant epithelial neoplasms that are either centered in or completely replace the ampulla according to the World Health Organization (WHO) definition. Two main histologic subtypes of ampullary adenocarcinoma are recognized: pancreatobiliary and intestinal types, with the former carrying a worse prognosis including worse survival, higher stage, and higher incidence of lymph node (LN) involvement (1,2)