Ampulla of Vater carcinoma: Molecular landscape and clinical implications

Figure 4 Immunohistochemical analysis of an ampullary adenocarcinoma of mixed subtype (original magnification 20 ×). A: Immunohistochemical analysis of an ampullary adenocarcinoma of mixed subtype, with cytokeratin 20 (CK20); B: Immunohistochemical analysis of an ampullary adenocarcinoma of mixed subtype, with cytokeratin 7 (CK7). This image highlights that, in the same area, some neoplastic glands may be positive not only for CK7 or for CK20, but for both markers even. The coexpression of an intestinal marker, such as CK20, and of a pancreatobiliary marker, such as CK7, supports the classification as mixed subtype.