Immunohistochemical analysis of the Wnt/β-catenin signaling pathway in pancreatic neuroendocrine neoplasms

Figure 2 A pancreatic neuroendocrine neoplasm from a familial adenomatous polyposis patient (original magnification 200 ×). A: Hematoxylin and eosin stain showing a well differentiated neuroendocrine tumor composed of monomorphic cells with “salt and pepper” chromatin; B and C: Immunohistochemical labeling for synaptophysin (B) and chromogranin (C) showing positive staining; D: Immunohistochemical labeling with β catenin showing β catenin nuclear accumulation and loss of membrane staining; E: Immunohistochemical staining for E-cadherin showing strong E-cadherin membranous expression; F: Immunohistochemical labeling for APC showing loss of APC expression. APC: Adenomatous polyposis coli.