Primary large cell neuroendocrine carcinoma in the common bile duct: First Asian case report

Figure 3 Histologic and immunohistochemical findings. A: High cellularity tumor cells invades into the bile duct wall (magnification × 12.5); B: tumor cells exhibit relatively abundant cytoplasm and hyperchromatic round nuclei with course chromatin and prominent nucleoli (magnification × 400); C: tumor cells exhibit immunopositivity for a neuroendocrine marker (synaptophysin) (magnification: × 400); D: immunohistochemical staining for Pan CK, and a combined adenocarcinoma component is not noted (magnification: × 40).