Unexpected metastasis of intraductal papillary neoplasm of the bile duct without an invasive component to the brain and lungs: A case report

Figure 8 Microscopic images of lung metastasis. A and B: Histologic appearance showed a well-demarcated nodule with marked necrosis in the center of the tumor (A: magnification × 20, B: magnification × 400). At high power magnification, there were eosinophilic, tall, columnar cells with nuclear pseudostratification. C-E: Immunohistological staining showed that the tumor cells were positive for CK7 (Panel C), CK20 (Panel D) and CDX2 (Panel E); F: Immunohistological staining showed that the tumor cells were negative for TTF-1.