Figure 1
Pathologic features of perihilar cholangiocarcinomas. (a) On cut sections, the nodular tumor focally extends along periductal connective tissue, consistent with the mixed mass-forming and periductal-infiltrating type. (b) The tumor consists of duct-forming adenocarcinoma and abundant fibrotic stroma. (c) Cancer cells have a clear cytoplasm. (d) Tubular components similar to reactive bile ductules are observed at the tumor–liver interface of the invasive front. (e) The expression of SMAD4 is lost in cancer cells, but is preserved in the non-neoplastic epithelium (right upper field). (f) BAP1 is strongly expressed in the cytoplasm and nuclei.
