Figure 3
Histological examination of the resected pancreatic tumor. (a) The pancreatic head tumor shows complex branching papillary structures and infiltrating tubules. (b) The tumor cells contain mildly pleomorphic nuclei and oncocytic cytoplasm. (c) The dilated duct displays a polypoid tumor with complex arborizing papillary and tubular structures. (d) The tumor cells exhibit mildly pleomorphic nuclei and oncocytic cytoplasm. (e) Tumor cells are immunohistochemically positive for mucin protein, MUC1. (f) Mucin protein MUC5AC is positive for tumor cells under immunohistochemical stain.