Fig. 4

Resected specimen findings. a The tumor was not clearly exposed to the surface of the pancreas. b The tumor consisted of a yellow nodular mass with the cystic lesion in the center of the mass. The cystic lesion was pathologically a pancreatic duct. A pancreatic calculus was found in this specimen. c, d Hematoxylin-eosin staining showed spindle cells and multinuclear giant cells, which are characteristic of anaplastic carcinoma of the pancreas. e, f These cells exhibited immunoreactivity for cytokeratin AE1/AE3. The tumor invaded pancreatic anterior fat tissue