Fig. 4

a Macroscopic fresh view of the resected specimen showing the main tumor with a rough surface seen in the tail of the pancreas; the macroscopic abnormalities are not recognized. b Macroscopic view of the cut surface of the resected pancreas’ body and tail showing the tumor marked in the red circle. The blue circle indicates MPD. Small intraductal papillary mucinous adenoma (IPMA) is visible in the neck of the pancreas (green). Yellow arrow indicates IPMA. Pancreatic intraepithelial neoplasia-3 (PanIN-3) cells are found near the MPD of the pancreatic body (pink), presented in d, e. c Loupe imaging of the pancreatic tail shows the tumor replacing acinar lobules and occupying the MPD. Tumor cells penetrate the MPD (arrows). d Tumor mass is noted in the center of MPD. Tumor cells do not invade into the MPD. PanIN-3 cells are in the branched pancreatic ducts near the MPD (see e). e H&E staining of PanIN-3 around the MPD. Carcinomas in site lesions are found in a section of the peripheral pancreatic duct (×100). f H&E staining reveals an acinar growth of tumor cells with eosinophilic and granular cytoplasm (H&E × 400). g This figure illustrates Ki67 immunohistochemistry from this patient. MIB1 index was 20–30% (×400)