Intraductal tubular carcinoma, intestinal type, of the pancreas.

Presented herein is an unusual case of intraductal tubular carcinoma, intestinal type, of the pancreas. This tumor was characterized by intraductal adenoma with a few malignant foci, and also by entire involvement of the main pancreatic duct and no involvement of its branches. A 67-year-old man was admitted to hospital because of abdominal pain. On endoscopy and endoscopic retrograde cholangiopancreatography, irregular pancreatic duct was seen. No mucus secretion was observed on endoscopy. Because a biopsy showed tubular atypical cells, pancreato-duodenectomy was performed. Grossly, the entire main pancreatic duct had intraductal tumor, sparing its branches. No intraductal mucus was noted. Microscopically, the entire main pancreatic duct had proliferation of tubular adenomatous tumor without secretory mucins. Goblet cells were present in some areas. No pyloric type tubules were recognized. Malignant transformation was present in a few areas. No invasive features were recognized. On mucin histochemistry the tumor cell cytoplasm contained a little or no neutral and acidic mucus, and no secretory mucins were recognized. Immunohistochemically, the tumor cells were positive for cytokeratins (CK), CK 8, 9, 18, 19 and 20, epithelial membrane antigen, CDX2, carbohydrate antigen 19-9, and Ki-67 (labeling 30%), MUC2, MUC5AC and MUC6, and CD10. The tumor cells were negative for C-erbB2, MUC1, trypsin, pancreatic amylase and pancreatic lipase. The tumor cells were negative for p53 protein, but the malignant foci were positive for p53 protein and had high Ki-67 antigen (labeling 60%). The patient was free of disease 4 years after the operation. In summary, presented here is an extremely rare case of intraductal tubular carcinoma, intestinal type, showing focal malignant foci.