Shunji Kitazawa

Early pancreatic duct adenocarcinoma

A 68-year-old Japanese woman presented with complaints of appetite and weight loss. Early pancreatic duct adenocarcinoma was diagnosed by endoscopic retrograde cholangiopancreatography (ERCP), which revealed partial obstruction of the main pancreatic duct. Pancreatoduodenectomy with lymph node dissection was performed. Macroscopically, no pancreatic tumor was detected. Histologically, the pancreatic lesion showed continuous changes consisting of duct epithelial cell hyperplasia, carcinoma in situ, and invasive carcinoma. Immunohistochemical stains for carcinoembryonic antigen and CA19-9 were positive in cancer cells.

Early ductal lesions of pancreatic carcinogenesis in animals and humans

SummaryTwo cases of human early pancreatic duct adenocarcinoma were presented, and ductal lesions observed histologically were compared to those induced in hamsters using a rapid-production model of pancreatic carcinoma. In human cases, direct histologic evidence was obtained to suggest that cancerous changes arose from duct epithelial cell hyperplasia, because lesions of hyperplasia and carcinoma coexisted in continuity. In hamster serialkilling studies, it was suggested that carcinoma developed through atypical ductal hyperplasia.

Intraductal carcinoma in a surgically resected pancreas with chronic pancreatitis

SummaryA 59-yr-old Japanese male presented with epigastralgia. Endoscopic retrograde cholangiopancreatography (ERCP) revealed narrowing of the inferior common bile duct and protein plugs in the main pancreatic duct. He was diagnosed as suffering from chronic pancreatitis with suspicion of a pancreatic head tumor, and a pancreatoduodenectomy was performed. Histologically, a diffuse chronic pancreatitis was evident in the resected pancreas. Although no tumors were seen in the head portion of the pancreas around the inferior common bile duct, an intraductal carcinoma was found in the second branch of Santorini’s duct. Precancerous alteration of the duct epithelium, presenting papillary hyperplasia, and atypical hyperplasia were observed in areas continuous with the intraductal carcinoma. Immunohistochemically, carcinoembronic antigen (CEA) was specifically expressed in atypical hyperplasia and intraductal carcinoma, but not in papillary hyperplasia.

Intracellular distribution of pancreatic tumor antigen purified from BHP-induced adenocarcinomas in Syrian hamsters

Pancreatic tumor antigen (PTA) was purified to apparent homogeneity from hamster pancreatic adenocarcinomas by a rapid and simple procedure using column chromatography on Mono P and Superose 6. Amino acid analysis indicated essential similarities between hamster PTA and human pancreatic cancer-associated antigen (PCAA, PCAAc), although differences in the contents of several amino acid residues between the two proteins did suggest species variation. Investigation of the binding pattern of antibody raised against PTA by peroxidase-labeled antibody immunocytochemistry revealed that, whereas PTA is absent or only faintly expressed in normal epithelium, it is very strongly positive in transplantable hamster pancreatic adenocarcinomas induced by nitrosamines. PTA was found to be distributed over the entire surface of neoplastic cells and it was concluded that the presence of PTA on the basolateral surface of malignant pancreatic epithelial cells, where it. might have access to the blood circulation, could be one explanation for the observed elevated concentrations of PTA in the serum. PTA is thus a potential marker for hamster neoplastic pancreatobiliary duct-type cells.