Sequential progression and intraductal spread of invasive ductal adenocarcinoma of the pancreas arising from around the main pancreatic duct.

A 76-year-old woman was admitted to our hospital after increased transaminase, hepato-biliary enzyme levels, and tumor markers were found. Abdominal contrast computed tomography revealed a mass (20 x 18 mm) in the uncus of the pancreas. Magnetic resonance cholangiopancreatography showed an abrupt narrowing with the dilatation of the peripheral main pancreatic duct (MPD) in the pancreatic head. Endoscopic retrograde cholangiopancreatography showed only dilatation of the lower bile duct; insertion of the cannula was not seen because the MPD was obstructed. The patient underwent a Whipple-pancreatoduodenectomy. Histopathological and immunohistochemical examinations led to a diagnosis of sequential progression and intraductal spread of invasive ductal adenocarcinoma of the pancreas arising from around the main pancreaticduct. Interestingly, the intraductal spread was approximately 20 mm to the point where the carcinoma began to infiltrate. To the best of our knowledge, there have been no other reported cases of such broad intraductal spread, indicating that noninvasive lesions that replace the normal epithelia can be broader than those reported previously.