Mucin-producing tumor of the pancreas: a unique clinical entity.

We report our experience with nine patients with "mucin-producing tumor of the pancreas," in which abundant mucin secreted by the tumor cells played a major role in the characteristic alterations of the pancreatic duct system. Four of nine patients presented with pancreatitis. Ultrasound and computed tomography demonstrated a well-defined cystic mass and dilated main pancreatic duct. Endoscopic retrograde pancreatography showed ductectatic character, i.e., diffuse dilatation of main duct and/or cystic dilatation of the branch ducts with filling defects of mucin. Ultrasound proved to be a good screening test. However, the diagnosis was confirmed on endoscopic retrograde pancreatography. Nine of our cases had no peripancreatic invasion or metastasis, resulting in a good prognosis after pancreatectomy. Mucin-producing tumor of the pancreas is a unique clinical entity that should be distinguished from "common" pancreatic carcinomas, and a favorable prognosis can be expected after surgical operation.