Mucin-hypersecreting intrahepatic biliary neoplasms

The radiologic findings are described in six patients with "mucin-hypersecreting" intrahepatic biliary neoplasms (biliary cystadenocarcinoma or papillary cholangiocarcinoma). Massive amounts of mucin were confirmed in the dilated bile ducts at surgery or autopsy. Computed tomography (CT) and ultrasound (US) demonstrated severe dilatation of the intrahepatic bile ducts distal to the tumor in all patients and of extrahepatic ducts in five. On cholangiograms, large, amorphous filling defects caused by retention of mucin were found in the dilated ducts in three patients. The tumor was multilocular and cystic in five patients; in the other patient it was too small to be detected at CT or US. The presence of liver tumor (mostly multilocular and cystic), marked biliary dilatation distal to the tumor, and filling defects in the dilated bile ducts are important findings that indicate a mucin-hypersecreting intrahepatic biliary neoplasm.