Monosegmental Hepatobiliary Fibropolycystic Disease Mimicking a Mass: Report of Three Cases
A 44-year-old woman presented with mild upper abdominal pain and a lobulated mass in the left lobe of the liver. This patient had undergone abdominal computed tomography (CT) scan for similar pain at a local hospital 4 years previously, and a hepatic mass had been detected. The laboratory tests showed no abnormal findings and physical examination was normal. The evidence of polycystic kidney or liver disease was absent. There was no family history of polycystic kidney or liver disease. On the present admission, ultrasound showed an ill-defined, isoechoic mass, with internal cystic components in the lateral segment of the liver (). A three-phase abdominal CT scan showed an irregularly-marginated multicystic mass with tubular components, and with no contrast enhancement (). The remaining liver was normal. This mass did not show a change in the size or contour as compared with that observed 4 years previously. Laparoscopic left lateral segmentectomy was performed. The cut surface of the hepatic left lobe showed aggregates of numerous small and large biliary cysts (). Microscopically, the left hepatic mass showed numerous dilated intrahepatic bile ducts with irregular contours, infoldings, and protrusions, surrounded by thick fibrous tissue, which are known features of ductal plate malformation. There were ductal plate malformations of numerous dilated biliary cysts (). Immunohistochemical stains for CD10 (), CK7 (), and MUC1 () showed positive reactions in the lining (epithelial cells) of dilated cysts, as well as proliferative bile ductules.