Monosegmental Hepatobiliary Fibropolycystic Disease Mimicking a Mass: Report of Three Cases
A 46-year-old man presented with incidentally discovered hepatic mass in the right lobe of the liver. The laboratory tests showed no abnormal findings, and physical examination was normal. The evidence of polycystic kidney or liver disease was absent. No family history of polycystic kidney or liver disease was recognized. A three-phase abdominal CT scan showed an ill-defined mass composed of numerous cysts and tubular lesions in segment VI of the liver (). Magnetic resonance (MR) images showed a cystic mass with very high T2 and low T1 signal intensities (). Post-contrast MR images showed no contrast enhancement of this mass (). The remaining liver was normal. Percutaneous biopsy was performed. Microscopic findings of the needle biopsy specimen showed several, irregular-shaped, dilated intrahepatic bile ducts, lined by the cuboidal biliary epithelial cells (). There were also ductal plate malformation and numerous inflammatory cells in a background of fibrous tissue. Immunohistochemical stains for CD10 (), CK7 (), and MUC1 () showed positive reactions in the lining (epithelial cells) of dilated cysts, as well as proliferative bile ductules. Follow-up imaging 18 months later showed no interval change of this cystic mass.