Monolobar hepatobiliary fibropolycystic disease

Area of Science:

• Hepatobiliary Medicine
• Gastroenterology
• Pathology

Background:

• Monolobar hepatobiliary fibropolycystic disease is a rare condition.
• Fibropolycystic liver disease can present with biliary abnormalities and may be associated with anomalous pancreaticobiliary union.

Observation:

• A 75-year-old woman presented with heartburn and was diagnosed with monolobar hepatobiliary fibropolycystic disease affecting the left lobe.
• Imaging revealed atrophy and multiple biliary cysts in the left hepatic lobe, with normal right lobe. ERCP showed anomalous pancreaticobiliary union, choledochal dilation, and a small non-invasive adenocarcinoma.
• Histopathology confirmed fibroelastosis, ductal plate malformation, persistent ductal plates, microhamartomas, and obliterative portal thrombosis in the affected lobe.

Findings:

• The resected left hepatic lobe showed marked atrophy, numerous biliary cysts, dilated intrahepatic bile ducts (Caroli's disease), and type I choledochal dilation.
• Microscopic examination revealed ductal plate malformation within the biliary cysts and ducts, along with fibroelastosis and portal vein thrombosis.
• Immunohistochemistry indicated biliary cells positive for CK7, CK8, CK18, CK19, MUC6, CD10, and MUC1, but negative for MUC2 and MUC5AC.

Implications:

• This case highlights the importance of considering rare hepatobiliary diseases in patients with complex biliary findings.
• The presence of ductal plate malformation and associated adenocarcinoma underscores the need for thorough evaluation and appropriate management.
• Understanding the histological and immunohistochemical features aids in differentiating this condition from other cystic liver diseases.