Polycystic kidney and hepatic disease 1 gene mutations in von Meyenburg complexes: Case report

ARTICLE HIGHLIGHTS

Case characteristics

A 62-year-old woman and a 57-year-old woman were both previously healthy, who were referred due to abnormal echographic presentation of the liver.

Differential diagnosis

Liver cirrhosis, metastases, microabscesses, and simple liver cysts.

Laboratory diagnosis

Proband A and B were diagnosed with chronic hepatitis B and HBeAg-negative chronic hepatitis B, respectively, by laboratory examinations of positive hepatitis B surface antigen (HBsAg), negative anti-hepatitis C virus and anti-human immuno-deficiency virus tests, and normal liver function tests.

Imaging diagnosis

Abdominal ultrasonography displayed intrahepatic diffuse lesions and magnetic resonance imaging (MRI) showed cystic lesions that shared no connection with the intra- and extra-hepatic bile duct system and were of normal size for von Meyenburg complexes (VMCs). A carcinoma in the right lobe of the liver was also found in proband A. No kidney cyst was seen in the imaging examinations of any family member.

Pathological diagnosis

Pathological diagnosis confirmed the diagnoses of hepatocellular carcinoma VMCs and chronic hepatitis B in proband A and of congenital hepatic fibrosis (CHF) and VMCs in proband B.

Treatment

Proband A was given entecavir and complete surgical resection of the hepatocellular carcinoma lesion. Proband B did not receive any medication and was followed up regularly.

Related reports

In most of cases, VMCs are incidentally detected, focusing on the location of the disease (liver surface, extrahepatic), relative symptoms, mimicking metastatic disease or malignancy, and association with liver tumor.

Term explanation

PKHD1 gene is located on chromosome 6p12. It encodes a protein named fibrocystin/polyductin (FPC). FPC protein is involved in the maintenance of the normal tubular structure of intrahepatic bile duct epithelial cells. Mutation of PKHD1 may cause the structural and functional disorder of FPC, leading eventually to the development of renal and hepatic cysts. VMCs are benign neoplasms characterized by the disorderly arrangement of biliary epithelium, which form abnormal biliary ducts surrounded by ample fibrous stroma.

Experiences and lessons

The PKHD1 gene mutations were identified in two VMCs patients, providing new insights into the pathogenesis, diagnosis, and progression of the VMCs.