Primary liver carcinoma exhibiting dual hepatocellular-biliary epithelial differentiations associated with citrin deficiency: a case report.

We report a 50-year-old male patient with primary liver carcinoma exhibiting dual hepatocellular and biliary epithelial differentiations associated with citrin deficiency (asymptomatic adult-onset type II citrullinemia, CTLN2). Although so far 14 CTLN2 patients with hepatocellular carcinoma have been reported, this report describes a unique case of liver carcinoma showing the features of both hepatocellular and cholangiocellular carcinoma. In addition to the clinical data of the 14 patients reported previously, the findings in our patient suggest that the citrin deficiency might be one of the key disorders causing hepatocellular carcinoma especially at younger ages and can also play an important role in hepatocarcinogenesis of the hepatic progenitor cells, which have the bipotential to differentiate into both hepatocytes and cholangiocytes.