Intrahepatic cholangiocarcinoma after Fontan procedure in an adult with visceral heterotaxy

Hepatic dysfunction, including development of hepatocellular carcinoma and other liver lesions has been increasingly reported following Fontan procedure for congenital heart disease. We report a unique case of intrahepatic cholangiocarcinoma 28 years after a Fontan procedure in a 31year old female with heterotaxy syndrome. The subcapsular mass-forming tumor was composed of poorly differentiated tumor cells arranged in small vague glandular or slit-lumen nests, and focally fused or anastomosing large trabecular patterns within the prominent fibrotic stroma. The tumor cells with immunoreactivity to CK7, CK19, Cam5.2, COX2, EMA, BCL-2, MOC-31 and AE1/AE3, supported a diagnosis of intrahepatic cholangiocarcinoma. Focal atypical ductular proliferation within the background liver may represent a precursor lesion to this tumor. Dysmorphic cilia observed by electron microscopy examination in the background liver may suggest cholangiociliopathy in heterotaxy. MYST3 mutation at Q1388H detected in intrahepatic cholangiocarcinoma is reported for the first time.