Cholangiohepatoma refers to a synchronous cholangiocarcinoma and hepatocellular carcinoma. It is a rare and aggressive primary hepatic tumor. The origin of cholangiohepatoma is closely linked to the origin of cholangiocarcinoma rather than hepatocellular carcinoma (HCC).
The incidence of this tumor varies between 0.4 and 4.7%.
Typically the presentation is with obstructive jaundice.
Histogenesis of tumor is thought to occur at the canal of Hering:
- the canals of Hering (CoH) or intrahepatic bile ductules are found near the outer edge of a liver lobule.
- they are lined partially by cholangiocytes and partly by hepatocytes
- hepatic stem cell niches (hepatic progenitor cells)have been identified in the canals of Hering
- they can differentiate into hepatocytes and cholangiocytes and can therefore give rise to HCC, cholangiocarcinoma and cholangiohepatoma sharing features of both HCC and cholangiocarcinoma
- conventional histology may be inconclusive
Glypican-3 is highly sensitive and specific for identification of HCC component and only weakly reactive with cholangiocarcinoma. Biliary cell stains are mucin, CK7, and CK19, whereas hepatocellular stains comprise polyclonal CEA, Hep Par 1, and CD10 .
Imaging features are a combined spectrum of intrahepatic cholangiocarcinoma andhepatocellular carcinoma.
Heterogeneous iso-to-hyperechoic mass with a peripheral hypoechoic halo of compressed liver. Capsular retraction and lobulated appearance with infiltration of biliary system is usually seen. Ultrasound appearance is non specific and usually parallels that of conventional cholangiocarcinoma.
The lesion is usually lobulated and well delineated although a well-defined capsule s not seen. Hepatic capsular retraction and infiltration of biliary tree are also usually seen.
On post contrast imaging, progressive delayed enhancing areas mixed with areas arterial enhancement and washout is very suggestive of cholangiohepatoma.
MRI features of cholangiohepatoma have not been described extensively.
- T1: low signal
- T2: intermediate-to-high signal intensity +/- central hypointense focus
- T1C+: progressive delayed enhancing areas mixed with areas arterial enhancement and washout
MR imaging with a hepatocellular agent like gadoxetic acid may also be useful to differentiate cholangiohepatoma and cholangiocarcinoma.
Treatment and prognosis
The prognosis of cholangiohepatoma is poor, even with resection.
Possible differential considerations include:
- liver metastases: central necrosis (high T2 signal) is more common
hepatocellular carcinoma (HCC)
- tumor thrombus more common
- capsular retraction uncommon
- may appear very similar
- other primary liver tumors
- intrahepatic cholangiocarcinoma
- peripheral location
- biliary obstruction
- delayed enhancement
- hepatic abscess
- 1. Maximin S, Ganeshan DM, Shanbhogue AK, Dighe MK, Yeh MM, Kolokythas O, Bhargava P, Lalwani N. Current update on combined hepatocellular-cholangiocarcinoma. European journal of radiology open. 1: 40-8. doi:10.1016/j.ejro.2014.07.001 - Pubmed
- 2. O'Connor K, Walsh JC, Schaeffer DF. Combined hepatocellular-cholangiocarcinoma (cHCC-CC): a distinct entity. Annals of hepatology. 13 (3): 317-22. Pubmed