Sarcomatoid cholangiocarcinoma with osteoclast-like giant cells associated with hepatolithiasis: A case report

Cholangiocarcinoma (CC) is an adenocarcinoma arising from epithelial cells of varying locations within the biliary tree, and is the second most common primary liver tumor, accounting for approximately 10-15% of all hepatobiliary malignancies. This disease has a high prevalence in Southeast and Eastern Asia, including Korea; during the period 2003-2005, the age-standardized incidence rates of intrahepatic CC and extrahepatic CC were reported to be 6.9 and 5.2 out of 100,000 in Korea, respectively. Sarcomatoid carcinoma is a rare tumor composed of mixed malignant epithelial and mesenchymal cells, and it can occur in various organs including liver. The prevalence of sarcomatoid CC has been reported to be about 4.5% of surgical and autopsied cases. Most sarcomatoid CCs have been reported to have sarcomatous component which show spindle cell or pleomorphic cell differentiation. Furthermore, sarcomatoid CC with osteoclast-like giant cells, which morphologically resemble those found in giant cell tumors of the bone is a very rare malignant liver tumor which was first reported as osteoclastoma-like giant cell tumor of the liver by Munoz et al. in 1980. To the best of our knowledge, sarcomatoid CC with osteoclast-like giant cells are extremely rare and only 5 cases were reported in the literature so far. Here we report a case of sarcomatoid CC with osteoclast-like giant cells, which is associated with hepatolithiasis.