Intrahepatic cholangiocarcinoma with sarcomatous change. Clinicopathologic and immunohistochemical evaluation of seven cases.

Background. Although there have been a few reports dealing with the sarcomatous changes of intrahepatic cholangiocarcinoma, its clinicopathologic features as well as immunohistochemical nature remain obscure. Methods. Among 155 cases of intrahepatic cholangiocarcinoma, 7 cases of sarcomatous cholangiocarcinoma were chosen. Immunohistochemical studies using the avidin-biotin-peroxidase complex method were performed on these cases. Results. The tumor showed both mucin-producing adenocarcinoma areas and sarcomatous areas, the latter being predominant in three cases and focal in the other four. All the sarcomatous areas consisted of atypical spindle cells arranged in sheets or bundles. Pleomorphic giant cells were observed in some sarcomatous components in five cases. Immunohistochemical staining for keratin and epithelial membrane antigen revealed apparent positivity in the sarcomatous components of five cases. The patients with these tumors showed aggressive intrahepatic spreading and widespread metastasis of the sarcomatous cells, and demonstrated poorer prognosis than those with ordinary cholangiocarcinoma, with one exception, a patient who remained disease-free for 3 years after surgery. Conclusions. These findings favor the possible epithelial origin of sarcomatous cells. Radical operation would be necessary for patients with this special type of cholangiocarcinoma.