Intrahepatic cholangiocarcinoma with extensive sarcomatous change: report of a case.

A 77-year-old woman was admitted to our hospital with severe upper abdominal pain. Ultrasonography showed a well-defined hypoechoic mass with heterogeneity in the left lobe of the liver, and computed tomography demonstrated a low-density mass with enhanced peripheral areas. Magnetic resonance imaging revealed a mass with iso- to low signal intensity on T1-weighted images (WI) and heterogeneous high and low signal intensity on T2 WI. The tumor was found to be hypovascular by angiography. During 5 months of observation, the tumor increased in size, which strongly suggested malignancy. A laparotomy was performed under the provisional diagnosis of a neoplasm other than hepatocellular carcinoma, revealing that the hepatic mass had invaded the gastric wall. Therefore, a left hepatic lobectomy with dissection of the lymph nodes and hemigastrectomy was carried out. Histologically, the tumor was found to be composed of a large amount of sarcomatous elements and a small amount of adenocarcinomatous elements, both of which were partly intermingled. Immunohistochemically, the sarcomatous element demonstrated the features of malignant fibrous histiocytoma (MFH). Thus, a diagnosis of intrahepatic cholangiocarcinoma with MFH-like sarcomatous change was confirmed.