A 69-year-old woman was admitted to our hospital with fever and abdominal pain in the epigastric region. Abdominal ultrasonography demonstrated a well-defined hypoechoic mass in the epigastric region with encasement of the left hepatic lobe and stomach. Computed tomography confirmed a low-density mass, 20 cm in diameter, with enhancing peripheral areas. Angiography revealed the tumor to be hypovascular. After admission, the patient had a persistent fever and anemia that required transfusions of concentrated red blood cells. On the twelfth day after admission, she suffered disseminated intravascular coagulation and underwent an emergency operation. A lateral segmentectomy with dissection of lymph nodes, cholecystectomy, and hemigastrectomy were carried out. The size of the tumor was 22 x 17 x 15 cm. Macroscopically, a cross-section revealed massive necrosis with hemorrhage. Histological examination of the tumor showed a malignant neoplasm with a carcinomatous component and a sarcomatous component, which were partly intermingled. The former consisted of moderately differentiated adenocarcinoma, while the latter consisted of pleomorphic spindle cells. Immunohistochemical examination of the sarcomatous component showed positive staining for vimentin, epithelial membrane antigen, and cytokeratin. The tumor was diagnosed as cholangiocarcinoma with extensive sarcomatous changes, based on these histological and immunohistochemical findings. The patient had an uneventful postoperative course. However, she died 3 months after surgery from dissemination of the carcinoma. The literature on this rare disease is reviewed and discussed.