Carcinosarcoma of the gallbladder: report of a case.

Carcinosarcoma is a rare neoplasm with epithelial and mesenchymal components. We herein report the case of a 68-year-old male with a carcinosarcoma of the gallbladder. Preoperative examinations revealed the gallbladder cancer infiltrating the liver with a multinodular mass with a portal vein tumor thrombus through the right anterior branch of the portal vein. Extended right hepatectomy with portal thrombectomy was performed. Histologically, the tumor comprised a distinct adenocarcinoma and pleomorphic mononuclear cell components. The adenocarcinoma mainly lined the gallbladder lumen, forming irregular papillary glands. The pleomorphic mononuclear cells formed the majority of the tumor. Immunohistochemical analysis revealed that the pleomorphic mononuclear component was strongly positive for vimentin and slightly positive for cytokeratin. These findings suggested that the mononuclear cells formed a degenerated neoplasm of adenocarcinoma cells. The pathological diagnosis was carcinosarcoma of the gallbladder. After curative surgery, adjuvant chemotherapy with gemcitabine chloride was conducted for 3 years. The patient was alive for 5 years without recurrence after resection. The present case showed the longest reported survival among patients with advanced stage carcinosarcoma.