[A Case of Gallbladder Carcinosarcoma Underwent Surgery with the Diagnosis of Acute Cholecystitis with Biliary Tract Bleeding].

We report a case of gallbladder carcinosarcoma in which surgery was performed based on the preoperative diagnosis of acute cholecystitis accompanied by biliary tract bleeding. The patient was an 84-year-old man who came to the emergency department complaining of abdominal pain. Upon close examination, he was diagnosed with acute hemorrhagic cholecystitis and underwent open cholecystectomy. A fresh specimen showed a nodular tumor protruding into the gallbladder lumen. Histopathological examination revealed a mixture of tubular to solid adenocarcinoma, areas showing sarcomatous changes, and findings consistent with chondrosarcoma or osteosarcoma, leading to the diagnosis of gallbladder carcinosarcoma. Although additional resection was not performed due to advanced age and other reasons, recurrence was observed on CT scan 3 months after surgery, and he is currently undergoing chemotherapy. Gallbladder carcinosarcoma is a rare tumor that is a combination of carcinoma of epithelial origin and sarcoma of non-epithelial origin. Even after resection, recurrence is common and the prognosis is poor.