Hepatic carcinosarcoma with predominant sarcomatous component mimicking intrahepatic cholangiocarcinoma: a case report and literature review.

[BACKGROUND] Hepatic carcinosarcoma (HCS) is an extremely rare primary malignant liver tumor characterized by aggressive biological behavior, early invasion, and poor prognosis. Owing to its non-specific clinical manifestations and imaging features, preoperative diagnosis remains challenging.

[CASE REPORT] We report a 54-year-old man who presented with persistent fever and unexplained weight loss for 2 weeks. Imaging studies revealed a large space-occupying lesion in the right hepatic lobe, with a preliminary suspicion of cholangiocarcinoma. Liver biopsy findings suggested a sarcomatous lesion. Further computed tomography (CT) evaluation revealed a heterogeneous hypodense mass (11 cm) in the right liver, encircling the right portal vein branch and accompanied by mild bile duct dilatation. Laboratory tests showed normal levels of tumor markers including alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 125 (CA125). The patient subsequently underwent laparoscopic right hepatectomy and cholecystectomy. Postoperative pathology revealed extensive tumor necrosis with residual components consisting of approximately 30% poorly differentiated hepatocellular carcinoma and 70% sarcomatoid tissue, confirming the diagnosis of hepatic carcinosarcoma.

[CONCLUSION] Hepatic carcinosarcoma often presents with insidious and non-specific clinical and radiological features, resulting in frequent misdiagnosis. Complete resection remains the primary treatment modality. This case underscores the importance of integrating imaging, histopathology, and immunohistochemical analysis for confirming this rare tumor.