Clinical and Imaging Comparison of Primary Liver Carcinosarcoma and Sarcomatoid Carcinoma

Objective: Primary liver carcinosarcoma (CS) and sarcomatoid carcinoma (SC) are rare malignant tumors of the liver. Although the two tumors often overlap in clinical and imaging manifestations, there are currently no reports comparing the imaging features of these two tumors. Our study aims to compare the clinical characteristics and imaging features of these two tumors to further describe their distinct features, thereby enhancing understanding and diagnostic accuracy. Methods: A retrospective analysis was conducted on the clinical and imaging data of 17 patients with CS and 27 patients with SC diagnosed by surgical or needle biopsy between September 2010 and December 2024 at our hospital. The data were summarized and statistically analyzed. Results: Both groups were predominantly male, with a lower mean age (56.65 ± 11.82) in the CS group compared to the SC group (64.93 ± 8.15) (P = 0.01). Compared to the SC group, the CS group more commonly presented with hepatitis B, cirrhosis, and elevated AFP levels. Both groups were more commonly located in the right hepatic lobe, with larger tumors that were often solitary, irregularly shaped, and lobulated. Most tumors exhibited necrosis and hemorrhage. Calcification was observed in two cases in the CS group on CT scans. The tumor margins were predominantly indistinct, and the majority of tumors did not show a capsule. Approximately half of the patients in the SC group had lymph node metastasis, which was significantly higher than in the CS group (P = 0.023). After contrast enhancement, all cases in both groups showed heterogeneous enhancement in the arterial phase. Regarding enhancement distribution, the CS group more commonly exhibited enhancement at the margins and in the solid components, while most cases in the SC group showed enhancement at the margins and in the septa. In terms of dynamic enhancement patterns, the CS group more commonly exhibited partial or complete regression in the delayed phase, while the SC group more commonly exhibited progressive or persistent enhancement in the delayed phase, with statistical significance (P=0.042). Conclusion: Patients in the SC group had significantly higher age and lymph node metastasis than those in the CS group. In terms of tumor enhancement patterns, the CS group primarily exhibited delayed-phase regression or partial regression, while the SC group primarily exhibited delayed-phase persistent or progressive enhancement.