Sonographic features of thoracoabdominal wall metastases of liver cancer after liver transplantation

Objective: Sonographic features are not well-defined in thoracoabdominal wall metastases (TAWM) of liver cancer after liver transplantation (LT), which is one of the most important reasons affecting the long-term survival of transplant recipients. The purpose of this study was to analyze the sonographic features of TAWM from liver cancer after LT and to identify the role of ultrasound (US) in the differential diagnosis between TAWM and benign lesions of the thoracoabdominal wall after LT.Methods: This retrospective study included 1,999 LT recipients between January 2008 and July 2021. Clinical characteristics and sonographic features of 32 patients with thoracoabdominal wall lesions were analyzed. The types of thoracoabdominal wall lesions were studied, and the US findings of benign and malignant lesions were compared. Whether TAWM from liver cancer after LT exhibited any distinctive sonographic appearance was evaluated.Results: All seven malignant cases were metastases from liver cancer. The benign group included 13 cases of thoracoabdominal wallencapsulated effusion/hematoma, nine of abdominal incisional hernia, and three of thoracoabdominal wall inflammatory mass. Sonographic features were significantly different between two groups. Compared with the benign group, metastases lesions were frequently located in the parietal peritoneum/pleura (4/7 vs 1/25, p = 0.009), fewer lesions were located at abdominal incisions (3/7 vs 23/25, p = 0.012), all metastatic lesions were hypoechoic (7/7 vs 5/25, p = 0.001), and most lesions had blood flow signals (4/7 vs 3/25, p = 0.026). Additionally, most metastatic cases had intrahepatic lesions (4/7 vs 1/25, p = 0.004) and multiple extrahepatic solid lesions in the abdomen (6/7 vs 0/25, p = 0.000).Conclusions: Compared with benign lesions, TAWM of liver cancer after LT exhibited unique sonographic features.