Fig. 3

Pathological analysis. Autopsy revealed that the left lobe of the liver was filled with tumors, accompanied by central necrosis (a). The tumors exhibited extrahepatic growth, including invasion into the stomach and left diaphragm. Severe peritoneal dissemination was also detected (b). The pathologic tests demonstrated that the tumors consisted of multiple spindle-shaped cells, suggesting a sarcomatous change in hepatocellular carcinoma (HCC) (c, d). Both sarcomatous and ordinary HCCs were identified as lung metastases (e–h). The result of immunohistochemical staining of the spindle-shaped cells was negative for hepatocyte antigen and arginase 1 (i, j). In contrast, vimentin was positively stained (k), and cytokeratin 7 (CK7) and pankeratin (AE1/AE3) appeared to be slightly positive (l, m)