case_images: PMC10722152_01
case_images: The CEUS and CECT images and histopathological picture of patient No. 1. (A-C) CEUS images show inhomogeneous patchy hyperenhancement in AP (A), continuous hyperenhancement in PP (B) and hypoenhancement in delayed phase (C). (D) In the right lobe of the liver, there is an approximately 103x133 mm slightly hypodense shadow. It has ill-defined borders, irregular shape, and inhomogeneous inner density. After being contrast-enhanced, the lesion shows moderate (E) and persistent (F) enhancement, with patchy marked enhancement in AP and progressive enhancement in PP. It is clearly visualized on a 1 mm thin section scanned PP image (G) and the local magnification image (H, green arrowheads); the right branch of the hepatic vein enters the lesion with a few filling defects (indicating the tumor has already invaded the right hepatic vein), while the right branch of portal vein enters the lesion with a natural course and a slightly brown border (not shown). In pictures of immunohistochemical staining, diffuse CD31 (I) and CD34 (J) expression suggest positive immunoreactivity in sinusoidal capillarization. (K) Diffuse vimentin expression shows a large number of mesenchymal cells. (L, M) are histopathological examinations with HE staining. The red ovoid area shows dilated vascular lumina anastomosed to each other. (L) shows spindled-shaped cells and epithelioid cells arranged in sheets with lacunae scattered between them. (M) shows that the dilated sinusoid-like lumina are lined with single- or multilayered atypical epithelial cells and spindle cells. Their nuclei are enlarged and hyperchromatic, displaying an abnormal shape (round or oval, with obvious nucleoli). Green arrowheads in (M) indicate atypical epithelial cells projecting into the lumen to form papillary structures. No obvious thrombosis is found in the sinuses. The red arrowheads seen in (A-F) indicate the border of the lesion.
case_images: fonc-13-1283544-g001.jpg
case_images: PMC10722152_01_fonc-13-1283544-g001.jpg
case_images: f1
case_images: They all died, with an average survival of 9.3 months, ranging from 2 to 20 months ( Supplementary Figure 1 ). According to  Table 2 ;  Figures 1 - 4 , and  Supplementary Figures 2 ,  3 , all the lesions displayed a similar appearance as inhomogeneous low-density masses in unenhanced CT.
case_images: The CEUS and CECT images and histopathological picture of patient No. 2. (A-C) CEUS images show most areas of the lesion have perfusion defects of contrast agent, except some sparse, thin, linear hyperenhancement in AP (A), continuous hypervascularity of these line-like structures in PP (B) and hypoenhancement in delayed phase (C). Unenhanced CT image (D) reveals a heterogeneous low-density mass of approximately 102x90 mm in the right lobe of the liver, with an irregular shape and ill-defined boundary. (E, F) indicate CECT. The mass is characterized by slightly linear peripheral enhancement (green arrowhead) in AP (E) and the enhancement is persistent in PP (F). Almost all areas of the lesion have no enhancement. (G, L) Histopathological examination with HE staining showing the structure of sinusoid-like lumina which are severely dilated, have complex constructions, and coincide with each other. Infiltrating spindle cell malignant tumors are surrounded by hepatocytes. Immunohistochemical staining of cytoplasm for vascular antigen CD31 (H) and CD34 (I) shows endothelial tumor cells differentiated in clusters and bundles. (J) Diffuse vimentin expression shows a large number of mesenchymal cells. Immunohistochemical staining for ERG (erythroblast transformation-specific (ETS)-related gene) (K) shows positive staining of the nucleus showing diffuse vascular endothelial differentiated tumor cells. The red arrowheads seen in (A-F) indicate the border of the lesion.
case_images: fonc-13-1283544-g002.jpg
case_images: PMC10722152_01_fonc-13-1283544-g002.jpg
case_images: f2
case_images: According to  Table 2 ;  Figures 1 - 4 , and  Supplementary Figures 2 ,  3 , all the lesions displayed a similar appearance as inhomogeneous low-density masses in unenhanced CT.
case_images: The CEUS and CECT images and histopathological picture of patient No. 3. (A-C) The contrast agent is filled unevenly during the whole period of CEUS. A few patchy strip areas or cord-like hyperenhancement are found in AP (A); these patchy strip areas are of continuous hyperenhancement in PP (B) and washout (hypoechogenicity) in delayed phase (C). Unenhanced CT (D) exhibited that in the right lobe of the liver, there is a low-density mass approximately 111x75 mm in size with clear boundary, irregular shape, and inhomogeneous low internal density. In the contrast-enhanced scan, the whole lesion demonstrates slight (E) and persistent (F) enhancement, and the border and septal-like areas are more obviously enhanced. In particular, the line-like enhancement at the edge of the lesion indicated by the green arrowhead in (E) is a small branch of the coeliac axis. (G) and (K) Histopathological examination with HE staining showing focally disrupted hepatic architecture with pleomorphic cell malignancy within disrupted sinusoids. Figures (H, I) show nodular areas with plenty of CD31 (H)- and CD34 (I)-positive neoplastic cells. (J) Diffuse vimentin expression shows a large number of mesenchymal cells. The red arrowheads seen in (A-F) indicate the border of the lesion.
case_images: fonc-13-1283544-g003.jpg
case_images: PMC10722152_01_fonc-13-1283544-g003.jpg
case_images: f3
case_images: According to  Table 2 ;  Figures 1 - 4 , and  Supplementary Figures 2 ,  3 , all the lesions displayed a similar appearance as inhomogeneous low-density masses in unenhanced CT.
case_images: The CEUS and CECT images and histopathological picture of patient No. 4. (A) The biggest lesion, located in the right lobe, appears as heterogeneous and hypoechoic, with an ill-defined border in the grayscale US. (B, C) In early and late AP of CEUS, the lesion is partially hyperenhanced. From PP (D) to postvascular phase (E), the perfusion of the agent gradually decreased. The lesion appears as iso to hypoenhanced. In unenhanced CT (F), the lesion appears as a low-density mass approximately 45x41 mm in size with unclear boundary, irregular shape, and inhomogeneous, slightly high internal density (G). (F) shows unenhanced CT. The lesion has an unclear border. In AP (G) of enhanced CT, the lesion shows patchy enhancement, while in PP (H) it shows persistent fill-in. In the postvascular phase (I), the lesion shows decreased enhancement. Histopathological examination with HE staining (J) shows endothelial cells are fusiform, and the nuclei are heavily stained. This is a pathologically early stage of hepatic angiosarcoma. Neither hepatocytes nor sinusoids have been completely destroyed. Tumor cells with nuclei of various sizes (nuclear heteromorphism) grow along the sinusoids. The staining of CD31 (K), CD34 (L), and P53 (M) is focally positive. The red arrowheads seen in (A-I) indicate the border of our target lesion.
case_images: fonc-13-1283544-g004.jpg
case_images: PMC10722152_01_fonc-13-1283544-g004.jpg
case_images: f4
case_images: According to  Table 2 ;  Figures 1 - 4 , and  Supplementary Figures 2 ,  3 , all the lesions displayed a similar appearance as inhomogeneous low-density masses in unenhanced CT.