Figure legends
Figure 1. Abdominal ultrasonography images. The tumor was present on segment 5 and showed a mosaic pattern (white arrow).
Figure 2. CT during angiography. The tumor showed low absorption on CT during arterial portography (a) and high absorption on CT during hepatic arteriography both in the early phase (b) and late phase (c).
Figure 3. EOB-MRI images. The tumor showed a high signal on early phase (a), low signal on T1-weighted hepatocyte phase (b), high signal on diffusion-weighted imaging (c), and low signal on apparent diffusion coefficient (d).
Figure 4. Histological findings in resected lymphocyte rich hepatocellular carcinoma (loupe image, H-E stain). The enlarged image is shown in the black frame. White line shows the border of the tumor and liver background. H-E staining showed poorly differentiated tumor cells with prominent nuclear irregularities and high degree of lymphocytic infiltration in the background.
Figure 5. H-E staining and immunostaining images of tumor. H-E (a), Glypican3 (b), Hepatocyte (c), EBV-encoded small RNA (EBER) (d). Many infiltrating lymphocytes were found around tumor cells stained with Glypican3 and Hepatocyte. EBER was negative.
Figure 6. Immunostaining images of infiltrating lymphocytes. CD8 (a), CD4 (b), CD3 (c), CD20 (d). Both CD8 and CD4 were positive in 50%. CD3 was positive in almost 100% and CD20 was negative.
Figure 7. Immunostaining images. FOXP3 (a), Programmed cell death 1 (PD-1) (b), Programmed cell death ligand 1 (PD-L1) (c). FOXP3 was weakly positive in CD4 positive cells. PD-1 was positive in almost all lymphocytes. PD-L1 was positive in about 40% of tumor cells.
Figure 8. Low-power field showing immunostaining of PD-L1 (a). High-power field showing Glypican 3 immunostaining (b) and PD-L1 (c). Multiple small foci of PD-L1 positive inflammatory cell clusters were founded around Glypican 3-positive tumor cells (circles).