A case of hepatocellular carcinoma arising within large focal nodular hyperplasia with review of the literature

Figure 1 A: Unenhanced transverse CT scan demonstrates multiple hypoattenuating masses located on both liver lobes. Fatty tissue (known angiomyolipoma) replaces the most of the upper pole of the right kidney; B: Post-contrast CT scan depicts multiple round liver lesions, with a smooth margin, which demonstrate intense homogeneous enhancement. The lesion located in segment three, has a small central area of hypodensity, consistent with a central scar.

Figure 2 A: Pre-contrast CT scan 3 mo later, revealing the significant increase in the size of the lesion located in the left liver lobe; B: Post-contrast image at the same level showing the increased contrast uptake of the lesion.

Figure 3 A: Photograph of the surgical specimen. The inset shows the cut surface: White arrow points at the scar of FNH and black arrow shows the hepatocellular carcinoma; B: Photomicrograph from the lesion. Left: Connective tissue from the core of FNH containing thin wall vessels (black arrows) and cholangioles (black arrowheads). Right: hepatocellular carcinoma. The tumor shows a trabecular growth pattern (white arrows) and focal pseudoglandular transformation (white arrowheads) (HE x 100).

Figure 4 Microphotograph showing details of the tumor. A, B: The tumor displays a trabecular growth pattern (A-arrow, B-arrow) with focal pseudoglandular transformation (A-arrowhead) (HE, A × 250, B × 400); C: Tumor cells show positive immunohistochemical stain for hepatocyte antigen (arrows-streptavidin biotin peroxidase × 250); D: Tumor cells show positive immunohistochemical stain for cytokeratin 18 (arrows-streptavidin biotin peroxidase × 400); E: Immunohistochemical stain for polyclonal carcinoembryonic antigen displays a canalicular pattern (arrows-streptavidin biotin peroxidase × 100).