PMC10320744_01
Contrast-enhanced computed tomography. horizontal view (a, b): A 70 x 60 x 55 mm mass is observed in the posterior right lobe of the liver. The limbus had slight early darkening in the arterial phase (a) and lower absorption than the liver parenchyma in the delayed phase (b).. Coronal view (c, d): There was a shadow extending from the medial side of the liver tumor, bordering the posterior bile duct, and extending into the hilar bile duct, which had a contrast effect (white arrow).
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The tumor was suspected to be medial, bordering the posterior bile duct and extending into the hilar bile duct (Figure 1).
(a) Hematoxylin and eosin staining x 40. Cancer cells with high nuclear density. (b-d): Immunohistochemical stain x 40. Positive for arginase-1 (b) and hepatocytes (c). Negative for cytokeratin-7 (d) and cytokeratin-19.
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These findings suggested that the main tumor was an HCC (Figure 2).
(a) Endoscopic retrograde cholangiopancreatography: stenosis of the right anterior segment bile duct and failure to visualize the posterior segment bile duct.. (b) Endoscopic ultrasound: The bile duct was filled with substantial structures (white arrow) and was contiguous with the mass in the posterior segment (green arrow).. (c) Peroral cholangioscopy: A villous mass was observed inside the posterior hepatic duct (white arrow); it was difficult to observe from the front. No tumor was observed at the anteroposterior bifurcation of the right hepatic duct to the left-right hepatic duct bifurcation.
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The extent to which the tumor had invaded the bile duct was unclear (Figure 3b). Endoscopic retrograde cholangiopancreatography showed stenosis of the right anterior segment bile duct and failed to visualize the posterior segment bile duct (Figure 3A). No tumor was observed in the left hepatic duct, right and left hepatic duct bifurcation, or right hepatic duct anteroposterior bifurcation, and a biopsy confirmed no pathological malignant findings (Figure 3C).
(a) Gross image of the resected right liver lobe.. Cancer cells resembling hepatocytes were growing prolifically (b): hematoxylin and eosin staining x20.. Cancer cells with pale cytoplasm were observed (c): Endoscopic ultrasound x40.. The tumor invaded the bile duct (d): Endoscopic ultrasound x20. The bile duct resection margins were negative.
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The tumor invaded the bile duct; however, the bile duct resection margins were negative, and the tumor could be curatively resected (Figure 4).