Ultrasound (US) revealed a 6-mm hypoechoic nodule in segment 6 of a 65-year-old man with alcoholic cirrhosis (Case 1) and a 7-mm hypoechoic nodule in segment 5 of a 70-year-old man with chronic hepatitis C (Case 2). Contrast-enhanced US (CEUS), CE computed tomogra-phy, and CE magnetic resonance imaging of the nodules in both cases revealed hypervascularity in the early phase and washout in the late phase. CEUS with the use of perflubutane revealed washout in the portal phase, which differentiates these nodules from hepato-cellular carcinoma. Histopathologically, the nodules showed proliferation of small 30-μm bile ducts with slight atypia. Immunohistochemically, these were posi-tive for p16INK4a and Ki67 index (0%-3%) and negative for EZH 2, distinguishing them from cholangiolocellular carcinoma.
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© 2021 The Japan Society of Hepatology.
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