We report a 72-year-old man who was admitted to our department with multiple nodules of hepatocellular carcinoma (HCC) in a cirrhotic liver because of HCV infection. Unlike most of the nodules, one in segment 2 (S2) showed hypoattenuation on computed tomography (CT) during hepatic arteriography (CTA), and hyperattenuation on CT during arterial portography (CTAP). Fine needle aspiration biopsy of the nodule established the diagnosis of hepatic adenomatous hyperplasia. Why the S2 nodule showed hyperattenuation on CTAP is not clear. Two possibilities are considered: i) greater portal blood flow into the nodule than into the surrounding cirrhotic parenchyma, ii) existence of a period during the course of hepatocarcinogenesis when the portal blood flow into the nodule is higher in density on CTAP.