Histologically proven hepatocellular carcinoma associated with burned-out nonalcoholic steatohepatitis.

A 64-year-old Japanese man was referred to our hospital because of liver dysfunction. He had no history of alcohol intake, diabetes, hypertension, and hyperlipidemia, and he was negative for hepatitis viral markers. His body mass index was 30.6 kg/m2. Homeostasis model assessment of insulin resistance was 6.1. Liver biopsy revealed mild steatosis, moderate inflammation, ballooning degeneration, and portal fibrosis with bridging fibrosis; on the basis of these findings, the diagnosis of nonalcoholic steatohepatitis was made. Thereafter, follow-up imaging study was performed every 4 months. At 16 months after liver biopsy, a 3 cm hepatic lesion was detected in the right hepatic lobe by computed tomography. Dynamic computed tomography revealed a hepatic tumor enhanced with contrast medium during the arterial phase and a low-density area during the portal phase. Based on the diagnosis of hepatocellular carcinoma, partial hepatectomy was performed. Histological examination revealed a moderately differentiated hepatocellular carcinoma accompanied by liver cirrhosis without steatosis or ballooning degeneration. Finally, the patient was diagnosed with hepatocellular carcinoma arising from burned-out nonalcoholic steatohepatitis.