We report on a 62-year-old man with chronic hepatitis C who developed rapidly growing hepatocellular carcinoma (HCC) after achieving sustained virological response at post-treatment week 24 (SVR 24) by direct-acting antiviral (DAA) treatment. In 2008, he failed interferon therapy at 56 years of age. He received daclatasvir plus asunaprevir for 24 weeks after confirmation of no liver tumor by abdominal ultrasonography. He had no advanced liver fibrosis. Three months after initiation of DAA treatment, a liver tumor measuring 6 mm in diameter was detected by ultrasonography and confirmed with magnetic resonance imaging. After achieving SVR 24, the tumor increased in size to 16 mm. Two months later, a tumor biopsy was performed, and histology revealed moderately to poorly differentiated HCC. The patient's alpha-fetoprotein (AFP) level was within the normal range, but the Lens culinaris agglutinin-reactive fraction of AFP level was elevated. The diameter of the tumor increased to 32 mm at 2 months after diagnosis. Lymph node metastasis in porta hepatis was found by positron emission tomography at 4 months after diagnosis. The patient received hepatic arterial infusion chemotherapy and radiation therapy, but died later. Careful monitoring is required during and after DAA treatment because HCC can grow fast even in patients with normal AFP and no advanced liver fibrosis.
Keywords: Chronic hepatitis C; Direct-acting antiviral treatment; Hepatocellular carcinoma; Rapidly growing; Sustained virological response.