A 36-year-old woman was referred to our clinic with a 7-day history of epigastric discomfort. According to her treatment history, at the age of 25 years, she had undergone the Fontan procedure for severe pulmonary stenosis and double-outlet right ventricle. She had visited another hospital 3 years before with the same symptoms, and abdominal computed tomography (CT) was performed (Fig. 1A). She had no history of alcohol consumption. Although her physical examination results were unremarkable, the laboratory test results were as follows: alanine aminotransferase, 50 IU/L; alkaline phosphatase, 336 IU/L; gamma-glutamyl transferase, 204 IU/L; albumin, 3.43 g/dL; and international normalized ratio, 1.3. Laboratory tests for viral hepatitis were negative. Abdominal CT revealed variable-sized homogenous hypervascular masses in both hepatic lobes without significant abdominal lymphadenopathy (Fig. 1B). Compared with the previous abdominal CT, the number and size of the masses had increased. Upper endoscopy and colonoscopy performed to evaluate the possibility of metastatic cancer revealed normal results.