A 55-year-old man presented at our hospital emergency room with a single large hepatic mass found on an abdominal computed tomography (CT) scan obtained 10 days prior at another hospital for abdominal pain. At our hospital, he did not present with any symptoms, such as abdominal pain. His vital signs were stable and there were no specific abnormal findings on physical examination. He had been diagnosed with hepatitis B 20 years earlier but had taken no antiviral medication. He had consumed a bottle of alcohol once a week and half a pack of cigarettes for 20 years. Initial laboratory tests revealed a hemoglobin level of 13.4 g/dL, an albumin level of 4.5 g/dL, a total bilirubin level of 1.1 mg/dL, a prothrombin time international normalized ratio of 0.93, an aspartate aminotransferase (AST) level of 35 IU/L, and an alanine aminotransferase (ALT) level of 55 IU/L. His serum alpha-fetoprotein (AFP) level was 4.3 ng/mL and protein-induced vitamin K absence-II (PIVKA-II) level was 11,485 mAU/mL. Tests for hepatitis B surface antigen and hepatitis B surface antibody yielded positive and negative results, respectively. His hepatitis B virus DNA level was 36 IU/mL. The anti-hepatitis C virus test result was negative.

The abdominal CT scan (performed at another hospital) revealed a large single hepatic mass at segment 8. A suspected focal and hypoattenuated rupture site was noted on the surface of the mass. In addition, fluid (density of 40–50 Hounsfield units) had collected in the pelvic cavity, suggestive of a hemoperitoneum and indicating a relatively recent tumor rupture (Fig. 1). No extrahepatic metastases were found. Magnetic resonance imaging was also performed and confirmed the presence of a single 12-cm-wide HCC at segment 8 without vascular invasion (Fig. 2). There was no evidence of ongoing bleeding from the rupture site in these images.

The patient’s overall performance was good with an Eastern Cooperative Oncology Group score of 0, and his liver function was preserved with a Child-Pugh classification of A. The ruptured tumor was a single nodule without vascular invasion or extrahepatic spread. It was categorized as stage II using the modified International Union Against Cancer system, and intermediate stage using the Barcelona Clinic Liver Cancer (BCLC) system. Based on these results, we started treatment with TACE.

TACE was performed via super-selected feeder vessels using a 10-mL lipiodol and 50-mg doxorubicin mixture with small polyvinyl alcohol particles to enhance the ischemic effects. After the procedure, the patient developed fever and elevated AST/ALT level for 3 days as part of postembolization syndrome, which resolved with conservative management. Follow-up imaging was performed at one month after TACE, and there was no definite evidence of remnant or recurrent tumor with an AFP level of 4.0 ng/mL and a PIVKA-II level of 26 mAU/mL. However, the residual tumor was detected at the margin of the treated mass 5 months later and assessed for partial response according to the modified Response Evaluation Criteria in Solid Tumors criteria. Secondary TACE was performed for that lesion (Fig. 3), after which complete response was maintained. The level of AFP and PIVKA-II after secondary TACE were 3.4 ng/mL and 28 mAU/mL, respectively. We planned additional surgical resection after secondary TACE because surgery is the curative treatment for single nodule without any lymphovascular invasion and distant metastasis. In addition, the liver function of our patient was classified as Child-Pugh A and BCLC stage B, which was good enough to administer additional treatment. No new lesions or extrahepatic metastases were found for 16 months after the first TACE. Thus, the patient underwent radical right hemihepatectomy for curative treatment. A single yellow mass in the resected specimen proved to be an area of complete necrosis, with no cancer cells observed in the postoperative pathology examination (Fig. 4), indicating that cure had been achieved by TACE alone. One month after surgery, the serum level of AFP was 3.6 ng/mL, which did not represent much change; however, the level of PIVKA-II decreased to 10 mAU/mL. The hepatitis B virus DNA level had remained inactive at low levels until October 2017, and then increased to 297 IU/mL. The patient started taking entecavir after which the DNA level decreased to less than 15 IU/mL. The patient was followed up every 3–6 months without any tumor recurrence or metastasis for more than 3 years after resection.