[Conversion Surgery Following Atezolizumab plus Bevacizumab Therapy for Massive Hepatocellular Carcinoma-A Case Report].

A 72-year-old man visited our hospital for evaluation of a liver tumor documented on abdominal ultrasonography. Computed tomography revealed a liver tumor measuring 13 cm and a tumor thrombus in the right branch of the portal vein. The patient was diagnosed with hepatocellular carcinoma(T4N0M0, Stage ⅢB, Union for International Cancer Control 8th edition), which was categorized as an advanced-stage malignancy based on the Barcelona Clinic Liver Cancer staging system, and the patient received atezolizumab and bevacizumab therapy. The tumor thrombus disappeared completely after 2 courses of chemotherapy, and the liver tumor shrank to 8 cm following 11 courses of chemotherapy. We performed right hemihepatectomy and R0 resection after 19 courses of chemotherapy, and the patient was recurrence-free at 6-month follow-up. This report highlights the usefulness of multimodal therapy for locally advanced hepatocellular carcinoma.