Double cancer of primary hepatic angiosarcoma and hepatocellular carcinoma treated with atezolizumab plus bevacizumab.

AIM: Primary hepatic angiosarcoma (PHA) is extremely rare, and its imaging findings are similar to those of other liver tumors including hepatocellular carcinoma (HCC). Here, we report a case of hepatitis C virus (HCV)-related HCC followed by PHA that showed remarkable clinical response to atezolizumab plus bevacizumab (Atezo/Bev) therapy. CASE PRESENTATION: A 78-year-old man with recurrent HCC had a liver tumor with lymphadenopathy. Although considered as HCC recurrence, microscopic examination of the resected liver and lymph node showed PHA. Three months later, a solitary lung nodule was newly detected and subsequently resected. The pathological diagnosis was poorly differentiated HCC. Therefore, the patient was finally diagnosed with double cancer of PHA and HCC. Thereafter, he developed a new liver tumor with lymphadenopathy and received Atezo/Bev therapy. Liver tumor biopsy was carried out before the treatment. The pathological diagnosis was angiosarcoma. The patient showed a partial response after two courses of Atezo/Bev therapy. CONCLUSION: To our best knowledge, this report is the first case to present HCV-related HCC followed by PHA and to show that Atezo/Bev therapy is beneficial for PHA.