High-grade neuroendocrine carcinoma differs from usual neuroendocrine carcinoma, and its prognosis is dismal. In this case report, a case of high-grade neuroendocrine carcinoma that improved with bevacizumab plus modified FOLFOX6 as the fourth-line chemotherapy is presented. A 29-year-old male with a huge liver tumor was diagnosed with high-grade neuroendocrine carcinoma originating from the liver. Multiple liver and bone metastases were found one month after surgery. He was treated with three chemotherapy regimens used for the management of small-cell lung cancer with extensive disease. However, none of them could be maintained because of tumor progression. He was then treated with bevacizumab plus modified FOLFOX6 as the fourth-line regimen. Dramatic tumor shrinkage was obtained, and a partial response was achieved. This case suggests that high-grade neuroendocrine carcinoma can be treated with bevacizumab in combination with cytotoxic chemotherapy
