The Successful Treatment of Metastatic Extraosseous Ewing Sarcoma with Pazopanib

The clinical efficacy and outcomes of pazopanib treatment for metastatic extraosseous Ewing sarcoma remain unclear. We herein report a case of heavily pre-treated metastatic extraosseous Ewing sarcoma in which pazopanib treatment achieved a significant improvement. A 17-year-old girl was referred to our hospital due to metastatic extraosseous Ewing sarcoma. The initial cytotoxic chemotherapy was temporarily effective, however, her disease eventually progressed, and she was subsequently treated with pazopanib. The recurrent tumor showed a marked response to pazopanib therapy; the therapeutic effect has lasted for more than 26 months. The present case suggests that pazopanib may be a therapeutic option for extraosseous Ewing sarcoma.