Extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor of the mediastinum: Significant response to chemoradiotherapy.

Primary mediastinal extraskeletal Ewing's sarcoma (EES) is quite rare. To the best of our knowledge, only five cases have been reported. Given the paucity of data, there is consequently no optimal treatment strategy available. The current study presents the case of a 51-year-old female with unresectable EES of the posterior mediastinum. Chemoradiotherapy achieved near complete remission without severe side-effects. The literature associated with EES is also reviewed. The present case highlights the possibility of the diagnosis of EES for a mediastinal mass. Chemoradiotherapy may be a good option for unresectable cases. In the future, large-scale collaborative clinical trials should be initiated to provide an improved understanding of the characteristics of EES and the best treatment strategy.