<prompt> Ewings sarcoma arises fromG cellsTotipotent cellsNeuroectodermal cellsNeurons  <response>: Refer Robbins page no 8e 1232 Ewing sarcoma is a malignant bone tumor characterized by primitive round cells without obvious differentiation. Recently, Ewing sarcoma and primitive neuroectodermal tumor PNET have been unified into a single category: the Ewing sarcoma family tumors ESFT based on shared clinical, morphologic, biochemical and molecular features discussed later. Although PNET demonstrates more neu- roectodermal differentiation than Ewing sarcoma, the dis- tinction is not clinically significant 