Aggressive small round cell tumor affecting bone and soft tissue in children and young adults. Ewing’s sarcoma (ES) and peripheral primitive neuroectodermal tumor (pPNET), also called neuroepithelioma, are currently defined as biologically closely related tumors along a gradient of limited neuroglial differentiation. Askin tumor is the historical designation of Ewing’s sarcoma of the chest wall. Today, all these neoplasms are summarized as Ewing tumors (ET) or Ewing sarcoma family tumors (ESFT). Although first described in 1866 and 1890 by Lücke and Hildebrand, respectively, the disease carries the name of the American pathologist James Ewing who, in 1921, was the first to recognize the tumor as a separate entity, which he defined as diffuse endothelioma of the bone.
On the genetic level, Ewing sarcoma family tumors are defined by the consistent presence of a...