embryonal neoplasm Ewing sarcoma/peripheral primitive neuroectodermal tumor Ewing family of tumours MONDO:0021038 NCIT:C27291 Ewing's family of tumors MEDGEN:760735 Ewing's sarcoma/peripheral primitive neuroectodermal tumor tumours of Ewing's family UMLS:C3536893 Ewing sarcoma/peripheral primitive neuroectodermal tumor EFTs Ewing's family of tumours tumours of the Ewing's family tumors of the Ewing's family Ewing sarcoma family of tumors Ewing sarcoma family of tumours Ewing family of tumors Ewing sarcoma/peripheral PNET Ewing's sarcoma/peripheral primitive neuroectodermal tumour A spectrum of malignant tumors, affecting mostly males under age 20, characterized morphologically by the presence of small round cells. Ewing sarcoma and peripheral primitive neuroectodermal tumor represent the ends of a spectrum, with Ewing sarcoma lacking evidence of neural differentiation and the markers that characterize the peripheral primitive neuroectodermal tumor. Ewing sarcoma and peripheral primitive neuroectodermal tumor may share cytogenetic abnormalities, proto-oncogene expression, cell culture and immunohistochemical abnormalities. These tumors may occur in the soft tissues or the bones. Pain and the presence of a mass are the most common clinical symptoms. tumors of Ewing's family