The diagnosis of Ewing sarcoma requires the integration of the information generated from numerous techniques, some of them being very sophisticated. However, the first steps of the diagnostic process are crucial to achieve the maximum possible diagnostic performance. In this chapter we will review how to handle the diagnostic specimen from its collection, how to prepare it for diagnosis, how to make a complete pathology report, and provide guidance for the reasonable use of immunohistochemical techniques in this malignancy.
Keywords: Decalcification; Diagnostic report; Differential diagnosis; Ewing sarcoma; Immunohistochemistry; Neoadjuvant therapy; Sarcoma.