Retroperitoneal blue cell round tumor (Ewing sarcoma in a 35 years old male)- case report.

Introduction: Ewing sarcoma is a highly aggressive tumor. It's common presentation is primary bone tumor, but very rarely as soft tissue sarcoma both of which are under the spectrum of Ewing sarcoma family of tumors (EFT).

Case Presentation: A 35 years old male who presented with advanced locally spreading tumor. He was diagnosed after presenting with epigastric pain and melena, CT abdomen revealed the retroperitoneal mass. CT guided core biopsy taken and was diagnosed as Ewing sarcoma. The patient presented with mass already grown so he was not a surgical candidate. Patient was managed symptomatically till he was sent for palliative care in a Sarcoma centre in Jordon and passed away on October 2021.

Discussion: Ewing Sarcoma family of tumors are group of small round blue cell tumors that are histogenetically related. The better known is Ewing 's sarcoma (EWS). It is a malignant small blue round cell tumor with variable degree of neuroectodermal differentiation. Retroperitoneal tumor are mostly malignant and accounts for one third of soft tissue sarcoma. They usually present as large masses at the time of the diagnosis. So they do not produce symptoms until they grow large enough to compress or invade contagious structures.

Conclusion: ES-EWS is an aggressive tumor with high incidence of local recurrence and distant metastasis that's why is was given its poor prognosis characteristic. Multimodality treatment including surgical resection, chemotherapy and High dose radiotherapy will help in better survival rate.