Complete pathological response of pelvic Ewing sarcoma in adult female-a case report

Background: Ewing sarcoma is a highly aggressive tumor that typically affects children and young adolescents. Around 87% of Ewing sarcoma are osseous tumors. However, there is a portion of these tumors that arise from soft tissue, otherwise known as extraosseous Ewing sarcoma (EES). Commonly affected places include the bones of the leg, pelvis, upper extremities axial skeleton, and ribs. Pelvic Ewing sarcoma is unique in that patients tend to experience higher rates of relapse, are more complex to surgically remove, and have lower disease -free and overall survival rates when compared to Ewing sarcoma in other locations. Ewing sarcoma tends to be a disease of childhood that is rarely seen in adults. When adults are impacted, survival rates are significantly lower than the survival rates of children. This case describes a complete pathologic response obtained after neoadjuvant chemotherapy in an adult female with pelvic Ewing sarcoma. Case Description: The case presented is a 41 -year -old non -Hispanic White female with no significant past medical history that presented with persistent right flank pain, whose intraoperative biopsy returned as stage III pelvic Ewing sarcoma and underwent chemotherapy treatment with vincristine, adriamycin, clophosphamide alternating with ifosfamide and etoposide (VAC-IE) followed by radical resection, with the unique finding of a complete pathological response to therapy. Conclusions: Final pathology demonstrated a complete pathologic response, a rare outcome in this aggressive histology. In clinical practice, there has been debate over the ability of adults to tolerate VAC-IE treatment without significant toxicity or end organ damage. This case highlights an example of a successful outcome under this treatment with acceptable tolerability and response, and thus provides support for further research into the use of VAC-IE as standard treatment for Ewing sarcoma in adults. This case also gives support to the consideration of surgical resection in patients whose tumor have significant response to chemotherapy.