Two Rare Presentations And Treatments Of Ewing'S Sarcoma: A Need For A Standard Treatment Approach.

e21000 Background: We describe two Caucasian boys with rare presentations of non-metastatic Ewings sarcoma (ES) with atypical primary sites. One was extradural but FISH negative for 22q11.2. Another was intradural but extramedullary, and FISH positive. Literature search showed few publications which describe such cases, and there is currently no standard of care. Methods: MG, an 11 year old male, presented with a frontal skull mass, with an intracranial epidural extension of about 5 mm. Biopsy confirmed ES. MG was treated with Vincristine, Doxorubicin, and Cyclophosphamide, alternating with Ifosfamide and Etoposide every 2 weeks, for 6 weeks. He underwent tumor excision for local control with good response. Chemotherapy continued, completing 14 cycles total. He is in remission 15 months after completion. AH, a 13 year old male, presented with lower back pain and paraesthesias of feet. MRI revealed an intradural, extra-medullary L1-L3 mass. Intra-operatively, all visible tumor peeled off readily, except fo...