A Rare Presentation of Ewing's Sarcoma Presenting in the Third Metatarsal.

Ewing's Sarcoma family of tumors are rare, malignant round cell tumors arising from undifferentiated mesenchymal cells. This aggressive neoplastic disease has a quick metastatic onset often resulting in a poor prognosis. In this case study we present a 21-year-old female diagnosed with Ewing's sarcoma of the third metatarsal bone. She initially presented in the emergency room with a 2-day onset of right foot pain following a minor injury. Radiographs taken in the emergency room revealed a cystic lesion in the third metatarsal. The patient presented to the author's clinic and following evaluation, surgical excision and curettage of the bone cyst was performed supplemented with allogenic bone graft. Due to a high clinical suspicion of malignancy, intraoperative culture and biopsy of the third metatarsal were sent to pathology and microbiology. Following evaluation of the bone biopsy with immunohistochemical staining as well as fluorescent in-situ hybridization studies, a diagnosis was made for Ewing's Sarcoma. This case report serves to display the significance of a timely workup as well as the importance of multiple pathology assessments to obtain a definitive pathologic diagnosis when clinical suspicion of malignancy is high.