Extra-skeletal Ewing's sarcoma of the leg with multiple skeletal and pulmonary metastases: A rare pediatric case report.

Being the second most common malignant bone tumor in children and young adults, Ewing's sarcoma can also occur as a primary soft-tissue tumor called extraosseous or extra-skeletal Ewing's sarcoma. It is a rare entity, especially in the pediatric population. We report the case of an adolescent who presented to our department for lower extremity magnetic resonance imaging to explore leg swelling. It revealed an extra-skeletal Ewing's sarcoma with multiple bone metastases. By reporting this case, we also review the literature on this rare abnormality.