A rare case of Ewing's sarcoma of the kidney.

We report the case of a 15-year-old girl presenting with distended abdomen, left flank pain, and a history of weight loss. Computed tomography showed a large tumor involving the left kidney that was initially diagnosed as renal cell carcinoma. She underwent exploratory open laparotomy and left radical nephrectomy followed by chemotherapy and showed good response. Histology of the resected tumor revealed features of Ewing's sarcoma of the kidney which was confirmed by molecular studies. This disease is rare, particularly in the pediatric population, and this report will help better understand the potential disease course and response to treatment.