Primary renal Ewing Sarcoma masquerading as Wilms in an adolescent female

Primary renal Ewing's sarcoma (ES) of the kidney represents a rare oncologic entity belonging to the collection of small round cell tumors, which typically feature osseous presentations. Renal ES is an aggressive disease entity with high metastatic potential, either at time of presentation or following initial extirpative therapy. Herein, we report the case of a 14-year-old female who initially presented with intermittent gross painless hematuria and a large left renal mass identified on ultrasound and confirmed on follow up MRI. Following partial nephrectomy (PN), patient was diagnosed with primary renal ES and subsequently underwent completion nephrectomy and chemotherapy.