Primary Ewing sarcoma of the kidney: a symptomatic presentation and review of the literature.

The objective of this review is to discuss the unique nature of primary renal Ewing sarcoma, including incidence, presentation and management. We also report on a common pattern of presentation, consisting of acute flank pain mimicking a renal stone colic, with or without hydronephrosis, and a renal mass discovered during imaging studies of renal Ewing sarcoma. We present our case of renal Ewing sarcoma along with imaging and pathological analysis. We also performed a retrospective review of all cases of renal Ewing sarcoma using PubMed. A total of 48 cases of renal EWS sarcoma have been reported and analyzed in this review. A mean age of 30.4 years was found along with a 61% male predominance. The mean survival was 26.14 months with a lower median survival in patients with advanced metastatic disease. Primary Ewing sarcoma of the kidney is rare. The diagnosis of primary renal EWS can be difficult and is based on a combination of electron microscopy, immunohistochemistry, chromosomal analysis, fluorescence in situ hybridization (FISH) and light microscopy.