Primary Ewing’s sarcoma of the kidney: a rare masquerader of renal cell carcinoma on imaging

Abstract

Background: The Ewing sarcoma family of tumors comprises a group of high-grade small round cell tumors, including Ewing sarcoma of bone, extra-skeletal Ewing sarcoma, peripheral primitive neuro-ectodermal tumor (PNET), and Askin tumor (thoraco-pulmonary PNET). They are more prevalent in young children and adolescents. Ewing's Sarcoma is an aggressive tumor majorly described in bones. Primary renal Ewing's sarcoma is an extremely rare entity, characterized by a very aggressive course, with very few reported cases in the literature. Case presentation: We present an 18-year-old girl who presented with sudden onset left flank pain and hematuria. The patient had histopathology-proven primary renal Ewing's sarcoma, which was initially misdiagnosed as renal cell carcinoma on imaging. Conclusions: Owing to its non-specific radiological appearance, a high index of suspicion and a systematic approach is essential for detection of renal Ewing’s Sarcoma.