Ewing Sarcoma Beyond the Bone A Rare Primary renal presentation care report

Background: Ewing sarcoma is a rare but aggressive malignant tumor that primarily affects adolescents and young adults. Although it typically arises in bone, in rare cases it may originate in parenchymal organs such as the kidney. Case Presentation: We present a 45-year-old woman with a history of breast carcinoma and a right renal mass. Imaging revealed a multicystic lesion with septations and nodular thickening. Histology and immunohistochemistry were consistent with extraskeletal Ewing sarcoma; FISH confirmed the characteristic rearrangement (t(11;22)(q24;q12)/EWSR1-ETS). The patient underwent nephrectomy followed by VDC/IE chemotherapy. Given her oncologic history and age, Li-Fraumeni syndrome was considered. Conclusions: This case highlights a rare primary renal localization of Ewing sarcoma and underscores the value of a multidisciplinary approach with molecular confirmation to secure diagnosis and guide therapy.