Primary Ewing's sarcoma/primitive neuroectodermal tumor of the kidney and its clinical features

INTRODUCTION: Ewing sarcoma family tumor is a malignant tumor that is primarily of bone origin; it rarely occurs in the kidney. CASE PRESENTATION: A 22‐year‐old woman presented with hematuria. Computed tomography revealed a 6 × 6‐cm mass in the lower pole of the right kidney with invasion into the right renal vein. A right laparoscopic radical nephrectomy was performed. The tumor was completely encapsulated. Based on the small‐round‐cell histology, diffusely CD99‐positive tumor cells, and EWS (ex7)–FLi1 (ex6) fusion gene break point transcript, we diagnosed Ewing sarcoma/primitive neuroectodermal tumor of the kidney. After surgery, eight cycles of adjuvant chemotherapy including vincristine, doxorubicin (Adriamycin®), cyclophosphamide, ifosfamide, and etoposide were given. No evidence of recurrence has been observed 13 months from diagnosis. CONCLUSION: This was a rare Ewing sarcoma family tumor in the kidney of a young female with no remarkable family medical history.