Metastatic Ewing's sarcoma/PNET of kidney in 40 year old patient.

INTRODUCTION Primary renal Ewing sarcoma/PNET is an uncommon and very aggressive tumor. PRESENTATION OF CASE : We report the case of a young woman who underwent nephrectomy for a renal mass from unknown etiology. Histologic analysis found small tumoral cells in rosette formation, and immunohistochemical staining was positive for CD99, and focally positive for vimentin and Protein S-100. A post operative abdominal computed tomography (CT) scan revealed a residual renal processus with hepatic wounds and abdominal metastatic nodes. After 6 cycles of chemotherapy including Vincristine, Doxorubicin, Cyclophosphamide, the response was considered as good. DISCUSSION Ewing's sarcoma/PNET of kidney is a member of the family of small round cell tumors and it should be differentiated from Wilms tumor, neuroblastoma, rhabdomyosarcoma and lymphoblastic lymphoma. The principle management of its treatment have been extrapolated from the treatment of osseous Ewing sarcoma of bone. CONCLUSION Despite aggressive treatment, primary renal Ewing sarcoma/PNET has a poor prognosis. It requires a multidisciplinary approach including oncologists, urologists and radiation oncologists.