title: Metastatic Ewing's sarcoma/PNET of kidney in 40 year old patient.
abstract: BACKGROUND
  Primary renal Ewing sarcoma/PNET is an uncommon and very aggressive tumor.
  
  
  METHODS
  : 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.
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  Despite aggressive treatment, primary renal Ewing sarcoma/PNET has a poor prognosis. It requires a multidisciplinary approach including oncologists, urologists and radiation oncologists.
authors.affiliation: Department of Medical Oncology, National Institute of Oncology, Rabat 10100, Morocco.
authors.forename: Mouna
authors.initials: M
authors.lastname: Kairouani
authors.forename: Maha
authors.initials: M
authors.lastname: Mokrim
authors.forename: Nawfel
authors.initials: N
authors.lastname: Mellas
authors.forename: Basma
authors.initials: B
authors.lastname: Khennoussi
authors.forename: Hind El
authors.initials: HE
authors.lastname: M'rabti
authors.forename: Saber
authors.initials: S
authors.lastname: Boutayeb
authors.forename: Hassan
authors.initials: H
authors.lastname: Errihani