title: Primary renal Ewing's sarcoma.
abstract: OBJECTIVE
  To report two new cases of Ewing's sarcoma/primitive neuroectodermal tumor of the kidney, one of  them with tumor thrombus in cava.
  
  
  METHODS
  Characterization of two new cases and literature review by PubMed search.
  
  
  RESULTS
  We report the cases of two men diagnosed with primary renal Ewing's sarcoma, who have been treated  with nephrectomy and adjuvant chemotherapy, being in complete remission to date.
  
  
  CONCLUSIONS
  Ewing's sarcoma / primitive neuroectodermal tumor of the kidney is a rare condition that mainly  affects young adults. The natural history of these tumors is the evolution towards metastatic disease and death.  Treatment is multimodal, combining surgery and chemotherapy. The role of radiotherapy is not well established.
authors.affiliation: Urology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain. adrhusillos@hotmail.com
authors.forename: Adrián Husillos
authors.initials: AH
authors.lastname: Alonso
authors.forename: Mercedes Moralejo
authors.initials: MM
authors.lastname: Gárate
authors.forename: Felipe Herranz
authors.initials: FH
authors.lastname: Amo
authors.forename: Ignacio Moncada
authors.initials: IM
authors.lastname: Iribarren
authors.forename: Roberto Molina
authors.initials: RM
authors.lastname: Escudero
authors.forename: Javier Piñero
authors.initials: JP
authors.lastname: Sánchez
authors.forename: Juan Tabares
authors.initials: JT
authors.lastname: Jiménez
authors.forename: Carlos Hernández
authors.initials: CH
authors.lastname: Fernández
mesh_terms: D000328:Adult; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D006801:Humans; D007668:Kidney / Q000473:pathology; D007680:Kidney Neoplasms / Q000473:pathology / Q000628:therapy*; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D009392:Nephrectomy; D012512:Sarcoma, Ewing / Q000473:pathology / Q000628:therapy*; D013927:Thrombosis / Q000473:pathology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014682:Vena Cava, Inferior / Q000473:pathology; D055815:Young Adult