title: Ewing sarcoma of the kidney: case series and literature review of an often overlooked entity in the diagnosis of primary renal tumors.
abstract: OBJECTIVE
  To evaluate our own experience with primary Ewing sarcoma family tumors (ESFTs) of the kidney and to review cases of this in published reports.
  
  
  METHODS
  Institutional cases of renal ESFT were identified in our pathology database. The retrieved records were reviewed for relevant data. Published cases of renal ESFTs were identified from the National Library of Medicine Medline database and restricted to English language studies. The factors associated with initial surgical management (diagnostic biopsy vs surgical resection) were analyzed using chi-square analysis.
  
  
  RESULTS
  We diagnosed and treated 10 cases of renal ESFT from 2002 to 2011 and identified an additional 97 published cases describing this tumor. A review of these 107 cases revealed that renal ESFTs more often presented with distant metastases than did ESFTs of the bone or soft tissue. Moreover, patients rarely received preoperative (neoadjuvant) chemotherapy, the current standard of care for ESFT, often because of early total tumor resection without diagnostic biopsy. Younger patients and patients with distant metastases were more likely to undergo diagnostic biopsy as initial management (P <.0001), allowing for use of neoadjuvant chemotherapy.
  
  
  CONCLUSIONS
  ESFTs of the kidney should be considered in the differential diagnosis of renal masses. Preoperative biopsy should be considered to identify these tumors to allow for delivery of neoadjuvant chemotherapy.
authors: Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-5848, USA.
authors: R Grant
authors: RG
authors: Rowe
authors: Dafydd G
authors: DG
authors: Thomas
authors: Scott M
authors: SM
authors: Schuetze
authors: Khaled S
authors: KS
authors: Hafez
authors: Elizabeth R
authors: ER
authors: Lawlor
authors: Rashmi
authors: R
authors: Chugh
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001706:Biopsy; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009392:Nephrectomy; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult