title: Ewing sarcoma/primitive neuroectodermal tumor of the kidney: a case report. Diagnosed by immunohistochemistry and molecular analysis.
abstract: BACKGROUND
  Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET) of the kidney is a rare and aggressive tumor. It has a rapid clinical progression with early metastasis and death. Few cases with documented t(11;22) have been reported in the literature.
  
  
  METHODS
  We report a case of EWS/PNET of the kidney in a 26-year-old woman with widespread metastasis at initial presentation. The tumor cells showed strong expression for CD99 and FLI-1 monoclonal antibodies and polyclonal antibodies and were negative for WT1 and numerous other markers. The diagnosis was subsequently confirmed by demonstrating t(11;22)(q24;q12) using cytogenetic karyotyping and fluorescence in situ hybridization.
  
  
  CONCLUSIONS
  Due to the different prognosis and management between EWS/PNET and other primary renal neoplasms with similar morphology, a histopathologic diagnosis with extreme accuracy should be made. Cytogenetic analysis is an important supportive tool to immunohistochemistry in making the final diagnosis.
authors.affiliation: Department of Surgical Pathology and Laboratory Medicine, Buffalo General Hospital, Buffalo, NY 14263, USA.
authors.forename: Rakhee
authors.initials: R
authors.lastname: Saxena
authors.forename: Sheila
authors.initials: S
authors.lastname: Sait
authors.forename: Paulette
authors.initials: P
authors.lastname: Mhawech-Fauceglia
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism; D017024:Chemotherapy, Adjuvant; D002880:Chromosomes, Human, Pair 11; D002892:Chromosomes, Human, Pair 22; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007399:Interphase; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D009378:Neoplasms, Multiple Primary / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009392:Nephrectomy; D018242:Neuroectodermal Tumors, Primitive / Q000235:genetics / Q000378:metabolism / Q000556:secondary* / Q000628:therapy; D012512:Sarcoma, Ewing / Q000235:genetics / Q000378:metabolism / Q000556:secondary* / Q000628:therapy; D032681:Spectral Karyotyping; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor