title: Cytologic diagnosis of Ewing sarcoma/peripheral neuroectodermal tumor with paired prospective molecular genetic analysis.
abstract: BACKGROUND
  Ewing sarcoma/peripheral neuroectodermal tumor (EWS/PNET), since its characterization immunophenotypically and cytogenetically, has emerged as one of most common sarcomas of childhood. Currently, it is recognized that EWS/PNET can occur in any number of extraosseous sites and is one of several distinctive tumor types with an EWS translocation. In the past, the pathologic diagnosis of EWS/PNET relied on an open biopsy with the application of various ancillary studies, ranging from periodic acid-Schiff stain to molecular testing, but the tumor increasingly is diagnosed on the basis of cytologic specimens alone.
  
  
  METHODS
  The authors report 3 cases of EWS/PNET in patients aged 11 years to 53 years. These 3 patients had tumors that involved the parotid gland, cervical soft tissue, and pelvis, and were diagnosed by cytologic evaluation of fine-needle aspiration (FNA) biopsy material alone. The FNA materials also were evaluated prospectively by fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction.
  
  
  RESULTS
  The results emphasized the diagnostic utility of FNA biopsy material for morphologic and molecular analysis without compromising conventional cytologic and immunocytochemical analysis, and that prospective molecular testing of FNA specimens has utility in routine practice although it is subject to many of the same limitations that impact molecular analysis when applied to conventional tissue biopsy specimens.
  
  
  CONCLUSIONS
  The current results demonstrated that molecular genetic techniques can provide clinically useful ancillary information for FNA specimens when cytologic features and/or immunophenotype are equivocal on the basis of limited sampling or secondary changes, such as hemorrhage and/or necrosis.
authors.affiliation: Lauren V Ackerman Laboratory of Surgical Pathology, Barnes-Jewish and Saint Louis Children's Hospitals, Washington University Medical Center, St Louis, MO 63110-1093, USA.
authors.forename: Souzan
authors.initials: S
authors.lastname: Sanati
authors.forename: Danielle W
authors.initials: DW
authors.lastname: Lu
authors.forename: Edith
authors.initials: E
authors.lastname: Schmidt
authors.forename: Arie
authors.initials: A
authors.lastname: Perry
authors.forename: Louis P
authors.initials: LP
authors.lastname: Dehner
authors.forename: John D
authors.initials: JD
authors.lastname: Pfeifer
mesh_terms: D000071443:12E7 Antigen; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D002648:Child; D003581:Cytodiagnosis / Q000379:methods; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000175:diagnosis* / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D051789:Proto-Oncogene Protein c-fli-1 / Q000235:genetics; D034802:RNA-Binding Protein EWS; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; C450460:EWS-ERG fusion protein, human; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors