title: Retrospective analysis of ploidy in primary osseous and extraosseous Ewing family tumors in children.
abstract: OBJECTIVE
  To retrospectively study the DNA content in a series of childhood Ewing Family Tumors (EFT), and to investigate its prognostic value.
  
  
  METHODS
  The study was performed on a series of 27 EFTs (osseous Ewing's sarcoma, 18 cases; extraosseous Ewing's sarcoma, 2; peripheral neuroepithelioma, 4; Askin Rosai tumors, 3). Ploidy was investigated using both flow cytometry (FCM) and image cytometry (ICM) on tumor cell suspensions from formalin-fixed paraffin-embedded specimens or fresh frozen tissue obtained from the primary tumor at diagnosis.
  
  
  RESULTS
  Ploidy was evaluable by FCM in all cases, and by ICM in 23/27. When fresh frozen tissue and paraffin-embedded samples from the same tumor were available for analysis, they yielded equal results. The rate of agreement between FCM and ICM was 82%. The majority of cases were diploid, and in the present series aneuploidy seemed to be associated with a poor outcome.
  
  
  CONCLUSIONS
  These results suggest that aneuploidy could be an indicator of a bad prognosis in EFT; however, the small number of cases precludes any conclusion of statistical value. Larger retrospective studies on ploidy using archival material could be performed and their reliability is supported by the concordance of results from fresh and formalin-fixed tissue.
authors.affiliation: Division of Pediatric Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milano, Italy. perotti@istitutotumori.mi.it
authors.forename: D
authors.initials: D
authors.lastname: Perotti
authors.forename: V
authors.initials: V
authors.lastname: Corletto
authors.forename: R
authors.initials: R
authors.lastname: Giardini
authors.forename: A
authors.initials: A
authors.lastname: Parafioriti
authors.forename: F
authors.initials: F
authors.lastname: Fossati-Bellani
authors.forename: R
authors.initials: R
authors.lastname: Luksch
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D019044:Image Cytometry; D007223:Infant; D008297:Male; D011003:Ploidies; D011379:Prognosis; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000235:genetics* / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm