title: MYCN gene amplification in rhabdomyosarcoma.
abstract: BACKGROUND
  Amplification of the MYCN oncogene, formerly known as N-myc, has been seen in several malignant tumors, particularly neuroblastoma, where its association with a poor clinical outcome is the clearest example of a clinically relevant oncogene mutation in any human cancer.
  
  
  METHODS
  The incidence and clinical significance of MYCN amplification in rhabdomyosarcoma (RMS) was assessed by Southern blot analysis in this retrospective study of seven alveolar RMS and six embryonal RMS.
  
  
  RESULTS
  MYCN amplification (4- to 13-fold) was present in three of seven alveolar RMS (42.9%) but in none of the embryonal RMS. There was no significant difference between the clinical behavior of the MYCN-amplified and unamplified tumors, and no correlation was found with the light microscopic appearances of the tumors or with desmin immunoreactivity.
  
  
  CONCLUSIONS
  The findings are compatible with previous studies that demonstrated cytogenetic evidence of gene amplification in RMS, and help to clarify conflicting reports in the literature about MYCN amplification in alveolar and embryonal RMS. The results raise the possibility of important biologic differences between these subtypes of RMS, differences that warrant further investigation.
authors.affiliation: Department of Pathology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Driman
authors.forename: P S
authors.initials: PS
authors.lastname: Thorner
authors.forename: M L
authors.initials: ML
authors.lastname: Greenberg
authors.forename: S
authors.initials: S
authors.lastname: Chilton-MacNeill
authors.forename: J
authors.initials: J
authors.lastname: Squire
mesh_terms: D015139:Blotting, Southern; D002648:Child; D002675:Child, Preschool; D005784:Gene Amplification; D016259:Genes, myc; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D008853:Microscopy; D012189:Retrospective Studies; D018232:Rhabdomyosarcoma, Alveolar / Q000235:genetics* / Q000473:pathology; D018233:Rhabdomyosarcoma, Embryonal / Q000235:genetics* / Q000473:pathology