title: DNA ploidy and chromosome (FISH) pattern analysis of peripheral nerve sheath tumors.
abstract: METHODS
  44 peripheral nerve sheath tumors (PNST) (27 schwannomas, 9 neurofibromas and 8 malignant peripheral nerve sheath tumors (MPNST)) were analyzed to determine DNA ploidy pattern and to clarify the conflicting data in the literature concerning this topic (whether benign PNSTs are aneuploid or not). For further insight we analyzed 6 schwannomas, one atypical neurofibroma and five MPNSTs by fluorescence in situ hybridization (FISH) technique using centromeric chromosome probes (7, 17 and 18) and automatic image analysis station, Metafer 4.
  
  
  RESULTS
  Benign schwannomas (including the problematic variants as ancient, cellular, neuroblastoma like and multiplex schwannomas) could be characterized by euploid-polyploidisation and by their 4c peak height value which was usually more than 10% of total cell number measured. These characters were not found among neurofibromas and MPNST-s. FISH analysis revealed and confirmed that the 'normal' euploid-polyploid cells are mainly eusomic-polysomic containing two, four, eight or sixteen signals for each chromosomes examined, but in a small proportion aneusomy was found among tumor cells of benign schwannomas (average: 2.58; range 1.33-3.44). In contrast, the atypical neurofibroma displayed marked aneusomy (18.44%) but it contained normal eusomic and polysomic cells too. Two diploid MPNSTs proved to be clearly aneusomic with trisomy of chromosome 17 and monosomy of chromosome 18.
  
  
  CONCLUSIONS
  All these data suggest that ploidy pattern determination combined with FISH analysis may be a very useful supplementary tool for making a right diagnosis (to differentiate benign versus malignant schwannomas in problematic variants) and to understand better the malignant transformation in PNSTs.
authors.affiliation: Semmelweis University, Institute of Morphology and Physiology, Szentkirályi 14, Budapest 1088, Hungary.
authors.forename: Anett
authors.initials: A
authors.lastname: Hruska
authors.forename: Reinhard
authors.initials: R
authors.lastname: Bollmann
authors.forename: Rita Beáta
authors.initials: RB
authors.lastname: Kovács
authors.forename: Magdolna
authors.initials: M
authors.lastname: Bollmann
authors.forename: Miklós
authors.initials: M
authors.lastname: Bodó
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Sápi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D045744:Cell Line, Tumor; D003582:Cytogenetics; D004247:DNA / Q000378:metabolism; D004273:DNA, Neoplasm; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D018317:Nerve Sheath Neoplasms / Q000235:genetics*; D009442:Neurilemmoma / Q000235:genetics*; D009447:Neuroblastoma / Q000378:metabolism; D011003:Ploidies; D013997:Time Factors
chemical_list: D004273:DNA, Neoplasm; D004247:DNA