title: MDM2 copy numbers in well-differentiated and dedifferentiated liposarcoma: characterizing progression to high-grade tumors.
abstract: OBJECTIVE
  MDM2 gene amplification is associated with well-differentiated (WDL) and dedifferentiated liposarcomas (DDL). Using fluorescent in situ hybridization (FISH), we sought to characterize various patterns of MDM2 amplification among the morphologic spectrum of liposarcoma.
  
  
  METHODS
  Forty-six cases of liposarcoma in various sites were examined and included 22 WDLs, 14 DLLs, and 10 negative control subjects.
  
  
  RESULTS
  The MDM2 amplification ratio (MDM2/CEP12) was lower in WDL (10.2) compared with DDL (18.3) cases (P = .0000002). An amplification ratio of 16 showed optimal sensitivity (0.86) and specificity (0.96) as a cutoff point for progression to DDL. Borderline areas, defined as tumors with increased cellularity and atypia but with preserved lipomatous differentiation, showed a significantly higher MDM2 ratio (17.5; P = .0007) compared with WDL. Central (retroperitoneal and intra-abdominal) tumors also showed a significantly higher MDM2 ratio than peripheral ones (P = .02).
  
  
  CONCLUSIONS
  Differences in MDM2 amplification profiles among liposarcomas could help further define and predict progression to high-grade neoplasia.
authors: Dept of Pathology, Wake Forest Baptist Health, Medical Center Blvd, Winston-Salem, NC 27157; sqasem@wakehealth.edu.
authors: Patrick L
authors: PL
authors: Ware
authors: Anthony N
authors: AN
authors: Snow
authors: Maya
authors: M
authors: Gvalani
authors: Mark J
authors: MJ
authors: Pettenati
authors: Shadi A
authors: SA
authors: Qasem
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics*; D056915:DNA Copy Number Variations; D018450:Disease Progression; D005260:Female; D006801:Humans; D008080:Liposarcoma / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2
keywords: Dedifferentiated liposarcoma; FISH; MDM2; Well-differentiated liposarcoma