title: Benign and malignant soft tissue mass: magnetic resonance imaging criteria for discrimination.
abstract: OBJECTIVE
  Determine MRI features to differentiate between benign and malignant lesions.
  
  
  METHODS
  The Magnetic resonance imaging (MRI) taken in the 5-year period (2003-2007) of 85 patients with benign and malignant soft tissue masses were analyzed. The criteria for discrimination were based on size, origin, signal homogeneity on T1- and T2-weighted, perilesional edema or invasion, hemorrhage, necrosis, and bone and neurovascular involvements.
  
  
  RESULTS
  There were 50 benign and 35 malignant lesions. Eighty-two lesions had histologic proof while three lesions had MRI characteristics of benign lipoma.
  
  
  CONCLUSIONS
  No single MRI feature was diagnostic for any soft tissue tumors in the present study. However, three individual MRI features were statistically significant for differentiation between benign and malignant soft tissue masses (p < 0.05). The features that favor malignancy were heterogeneous signal on T2-weighted, perilesional edema or invasion, and necrosis in the masses.
authors.affiliation: Department of Radiology, Rajavithi Hospital, College of Medicine, Rangsit University, Bangkok, Thailand.
authors.forename: Siripan
authors.initials: S
authors.lastname: Kalayanarooj
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008067:Lipoma / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000473:pathology*; D012307:Risk Factors; D012983:Soft Tissue Neoplasms / Q000473:pathology* / Q000503:physiopathology