title: The value of magnetic resonance imaging in the differentiation between malignant peripheral nerve-sheath tumors and non-neurogenic malignant soft-tissue tumors.
abstract: OBJECTIVE
  To assess the sensitivity and specificity of MRI criteria in the differentiation between malignant peripheral nerve sheath tumors (MPNST) and non-neurogenic malignant soft-tissue tumors (MSTT).
  
  
  METHODS
  MRI examinations of 105 patients with pathologically proven malignant soft-tissue lesions (35 MPNST and 70 MSTT) were retrospectively reviewed, the reviewers being unaware of the pathological diagnosis. Using a standardized protocol, the tumors were evaluated for multiple parameters regarding morphology and appearance on different sequences before and after gadolinium contrast administration (location, distribution, delineation, homogeneity, size, shape, relationship to bone and neurovascular bundle, intralesional hemorrhage, necrosis, perilesional edema, lymphangitis and signal intensities). Results were compared using a chi-square or Fisher's exact test.
  
  
  RESULTS
  MRI findings suggestive of MPNST (p<0,05) were intermuscular distribution, location on the course of a large nerve, nodular morphology, and overall non-homogeneity on T1-weighted images, T2-weighted images and T1-weighted images after gadolinium contrast injection. MRI findings in favor of MSTT were intramuscular distribution, ill-delineated appearance of more than 20% of the lesion's circumference, and presence of intralesional blood vessels, perilesional edema and lymphangitis. There is no significant difference for degree and pattern of enhancement after gadolinium contrast injection, nor for presence of bone involvement or cystic or necrotic areas.
  
  
  CONCLUSIONS
  MRI provides several features that contribute to the differentiation between MPNST and non-neurogenic malignant soft-tissue tumors. MRI findings suggestive of MPNST should be helpful to pathologists in the strategy for further examination.
authors.affiliation: Department of Radiology, University Hospital of Antwerp, Wilrijkstraat 10, 2650, Edegem, Belgium. brunovanherendael@gmail.com
authors.forename: B H
authors.initials: BH
authors.lastname: Van Herendael
authors.forename: S R G
authors.initials: SR
authors.lastname: Heyman
authors.forename: F M
authors.initials: FM
authors.lastname: Vanhoenacker
authors.forename: G
authors.initials: G
authors.lastname: De Temmerman
authors.forename: J L
authors.initials: JL
authors.lastname: Bloem
authors.forename: P M
authors.initials: PM
authors.lastname: Parizel
authors.forename: A M
authors.initials: AM
authors.lastname: De Schepper
mesh_terms: D016009:Chi-Square Distribution; D003287:Contrast Media; D003937:Diagnosis, Differential; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018317:Nerve Sheath Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012983:Soft Tissue Neoplasms / Q000473:pathology*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA