title: A re-evaluation of imaging criteria to assess aggressive masticator space tumors.
abstract: OBJECTIVE
  To evaluate the correlation between the gross imaging evidence of an aggressive masticator space (MS) tumor and the presence of such a MS malignancy.
  
  
  METHODS
  Thirty patients were identified retrospectively who had a malignancy that either arose in or metastasized to the MS, had pathologic verification of the diagnosis, and had magnetic resonance (MR) and/or computed tomographic (CT) images. Specifically evaluated was the presence or absence of gross imaging evidence of mandibular erosion and the integrity of the medial MS fascia as evaluated by a smooth margin between this fascia and the parapharyngeal space fat.
  
  
  RESULTS
  Of the 30 tumors, 28 were high-grade malignancies and 2 were histiocytoses. Of these, 5 had mandibular erosion and violation of the MS fascia, 19 had bone erosion with an intact fascia, 4 had neither bone erosion nor fascial violation (3 of these patients were under the age of 20 years), and 2 had fascial violation with no bone erosion.
  
  
  CONCLUSIONS
  In 76.7% of patients with a malignancy arising in the MS, on imaging the medial MS fascia was grossly intact. There were 4 patients with MS malignancy and neither violation of the medial MS fascia nor mandibular bone erosion. Thus, these imaging findings may not be good criteria to evaluate the presence of a high-grade MS malignancy, especially if the patient is under the age of 20 years, in which age group MS sarcomas are more likely to arise.
authors.affiliation: Department of Radiology, Mount Sinai Hospital, New York, NY 10029, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Som
authors.forename: H D
authors.initials: HD
authors.lastname: Curtin
authors.forename: A R
authors.initials: AR
authors.lastname: Silvers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005205:Fascia / Q000000981:diagnostic imaging / Q000473:pathology; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed