title: Differentiation of myxoid liposarcoma by magnetic resonance imaging: a histopathologic correlation.
abstract: BACKGROUND
  Myxoid liposarcomas represent a heterogeneous group of soft tissue tumors in which prognosis is dependent on differentiation.
  
  
  OBJECTIVE
  To identify magnetic resonance imaging (MRI) criteria to distinguish low-grade from high-grade myxoid liposarcomas.
  
  
  METHODS
  MR images of 30 histologically proven myxoid liposarcomas were retrospectively reviewed. Tumors were evaluated according to size, localization, tumor border, and structure as well as tumor composition. These imaging criteria were correlated with histopathological findings.
  
  
  RESULTS
  Nineteen myxoid liposarcomas were histologically classified as low-grade myxoid liposarcomas, whereas 11 were considered high-grade myxoid liposarcomas. Mean tumor volume of low-grade myxoid liposarcomas (710.1 ± 960.1 ccm) was significantly smaller as compared to high-grade myxoid liposarcomas (2737.0 ± 3423.7 ccm; P = 0.04). In addition to necrotic areas, three tumor components - fatty, myxoid, as well as contrast-enhancing non-fatty, non-myxoid - could be identified. The mean fraction of fatty tumor areas in low-grade myxoid liposarcomas was 10 ± 11% as compared to 6 ± 4% for high-grade myxoid liposarcomas (P = 0.66). Myxoid components accounted for 88 ± 16% in low-grade myxoid liposarcomas, but only for 45 ± 25% in high-grade myxoid liposarcomas (P < 0.0001). The non-fatty, non-myxoid tumor fraction was significantly higher in high-grade myxoid liposarcomas (50 ± 25%) as compared to low-grade myxoid liposarcomas (2 ± 9%; P < 0.0001). A proportion of > 5% of this tumor fraction was found to be a precise unique predictor for high-grade myxoid liposarcomas with a sensitivity of 100% and a specificity of 95%.
  
  
  CONCLUSIONS
  Tumor components with contrast-enhancing non-fatty, non-myxoid imaging features were predominantly found in high-grade myxoid liposarcomas, which may histologically resemble round cell clusters.
authors.affiliation: Department of Radiology and Nuclear Medicine, Otto-von-Guericke University, Magdeburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Löwenthal
authors.affiliation: Department of Radiology, Hospital Reinbek, Reinbek, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Zeile
authors.affiliation: Dr. Senckenbergisches Institute for Pathology, University Hospital Frankfurt, Frankfurt, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Niederhagen
authors.affiliation: Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, Helios Klinikum Berlin-Buch, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Fehlberg
authors.affiliation: Department of Radiology, Charite Universitätsmedizin, Berlin, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Schnapauff
authors.affiliation: Department of Hematology, Oncology and Palliative Care, Sarcoma Center Berlin-Brandenburg, Helios Klinikum Bad Saarow, Bad Saarow, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Pink
authors.affiliation: Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, Helios Klinikum Berlin-Buch, Berlin, Germany.
authors.forename: P U
authors.initials: PU
authors.lastname: Tunn
authors.affiliation: Department of Hematology, Oncology and Palliative Care, Sarcoma Center Berlin-Brandenburg, Helios Klinikum Bad Saarow, Bad Saarow, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Reichardt
authors.affiliation: Department of Radiology, Charite Universitätsmedizin, Berlin, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hamm
authors.affiliation: Department of Radiology and Nuclear Medicine, Otto-von-Guericke University, Magdeburg, Germany Department of Radiology, Charite Universitätsmedizin, Berlin, Germany oliver.dudeck@med.ovgu.de.
authors.forename: O
authors.initials: O
authors.lastname: Dudeck
mesh_terms: D003287:Contrast Media; D003937:Diagnosis, Differential; D019786:Gadolinium DTPA; D006615:Hip / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D018208:Liposarcoma, Myxoid / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D010388:Pelvis / Q000473:pathology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012782:Shoulder / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000473:pathology*; D013848:Thigh / Q000473:pathology; D047368:Tumor Burden
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Criteria; grading; magnetic resonance imaging; myxoid liposarcoma; round cell component