title: Primary Extremity Liposarcoma: MRI Features, Histopathology, and Clinical Outcomes.
abstract: OBJECTIVE
  This study aimed to describe magnetic resonance imaging (MRI) features of extremity liposarcoma (LPS) subtypes, correlating with histopathology and clinical outcomes.
  
  
  METHODS
  In this retrospective study, we included 125 patients (80 men, 45 women; mean age, 53 years) with extremity LPS [23 atypical lipomatous tumor (ALT), 9 dedifferentiated (DDLPS), 70 myxoid (MLPS), 23 pleomorphic (PLPS)]. Pretreatment MRI of primary tumors in 56 patients (10 ALT, 4 DDLPS, 28 MLPS, 14 PLPS) was reviewed.
  
  
  RESULTS
  All subtypes were predominantly T1 isointense relative to skeletal muscle (DDLPS = 3/4, MLPS = 28/28, PLPS = 13/14) and T2 hyperintense (ALT = 10/10, DDLPS = 3/4, MLPS = 28/28, PLPS = 14/14) except for ALT which were T1 hyperintense (8/10). Within MLPS, high grade was associated with unencapsulated margins (P = 0.05) and solid, nodular enhancement (P < 0.0001). Peritumoral edema (P = 0.03) and T2 heterogeneity (P = 0.05) predicted pulmonary (rather than extrapulmonary) metastases in MLPS. Tumor subtype correlated with mortality (P = 0.04).
  
  
  CONCLUSIONS
  The MRI features can help to distinguish between extremity LPS subtypes, and can predict histopathologic grade and metastatic pattern in myxoid LPS.
authors.affiliation: From the *Department of Radiology, Brigham and Women's Hospital, †Department of Imaging, Dana Farber Cancer Institute, and ‡Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Wortman
authors.forename: Sree Harsha
authors.initials: SH
authors.lastname: Tirumani
authors.forename: Jyothi P
authors.initials: JP
authors.lastname: Jagannathan
authors.forename: Harika
authors.initials: H
authors.lastname: Tirumani
authors.forename: Atul B
authors.initials: AB
authors.lastname: Shinagare
authors.forename: Jason L
authors.initials: JL
authors.lastname: Hornick
authors.forename: Nikhil H
authors.initials: NH
authors.lastname: Ramaiya
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005121:Extremities / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008080:Liposarcoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D055815:Young Adult