title: MR imaging of myxofibrosarcoma and undifferentiated sarcoma with emphasis on tail sign; diagnostic and prognostic value.
abstract: OBJECTIVE
  To assess the prevalence of the tail sign in soft tissue sarcomas and determine whether the local recurrence rate differed based on the presence of the tail sign.
  
  
  METHODS
  In our retrospective study, myxofibrosarcoma (MFS, n = 25) and undifferentiated sarcoma (US, n = 38) comprised group 1, and the remaining tumours (n = 115) were assigned to group 2. Location, size, and imaging features of the tumours were assessed on MRI. The radiological-pathological correlation of the tail sign was analysed.
  
  
  RESULTS
  The tail sign, thick fascial enhancement extending from the tumour margin, was more common and significantly thicker in group 1. In the subgroup analysis between MFS and US, there was no significant difference in the presence of a tail sign. Histological examination revealed extensive tumour cell infiltrations along the deep fascia from the main mass. Patients with a tail sign had a worse local recurrence-free survival than patients without it, not only in all tumours (p < 0.01), but also in group 1 (p = 0.019) CONCLUSIONS: The tail sign was a common MRI feature of both MFS and US, and was also associated with worse local recurrence-free survival. Radiologists should be aware of these MRI findings and inform the surgeon preoperatively in order to obtain a sufficient surgical margin to minimise the risk of local tumour recurrence.
  
  
  CONCLUSIONS
  • The tail sign was a common MRI feature of myxofibrosarcoma and undifferentiated sarcoma. • The tail sign may be associated with worse local recurrence-free survival • Radiologists should be aware of this MRI finding and inform the surgeon.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, 101, Daehak-Ro, Jongno-Gu, Seoul, 110-744, Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Yoo
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Hong
authors.forename: Yusuhn
authors.initials: Y
authors.lastname: Kang
authors.forename: Ja-Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Kyung Chul
authors.initials: KC
authors.lastname: Moon
authors.forename: Han-Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Ilkyu
authors.initials: I
authors.lastname: Han
authors.forename: Minkyong
authors.initials: M
authors.lastname: Yi
authors.forename: Heung Sik
authors.initials: HS
authors.lastname: Kang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D005354:Fibrosarcoma / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult