title: Does size reliably predict malignancy in soft tissue tumours?
abstract: OBJECTIVE
  In this retrospective study we examined whether size is a viable marker of tumour malignancy in soft tissue masses (STM) and if the ratio of width and length (RALD) of an STM reflects tumour biology more accurately.
  
  
  METHODS
  Measurements of maximal lesion size and perpendicular diameter were performed in available MRI and ultrasonography studies of 212 patients (mean age 54.4 ± 17.2 years, male:female 1:1.12) with a histologically verified diagnosis.
  
  
  RESULTS
  Overall, 28.2 % of lesions were malignant, 11.1 % intermediate, and 58.8 % benign. Size alone was a weak predictor of malignancy in STMs (sensitivity 68.8 %, specificity 50.3 %, positive predictive value [PPV] 44.0 %, negative predictive value [NPV] 80.4 %). RALDshowed better discriminatory power with greater separation between benign and malignant entities and higher values for sensitivity (83.6 %), specificity (53.6 %), and NPV (89.0 %). A weighted combination of size, age and RALDimproved diagnostic power, demonstrating higher values for sensitivity (77.0 %), specificity (80.1 %), PPV (61.0 %), and NPV (89.6 %).
  
  
  CONCLUSIONS
  Size should not be used alone to estimate an STM's malignancy. RALDbetter reflects a lesion's growth pattern and a combination of age, size, and RALDhelps to discriminate more accurately between benign, intermediate, and malignant entities. These findings should help to estimate easily whether a newly found STM is benign or malignant prior to further workup.
  
  
  CONCLUSIONS
  •Size does not reliably differentiate between benign, intermediate, and malignant tumours •The RALD(ratio of lateral to axial diameter) improves diagnostic confidence •When combined with age and size, STM differentiation was further enhanced •These measurements can aid in earlier detection of sarcomas.
authors.affiliation: Department of Radiology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors.forename: Leonhard
authors.initials: L
authors.lastname: Gruber
authors.affiliation: Department of Radiology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria. alexander.loizides@i-med.ac.at.
authors.forename: Alexander
authors.initials: A
authors.lastname: Loizides
authors.affiliation: Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21/3, Innsbruck, Austria.
authors.forename: Laurin
authors.initials: L
authors.lastname: Ostermann
authors.affiliation: Department of Radiology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Glodny
authors.affiliation: Department of Radiology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors.forename: Michaela
authors.initials: M
authors.lastname: Plaikner
authors.affiliation: Department of Radiology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors.forename: Hannes
authors.initials: H
authors.lastname: Gruber
mesh_terms: D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014463:Ultrasonography / Q000379:methods*
keywords: Classification; Prediction; Sarcoma; Size; Soft tissue tumours