title: Shear-wave elastography and greyscale assessment of palpable probably benign masses: is biopsy always required?
abstract: OBJECTIVE
  To establish if palpable breast masses with benign greyscale ultrasound features that are soft on shear-wave elastography (SWE) (mean stiffness <50 kPa) have a low enough likelihood of malignancy to negate the need for biopsy or follow-up.
  
  
  METHODS
  The study group comprised 694 lesions in 682 females (age range 17-95 years, mean age 56 years) presenting consecutively to our institution with palpable lesions corresponding to discrete masses at ultrasound. All underwent ultrasound, SWE and needle core biopsy. Static greyscale images were retrospectively assigned Breast Imaging Reporting and Data System (BI-RADS) scores by two readers blinded to the SWE and pathology findings, but aware of the patient's age. A mean stiffness of 50 kPa was used as the SWE cut-off for calling a lesion soft or stiff. Histological findings were used to establish ground truth.
  
  
  RESULTS
  No cancer had benign characteristics on both modalities. 466 (99.8%) of the 467 cancers were classified BI-RADS 4a or above. The one malignant lesion classified as BI-RADS 3 was stiff on SWE. 446 (96%) of the 467 malignancies were stiff on SWE. No cancer in females under 40 years had benign SWE features. 74 (32.6%) of the 227 benign lesions were BI-RADS 3 and soft on SWE; so, biopsy could potentially have been avoided in this group.
  
  
  CONCLUSIONS
  Lesions which appear benign on greyscale ultrasound and SWE do not require percutaneous biopsy or short-term follow-up, particularly in females under 40 years.
  
  
  CONCLUSIONS
  None of the cancers had benign characteristics on both greyscale ultrasound and SWE, and 32% of benign lesions were BI-RADS 3 and soft on SWE; lesions that are benign on both ultrasound and SWE may not require percutaneous biopsy or short-term follow-up.
authors.affiliation: 1 Division of Imaging and Technology, Medical Research Institute Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Giannotti
authors.affiliation: 1 Division of Imaging and Technology, Medical Research Institute Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Vinnicombe
authors.affiliation: 2 Breast Imaging Department, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Kim
authors.initials: K
authors.lastname: Thomson
authors.affiliation: 2 Breast Imaging Department, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Dennis
authors.initials: D
authors.lastname: McLean
authors.affiliation: 3 Department of Pathology, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Purdie
authors.affiliation: 3 Department of Pathology, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Lee
authors.initials: L
authors.lastname: Jordan
authors.affiliation: 1 Division of Imaging and Technology, Medical Research Institute Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Evans
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D010173:Palpation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D016217:Ultrasonography, Mammary / Q000379:methods*; D055815:Young Adult