title: Shear-wave sonoelastographic features of invasive lobular breast cancers.
abstract: OBJECTIVE
  To evaluate shear-wave elastographic (SWE) and related gray-scale features of pure invasive lobular breast carcinoma (ILC) and compare them with invasive ductal breast cancers (IDC).
  
  
  METHODS
  Quantitative SWE features of mean (El-mean), maximum (El-max), minimum (El-min) elasticity values of the stiffest portion of the mass, and lesion-to-fat elasticity ratio (E-ratio) were measured in 40 patients with pure ILC and compared with 75 patients with IDC. Qualitative gray-scale features of lesion size, echogenicity, orientation, and presence of distal shadowing were determined and compared between the groups.
  
  
  RESULTS
  ILC were significantly larger than IDC (P=0.008) and exhibited significantly higher El-max (P=0.015) and higher El-mean (P=0.008) than IDC. ILC were significantly more often horizontally oriented, while IDC were significantly more often vertically oriented (P<0.001); ILC were significantly more often hyperechoic than IDC (P<0.001). Differences in stiffness between ILC and IDC determined by quantitative SWE parameters were present only in small tumors (≤1.5 cm in size), ie, small ILC had significantly higher El-max (P=0.030), El-mean (P=0.014), and El-min (P=0.045) than small IDC, while tumors larger than 1.5 cm had almost equal stiffness, without significant differences between the groups.
  
  
  CONCLUSIONS
  Specific histopathologic features of ILC are translated into their qualitative sonographic and quantitative sonoelastographic appearance, with higher stiffness of small ILC compared to small IDC. Gray-scale and sonoelastographic features may help in diagnosing ILC.
authors.forename: Boris
authors.initials: B
authors.lastname: Brkljačić
authors.forename: Eugen
authors.initials: E
authors.lastname: Divjak
authors.forename: Čedna
authors.initials: Č
authors.lastname: Tomasović-Lončarić
authors.forename: Vanja
authors.initials: V
authors.lastname: Tešić
authors.affiliation: Gordana Ivanac, Department of Diagnostic and Interventional Radiology, Breast Unit, University Hospital Dubrava, University of Zagreb School of Medicine, Avenija G.Šuška 6, 10000 Zagreb, Croatia, gordana.augustan@gmail.com.
authors.forename: Gordana
authors.initials: G
authors.lastname: Ivanac
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000473:pathology; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging* / Q000473:pathology; D004548:Elasticity; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D047368:Tumor Burden