Shear-wave sonoelastographic features of invasive lobular breast cancers.

AIM 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. CONCLUSION 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.