Range of pathological findings in lesions suspected of having an intraductal component in ultrasound and role of shear wave elastography in differential diagnosis

Purpose: To investigate pathological findings in lesions suspected to have intraductal component in ultrasound and to assess role of SWE in differential diagnosis Methods and Materials: Out of 567cases, 36 lesions with initial suspicion of being intraductal, B-mode and SWE images were correlated with pathological results. Qualitative and quantitative tissue elasticity were displayed with color-coded map and color scale ranging from 0kPa (dark blue; soft) to180kPa (red; stiff).Quantitative elasticity values were measured by drawing a Q box over the stiffest portion and another box on adjacent normal breast tissue. Maximum color and presence of a stiff rim was recorded. Maximum and mean stiffness, also ratio of lesion stiffness to surrounding tissue were compared between benign and malignant pathologies using Mann Whitney U test Results: Morphologically the ductal lesions were categorized as single discrete intraductal lesions14,multiple discrete intraductal lesions3 and diffuse intraductal thickening6.Out of these36lesions,only12 showed various pathologies related to the ducts including papillary carcinoma1, IDC2, DCIS 2,typical 3or atypical ductal hyperplasia5 and benign papillomatous lesions3.The other19 lesions with nonductal pathologies included fibrocystic changes10,fat necrosis3,benign fibroepithelial lesions4, and chronic inflammation2.The most common morphological appearances among lesions with ductal pathologies was single intraductal mass. The most common morphological appearances among non-ductal pathologies was non-mass lesion with ductal pattern. The mean lesion stiffness and ratio were not significantly different between malignant and benign lesions (P=0.172 and0.35) however the maximum lesion stiffness was significantly higher in the malignant lesions(P=0.32) Conclusion: Various benign pathologies such as fibrocystic changes, fat necrosis and benign fibroepithelial changes can mimic intraductal lesions in ultrasound.SWE helps differentiate between benign and malignant intraductal lesions.