Value of Shear Wave Elastography for the Differentiation of Benign and Malignant Microcalcifications of the Breast.

OBJECTIVE. The objective of our study was to evaluate whether shear wave elastography (SWE) can differentiate benign from malignant microcalcifications of the breast when detected on ultrasound (US). SUBJECTS AND METHODS. Between February 9, and June 23, 2016, 74 patients with mammographically detected suspicious microcalcifications underwent breast US. When microcalcifications were identified on US, stiffness was assessed using SWE. Biopsy was subsequently performed under US guidance using a 10-gauge vacuum-assisted needle. Qualitative and quantitative elastography results were compared between benign and malignant calcifications as well as between pure ductal carcinoma in situ and lesions with invasive components using the Mann-Whitney U test. ROC curves were created to assess the performance of SWE in detecting malignancy and invasive components. RESULTS. Twenty-nine groups of microcalcifications in 29 patients were identified on US. At pathology, 16 groups were benign and 13 were malignant. Stiffness of malignant calcifications was significantly higher than that of the benign ones (p = 0.0004). The AUC, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of SWE for the diagnosis of malignancy were 0.89, 69%, 100%, 80%, 100%, and 86%, respectively, and for detection of an invasive component were 0.93, 75%, 100%, 75%, 100%, and 85%. CONCLUSION. SWE has the potential to differentiate benign from malignant micro-calcifications of the breast when detected on US with high specificity.

Flat epithelial atypia of the breast: pathological-radiological correlation.

OBJECTIVE: This study was undertaken to determine the prevalence of flat epithelial atypia at ultrasound-guided and stereotactically guided needle biopsies, to describe the mammographic and sonographic features of flat epithelial atypia, and to determine the significance of lesions diagnosed as flat epithelial atypia at imaging-guided needle biopsies. MATERIALS AND METHODS: Retrospective review of a database of 1369 consecutive sonographically and stereotactically guided needle biopsies performed during a 12-month period yielded 33 lesions with flat epithelial atypia as the most severe pathologic entity (32 patients). Two radiologists retrospectively reviewed the imaging presentation, by combined consensus, according to the BI-RADS lexicon. RESULTS: Twenty-two of 33 flat epithelial atypia diagnoses (67%) were obtained under stereotactic guidance, and 11 (33%) were obtained under sonographic guidance. Six patients had synchronous breast cancer. Flat epithelial atypia lesions presented mammographically most often as microcalcifications (20/33 [61%]) distributed in a cluster (14/20 [70%]) with amorphous morphology (13/20 [65%]). Sonographically, flat epithelial atypia lesions appeared most often as masses (9/11 [82%]), with an irregular shape (6/9 [67%]), microlobulated margins (5/9 [56%]), and hypoechoic or complex echotexture (7/9 [78%]). Twenty-eight of 33 lesions (85%) were surgically excised, confirming the flat epithelial atypia diagnosis in 11 of the 28 lesions (39%), yielding carcinoma in four (14%) and atypical ductal hyperplasia in six (21%). Columnar cell changes without atypia were diagnosed in four lesions (14%), and lobular carcinoma in situ was diagnosed in three lesions (11%). CONCLUSION: Mammographic and sonographic presentation of flat epithelial atypia is not specific (clustered amorphous microcalcifications and irregular, hypoechoic or complex masses). Given the underestimation rate of malignancy, surgical excision should be considered when imaging-guided biopsy yields flat epithelial atypia.