Sonography of invasive apocrine carcinoma of the breast in five cases

Objective: To evaluate the sonographic features of invasive apocrine carcinoma (IAC) of the breast. Materials and Methods: This study included five pathologically proven cases of IAC, and their sonographic features were retrospectively analyzed according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon. Results: All five lesions involved the left breast and were seen as irregularly shaped masses. All lesions, except one, had a parallel orientation to the chest wall. All five lesions showed noncircumscribed margins and heterogeneous echotexture; however, they showed various posterior features. One lesion had edema as an associated feature. Sonographic assessments were classified as BI-RADS category 4 in all five cases. Conclusion: Invasive apocrine carcinoma sonographic findings are difficult to differentiate from those of invasive ductal carcinoma of no special type.