Imaging features of benign adenomyoepithelioma of the breast.

Purpose: The purpose of our study was to evaluate the imaging features of benign adenomyoepithelioma of the breast with a focus on sonographic (US) appearances.

Methods: Ten benign adenomyoepitheliomas in 9 patients were included in this study. Mammographic and US findings were analyzed retrospectively by 2 radiologists according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. The BI-RADS final assessment category was also recorded.

Results: Of the 8 lesions for which mammography was available, 4 lesions presented with abnormal findings. Two lesions presented with an indistinct, irregular, isodense mass and a circumscribed, oval, isodense mass. The other 2 lesions presented with areas of focal asymmetry and asymmetry, respectively. On US, all of 10 lesions presented as a mass. The masses measured 0.5-1.2 cm (mean, 0.8 cm), were irregular (n = 8) or oval (n = 2) with microlobulated (n = 5), indistinct (n = 3), or angular (n = 2) margins. They were all hypoechoic, had non parallel orientation in 6 cases, and increased peripheral vascularity in 7 cases. The BI-RADS final assessment category was 4B in 6, and 4A in 4.

Conclusions: Mammographic findings of benign adenomyoepithelioma were nonspecific. An irregular, non parallel orientation, microlobulated or indistinct margin, hypoechogenicity, and increased peripheral vascularity were the most frequent US features.