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.