Lactating Adenoma: Sonographic Features.

The lactating adenoma is a benign breast lesion occurring as a palpable mass in pregnant or lactating patients. The ultrasound characteristics of 15 lactating adenomas in 15 patients were reviewed retrospectively. Most of the lactating adenomas in this series (10 of 15) had one or more typically benign features such as circumscribed borders, smooth lobulations, or an echogenic pseudocapsule. The remaining five, however, had features typically associated with malignancy, including irregular, angulated, or ill-defined margins, or posterior acoustic shadowing.