Ultrasound Findings of Breast Adenomas

Breast adenomas are rare benign tumors. The aim of this study was to describe the ultrasound findings of breast adenomas, including less common worrisome features that can mimic malignancy.

From November 2014 to November 2019, we performed 1605 core needle biopsies guided by ultrasound in our department. In all, 229 corresponded to fibroadenomas and 12 to breast adenomas.

Breast adenomas represented 0.75% of all core needle biopsies; 50% (6 of 12) were tubular adenomas; 17% (2 of 12) were ductal adenomas; and 33% (4 of 12) were lactating adenomas. Tubular and lactating adenomas occurred in young women and ductal adenomas in postmenopausal women. Lactating adenomas occurred in pregnant or breastfeeding women and were larger than the other adenomas. Ultrasound showed a mass with an oval shape, a parallel orientation, circumscribed margins, and hypoechoic and homogeneous patterns in most cases. However, up to one-third of them presented with suspicious findings.

Breast adenomas are rare benign entities with no specific clinical and radiologic features. Sometimes, they appear as suspicious tumors on radiologic modalities, requiring a histopathologic assessment to rule out malignancy. Radiologists need to be familiar with this entity to determine concordance between imaging and the final pathologic analysis.