Ultrasound Features of Mammographic Developing Asymmetries and Correlation With Histopathologic Findings

The purpose of this study is to review the ultrasound (US) features of developing asymmetries and correlate them with histopathologic findings.

We searched the mammography database of an academic medical center, affiliated cancer center, and two ambulatory imaging facilities from 2009 to 2012 and identified 201 patients with developing asymmetries, 187 of whom had US at the time of, or within 1 month of, diagnostic mammography evaluation. Seventy-five (40.1%) of these 187 patients had a US correlate, and three additional patients had a positive second-look US after MRI (US results were initially negative), and one patient had a US correlate for a newly palpable developing asymmetry 1 month after receiving a BI-RADS category 3 mammography-only assessment. These 78 developing asymmetries with US correlates comprised the study cases. US features were obtained by consensus image review; patient demographic characteristics and outcomes were obtained from the electronic medical record.

Thirty-six of 78 US correlates (46.2%) were masses, the echotexture of which was as follows: 26 (72.2%) were hypoechoic, four (11.1%) were hyperechoic, three (8.3%) were mixed hyperechoic and hypoechoic, and three (8.3%) were anechoic. Forty-two of 78 US correlates (53.8%) were nonmass findings, the echotexture of which was as follows: 24 (57.1%) were mixed hyperechoic and hypoechoic, 13 (31.0%) were hypoechoic, and five (11.9%) were hyperechoic. Twenty-one of 78 lesions (26.9%) were malignant; of these, eight were invasive ductal carcinoma, seven were invasive lobular carcinoma, three were mixed invasive ductal and lobular carcinoma, and three were ductal carcinoma in situ. Malignant findings on US included 17 masses (81.0%) (13 hypoechoic and four mixed hyperechoic and hypoechoic), and four nonmass findings (19.0%) (three mixed hyperechoic and hypoechoic and one hypoechoic).

When present, US correlates for developing asymmetries are often nonmass findings with mixed echotexture. Most malignant developing asymmetries with US correlates present as a hypoechoic mass, but 19% present as a nonmass finding with either mixed hyperechoic and hypoechoic echotexture or hypoechoic echotexture.