Hyperechoic lesions of the breast: not always benign.

OBJECTIVE. The purposes of our study were, first, to evaluate the frequency, clinical presentation, and associated imaging findings of malignant breast lesions presenting as hyperechoic nodules in a large series of consecutive sonographically guided core needle biopsies (CNBs) and, second, to investigate sonographic features that are able to predict malignancy in hyperechoic breast lesions. MATERIALS AND METHODS. The radiologic and pathologic records for 4511 consecutive sonographically guided CNBs were retrospectively reviewed. Hyperechoic lesions were identified, and clinical notes and related mammography or MRI reports were reviewed. The sonographic images were evaluated according to the BI-RADS lexicon by two experienced breast radiologists. Surgical pathology results and follow-up served as the reference standard for lesions diagnosed as malignant or high-risk and benign at CNB, respectively. The frequency of hyperechoic carcinomas among all carcinomas was calculated. Differences in sonographic appearance between hyperechoic benign and malignant lesions were evaluated using the chi-square test or the Fisher exact test. RESULTS. Of all biopsied lesions, 25 (0.6%) were hyperechoic. Among the 1849 malignant lesions, nine (0.4%) were hyperechoic. The remaining 16 were benign. None of the hyperechoic malignancies was a “purely” sonographic lesion, because all were palpable, mammographically visible, or detectable on breast MRI. Malignant lesions were more likely than benign lesions to have noncircumscribed margins (9/9 vs 7/16; p = 0.008) and nonparallel orientation (6/9 vs 1/16; p = 0.003). CONCLUSION. When encountering a hyperechoic nodule, malignant nature cannot be excluded. Suspicious sonographic signs and correlation with other imaging techniques may help avoid misdiagnosis.