Benign Lesions with Posterior Acoustic Shadowing on Ultrasound: The Pathologic Correlation

ABSTRACT

A breast lesion with posterior acoustic shadowing is often encountered on sonography and this finding is generally accepted as a sign of malignancy. Although its detection is important for differentiating a malignant breast mass from a benign breast mass, posterior acoustic shadowing is the result of attenuation of the sound beam by a desmoplastic host response to breast cancer rather than the posterior acoustic shadowing being due to the tumor itself. Therefore, many breast conditions that contain fibrous elements also can induce some degree of acoustic shadowing. In this article, we present various benign breast lesions that display posterior acoustic shadowing and we discuss the radiologic findings along with the pathologic correlation.