What is a common feature of cystic structures in breast imaging?

Cystic structures in breast imaging are fluid-filled sacs that often reflect benign conditions. One of their hallmark characteristics is that they tend to appear well-defined with smooth, regular outlines on imaging studies such as mammograms and ultrasounds. This well-defined appearance indicates that the lesion is likely benign, as malignant tumors usually present with irregular, spiculated, or blurred margins.

In breast imaging, cysts can vary in size and may contain anechoic fluid on ultrasound, which helps to distinguish them from solid masses. The clear, well-circumscribed borders of cysts aid radiologists in making differential diagnoses when reviewing breast imaging results.

Other options may suggest potential misconceptions about cystic structures. While cysts can sometimes accompany malignancies or be mistaken for them, they do not typically indicate malignancy on their own. Biopsy is not always indicated solely based on the presence of a cyst if it demonstrates the characteristic features of being benign. Furthermore, cysts are not uniformly dense; instead, they typically have varying appearances depending on their contents, which may include fluid that appears darker (hypoechoic) on ultrasound compared to surrounding tissue.