Which characteristic is true about the appearance of lipomas in mammograms?

Lipomas are benign tumors composed of adipose (fat) tissue, and their appearance on mammograms is characterized by smooth, well-defined borders. This is important clinically because the well-circumscribed nature of lipomas contrasts with malignant lesions, which often have irregular contours. The smooth borders of lipomas help radiologists differentiate them from potential cancers, which can appear more heterogenous and irregular in shape.

Additionally, lipomas are typically of lower density than surrounding breast tissue because they are primarily made of fat, which contributes to their contrast against the denser glandular or fibrous breast tissue. They do not typically present with calcifications, as these are more characteristic of other types of breast lesions. Understanding these characteristics aids in the accurate interpretation of mammograms and the appropriate management of findings.