What are the typical morphologic and kinetic features of a benign mass on breast MRI?
Features that are suggestive of a benign lesion are a round or oval shape, circumscribed margin, and homogeneous internal enhancement or dark nonenhancing internal septations. Additionally, the T2-weighted images can be used for lesion characterization. A round or oval mass with homogeneous high T2-weighted signal intensity that is greater than that of normal fibroglandular tissue and circumscribed margins has a very high likelihood of being benign.
Another commonly observed benign mass is a fibroadenoma. This will commonly present as an oval mass with circumscribed margins and homogeneous enhancement. Fibroadenomas will also generally have homogeneous high T2-weighted signal intensity and persistent enhancement kinetics.