Enhancement of intramammary lymph nodes with lymphoid hyperplasia: a potential pitfall in breast MRI.

We present three cases of breast lesions labeled as probable intramammary lymph nodes that showed an increase in size on follow-up mammography. Contrast-enhanced MRI was performed and the three lesions showed strong and rapid uptake of the intravenous contrast. Core needle biopsy established the diagnosis of lymphoid hyperplasia in all three patients. Because intramammary lymph nodes affected by benign processes can present findings similar to malignant lesions, the usefulness of contrast-enhanced MRI in these cases is controversial.