Imaging of fat-containing lesions of the breast: A pictorial essay

Fat-containing breast lesions constitute a heterogeneous group of predominantly benign tumors and non-neoplastic conditions. The role of imaging is to distinguish leave-me-alone lesions from rarely occurring malignant fat-containing tumors that require histologic analysis. Correlating mammographic findings with appearance at ultrasonography often helps in identifying lesions that do not require further work-up. MRI can be valuable to confirm the presence of fat and characterize lesions indeterminate on conventional imaging. The purpose of this multimodality imaging review is to exemplify the radiologic appearances of common and uncommon fat-containing breast lesions to facilitate accurate diagnosis, avoid unnecessary interventions, and ensure appropriate management.