Fat necrosis in the breast: a multimodality imaging review of its natural course with different aetiologies

Fat necrosis of the breast is a commonly encountered condition in daily practice. It is a benign pathology, but it can have variable manifestations and patterns that may sometimes mimic malignancy, depending on its stage of evolution and its underlying cause. This review demonstrates the wide spectrum of appearances of fat necrosis on mammography, digital breast tomosynthesis (DBT), ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and positron-emission tomography (PET). Sequential follow-up images are included in some cases to illustrate the temporal change of the findings. The typical location and distribution of fat necrosis from a comprehensive list of aetiologies are discussed. Improved knowledge of the multimodality imaging features of fat necrosis could enhance diagnostic accuracy and clinical management, thus avoiding unnecessary invasive investigations.