FDG Avid Abnormalities in the Breast: Breast Cancer Mimics

Purpose of Review: FDG PET/CT is a highly sensitive tool for the diagnosis, staging, and response assessment of multiple malignancies and conditions. Incidental findings requiring further diagnostic workup are often identified, including increased FDG uptake in the breast. Familiarity with causes of increased FDG uptake in the breast is essential. Recent Findings: Benign and malignant etiologies can cause uptake in the breast at FDG PET/CT that mimics primary breast cancer. The radiologist plays an important role in identifying the finding, recommending appropriate breast imaging follow-up that may confirm an etiology, and performing image-guided biopsy. Timely diagnosis is essential, as this can alter patient treatment strategies. Summary: While the imaging characteristics of benign and malignant findings in the breast can overlap, the radiologist must be familiar with relatively common benign and malignant causes of FDG uptake in the breast.