False-Positive Lesions Mimicking Breast Cancer on FDG PET and PET/CT

OBJECTIVE. Incidental F-18-FDG-avid breast lesions are commonly encountered in patients with cancer who undergo staging PET/CT. This pictorial essay discusses breast lesions that show increased FDG activity, mimicking breast cancer, with biopsy-confirmed benign diagnosis. CONCLUSION. Acute and chronic inflammation, physiologic lactation, and benign breast masses, including silicone granuloma, fat necrosis, fibroadenoma, and postsurgical changes, may show increased FDG uptake on PET/CT. These conditions can often be differentiated from malignancy by correlative imaging, including mammography, sonography, or MRI.