Diffuse Intense 18F-FDG Uptake at PET in Unilateral Breast Related to Breastfeeding Practice
A 38-year-old woman underwent 18F FDG positron emission tomography (PET) for a follow-up after thyroidectomy. Three years ago, she was diagnosed as papillary thyroid cancer and underwent total thryoidectomy and modified radical neck dissection. After the operation, she received radioablation therapy. On a whole body FDG PET, diffuse intense FDG uptake was demonstrated in the entire left breast (). There was no abnormal FDG uptake in other organs. On clinical examination, the breasts were soft without lumps.\nMammography and breast ultrasound were performed for further evaluation of the left breast. There was no mass or abnormal finding in the breast ultrasound (). On mammography, her left breast was asymmetrically larger than the right breast without mass or focal asymmetry (). She had delivered the baby 14 months before and stopped breast-feeding 1 day before the FDG PET. Her one-year-old infant had refused to feed from the right breast and she fed only from her left breast. Intense FDG uptake in her left breast was likely caused by normal physiologic lactation and no additional work up was required.