Breast Cancer and Physiologic Avidity From Breast Feeding on FDG PET/CT

A 35-year-old woman presented with breast cancer diagnosed during pregnancy. Eleven days after delivery, the patient underwent FDG PET/CT for systemic staging. Avidity was seen diffusely in both breasts, with a more avid focus at the site of a biopsy clip in the right breast. There were no lymph nodes or distant metastases. The patient was actively breast feeding, explaining the diffuse breast avidity. This case demonstrates both malignant and benign FDG avidity in the breasts at the same time, with a focal FDG-avid right breast malignancy identified among bilateral breast parenchyma with elevated physiologic FDG-avid secondary to breast feeding.