Abstract
A 43-year-old woman, who presented with a suspected left breast abscess, underwent serial ultrasounds, which demonstrated inflammatory changes that were nonresponsive to antibiotics and which spread to the contralateral breast. 18 F-FDG PET/CT demonstrated diffuse heterogeneous intense FDG uptake in both breasts with reactive axillary nodes. Breast biopsy confirmed granulomatous inflammation, and overall findings were consistent with idiopathic granulomatous mastitis. In the absence of histological analysis, idiopathic granulomatous mastitis is an important differential diagnosis to consider for bilateral abnormal breast uptake, and early recognition can facilitate prompt commencement of treatment.