Fat necrosis may mimic local recurrence of breast cancer in FDG PET/CT.

Fat necrosis of the breast is a benign condition that most commonly occurs as the result of trauma. The radiographic and clinical significance of fat necrosis of the breast is that it may mimic malignancy. We present a case of false positive FDG PET/CT scan caused by fat necrosis and mimics local recurrence of breast carcinoma 3 years after radical mastectomy. Physicians must be aware of fat necrosis as a potential pitfall for PET/CT. Fat necrosis must be considered in the differential diagnosis of hypermetabolic breast masses in patients who previously had mastectomy or mammoplasty.