Breast implant foreign body reaction mimicking breast cancer recurrence on FDG PET/CT

A woman with bilateral breast cancer treated with bilateral mastectomies, implant reconstructions, chemotherapy, and hormonal therapy underwent FDG PET/CT imaging. Imaging demonstrated sternal, nodal, and lung lesions which were stable or slowly increasing, as well as a parasternal chest wall mass which was enlarging much more rapidly and was excised. Pathology of the chest wall mass demonstrated only benign soft tissue with fat necrosis and foreign body giant cell reaction, without evidence of malignancy or implant rupture. This case demonstrates how a benign FDG-avid foreign body reaction, induced by an intact breast prosthesis, could easily be mistaken for malignancy.