A 74-y-old woman with a 4-y history of left arm lymphedema and multiple negative mammography studies presented to her physician with a palpable subcutaneous nodule in the left upper arm. After biopsy the nodule was read pathologically as secondary breast carcinoma. We report a finding of a positive 99mTc-sestamibi scintimammography in the presence of an unremarkable mammogram. The study also revealed a positive uptake in a metastatic lesion in the manubrium of the sternum.