Tc-99m sestamibi has been reported to accumulate in several tissues with increased metabolism and particularly in solid tumors. Although the clinical utility of this radiopharmaceutical has been described in primary breast cancer and its axillary involvement, it has not been fully evaluated in local recurrence or distant metastasis. We illustrate the case of a post-mastectomy patient in whom Tc-99m sestamibi single photon emission tomography (SPET) myocardial perfusion scintigraphy, performed to evaluate chest pain mimicking angina, aided in discovering local recurrence of breast cancer in the chest wall. This example underlines that myocardial scintigraphy requires--particularly in a selected group of patients with previous neoplasms of the chest or neck--careful scrutiny for extracardiac uptake and why any unusual or unexpected localization should be pursued and clarified for diagnosis.