MIBI Uptake in a Huge Breast Mass Obscuring the Anterior and Lateral Myocardial Walls in Perfusion Imaging

Cardiac risk assessment with myocardial perfusion imaging (MPI) is a common practice for some elderly breast cancer patients who are candidates for operation. In rare cases the tumor may become visible in the images. This is the report of a case with a huge slow-growing breast tumor suspicious for malignancy and presenting with methoxy-isobutyl-isonitrile (MIBI) uptake in the tumor. The patient was referred to the nuclear medicine department for preoperative cardiac risk assessment with MPI. There was high uptake in the tumor was note worthy in two different aspects: 1)high MIBI uptake in the tumor is more suggestive of malignant rather than benign tumors and thus, underscores the importance of extra-cardiac uptake sites in pre-operation MPI; and 2)high uptake in the left breast tumor may obscure the MPI image and hinder proper interpretation.