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

Background: 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. Case presentation: 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. Conclusion: 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.