Incidental Mammary Fibromyoblastoma on 82Rb Myocardial Perfusion Imaging

82Rb is frequently used in PET myocardial perfusion imaging to detect ischemia. We present the case of a 64-year-old man referred for PET myocardial perfusion imaging to rule out ischemia. On PET images, an abnormal focus of uptake was present in the subcutaneous soft tissue overlying the right chest, which corresponded to a soft-tissue nodule on CT. This lesion was biopsied and proved to be a mammary fibromyoblastoma, an extremely rare and benign lesion. This case is presented to emphasize the importance of reviewing extracardiac structures on PET/CT myocardial perfusion studies.