Thallium (Tl) 201 and technetium (Tc) 99m tetrofosmin
single-photon emission CT are routinely used in the evaluation of
coronary artery disease. Mediastinal tumors demonstrate Tl 201 and Tc
99m tetrofosmin uptake. We report a 56-year-old man who developed chest
pain after a previously successful angioplasty and stent of the left
anterior descending coronary artery. He underwent a Tl 201, Tc 99m
tetrofosmin exercise study. Abnormal mediastinal activity was
visualized in both the Tl 201 and Tc 99m tetrofosmin images.
Subsequently, the patient underwent resection of a stage II thymoma.
Unanticipated focal extracardiac accumulation during myocardial
scintiscanning should lead to further investigation to exclude