A 72-year-old man was admitted with exercise induced chest pain and dy
spnea. Clinical and laboratory examination revealed coronary artery di
sease and a large, anterior mediastinal mass. A large area of Increase
d activity was observed during Tl-201 SPECT Imaging in the left anteri
or mediastinum close to the anterior wall of the left ventricle. Tc-99
m MIBI planar imaging showed radionuclide accumulation in the mass. CT
and MRI confirmed the mediastinal mass. A biopsy showed a benign thym
oma.