65-year-old man in cardiac failure with history of prior asbestos exposure. Chest mass was detected, as incidental finding, on CT angiogram and subsequently proven to be solitary fibrous tumor of pleura. (A-C) Unenhanced axial CT images in lung windows completed at yearly intervals from 2006 through 2010 (images from 2007 and 2009 not shown). Dominant left lower lobe nodule (arrow) shows significant side-to-side motion and change in position from posterior costophrenic sulcus to lateral costophrenic sulcus. Initial axial PET/CT images (not shown) revealed minimal 18F-FDG uptake within nodule with maximal standardized uptake value less than mediastinal blood uptake. Although bilateral calcified pleural plaques are present, solitary fibrous tumors are unrelated to asbestos exposure.