Fig. 1

A 72-year-old male patient with pT3N0M0 pulmonary pleomorphic carcinoma. a Fused PET/CT image obtained before surgery shows ringed FDG uptake in the tumor (b) Axial non-contrast CT image on the same day shows peripheral solid mass without cavity formation. c The gross specimen shows a mainly solid tumor with a crescent-like cavity. d Microscopic examination of areas in the red squares shows necrosis on the upper left side (arrow) and spindle cell on the lower right side (triangle) (Hematoxylin and eosin staining, × 100)