PET-CT imaging features and macroscopic features. CT revealed a large lobular mass in the superior lobe of left lung. The largest dimension of the mass is 3.2 cm. It invaded the anterior segment and superior segment of the left lung, and invaded pleura mediastinalis. The imaging of the rest lung looks normal (a). PET and CT fusion image showed the nodule had intense FDG uptake. The SUVmaxs was 5.2, which suggested a malignant tumor on PET-CT, and probably lung primary cancer (b). Gross examination showed a tumor (▲) in the peripheral of the lung, with the largest diameter of 3.5 cm. The cut section surface of the tumor was hard, grey and fine granular, and there were many small grey nodes (arrows) in the rest lung, with a diameter of 0.1 cm to 0.3 cm (c). There were plenty of small nodes (arrows) on the visceral pleura (d).