Figure 3.

Representative images of an adenocarcinoma with EGFR exon 21 mutation in a 48-year-old male who had never smoked with abnormal serum CEA levels (11.2 ng/ml). (A) ¹⁸F-FDG PET/CT in the axial plane and whole body maximum-intensity projection images, demonstrating abnormal FDG uptake in a right upper lobe tumor (SUV_max, 7.7) and the SUV_max of mediastinal lymph node was 7.9. (B) Hematoxylin and eosin-stained tissue indicating adenocarcinoma features. Magnification, ×100. (C) Polymerase chain reaction confirming the EGFR exon 21 mutation. EGFR, epidermal growth factor receptor; SUV_max, maximum standardized uptake value; CEA, carcinoembryonic antigen; ¹⁸F-FDG PET/CT, ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography.