Abbreviations: TC, typical carcinoid; AC, atypical carcinoid; SCLC, small cell lung carcinoma; LCNEC, large cell neuroendocrine carcinoma. Hematoxylin and eosin (H&E) stains and immunohistochemical stains of 4 representative cases are shown here. The magnification is 400× for all images. TC: 1A, H&E; 1B, negative PAX5; 1C, strong c-Met; 1D, strong p-c-Met; 1E, strong paxillin. AC: 1F, H&E; 1G, weak PAX5; 1H, weak c-Met; 1I, strong p-c-Met; 1J, strong paxillin. SCLC: 1K, H&E; 1L, strong PAX5; 1M, strong c-Met; 1N, strong p-c-Met; 1O, strong paxillin. LCNEC: 1P, H&E; 1Q, weak PAX5; 1R, weak c-Met; 1S, weak p-c-Met; 1T, weak paxillin.