ENO2 and small cell lung carcinoma: The results were shown in Table 3 and demonstrated that SUVmax shown significant difference among above histological types (P<0.001), and it was highest for SCC, followed by NSCLC and adenocarcinoma, and lowest for benign lesions; CYFRA21-1 and SCC-Ag were significantly higher in SCC than in other histological types (P<0.001 for both); similarly, NSE was found significantly higher in SCLC (P<0.001); in contrast, CEA was at a higher level in adenocarcinoma than in other histological types, but without reaching significant (P = 0.343).