AIMTo compare 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODSPatients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent 18F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ2 test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma.RESULTSFifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSIONPET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

Background We sought to investigate the clinical features and 18F‐FDG PET/CT characteristics of pulmonary sclerosing pneumocytoma (PSP). Methods We retrospectively reviewed and comparatively analyzed 18F‐FDG PET/CT imaging results of 22 patients with diagnosed PSP in our hospital from November 2009 to September 2015. Results The SUVmax in tumors was positively correlated with tumor size in typical PSPs (R = 0.806, R2 = 0.650, P = 0.001); however, the SUVmax in tumors had no significant correlation with tumor size of atypical PSPs (R = 0.479, R2 = 0.229, P = 0.162), and the degree of correlation between them attenuated when atypical PSPs were included (R = 0.518, R2 = 0.268, P = 0.011). A majority (90%) of atypical PSPs were found in males. Symptomatic patients showed a higher SUVmax than the asymptomatic group (5.68 ± 3.63 vs. 2.76 ± 1.18, respectively, P = 0.002). Conclusion Tumor size and clinical features may be associated with increased FDG uptake in PSPs. Morphological differences may affect the correlation between tumor size and SUVmax in PSPs. The atypical form of PSP may be more common in men.