ABSTRACT
Objective To compare the CT findings of poor-differentiated gastric neuroendocrine carcinomas (PD-NECs) and poordifferentiated gastric adenocarcinomas (PD-ADCs),and to increase the diagnostic accuracy rate.Methods In this retrospective study that enrolled 29 gastric PD-NECs and 29 gastric PD-ADCs,whose diagnoses were proven pathologically,we assessed their clinical characteristics and CT findings and then used univariate and multivariate analyses for statistical comparisons.Results The univariate analysis revealed that gastric PD-NECs were significantly smaller (P =0.002),more often showed well-defined margins (P＜0.001),and more frequently accompanied with intact overlying mucosa on CT when compared with gastric PD-ADCs (P ＜0.001).In the multivariate analysis,the presence of intact overlying mucosa (OR=0.028,95 ％ CI:0.001-0.863,P =0.041) and tumor-to-mucosa HU ratio on the arterial phase (OR=0.015,95 ％ CI:0.000-0.495,P =0.019) were two independent factors affecting the identification of gastric PD-NECs and gastric PD-ADCs.Receiver operating characteristic analysis (ROC) showed that the value of tumor-to-mucosa H U ratio on the arterial phase in differentiating them was moderate (AUC=0.72).Conclusion Gastric PD-NECs have better-defined margin,more intact overlying mucosa and higher tumor-to-mucosa HU ratio on the arterial phase than gastric PD-ADCs.