MSCT features of partially or completely low enhancement of pancreatic neuroendocrine tumors / 中华胰腺病杂志

ABSTRACT

Objective To observe MSCT features of partially or completely low enhancement of pancreas neuroendocrine tumors (PNENs).Methods The clinical data and MSCT features before pancreatectomy in 44 patients with confirmed PNENs were retrospectively reviewed.The MSCT findings were evaluated including tumor size, location, margin, density, intratumoral structure, bile duct and pancreatic ductal dilation and distant metastasis.Tumors were classified into complete enhancement type, partially or completely low enhancement type for further comparative analysis based on MSCT enhancement during pancreatic stage.Results A total of 56 PNENs in 44 patients were found, and there were 31 partially or completely low enhanced PNENs and 25 completely enhanced PNENs.The former were larger than the latter [mean tumor size, (3.3±2.2)cm vs (1.4±0.9) cm], and irregular shape and cystic components within tumors were more often observed (all P<0.05).There were no significant differences between the two types of PNENs in terms of gender, the presence of functional tumor, tumor location, clear tumor margin, intratumoral calcification, bile and pancreatic duct dilation and metastasis.76.0%(19/25) of completely enhanced PNENs reached peak enhancement in arterial phase, and 71.0%(22/31) of low enhancement PNENs reached peak in pancreatic phase.Enhanced intratumoral blood vessels in the arterial phase were more frequent in low enhancement PNENs, and the difference was statistically significant (P<0.05).There were significant differences on pathological grade between the two types of PNENs (G1=21,G2=4,G3=0 vs G1=18,G2=5, G3=8), and the difference was statistically significant (P<0.05).Conclusions Compared with complete enhancement PNENs, partially or completely low enhancement PNENs had bigger size, irregular shape, and cystic component.Intratumoral blood vessels in the arterial phase were observed, peak enhancement arrived later and the pathological grade was higher.