Non-hypervascular pancreatic neuroendocrine neoplasms differentiation from CA19-9 negative pancreatic ductal adenocarcinomas based on contrast CT: A large sample series.

PROPOSE: This study aims to evaluate the effectiveness of contrast-enhanced computed tomography (CT) in distinguishing non-hypervascular pancreatic neuroendocrine neoplasms (PNENs) from pancreatic ductal adenocarcinomas (PDACs) with a normal serum level of carbohydrate antigen 19-9 (CA19-9) levels.

METHODS

This retrospective study included 134 patients with pathologically confirmed non-hypervascular PNENs and 128 patients with CA19-9-negative PDACs, all of whom underwent contrast-enhanced CT prior to surgery between January 2015 and March 2024. Following independent evaluation by two radiologists, qualitative features from both groups were extracted in the arterial and portal venous phase and subsequently compared using univariate and multivariate analysis.

RESULTS

Patients with CA19-9 negative PDACs were significantly older than those with non-hypervascular PNENs (p < 0.001), and the majority of PDACs were located in the head of the pancreas (p < 0.01).Univariate analysis showed that non-hypervascular PNENs exhibited a higher frequency of well-defined tumor margins (p < 0.001) and calcification (p = 0.032) and a lower frequency of local invasion (p < 0.001), peripancreatic vascular invasion (p = 0.001), intra- or extrahepatic bile duct dilatation (p < 0.001), distal main pancreatic duct dilatation (p < 0.001), regional lymphadenopathy (p < 0.001) and tumor homogeneity (p < 0.001) when compared to CA19-9 negative PDACs. Multivariate analysis identified the absence of local invasion (Odds Ratio (OR) = 0.233; 95 % Confidence Internals (95 % CI):0.114-0.476; p < 0.001), absence of peripancreatic vascular invasion (OR = 0.434; 95 % CI:0.217-0.870; p = 0.019), a normal distal main pancreatic duct diameter (OR = 0.398; 95 % CI:0.202-0.785; p = 0.008), absence of regional lymphadenopathy (OR = 0.455; 95 % CI:0.238-0.870; p = 0.017) and tumor heterogeneity (OR = 0.240; 95 % CI:0.126-0.456; p < 0.001) as significant predictors of non-hypervascular PNENs. The area under the receiver operating characteristic curve for the radiological feature model was 0.829 based on logistic regression.

CONCLUSIONS

Qualitative features in contrast-enhanced CT images could be beneficial in differentially diagnosing non-hypervascular PNENs and CA19-9 negative PDACs.