Computed Tomography-based Morphological Differences between Histologic Subtypes of Periampullary Ductal Adenocarcinoma

Abstract

Objective: To evaluate the computed tomography (CT)-based differences between pancreaticobiliary (PBST) and intestinal (IST) subtypes of periampullary pancreatic ductal adenocarcinomas (PDAC). Study Design: Analytical study. Place and Duration of Study: Faculty of Medicine, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Turkey between 2015 and 2018. Methodology: Overall 24 periampullary PDAC cases, in whom histomorphologic evaluation and CDx2 expression were used to discriminate between PBST and IST, were included. The lesion morphology (infiltrative versus nodular), common bile and main pancreatic ducts' dilation, tumor grade, enhancement pattern, pancreaticoduodenal groove, pancreaticoduodenal artery and lymphatic involvement were evaluated by CT. Results: Overall 24 PDAC cases [median age 67.5 (60.5-76.5) years] were enrolled. Histopathology revealed 9 (25%) IST and 18 (75%) PBST. The age [ 72.5 (69-81) versus 63 (57.75-75.5) years, respectively, p=0.204] and gender [3 (50%) versus 12 (66.7%) males, respectively, p=0.635] and the prevalence of all CT characteristics were similar between groups (p>0.05 for all) except for lesion morphology. Infiltrative morphology was more frequent in PBST than IST [14 (77.8%) versus 1 (16.7%), respectively, p=0.015]. Multiple variable logistic regression analysis revealed infiltrative morphology as the only independent CT predictor of PBST [OR: 14.9, 95% CI: 1.2-186), p=0.036]. The interrater reproducibility for lesion morphology was moderate (Cohen's Kappa: 0.55, p<0.007). Conclusion: Infiltrative appearance is associated with PBST; whereas, nodular appearance more likely predicts IST. The potential role of CT lesion morphology on guiding appropriate chemotherapy in cases with no chance for surgery or biopsy requires addressing.