Multidetector CT in the evaluation of retroperitoneal fat tissue infiltration in ductal adenocarcinoma of the pancreatic head: correlation with histopathological findings.

Neoplastic infiltration of the retroportal fat tissue is a critical parameter in tumor staging and in surgical planning because it frequently represents a site of persistence and recurrence of disease. We evaluated 64 patients affected by ductal adenocarcinoma of the pancreatic head/uncinate process, submitted to curative surgery. Suspicion of infiltration (micro or macroinfiltration) of the retroportal margin arose at MDCT in cases of obliteration, irregularity, or abnormal density of the fatty layer localized between the medial surface of the pancreatic head/uncinate process and the mesenteric artery. CT suggested the infiltration of the retroportal tissue in 27 cases (10 microinfiltration, 17 macroinfiltration). At histopathology, the presence of infiltration was confirmed in 21/27 (78%) cases. In all CT cases of microinfiltration, the retroperitoneal resection margin was not infiltrated, while all cases (6) with infiltration of the retroperitoneal margin were macroinfiltrated at CT. The sensitivity of CT was 80%, specificity of 84% with an overall diagnostic accuracy of 82%. MDCT is accurate in the assessment of the neoplastic infiltration of the retroportal fat tissue.