OBJECTIVETo investigate the findings of contrast-enhanced multislice computed tomography (MSCT) that characterize intraductal papillary neoplasms of bile ducts (IPNB).

METHODSThe MSCT findings and clinical data of 16 cases of IPNB proven by surgical pathology were reviewed retrospectively.

RESULTSAmong the 16 cases, nine were adenoma (multi-lesions, n = 5; single lesions, n = 4) and seven were adenocarcinoma (multi-lesions, n = 4; single lesions, n = 3). Among the nine adenoma cases, seven showed nodules or masses in the expanding intrahepatic bile ducts with asymmetrical low density on plain scan, and two showed obvious expansion of biliary ducts and the inner wall of bile ducts was rough. All seven of the adenocarcinoma cases showed nodules or masses in the expanding intrahepatic bile ducts with asymmetrical low density-like adenoma. When contrast enhancement was applied, the nine adenoma cases manifested slight-to-moderate degrees of asymmetrical enhancement. For the seven adenocarcinoma cases, two showed asymmetrical enhancement similar to that of the adenoma cases and five showed continued enhancement; one case showed malignant infiltration of the bile duct and evident damage in the adjacent hepatic tissue. The CT plain scan findings for the two groups (adenoma and adenocarcinoma) were not significantly different (t = -1.17, P = 0.2632). Significantly different findings were obtained with the MSCT imaging analysis for the arterial phase (t = 6.53, P less than 0.01) and the portal vein phase (t = 5.63, P less than 0.01). All cases showed asymmetrical expansion of intrahepatic biliary ducts, diffuse or local, and four cases showed moderate expansion of the common bile duct. One adenocarcinoma case showed intumescence in the celiac lymph node by moderate asymmetrical enhancement.

CONCLUSIONMSCT is helpful for the differential diagnosis of IPNB from other hepatic lesions.