Biliary cystic intraductal papillary mucinous tumor and cystadenoma/cystadenocarcinoma: differentiation by CT.

PURPOSE: To identify differential findings of biliary cystic intraductal papillary mucinous tumor (IPMT) and biliary cystadenoma/cystadenocarcinoma on CT images.

MATERIALS AND METHODS: Records of 7 patients with biliary cystic IPMT and 17 patients with biliary cystadenoma/cystadenocarcinoma were accessed. A pathologist reviewed gross morphologic and microscopic findings and confirmed the diagnosis. Two radiologists who were blind to the pathologic diagnosis reviewed CT images regarding size of cystic mass, mural nodule, septa, calcification, dilatation of the proximal, and distal bile ducts to the tumor, and the results were analyzed using multivariate analysis.

RESULTS: Mural nodule and dilatation of the bile ducts distal to the cystic tumor were more commonly seen in patients with cystic IPMT than in patients with biliary cystadenoma/cystadenocarcinoma and these are statistically significant, the P values being 0.029 and 0.016, respectively. Size of the cystic tumor, presence of septa, calcification, and dilatation of the bile duct proximal to the cystic tumor were not statistically different.

CONCLUSION: Biliary cystic IPMT could be differentiated from biliary cystadenoma/cystadenocarcinoma on CT images based on the presence of mural nodules and dilatation of the bile ducts distal to the cystic tumor.