The CT findings of hepatic biliary cystadenoma and cystadenocarcinoma

Objective: To evaluate the CT features and the pathologic basis of intrahepatic biliary cystadenoma and cystadenocarcinoma. Methods: Six cases of biliary cystadenoma and cystadenocarcinoma were collected. All cases were conformed by operation and pathology. Plain scan and enhanced scan were performed in three cases. Plain scan and double phase (arterial and portal) enhanced scan with spiral CT were performed in other three cases. The CT features of 6 cases of biliary cystadenoma and cystadenocarcinoma were analyzed retrospectively and correlated with the pathologic findings. Results: one case was biliary cystadenoma with multilocular cyst and one was canceration from the biliary cystadenoma. The other four cases were cystadenocarcinoma, three with single cyst and the other one with multilocular cyst. All of six cases were revealed as cystic mass in CT scan. Of the 5 malignant tumors, four cases had mural nodules and/or papillary excrescences and the other one had cystic wall thickening. Irregular thickening of internal septa was shown in three cases. Two had calcification and one had bleeding in the cyst and fluid-fluid level. Conclusion: CT scan can reveal the some characteristic features of biliary cystadenoma and cystadenocarcinoma. But differentiation between biliary cystadenoma and cystadenocarcinoma is still difficult on CT scan. Manifestations with irregular thickening of internal septa, mural nodules, papillary excrescences, bleeding in the cyst and coarse calcifications increase the likelihood of the diagnosis of biliary cystadenocarcinoma. (authors)