A case report of biliary cystadenoma and cystadenocarcinoma.

Three cases of intrahepatic biliary cystadenoma with mesenchymal stroma and one case of biliary cystadenocarcinoma are presented. Their immunohistochemical features and the surgical treatment are discussed together with a brief review of the literature. The benign cystadenomas stained positive for cytokeratin and CA 19-9 in the epithelium of the cyst wall. Mesenchymal stromal cells were strongly positive for a-SMA and moderately positive for desmin. The epithelium of the cystadenocarcinoma, however, was positive only for cytokeratin and the stroma only for a-SMA. Our findings indicate that biliary cystadenomas seem to be of primitive hepatobiliary origin. Furthermore, the malignant variant cystadenocarcinoma may loose its immunoreactivity for CA 19-9 and desmin.