Hepatobiliary cystadenoma with mesenchymal stroma: presentation of one case and review of the literature.

We present one case of hepatobiliary cystadenoma with mesenchymal stroma (CMS) which is a very unusual tumor of the biliary tract. These rare neoplasms have been identified as a distinct clinicopathological entity. They occur exclusively in middle-aged women with an average age of 45 years, and are located on the right hepatic lobe. Histologically, CMS are characterized by the presence of a typical dense stroma between an inner epithelial lining and an outer loose connective layer. Malignant transformation may occur and therefore a complete surgical resection of these premalignant neoplasms is indispensable.