Case 7 -

Biliary Cystadenoma Linda D. Ferrell, M.D. Wendy L. Frankel, M.D.

Clinical history: 32 year old asymptomatic woman with a large palpable non-tender mass in her RUQ found on physical exam. CT scan showed a mass in the liver. The mass was cystic and measured 8 cm. Case 7 - Figure 1 - Multilocular cyst partially denuded with an epithelial lining, low power Case 7 - Figure 2 - Mucinous epithelium with basally oriented nuclei and an underlying "ovarian type" stroma, medium power Pathologic findings: Multilocular cyst partially denuded with a focal epithelial lining. Mucinous epithelium with basally oriented nuclei and an underlying "ovarian type" stroma. Diagnosis- Biliary Cystadenoma Comment Hepatobiliary (biliary) cystadenoma (and cystadenocarcinoma) Clinical features. Hepatobiliary, or biliary, cystadenomas are rare lesions, with a higher incidence in women and histological counterparts in the pancreas and ovary. These cystic tumors are typically associated with an ovarian type of stroma when they occur in women, but not in men. The lesion can also be associated with the development of cystadenocarcinoma, which tends to be a low-grade adenocarcinoma in the women, but has greater malignant potential in men. Gross features. Hepatobiliary cystadenomas are almost always multilocular with a smooth or somewhat trabeculated inner surface to the cyst walls. The cysts contain fluid of variable appearance, including serous, mucinous, gelatinous, occasionally hemorrhagic, or even purulent. There is no communication between the cysts and the biliary tree. Large polypoid projections from or dense masses in the wall of a cyst often indicate zones of malignant transformation. Microscopic features. The cysts are lined by a single layer of epithelial cells, usually of a mucinous type. The cells can vary from flattened to cuboidal to columnar shapes, and small papillary tufts may be present along the surface. The epithelial nuclei are bland and basally located without mitotic activity. The underlying stroma often has an appearance similar to ovarian stroma (when the lesion occurs in a woman), but this stroma may not be uniformly present. A more densely, hyalinized stroma often separates the ovarian-like stroma from the adjacent liver. The cyst walls may also be lined focally by macrophages, calcification, or scar-like tissue. Cystadenocarcinomas arising in this lesion often have a tubulopapillary type of histology. Features such as marked nuclear pleomorphism, loss of polarity, mitotic figures, and multilayering of the epithelium all could suggest the possibility of transformation to malignancy, and be designated as in situ cystadenocarcinoma, but invasion of the tumor into the stroma is the best evidence for the presence of carcinoma. Simple cyst Clinical features. Simple biliary cysts are generally an incidental finding. When multiple cysts are present, they often represent a component of polycystic disease and are often accompanied by von Meyenburg complexes (biliary hamartomas). Simple cysts have no or only slight premalignant potential. Gross features. Simple cysts are usually found in a subcapsular location, but some can occur deeper in the parenchyma. They typically contain a clear, light-yellow fluid. Microscopic features. Simple cysts are lined by a cuboidal to low columnar epithelium with a fibrous wall. The epithelium may be disrupted or may be flattened, and the wall may be thickened. Evidence for reactive changes such as recent or remote hemorrhage in the cyst wall may be present.