Biliary cystic
tumors, such as
cystadenoma and
cystadenocarcinoma, are rare cystic
tumors of liver accounting for fewer than 5% of all intrahepatic
cysts of biliary origin. Most biliary cystic
tumors arise from intrahepatic bile duct and 10-20% arise from extrahepatic bile duct like common hepatic duct, common bile duct, and gallbladder. The first case report of biliary
cystic neoplasm in Korea dated back to 1975 by Bae et al, and over 40 cases of
cystadenoma and 35 cases of
cystadenocarcinoma were reported since then. These
tumors usually present in middle-aged women with a mean age of 50 years. Biliary
cystadenomas are lined by single layer of cuboidal or columnar epithelium and are very often multilocular with septal or papillary foldings. Over 80% of
cystadenoma have dense mesenchymal stroma composed of dense spindle cells, like ovary. The epithelial lining of
cystadenocarcinoma exhibits cellular atypia, mitotic activity, and infiltrative growth, but part of lining epithelium retain the feature of
cystadenoma, which support the
adenoma-
carcinoma sequence. The size of
tumors varies from 1.5 to 35 cm. Many patients are asymptomatic, except for the presence of palpable mass. When symptoms are present, they include epigastric or right upper quadrant
pain or
jaundice by enlarged mass. Biliary cystic
tumor should be considered when a single or multilocular cystic lesion with papillary infoldings is detected in the liver by computed tomogram (CT) or ultrasound (US). Cystic wall and internal foldings can be seen enhanced by enhanced CT. US reveals a hypoechoic cystic mass with echogenic septation or papillary infoldings.
Cystadenocarcinoma should be suspected when there is elevated mass or nodule in the wall or foldings, or thickened cystic wall on CT or US. But it is extremely difficult to differentiate between
cystadenoma and
cystadenocarcinoma by imaging alone. Increased
tumor markers,
carcinoembryonic antigen and
carbohydrate antigen 19-9, in serum or cystic fluid have been reported in biliary cystic
tumor. But
tumor markers cannot distinguish
cystadenocarcinoma from
cystadenoma or both from other cystic lesions of liver. Malignant cells are not usually recovered in patients with
cystadenocarcinoma who underwent cystic fluid cytology before and during surgery. The treatment of choice is radical excision of the mass by means of lobectomy or wide
tumor excision. Aspiration, marsupialization, and drainage must be avoided. Inadequate excision of both
cystadenoma and
cystadenocarcinoma may lead to recurrence. Prognosis after complete excision is excellent.