Atypical Biliary Adenofibroma of the Liver: Related Treatment and Performance.

Biliary adenofibroma is an extremely rare benign liver tumor, but it may be a precancerous lesion of cholangiocarcinoma. So far, only 29 cases have been reported in the literature. A 30-year-old woman was admitted to our department for upper abdomen mass. The computed tomography scan showed a huge cystic and partly substantial mass between the left lobe of the liver and the descending duodenum, which was considered to be an exophytic tumor derived from the left lobe of the liver. Laparoscopic liver segment IVb resection and cholecystectomy were performed. Microscopic examination showed that the tumor was composed of glandular cavities of varying sizes and fibrous interstitium. The glandular cavity was covered with cubic or columnar epithelium without atypia. Some of the mesenchymal cells are myofibroblast-like and spindle-shaped with red-stained cytoplasm. The mesenchymal cells in some areas proliferate densely with moderate atypia. It was considered to be an atypical biliary adenofibroma with focal necrosis and active cell proliferation which may have malignant transformation potential. There was no recurrence and metastasis at a 6-month follow-up. Biliary adenofibroma is a rare benign tumor derived from the bile duct, but it may progress to malignancy and develop distant metastasis. It is difficult to distinguish it from other liver tumors through imaging examination and the gold standard of diagnosis is histopathological examination. Close clinical follow-up is recommended.