Incidentally discovered white subcupsular liver nodules during laparoscopic surgery: biliary hamartoma and peribiliary gland hamartoma.

During routine laparoscopic surgery, the surgeon may encounter the presence of small white subcapsular liver nodules, either solitary or multiple. The lesions may mimic liver metastasis and in many cases are not demonstrated in the preoperative ultrasound or computed tomography. The aim of this article is to familiarize the laparoscopic surgeon with the incidental discovery of these nodules which represent the two types of intrahepatic benign bile duct proliferations and include biliary hamartomas, which are usually multiple benign malformations of the intrahepatic bile ducts, and peribiliary gland hamartoma, which is usually solitary and consists of a benign epithelial tumor of the liver derived from bile duct cells.