Ciliated hepatic foregut cyst.

This study describes a solitary unilocular cyst of the liver, lined by ciliated, pseudostratified, columnar epithelium supported by a loose, relatively acellular lamina propria. The cyst wall was composed of a prominent smooth muscle band, of up to three layers, surrounded by an outer fibrous capsule. These features distinguish the cyst from biliary cystadenoma and make it histologically similar to previously described ciliated bronchial and esophageal cysts. This ciliated hepatic cyst and similar bronchial and esophageal cysts appear to represent a common spectrum of derivatives from the embryonic foregut. Cysts of this type have not been generally recognized to occur in the liver.