Ciliated hepatic foregut cyst: a study of six cases and review of the literature.

Ciliated hepatic foregut cyst (CHFC) is a rare, benign, solitary cyst consisting of ciliated pseudostratified columnar epithelium, subepithelial connective tissue, a smooth muscle layer, and an outer fibrous capsule. We studied six previously unreported cases of CHFC and 50 cases from the literature. The literature search revealed that Friedreich first described the lesion in 1857 and hypothesized its congenital origin. The cyst generally is found incidentally on radiologic imaging or during surgical exploration, although one case presented with portal vein compression. It occurs more frequently in men and is found most commonly in the medial segment of the left hepatic lobe, unlike most other solitary cysts that show a female predominance and greater occurrence in the right hepatic lobe. Two of the 56 cases were multilocular. There has been an increase in the number of reports of CHFC during the past 15 years. This may reflect the increased availability and use of various radiologic imaging modalities. A large number of cases have been reported in the Japanese population, but the significance of this is unclear. CHFC should be considered in the differential diagnosis of other solitary liver cysts, including simple cysts, hepatobiliary cystadenomas, and parasitic cysts.