Ciliated hepatic foregut cyst with extensive squamous metaplasia: report of a case.

Ciliated hepatic foregut cysts (CHFC) are rare cystic lesions of the liver composed of a ciliated pseudostratified columnar epithelium with mucous cells, connective tissue, and smooth muscles bundles. We report the first case of CHFC with extensive squamous metaplasia without dysplasia or carcinoma. A unilocular, avascular, hypoechoic 60-mm liver lesion located in segment IV was detected by ultrasonography in a 31-year-old woman. The cyst was surgically removed and was lined mainly by a regular squamous epithelium without keratin formation. After extensive sampling, a ciliated pseudostratified columnar epithelium with some alcian blue-positive goblet cells was identified. The lesion was totally examined and there was no epithelial dysplasia or carcinoma. Squamous epithelium is very rare in hepatic foregut cysts and may degenerate into squamous carcinoma. Squamous epithelium is also described in biliary cysts. When squamous epithelium is identified in a liver cyst, an extensive sampling is recommended to identify possible foci of squamous carcinoma and to classify more precisely the histological type of the lesion. Because some cases of squamous carcinoma have been described in CHFC, surgical removal of the lesion may be more appropriate than close follow-up or sclerosing therapy.