Ciliated hepatic foregut cyst mimicking neoplasm

We describe a ciliated hepatic foregut cyst that was clinically considered neoplastic because it was large, bilocular, and associated with a high serological level of carbohydrate antigen 19-9 (CA 19-9). Histologically, the wall of the cyst showed characteristic pseudopapillae lined by ciliated stratified columnar epithelium with interspersed goblet cells and underlying smooth muscle. The epithelium was strongly immunoreactive for CA 19-9. We therefore conclude that large size, multilocularity, and elevated CA 19-9 do not exclude ciliated hepatic foregut cysts from diagnostic consideration.