Type I choledochal cyst in association with familial adenomatous polyposis.

Choledochal cysts and familial adenomatous polyposis are infrequent disorders that are often manifest in childhood or in early adult life. The rarity and early presentation of these diseases suggests a genetic basis, which has been established for familial polyposis but not for choledochal cysts. We report a case of a 26-yr-old woman with both disorders and offer an alternative genetics-based etiology for the formation of choledochal cysts.