Occult carcinoma in an adult choledochal cyst.

The complications of choledochal cyst are avoidable if diagnosed early, and adequate resection undertaken. This case report describes the long history of right subcostal pain in a young man of 26 who had a squamous carcinoma in a choledochal cyst diagnosed after serial section of the excised cyst. Subsequent resection of the head of the pancreas showed histological residual tumour from which he died 4 months later. This case illustrates the need for complete early excision of a choledochal cyst to prevent this complication.