Difficulty in diagnosing complications of Caroli's disease.

Congenital cystic dilatation of the biliary tree (Caroli's disease) is a rare condition that usually presents with ascending cholangitis. This report demonstrates the difficulty of recognizing other complications of Caroli's disease antemortem. A 35-year-old man developed a subphrenic abscess and malignant transformation of the biliary tree; both were clinically undetected. Episodes of pain, pyrexia, or weight loss should be assessed carefully and the complications of Caroli's disease considered before attributing such symptoms to recurrent cholangitis.