Trousseau's syndrome caused by malignant degeneration of a choledochal cyst.

The patient described in this report represents the first reported case of Trousseau's syndrome caused by a malignancy arising in a choledochal cyst. The clinical features were classic, with thrombophlebitis migrans, resistance to anticoagulation, and an occult, mucin-producing adenocarcinoma. The increased recognition of the malignant potential of choledochal cysts should encourage clinicians to consider these unusual anomalies in patients with jaundice or other abnormalities of hepatic function. When possible, the cyst should by excised to minimize the risk of malignant degeneration.