Choledochal cystic malignancies.

Cystic diseases of the bile ducts are rare, but relatively more prevalent in females, and more common in Japan and Asia. Most are diagnosed in children under 10 years of age, with varying patterns of symptoms including right upper quadrant pain, jaundice, and fever. Up to 20% of bile duct cysts are diagnosed in adults, including during pregnancy, in whom the diagnosis can be confounded by associated cholelithiasis, or by abnormalities of the pancreatic junction with pancreatitis. The risk of malignant transformation increases with age, and is more common in cysts of Alonso-Lej Types I, IV, and V (Caroli's Disease). Intracystic lithiasis is frequently associated with tumour, and can give similar radiological appearances. Tumours are often first diagnosed at laparotomy, and can already be unresectable. More than half the tumours are intracystic, but malignant change in cyst mucosa without a tumour mass is often not recognised at surgery. In addition, malignant change in bile duct epithelium can occur after cyst excision, sometimes after many years, and in areas of the biliary tree remote from the cyst, including the gall-bladder. Cyst excision should be attempted at all ages, and patients closely monitored thereafter. Malignancy should be suspected in all adults with bile duct cysts. Hepatectomy, partial or total with transplantation, is the treatment of choice in Caroli's disease.