Primary sclerosing cholangitis mimicking choledocal cyst type 1 in a young patient.

A choledochal cyst type I was diagnosed in a 12-year-old boy in 1984. The diagnosis was made using ultrasound and confirmed using computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP). Instead of the usual surgical treatment, endoscopic balloon dilatation of the sphincter of Oddi and the distal common bile duct was carried out using an endoscopic procedure. The patient experienced relief of symptoms, gained weight and felt healthy again. An ERCP performed in 1990, because of increasing levels of liver enzymes and clinical features of abdominal pain and fatigue, revealed typical cholangiographic findings associated with primary sclerosing cholangitis, including bile duct irregularities with diffuse narrowing and twisting of the bile ducts with localized ectatic and strictured areas. Percutaneous needle liver biopsy confirmed the diagnosis. We conclude that primary sclerosing cholangitis should be considered when interpreting ERCP films from patients who are supposed to have choledochal cysts type I.