The double duct sign refers to the presence of simultaneous dilatation of the common bile and pancreatic ducts. Being an anatomical sign it can be seen on all modalities that can visualise the region, including: MRI, CT, ultrasound and endoscopic retrograde cholangiopancreatography (ERCP). In general, the double duct sign represents a malignant cause until disproved.
Pathology
Aetiology
Common
Less common
-
malignant
cholangiocarcinoma involving distal common bile duct
lymphoma
impacted gallstone in distal duct, with associated oedema, resulting in pancreatic duct obstruction
Rare
Case reports 1-3