The double duct sign is a radiological finding characterized by the simultaneous dilation of the common bile duct and the main pancreatic duct. This sign is significant because it often indicates an obstruction in the distal bile duct and pancreatic duct, frequently caused by serious underlying pathologies such as pancreatic carcinoma or periampullary tumors. [1] The double duct sign is most commonly visualized on imaging modalities such as computed tomography, magnetic resonance imaging, or endoscopic retrograde cholangiopancreatography.
The double duct sign results from the anatomical convergence of the biliary and pancreatic ducts at the ampulla of Vater, where obstructions can disrupt the drainage of both systems simultaneously. Common causes of such obstructions include pancreatic adenocarcinoma, periampullary cancer, cholangiocarcinoma, chronic pancreatitis, gallstone-related obstruction and strictures. [1] [2]
The double duct sign is a red flag finding in radiology, with malignancies accounting for the majority of cases. Early identification is crucial for diagnosis, staging in case of malignancy, management and for performing therapeutic interventions.