Endoscopic ultrasonography in the evaluation of indeterminate biliary strictures

Biliary strictures may be due to a variety of benign and malignant processes. Imaging with endoscopic ultrasonography (EUS) often suggests the diagnosis, but is usually not definitive. EUS-guided fine needle aspiration (FNA) facilitates the diagnosis of extrahepatic biliary strictures, although peritioneal metastases due to needle tract seeding may occur after EUS-FNA of cholangiocarcinoma. In addition to diagnosis of strictures, EUS may play an important role in staging of cholangiocarcinoma.