American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: summary and recommendations.

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for the diagnosis of malignancy in patients with biliary strictures of undetermined etiology. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework and addresses the role of fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS in the diagnosis of malignancy in patients with biliary strictures. In the endoscopic workup of these patients, we suggest the use of fluoroscopic-guided biopsy sampling in addition to brush cytology over brush cytology alone, especially for hilar strictures. We suggest the use of cholangioscopic and EUS-guided biopsy sampling especially for patients who undergo nondiagnostic sampling, cholangioscopic biopsy sampling for nondistal strictures and EUS-guided biopsy sampling distal strictures or those with suspected spread to surrounding lymph nodes and other structures.