Endoscopic techniques to diagnose and manage biliary tumors

Malignancies of the bile duct are often suspected in patients with abnormal serum hepatic enzyme levels and obstruction of the biliary system. Although cross-sectional imaging can provide evidence for biliary obstruction and a malignancy arising from the bile duct, a definitive diagnosis is often obtained through the use of endoscopic procedures. Endoscopic retrograde cholangiopancreatography (ERCP), the most commonly performed procedure for cholangiocarcinoma, can provide a tissue diagnosis through brush cytology of the bile duct. Relief from biliary obstruction can be provided with temporary plastic stenting or permanent metal stenting. Photodynamic therapy guided by ERCP may provide improved palliation from biliary obstruction in the future. Endoscopic ultrasonography complements the role of ERCP and may provide a tissue diagnosis through fine-needle aspiration and staging through ultrasound imaging. High-resolution ultrasound images can provide detailed information regarding the relationship between a mass and the bile duct wall. Despite these advances in endoscopic techniques and imaging of the bile duct, a tissue diagnosis often remains elusive in many patients. In the future, molecular markers will be employed to improve the sensitivity for the detection of malignancy in bile duct samples obtained through brushing, aspiration, and biopsy.