Endoscopic methods for cytopathologic diagnosis of bile duct strictures

Differential diagnosis of malignant and benign bile duct strictures carries an important meaning in determining the most appropriate therapeutic approaches. However, this is not always easily achieved, and the bile duct strictures is considered indeterminate when cross-sectional imaging is unrevealing and pathology is nondiagnostic. Endoscopic retrograde cholangiopancreatography (ERCP) with brush cytology and intraductal forceps biopsy technique are traditionally deemed to be a first coming endoscopic technique for obtaining cytopathologic materials from the indeterminate bile duct strictures. Recently, various non-ERCP techniques, such as endoscopic ultrasound guided fine needle aspiration (EUS-FNA) and targeted biopsy with single operator cholangioscopy was developed and widely used in clinical practice. EUS-FNA for hilar cholangiocarcinoma and distal bile duct strictures (especially caused by pancreas head cancer) showed comparable to superior test performances compared to standard ERCP tissue sampling techniques. Single operator cholangioscopy with SpyBite biopsies were reported to have reliable test performance in detecting or excluding malignant bile duct strictures.