Endoscopic transpapillary biopsies are of limited value in the diagnostics of bile duct strictures of unknown etiology-results of a histopathologically controlled study in 312 patients.

Our investigation aimed to evaluate the impact of endoscopic transpapillary forceps biopsies (ETP) in bile duct strictures of unknown etiology based on the largest European patient cohort at a tertiary referral center. To date only studies with limited patient numbers exist.Three-hundred-and-twelve patients (162 males, 150 females, mean age 62±12.7 years) with bile duct strictures of unknown etiology were examined with ETP. Sensitivity, specificity and accuracy of ETP were compared to the definite diagnosis proved by histopathology of surgical resection specimens or long-term follow-up of those patients not undergoing surgery.Using ETP a correct pe-interventional diagnosis was achieved in 211 out of 312 patients resulting in an accuracy rate of 67.6%. Eighty-six out of 187 malignant stenoses were correctly diagnosed by ETP, giving rise to sensitivity and specificity rates of 46 and 100%, respectively. Sensitivity of ETP in cholangiocellular carcinoma was significantly superior to that in pancreatic carcinoma (52.5% vs. 35.6%, p = 0.026). Sensitivity and accuracy rates of ETP did not depend on the localization of the stenosis in the common bile duct.ETP alone is not reliable enough in diagnosing bile duct malignancies as shown by low sensitivity and accuracy rates (false-negative rate of 32%).