Park JG, et al. – The purpose of this study was to analyze predictive factors for false–negative diagnosis of percutaneous forceps biopsies in patients suspected of having a malignant biliary obstruction. The evidence showed that percutaneous forceps biopsy serves relatively high accuracy in the diagnosis of malignant biliary obstructions. Remarkably, the predictive factors of false–negative biopsy were determined to be biopsy site and origin of primary tumour.