Endoscopic retrograde brush cytology. A new technique. Endoscopic retrograde cholangiopancreatography has been shown to be a very valuable adjunct in the diagnosis of malignancy involving the biliary and/or pancreatic ductal system. However, characteristic endoscopic retrograde cholangiopancreatography radiographic findings associated with malignant strictures are frequently not specific and cytological confirmation becomes essential for the diagnosis. Unfortunately, the current overall diagnostic yield of positive cytology in such circumstances ranges from 18%-56% depending on the technique. A new brush device has been designed which is uniquely adapted to pancreaticobiliary strictures of varying anatomical configurations. This study shows results using this new cytology brush in a series of 53 patients with pancreaticobiliary malignancy. A significant improvement in the cytological yield of tumor confirmation was obtained with a diagnostic sensitivity of 70% and specificity of 100% using the new brush technique. 