Accuracy and complication rate of brush cytology from bile duct versus pancreatic duct

Background: The accuracy and complication rates of brush cytology obtained from pancreaticobiliary strictures have not been fully defined. In this study we compared the accuracy and complications of brush cytology obtained from bile versus pancreatic ducts. Methods: We identified 148 consecutive patients for whom brush cytology was done during an ERCP from a database with prospectively collected data. We compared cytology results with the final diagnosis as determined by surgical pathologic examination or long-term clinical follow-up. We followed all patients and recorded ERCP-related complications. Results: Forty-two pancreatic brush cytology samples and 101 biliary brush cytology samples were obtained. The accuracy rate of biliary cytology was 65 of 101 (64.3%) and the accuracy rate of pancreatic cytology was 30 of 42 (71.4%). Overall sensitivity was 50% for biliary cytology and 58.3% for pancreatic cytology. Of 67 patients with pancreatic adenocarcinoma, sensitivity for biliary cytology was 50% versus 66% for pancreatic cytology. Concurrent pancreatic and biliary cytology during the same procedure increased the sensitivity in only 1 of 10 (10%) patients. Pancreatitis occurred in 11 (11%) patients (9 mild cases, 2 moderate cases) after biliary cytology and in 9 (21%) patients (6 mild cases, 3 moderate cases) after pancreatic cytology (p = 0.22). In 10 patients who had pancreatic brush cytology, a pancreatic stent was placed. None of these patients developed pancreatitis versus 9 of 32 (28%) patients in whom a stent was not placed (p = 0.08). Pancreatic cytology samples obtained from the head of the pancreas were correct in 13 of 18 (72%) cases, from the genu in 7 of 7 (100%) cases, from the body in 5 of 9 (55%) cases, and from the tail in 4 of 7 (57%) cases. Conclusion: The accuracy of biliary brush cytology is similar to the accuracy of pancreatic brush cytology. The yield of the latter for pancreatic adenocarcinoma is similar to that of the former. Complication rates for pancreatic cytology are not significantly higher than the rates for biliary cytology. The placement of a pancreatic stent after pancreatic brushing appears to reduce the risk of postprocedure pancreatitis.