Pancreatic duct strictures: Identifying risk of malignancy

Background: This study aimed to define PDS characteristics that predict malignancy and would thus invoke further diagnostic evaluation or aggressive treatment. Methods: 355 cases of PDS were diagnosed by ERCP during a 7-year period at a single institution. A retrospective review identified clinical/demographic patient data and ERCP results. Results: 218 (61%) patients with a PDS were found to have an isolated PDS. Twelve percent of isolated PDS and 79% of CBD stricture-associated PDS were malignant. The sensitivity and specificity for the double duct sign for malignancy were 77% and 80% respectively, and the positive predictive value was 65%. Predictors of malignancy were statistically similar for both isolated PDS and those associated with a CBD stricture. Univariate predictors of malignancy included stricture location in the pancreatic head/neck, jaundice, and patient age. Predictors of benign disease included a history of pancreatitis, the presence of multiple strictures, pancreatic duct stones, pseudocyst, pancreas divisum anatomy, irregular side branches, and irregular pancreatic duct morphology. Less than 1% of patients with either pancreas divisum anatomy, pancreatic duct stones, or pancreatic pseudocyst had malignancy. Using malignancy as the dependent variable, multivariate factors included in the final prognostic equation were history of pancreatitis (odds ratio 0.009 with history of pancreatitis), stricture location in the head or neck (odds ratio 42) and irregular pancreatic duct side branches (odds ratio 0.05 with irregular branches). Conclusions: This study demonstrates that certain characteristics of PDS can predict the subset of patients who have an increased risk of cancer.