Are a Double Duct Sign or Endoscopic Biopsies Reliable Predictors of Malignancy in Periampullary Lesions

To determine the predictive value of a double duct sign (DDS) and endoscopic biopsies to differentiate invasive carcinoma from premalignant lesions.

Two hundred and forty one patients (mean age 65.8; male 55.6%) diagnosed with a periampullary lesion from January 1987 through March 2013 were reviewed retrospectively with regard to background characteristics, histology of endoscopic biopsy, diameter of both common bile duct (CBD) and main pancreatic duct (PD), bilirubin levels and final diagnosis.

DDS predicted malignancy with 73% specificity and 72% sensitivity. Endoscopic biopsies predicted malignancy with 96% specificity, 71% sensitivity and a negative predictive value (NPV) of 51%. Multivariable logistic regression analysis showed that DDS is a significant predictor for the presence of malignancy with an odds ratio of 6.37 adjusted to age, gender and endoscopic biopsy.

Although DDS is indicative of malignancy in periampullary lesions, its clinical use is limited, given the low sensitivity and specificity. The diagnostic value of endoscopic biopsies is also poor due to a low sensitivity and NPV. If a double duct sign is present, physicians must be aware of an increased possibility of a malignant underlying cause, even if the histopathological examination of the biopsies did not show invasive malignancy.