Double-duct sign in the era of endoscopic ultrasound: the prevalence of occult pancreaticobiliary malignancy.

Background And Aim: Simultaneous dilatation of the common bile duct and pancreatic duct, "double-duct sign" (DDS), is an ominous finding concerning for pancreaticobiliary malignancy. Little evidence exists to guide the initial evaluation and subsequent follow-up for patients with DDS in the absence of jaundice or focal mass noted on computed tomography (CT)/ magnetic resonance imaging (MRI). Endoscopic ultrasound (EUS) is often recommended in the evaluation of such patients, however, the prevalence of malignancy remains unclear. We sought to determine the prevalence of pancreaticobiliary neoplasm in this patient group on initial EUS evaluation and on subsequent clinical follow-up.

Methods: We performed a retrospective analysis of a prospective database at a tertiary-care academic medical center between 2010 and 2012. Eighty-two patients were identified who underwent EUS evaluation for DDS without evidence of a mass on CT/MRI and without jaundice.

Results: Sixty-eight of 82 patients had confirmed DDS on EUS with biductal dilation. Six (9 %) of 68 patients were found to have a mass lesion on EUS. In these patients, final diagnoses were pancreatic carcinoma (n = 4), ampullary carcinoma (n = 1) and ampullary adenoma (n = 1). In the 62 patients without evidence of a focal mass on initial EUS, the most common diagnoses were benign ductal dilation (n = 42), chronic pancreatitis (n = 9) and choledocholithiasis (n = 8). Fifty-eight (94 %) of 62 patients had documented median follow-up of 13 months, and none developed subsequent evidence of previously unrecognized malignancy.

Conclusions: The presence of double-duct sign on EUS in patients without jaundice or mass lesion on CT/MRI is most frequently associated with benign conditions. When a mass is not detected on EUS, subsequent evidence of malignancy is unlikely.