Biliary Stent Migration: A Rare Cause of a Bladder Stone.

Our patient presented with dysuria and pneumaturia without any prior urologic instrumentation. History included choledocolithiasis requiring endoscopic retrograde cholangiopancreatography and biliary stenting. Imaging showed a large bladder stone. The patient was taken to surgery and found to have diverticulitis. The sigmoid was resected and the bladder was found to have a small fistula tract. The bladder was opened and a large calculus was identified and extracted. The stone was opened and found to contain a biliary stent. Although biliary stenting is generally considered safe, migration can occur. This is the only report of biliary stent migration into the bladder and subsequent stone formation.