Edema of the papilla of Vater simulating retained common duct stone.

A prominent or edematous papilla of Vater may prodce a rounded filling defect in the duodenum. During T tube or operative cholangiography, this may simulate a calculus impacted in the distal or intramural portion of the common bile duct. This communication reports such an occurrence. Recognition of this potential cause for a false positive cholangiogram should prevent some instances of unnecessary instrumentation of the common bile duct.