Choledocholithiasis associated with malignant biliary obstruction--significance and management.

Distal bile duct stones and proximal extra-hepatic malignant biliary obstructions may coexist. These stones, probably predating the development of the malignant obstruction but of unknown aetiological significance, were found in seven of 60 patients with proximal tumours (11.6%) at percutaneous biliary drainage. In two of these cases, stones blocked outflow from a supra-ampullary stent. All seven patients also had evidence of gall-bladder stones. Five of the seven patients had cholangiocarcinoma, giving an incidence of duct stones in such patients (n = 27) of 18.5%. In one case, the stones were removed endoscopically, in four, the stones were removed percutaneously and, in the remaining two cases, they were left in situ beside a stent. None of 120 cases with malignant obstruction had stones proximal to the obstruction. Distal common duct stones are associated with proximal malignant biliary duct obstruction, especially with cholangiocarcinoma and coexisting gall-bladder stones. They may interfere with stent function and cause diagnostic confusion at cholangiography.