[Computerized tomography in the assessment of obstructive jaundice caused by hepatic hydatid cysts]

This paper reports on the CT findings of obstructive jaundice caused by hydatid cysts of the liver, which are an unusual event occurring in 5-10% of cases. Thus, only a few reports can be found in the literature dealing with the CT features of this syndrome. Eight patients with obstructive jaundice were selected from 87 patients with hydatid disease of the liver and examined with CT. The CT diagnosis of rupture into the largest bile ducts is based upon the demonstration of hepatic hydatid cysts together with intrabiliary hydatid sand, membranes and scolices and/or the identification of parietal discontinuity with communication between the cyst and the biliary tree. Rupture into the largest bile ducts was demonstrated in 7 patients. The following CT patterns were observed: 1) intrahepatic biliary tract dilatation (all cases); 2) extrahepatic biliary tract dilatation (6 cases); 3) cyst wall interruption (5 cases--in 3 of them the communication between the cyst and the dilated bile duct was demonstrated); 4) daughter cysts, fragmented membranes or hydatid sand in the biliary tree (5 cases); 5) hydatid material in the gallbladder (1 case) and, finally, disappearance of the daughter cyst visible on a previous CT examination (1 case). In another patient, the diagnosis of compressive jaundice without biliary communication was suggested because a bulky hydatid cyst was found near the hilum of liver. CT findings were confirmed with ERCP or at surgery. CT failed to reveal small tears with minute biliary radicles, which are usually asymptomatic, whose diagnosis could be made only with preoperative cholangiography. Hydatid cysts of the liver can cause obstructive jaundice because of main bile duct compression or of large bile duct perforation with consequent passage of hydatid material into the biliary tree. This complication should be promptly managed surgically to avoid potentially fatal complications, which makes a preoperative diagnosis essential.