Choledochal Cyst

  • Etiology: common channel
  • Types – 1. fusiform dilation of common bile duct (80-90%), 2. common bile duct diverticulum, 3. choledochocoele (intraduodenal diverticulum), 4. cystic dilation of intrahepatic and or extrahepatic ducts / Caroli’s disease
  • US: cystic mass in the liver that appears to communicate with the biliary tree
  • HIDA scan: radiotracer uptake in the lesion, confirming its communication with the biliary tree
  • Complications: stasis, stones, cholangitis, pancreatitis, malignancy (rhabdomyosarcoma in kids, cholangiocarcinoma in adults)
  • Clinical: classic triad is pain, jaundice, and RUQ mass
  • Clinical: presentation varies with age
    — Infant – jaundice + acholic stool
    — Child – biliary obstruction, jaundice, RUQ mass – or – recurrent pancreatitis – or – pain
    — Adult – pain

Cases of Choledochal Cyst

CT and US of choledochal cyst
Axial CT with contrast of the abdomen (upper left) shows a large round low density structure inferior to the liver and separate from the gall bladder. Transverse and sagittal US of the liver show the round structure to be cystic and in communication with a dilated biliary tree. Delayed image (lower left) from a hepatobiliary scintigraphy exam shows concentration of radiotracer into the round structure which is slowly excreted into the bowel. AP image of an intraoperative cholangiogram (lower right) shows dilation of the intrahepatic and extrahepatic biliary tree with free flow of contrast into the bowel.
US and nuclear medicine scan of choledochal cyst
Sagittal US of the liver (left) shows a cystic mass in the liver that appeared to communicate with the biliary tree. Image from a hepatobiliary scan (right) shows radiotracer uptake in the lesion, confirming its communication with the biliary tree.
US of choledochal cyst
Transverse US of the liver shows a cystic lesion distinct from the gallbladder in the liver. Hepatobiliary imaging showed it communicating with the biliary tree.