Choledochal cyst

Case contributed by Daniel Hyeong Seok Kim
Diagnosis certain


History of prematurity and bronchopulmonary dysplasia born at 34 weeks gestation. No history of fever, normal liver function tests without jaundice presenting with abdominal pain.

Patient Data

Age: 5 month old
Gender: Male

There is diffuse fusiform dilation of the common hepatic duct and the common bile measuring 15 mm in the maximum diameter and measuring 5 mm at its distal end. Also, noted is mild diffuse prominence of the left hepatic duct measuring 2-3 mm in maximum diameter and diffuse prominence and tortuosity of the cystic duct. The constellation of findings with fusiform dilation and tortuosity of common hepatic duct and common bile duct is concerning for type I fusiform choledochal cyst.  The possibility of type IVB choledochal cyst with cystic dilation versus cysts of the distal CBD is also considered.

The gallbladder is normal. No gallstones or discrete extrinsic compression. No focal lesion in the liver. The liver appears normal in size and signal intensity.

No acute process in the abdomen and pelvis.

Case Discussion

Choledochal cyst, characterized by cystic dilation of extrahepatic bile duct, is considered a premalignant condition most often found during childhood. Clinically it can present conditions of jaundice, abdominal pain, and palpable abdominal mass. Multiple classifications for choledochal cyst exist however Todani's modified classification includes five types.

Type I:

  • Type IA involves cystic dilation of whole extrahepatic biliary tree with anomalous pancreaticobiliary junction.

  • Type IB involves segmental dilation of extrahepatic biliary tree without anomalous pancreaticobiliary junction.

  • Type IC involves diffuse fusiform dilation of the whole extrahepatic biliary tree with anomalous pancreaticobiliary junction.

Type II: Diverticular dilation anywhere along the extrahepatic duct.

Type III: (Choledochocele) Involves intraduodenal cystic dilation of the distal common bile duct.

Type IV:

  • Type IVA multiple dilations affecting both intra and extrahepatic biliary tree.

  • Type IVB involves multiple dilations confined to the extrahepatic biliary tree.

Type V: (Caroli's disease) Multiple dilations confined to the intrahepatic biliary tree.

For treatment, all choledochal cysts should be resected and bile flow should be restored.


This case was submitted with supervision and input from:
Soni C. Chawla, M.D.
Health Sciences Clinical Professor,
Department of Radiological Sciences,
David Geffen School of Medicine at UCLA.
Attending Radiologist,
Olive View - UCLA Medical Center.

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