ConditionDigestive system
Choledochal Cyst (Bile Duct Cyst)
A choledochal cyst is a congenital (present from birth) balloon-like widening of the bile ducts, the tubes that carry bile from the liver to the intestine. It is rare and more common in girls and in people of East Asian descent. It may cause jaundice, belly pain or a lump in infants and children, or pancreatitis and cholangitis in adults. Because cysts carry a raised lifetime risk of bile duct cancer, the standard treatment is surgical removal with a new bile drainage route.
Also called: Bile duct cyst, biliary cyst, congenital bile duct dilatation, choledochal cysts
At a glance
- What it is
- A congenital dilation of the bile ducts inside and/or outside the liver.
- Who gets it
- Rare in Western countries; about 4 times more common in females; often found in childhood.
- Symptoms
- Jaundice, upper right belly pain, a belly mass, pale stools, and in adults pancreatitis or cholangitis.
- Diagnosis
- Ultrasound (including before birth), MRCP and sometimes ERCP.
- Treatment
- Surgical removal of the cyst and connection of the liver ducts to the intestine.
When to get help
Call 911 or go to the ER
- Fever with chills, jaundice and upper right belly pain (possible cholangitis)
- Severe upper belly pain spreading to the back with vomiting (possible pancreatitis)
See a doctor within a day or two
- A baby with yellow skin or eyes beyond 2 weeks of age, pale or white stools, or dark urine
- A child with recurrent upper belly pain, vomiting and jaundice
- A lump in the upper right belly
Book a routine appointment
- A choledochal cyst seen on a prenatal or incidental scan, which needs specialist review
- Long-term follow-up after cyst surgery
What a choledochal cyst is
Bile is made in the liver and flows through small ducts that join into the common bile duct, which empties into the small intestine near the pancreatic duct. In a choledochal cyst, part of this duct system is abnormally widened.
The leading explanation is an abnormal pancreaticobiliary junction: the pancreatic duct joins the bile duct too early, outside the normal muscular valve. Pancreatic juice can then flow back into the bile duct, irritating and weakening its wall so it balloons out.
Types (Todani classification)
| Type | Description | Frequency |
|---|---|---|
| I | Dilation of the common bile duct outside the liver | Most common, about 50 to 80 percent |
| II | A pouch (diverticulum) off the common bile duct | Rare |
| III | Dilation of the bile duct end inside the duodenal wall (choledochocele) | Rare |
| IV | Multiple cysts: IVa inside and outside the liver; IVb outside only | Second most common |
| V | Multiple cysts inside the liver only (Caroli disease) | Rare |
Symptoms
Infants and children
- jaundice (yellow skin and eyes)
- pale or clay-colored stools and dark urine
- a mass in the upper right abdomen
- belly pain, vomiting and poor feeding
- the classic triad of pain, jaundice and a mass is seen in a minority
In newborns, a cyst must be distinguished from biliary atresia, which also causes jaundice and pale stools but needs very early surgery.
Adults
- upper belly pain
- recurrent pancreatitis
- cholangitis: fever, jaundice and pain from bile duct infection
- gallstones and stones within the cyst
Some cysts are found by chance on a scan.
Complications
- cholangitis and liver abscesses
- pancreatitis
- stones in the bile ducts
- biliary cirrhosis from long-term obstruction
- cyst rupture (rare)
- bile duct cancer (cholangiocarcinoma): risk increases with age and is much higher than in the general population, which is the main reason for removal
Diagnosis
- Ultrasound: usually the first test; many cysts are now detected on prenatal ultrasound.
- MRCP (magnetic resonance cholangiopancreatography): a noninvasive MRI that maps the bile and pancreatic ducts and shows the junction.
- ERCP: a scope-based test used when treatment of stones or drainage is also needed.
- CT scan in some cases.
- Blood tests: liver function (bilirubin, enzymes), amylase or lipase.
Treatment
The standard treatment for types I and IV is complete removal of the cyst and the gallbladder, with a new connection between the liver bile ducts and a loop of small intestine (Roux-en-Y hepaticojejunostomy). This removes the abnormal duct tissue and separates bile from pancreatic juice. It can be done by open or laparoscopic surgery.
- Type II: removal of the pouch.
- Type III: often treated endoscopically.
- Type V (Caroli disease): may need partial liver removal or, if widespread, liver transplantation.
Simply draining the cyst into the intestine without removing it is no longer recommended, because cancer risk remains.
Infants with prenatally detected cysts are usually operated on in the first months of life, often before symptoms appear.
Outlook
After complete removal, most children and adults do very well. Long-term follow-up with liver blood tests and imaging is advised because of a small risk of narrowing of the new connection, stones and, rarely, cancer in remaining ducts.
Frequently asked questions
Is a choledochal cyst cancerous?
The cyst itself is not cancer, but the abnormal bile duct lining has a raised risk of developing bile duct cancer over time, especially in adults. This is why surgical removal is recommended even when the cyst causes no symptoms.
What causes a choledochal cyst?
It is present from birth. The most widely accepted cause is an abnormal junction where the pancreatic duct meets the bile duct, allowing pancreatic juice to flow back and weaken the bile duct wall. It is not caused by anything the parents did.
Can a choledochal cyst be found before birth?
Yes. Many are now seen on routine prenatal ultrasound as a cyst under the liver. After birth, further scans confirm the diagnosis, and surgery is usually planned in the first months of life.
What is recovery like after choledochal cyst surgery?
Most patients stay in the hospital for about 5 to 10 days. Children usually recover quickly and lead normal lives. Long-term follow-up with blood tests and ultrasound checks for complications such as narrowing or stones.
Sources
This guide was written from current patient and clinical guidance, including:
- American Pediatric Surgical Association: Choledochal cyst
- MedlinePlus: Choledochal cyst
- National Organization for Rare Disorders (NORD): Choledochal cysts
- American College of Gastroenterology: Clinical guideline on biliary disease
- Children's Hospital of Philadelphia: Choledochal cyst