Choledochal Cyst

Overview

A choledochal cyst is a condition, usually present from birth, in which part of the bile duct system becomes abnormally widened into a balloon-like sac, or cyst. The bile ducts carry bile from the liver and gallbladder to the intestine to help digest fats. When a portion of these ducts is abnormally enlarged, bile flow can be disrupted, leading to a backup of bile, infection, or other problems.

Choledochal cysts can appear at any age but are often found in infancy or childhood. They are more common in girls and in people of Asian descent. Although they are usually benign, they need treatment because, over time, they can cause repeated infections, stones, and an increased risk of cancer in the bile ducts. Surgery to remove the cyst is the standard treatment.

Symptoms

Symptoms vary with age and the size of the cyst. The classic combination, more often seen in children, includes:

• Jaundice, yellowing of the skin and eyes from disrupted bile flow
• Abdominal pain, often in the upper right side
• A palpable lump or mass in the upper abdomen

Other possible features include nausea and vomiting, pale stools, dark urine, fever from infection of the bile (cholangitis), and, in infants, persistent jaundice and poor feeding. Some cysts cause few symptoms and are found incidentally on imaging done for another reason.

Causes

The exact cause of choledochal cysts is not fully understood, but they are considered a congenital problem, meaning they develop before birth. A leading theory is that there is an abnormal junction where the bile duct and the pancreatic duct join, allowing digestive juices from the pancreas to flow back into the bile duct. This reflux is thought to weaken and damage the duct wall, causing it to widen over time.

Because the abnormality is present from birth, choledochal cysts are not caused by diet, lifestyle, or anything done during pregnancy. There are several types, classified by where the widening occurs in the bile duct system.

Risk Factors

• Female sex, as choledochal cysts are more common in girls and women
• Asian ancestry, where the condition is reported more often
• An abnormal junction of the bile and pancreatic ducts

In most cases, the condition arises without any identifiable preventable risk factor.

Diagnosis

Diagnosis relies mainly on imaging that shows the widened bile duct.

• Ultrasound: often the first test, and able to detect cysts even before birth in some cases.
• MRI with MRCP: detailed imaging of the bile and pancreatic ducts that shows the size and type of cyst.
• CT scan: may be used to assess the cyst and surrounding structures.
• Blood tests: liver tests and bilirubin to assess bile flow and check for infection.

Identifying the type of cyst helps guide the surgical approach.

Treatment

The standard treatment for most choledochal cysts is surgery to remove the cyst, because leaving it in place carries a risk of infection, stones, and bile duct cancer.

• Surgical removal of the cyst: the affected portion of bile duct is taken out.
• Reconstruction of bile drainage: a loop of intestine is connected to the remaining healthy duct so bile can flow into the intestine again.
• Treating complications: infection (cholangitis) is treated with antibiotics, and any stones are managed.
• Long-term follow-up: ongoing monitoring is recommended because a small cancer risk can remain even after surgery.

With timely surgery, most people do well, and removing the cyst greatly reduces the risk of serious complications.

Prevention

Choledochal cysts cannot be prevented because they are present from birth. The focus is on early diagnosis and treatment to prevent complications:

• Prompt evaluation of persistent jaundice, abdominal pain, or an abdominal mass
• Timely surgery once a cyst is diagnosed, to lower the risk of infection and cancer
• Long-term follow-up after surgery to monitor the bile ducts and liver

When to See a Doctor

See a doctor if you or your child have unexplained jaundice, persistent upper abdominal pain, or a lump in the abdomen. Seek prompt or emergency care if there are signs of bile duct infection or blockage, such as:

• Fever and chills with abdominal pain and jaundice
• Severe or worsening abdominal pain
• Persistent vomiting, pale stools, and dark urine
• In an infant, ongoing jaundice with poor feeding or lethargy

These can indicate a serious complication that needs urgent treatment.

Related Topics

Frequently Asked Questions

References

1. MedlinePlus, U.S. National Library of Medicine. Bile duct diseases.
2. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Bile duct disorders.
3. American Liver Foundation. Bile duct conditions.
4. National Organization for Rare Disorders (NORD).