Choledochal Cyst

A choledochal cyst, or biliary cyst, is a rare condition that affects your biliary tree. It causes one or more of your bile ducts to widen or enlarge (dilate). Your bile ducts are tubes that carry bile from your liver to your gallbladder and small intestine.

Choledochal cysts usually affect the ducts outside your liver (extrahepatic ducts), like your common bile duct. But they can also affect the ducts inside your liver (intrahepatic ducts). Healthcare providers diagnose children with bile duct cysts most often. But they can also affect adults.

How serious is a choledochal cyst?

A choledochal cyst can be serious because it can lead to severe complications without treatment. It may cause bile to back up, leading to infections and other health issues. Over time, the cyst can increase the risk of cancer in your bile ducts or gallbladder.

Because they’re considered potentially dangerous, healthcare providers generally recommend immediate treatment.

Choledochal cyst types

Healthcare providers classify choledochal cysts by type. These types are based on their location and number:

• Type I: Type I is the most common type. Your common bile duct widens in a spindle shape. It may look like a balloon or a fat cigar, depending on its subtype.
• Type II: This type is rare. A small pouch (diverticulum) forms anywhere along your outer bile ducts.
• Type III (choledochocele): Also rare, this type forms when the lower part of your common bile duct swells inside the first part of your small intestine (duodenum).
• Type IV: Type IV is the second most common. Multiple cysts form, and there are subtypes. Cysts may affect the inner and outer ducts. Or they may affect just the outer ducts.
• Type V (Caroli disease): This type involves multiple cysts of the inner bile ducts only. It can lead to infections that keep coming back. It may require a liver transplant.
• Type VI: This type occurs when a cyst forms on your cystic duct. That’s where the neck of your gallbladder connects to your common hepatic (liver) duct. It’s very rare.

What is the classic triad of a choledochal cyst?

The classic triad describes the three main symptoms that a choledochal cyst may cause. These three symptoms are:

• Abdominal pain: Pain that usually affects your upper right abdomen
• Jaundice: Yellowing of your skin and the whites of your eyes due to bile buildup
• A mass you can feel: A lump in your abdomen, often in the upper right quadrant

But most people don’t have all three symptoms. Many only have one or two. Other possible symptoms include:

• Nausea
• Vomiting
• Fever
• Itching
• Unexplained weight loss

Choledochal cyst causes

Choledochal cysts are congenital. That means they’re present at birth. Scientists aren’t exactly sure why these form.

They may form due to a problem with the way your bile duct and pancreatic duct connect. Or they may occur because your bile ducts didn’t form properly during fetal development.

What are the complications associated with a choledochal cyst?

Without treatment, choledochal cysts can cause both immediate problems and long-term risks. Complications can include:

• Bile duct infection (cholangitis)
• Pancreas inflammation (pancreatitis)
• Gallstones or bile duct stones
• Liver damage
• Cyst rupture
• Cancer (bile duct cancer)

How doctors diagnose this condition

Your healthcare provider may first see a choledochal cyst on a prenatal ultrasound.

Sometimes, they find them by accident if you’re having an imaging test for an unrelated condition.

They’ll use imaging tests to confirm a diagnosis. These tests include:

• Abdominal ultrasound
• CT scan
• MRI scan
• Magnetic resonance cholangiopancreatography (MRCP)
• Endoscopic ultrasound (EUS)
• Endoscopic retrograde cholangiopancreatography (ERCP)
• Hepatobiliary scintigraphy (HIDA scan)

How do you treat a choledochal cyst?

Choledochal cyst treatment depends on the type. Healthcare providers surgically remove most cysts to prevent complications. They often use minimally invasive methods like laparoscopic or robotic surgery. Treatment for each type includes:

• Types I and IV: Providers completely remove these cysts. They also remove most of the bile ducts outside your liver and your gallbladder. They’ll reconstruct where your bile flows.
• Type II: Providers often treat this type with a simple surgical removal.
• Type III: Providers only treat this type if it causes symptoms.
• Type V: For this type, providers focus on managing your symptoms and preventing infections. You may eventually need a liver transplant.
• Type VI: These cysts are so rare that providers don’t have a standard procedure. But they’ll likely remove the cyst completely.

If you have an infection or a blockage, you may need antibiotics, digestive rest and monitoring. Your provider may also place temporary stents or tubes to help with drainage.

When should I see my healthcare provider?

After treatment, you’ll have follow-up appointments with your provider. These are important because even after removal, you can develop problems in your remaining bile ducts. These include narrowing, stones or, rarely, cancer.

You should get medical attention right away if you have:

• Sudden, severe pain
• Vomiting that won’t stop
• High fever
• Worsening jaundice

These signs may mean you have a complication like an infection or a blockage.

What is the outlook (prognosis) for someone with a choledochal cyst?

The prognosis depends on several factors, including:

• The type of cyst
• Whether it’s treated
• If you have any complications

With treatment, most people do very well. Surgery lowers the risk of developing a serious health issue. Early diagnosis and complete surgical removal usually lead to a good long-term outcome.

Without treatment, a choledochal cyst carries a higher risk of complications. These include repeated infections, bile duct blockage and an increased risk of cancer over time.