Do Bile Duct Hamartomas Cause Cancer? What to Know

Bile duct hamartomas are lesions that grow in the liver. These rare growths are usually harmless, but there’s a small chance they could become cancerous. Your doctor may recommend treating them with surgery.

Experts consider bile duct hamartomas a type of liver disease.

These benign (noncancerous) lesions are also known as von Meyenburg complexes. Made up of thickened tissues and inflammatory cells, they generally show up as multiple growths, often arranged in a “starry sky”-like pattern. They’re believed to stem from the abnormal development of bile ducts.

Usually, these growths remain small — no more than 5 millimeters . They’re also uncommon, though research from 2017 suggests that they’ve become more common in recent years. Research involving autopsy data suggests that an estimated 0.6% to 5.6% of adults have bile duct hamartomas.

Here’s what else to know about bile duct hamartomas, including their diagnosis and potential treatment.

Hamartomas vs. adenomas

Bile duct hamartomas are sometimes also called bile duct adenomas. These two growths are only subtly different, and some experts use the terms interchangeably.

Adenomas are benign tumors, while hamartomas are benign masses of abnormal cells and tissues that resemble tumors. Unlike tumors, hamartomas typically don’t spread to other areas.

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Since they’re rare and usually don’t show any symptoms, bile duct hamartomas are usually only discovered during an autopsy or a surgical procedure, such as a laparotomy, performed for another reason.

Their small size makes them difficult to detect, even with imaging tests like X-rays and CT scans.

In rare cases, bile duct hamartomas might cause :

• abdominal pain or discomfort
• fever
• weight loss
• jaundice (yellowing of the skin)
• swollen or bloated stomach

Some evidence suggests that abdominal discomfort is the most common of these symptoms, followed by fever, weight loss, and jaundice.

But since most people don’t have any symptoms, doctors often have a hard time diagnosing these growths.

Experts still don’t know exactly what causes hamartomas. According to 2022 research , they may grow from smaller bile ducts that failed to develop properly.

They’re also often associated with other conditions, including:

• Pallister-Hall syndrome: This genetic disorder causes irregular bodily development, such as extra fingers or toes.
• Cowden syndrome: This condition causes the growth of many benign lesions throughout the body.
• Tuberous sclerosis: This condition can cause the growth of benign tumors in your vital organs.

Most people who get bile duct hamartomas are over the age of 35 , with women developing them three times more frequently than men.

Long-term tobacco use may increase the chances of these growths becoming cancerous.

A doctor may discover growths that resemble bile duct hamartomas during an imaging test or surgical procedure.

To confirm a diagnosis, they may recommend imaging tests to get a closer look. Examples of these tests include:

• sonogram
• endoscopic ultrasound
• CT scan
• endoscopic retrograde cholangiopancreatography (ERCP)
• magnetic resonance cholangiopancreatography (MCRP)

Sometimes, these imaging tests may not be enough to determine whether the lesions are cancerous or noncancerous. In these cases, your doctor may recommend removing the growths as a precautionary measure.

While hamartomas are noncancerous, there’s a slight risk that they can transform and progress to cholangiocarcinoma (bile duct cancer). For that reason, if your doctor considers any lesions suspicious, they’ll most likely recommend repeated imaging checkups and potentially a liver biopsy. They may also advise surgery.

As gastroenterologist Pratima Dibba, MD, explains, there’s currently no medical consensus as to when surgical resection might be necessary.

According to Dibba, some experts suggest resection of all bile duct hamartomas, if they’re operable, due to the risk of progression to cholangiocarcinoma. The authors of a 2017 review echo this, noting that surgery is the preferred treatment for these hamartomas.

However, other experts may recommend surgery only if you develop symptoms that pose a cause for concern, such as weight loss, increasing size of the lesion, recurrent bile duct inflammation, or jaundice, Dibba says. This is because of the risks of invasive surgery and the fact that it remains relatively rare for bile duct hamartomas to progress.

To date, medical literature also contains very few reported cases of bile duct hamartomas becoming malignant. So, opting for surgery tends to be a case-by-case scenario.

For the best outcome, she recommends that all lesions on the liver be evaluated with imaging tests. You’ll also want to talk through the benefits and risks of surgical treatment with your care team, especially if you have other health conditions.

Surgery for bile duct hamartomas

The most common procedure used to treat bile duct hamartomas is endoscopic retrograde cholangiopancreatography (ERCP). This procedure can both diagnose and treat bile duct obstruction issues, including hamartomas.

During the procedure, a gastroenterologist or surgeon will insert a catheter (a skinny, flexible tube) through the endoscope and into the affected bile ducts. From there, they can use specialized tools to open the ducts and remove any abnormal lesions.

The process takes about 1 to 2 hours . You’ll need to stay in the hospital for about 1 to 2 hours afterward until the sedative or anesthesia wears off.

You may experience some temporary bloating and nausea after the procedure. You may also have a sore throat for a few days.

Potential complications, which occur in about 5% to 10% of cases, may include :

• pancreatitis
• gallbladder or bile duct infections
• hemorrhage (excessive bleeding)
• tissue damage from X-ray exposure
• an allergic reaction to the sedative used
• holes in the bile ducts
• death, in very rare cases

Bile duct hamartomas are benign lesions of abnormal tissues and cells found in the liver. Though they don’t usually pose a cause for concern, there’s a slight risk they could eventually become cancerous.

For that reason, your care team may recommend surgery to remove these lesions, especially if they’re on the larger side or they begin to grow. If your doctor has discovered these lesions in your liver, they can offer more guidance on the best treatment approach for you.

Last medically reviewed on April 3, 2023