Hepatic adenoma is an uncommon, benign liver tumor. Benign means that it’s not cancerous. It’s also known as hepatocellular adenoma or liver cell adenoma.

Hepatic adenoma is extremely rare. It most often affects women, and has been linked to the use of birth control pills.

Read on to find out about the symptoms, causes, diagnosis, and treatment of this noncancerous liver tumor.

Hepatic adenoma doesn’t often cause symptoms. Sometimes it causes mild symptoms, though, such as pain, nausea, or a full feeling. This typically occurs when the tumor is large enough to put pressure on neighboring organs and tissues.

You may not know you have a hepatic adenoma unless it ruptures. A ruptured hepatic adenoma is serious. It can cause:

  • sudden abdominal pain
  • low blood pressure
  • internal bleeding

In rare cases, it can be life-threatening.

As imaging tests improve, it’s becoming more common to discover hepatic adenomas before they rupture and cause symptoms.

The most common risk factor for hepatic adenoma is the use of estrogen-based oral contraceptive pills. Your risk increases with prolonged use and with high-estrogen doses.

Pregnancy can also increase your risk. Pregnancy stimulates the release of certain hormones related to the development of these tumors.

Other, less common risk factors include:

  • steroid use
  • barbiturate use
  • type 1 diabetes
  • hemochromatosis, or excess iron buildup in your blood
  • glycogen storage diseases type 1 (von Gierke disease) and type 3 (Cori or Forbes disease)
  • metabolic syndrome
  • being overweight or obese

If a liver tumor is suspected, your doctor might suggest tests to identify the tumor and its cause. They might also suggest tests to rule out other potential diagnoses.

An ultrasound is often one of the first steps your doctor will take to help them make a diagnosis. If your doctor finds a large mass through an ultrasound, additional tests might be required to confirm that the mass is a hepatic adenoma.

Other imaging tests, such as CT scans and MRIs, can be used to learn more about the tumor.

If the tumor is large, your doctor might also suggest a biopsy. During a biopsy, a small tissue sample is removed from the mass and evaluated under a microscope.

There are four proposed types of hepatic adenoma:

  • inflammatory
  • HNF1A-mutated
  • β-catenin activated
  • unclassified

According to a 2013 review:

  • Inflammatory hepatic adenoma is the most common type. It’s seen in about 40 to 50 percent of cases.
  • HNF1A-mutated type is seen in approximately 30 to 40 percent of cases.
  • β-catenin activated is seen in 10 to 15 percent of cases.
  • Around 10 to 25 percent of hepatic adenoma cases are unclassified.

Each type is associated with distinct risk factors. However, the type of hepatic adenoma doesn’t usually change the suggested treatment.

Tumors that are under 2 inches in length are rarely associated with complications. If you have a small tumor, your doctor might suggest monitoring the tumor over time instead of treating it. You might also be asked to stop taking birth control pills to slow the growth of the tumor.

Research suggests that most small hepatic adenomas tend to remain stable during observation periods. A small percentage of them disappear. Your doctor can use an ultrasound to monitor the size of the tumor.

If you have a large tumor, your doctor may recommend liver resection surgery to remove the tumor. That’s because large tumors are more likely to lead to complications, such as spontaneous rupture and bleeding.

Surgery is recommended:

  • when the hepatic adenoma is more than 2 inches in length
  • for people unable to stop taking birth control pills
  • for men with hepatic adenomas
  • for inflammatory and β-catenin activated hepatic adenoma types

When left untreated, hepatic adenomas can rupture spontaneously. This can cause abdominal pain and internal bleeding. A ruptured hepatic adenoma requires immediate medical treatment.

In rare cases, untreated hepatic adenomas can become cancerous. This is more likely when the tumor is large.

Several studies suggest that β-catenin activated hepatic adenomas are more likely to become cancerous. Additional research is needed to understand the link between hepatic adenoma types and cancer.

Hepatic adenoma is extremely rare. This tumor is most often associated with the use of birth control pills, but it can also be seen in men or in women who don’t take birth control pills.

Hepatic adenoma may not cause any symptoms. This can make it difficult to know whether you have it. In rare cases, untreated hepatic adenoma results in serious complications.

Hepatic adenoma is treatable. The long-term outlook is good for people with this condition when it’s identified and treated early.