Liver Lesion on a Scan: Cysts, Hemangiomas, and Next Steps

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A liver lesion is any spot in the liver that looks different from the tissue around it on an imaging test, and most liver lesions found by accident turn out to be benign. The usual story starts somewhere else: a CT scan in an emergency room after a fall, an ultrasound ordered for gallbladder pain, an MRI of the spine. The report comes back with a line about a "hypodense lesion" or a "small hepatic cyst" and a suggestion to consider further evaluation. This page is for adults in Arlington, Annandale, and the rest of Northern Virginia who are holding a report like that. It explains the common types of liver lesion, which ones need no follow-up at all, which ones need a closer look, and what that closer look involves, based on the American College of Gastroenterology's 2024 clinical guideline on focal liver lesions.

This article is general education, not medical advice. It cannot tell you what the spot on your own scan is. That takes your imaging, your history, and a physician who can put them together.

What a liver lesion is

"Lesion" is a neutral word. It means an area that looks abnormal on a scan, solid or filled with fluid, and says nothing about whether it is harmful. The ACG guideline uses "lesion" rather than "mass" on purpose, because the term covers both solid spots and cysts and matches the vocabulary radiologists now use. A cyst is a liver lesion. So is a hemangioma, which is a cluster of blood vessels, and so is a cancer. The word alone does not separate them.

What does separate them is a combination of how the lesion looks on the right kind of imaging and what is known about the person: whether the liver underneath is healthy, whether there is a history of cancer, and whether there are risk factors for chronic liver disease. That combination is the whole logic of the evaluation, and it is why two people with similar-looking spots can get very different advice.

How common an incidental liver lesion is

Very common. The ACG guideline cites the American College of Radiology's estimate that up to 15 percent of people have an incidental liver lesion on routine imaging done for another reason, and studies in which up to 52 percent of people without cancer had a benign liver lesion at autopsy. Liver lesions are being found more often because more scans are being done, and better ones, not because livers have changed.

The guideline also offers the reassurance most people are looking for. In a person with no known liver disease and no risk factors, most solid liver lesions are benign, usually a hemangioma, focal nodular hyperplasia, or an adenoma. Simple cysts, which are fluid-filled rather than solid, are benign too and are common enough that recent ultrasound and CT studies put their prevalence between 2.5 and 18 percent.

Why the first scan often cannot name the liver lesion

The scans that find a liver lesion by accident are usually an abdominal ultrasound or a routine CT taken at a single moment after contrast dye is injected. The ACG guideline is direct about this: those tests detect a lesion but often cannot adequately characterize it. That is why a report so often ends with a recommendation for more imaging. It is a statement about the limits of the first test, not a signal that something worrying was seen.

There are two exceptions. If a lesion looks like a classic simple cyst or a classic hemangioma on that first ultrasound or CT, in a person without risk factors, the guideline says no further workup is needed. For everything else, the first recommendation in the guideline is multiphasic contrast-enhanced imaging, preferably MRI or CT, with pictures taken at several points as the contrast moves through the liver: an early arterial phase, a portal venous phase, and a delayed phase.

In practice that means a specific order. A CT done this way is a triple-phase liver protocol CT, which is different from a routine abdominal CT. An MRI done this way is a dynamic contrast liver MRI. The guideline reports that up to 95 percent of liver lesions seen on ultrasound can be diagnosed with proper contrast imaging, without a biopsy. CT and MRI perform similarly overall, but MRI is generally favored for lesions that look benign, partly because it uses no radiation, which matters for younger people who may need repeat scans over years. For one specific question, telling focal nodular hyperplasia from an adenoma, the guideline suggests MRI with a liver-specific contrast agent such as gadoxetic acid.

What your physician will ask about

The scan is only half the evaluation. The ACG guideline lists what a workup for an incidental liver lesion should include, and knowing the list helps you prepare:

• Any history of cancer, current or past
• Weight loss, loss of appetite, or fevers
• Medicines, especially birth control pills, other hormones, and steroids, including anabolic steroids
• Risk factors for chronic liver disease: viral hepatitis, past blood transfusions, tattoos, injection drug use, and heavy alcohol use
• Features of metabolic syndrome, such as excess weight, diabetes, high blood pressure, high cholesterol, or heart disease
• Blood tests, including liver enzymes, a viral hepatitis panel, and in some cases tumor markers

If any blood work comes back abnormal, our guide to elevated liver enzymes explains what the common results mean. If the scan also mentions a fatty liver, which is frequent, our page on fatty liver disease covers that separately.

Liver hemangioma: the most common solid liver lesion

A hemangioma is a benign cluster of blood-filled spaces, and the ACG guideline calls it the most common benign solid liver lesion, found in up to 20 percent of people and about four times as often in women as in men. Hemangiomas are thought to be present from birth and to grow slowly, if at all. They range from a few millimeters to more than 20 centimeters. Most cause no symptoms. Large ones can cause pain, a poor appetite, or a feeling of fullness.

The guideline's key points about hemangiomas are mostly reassuring:

• A small hemangioma, under 2 centimeters, with the classic bright, well-defined look and no blood flow on ultrasound, can be diagnosed on ultrasound alone in a person with a normal liver and no risk factors for liver disease or cancer.
• Anything that does not meet that description gets contrast CT or MRI to confirm it.
• Biopsy of a suspected hemangioma should be avoided when possible, because of the risk of bleeding.
• Once a hemangioma is confirmed, no further follow-up is needed, unless the person has cirrhosis or another risk for liver cancer such as hepatitis B.
• Even a large hemangioma, generally over 10 centimeters, does not need surgery if it causes no problems.
• There is no clear link to female hormones. The guideline says it is not recommended to avoid birth control pills or pregnancy because of a hemangioma, and pregnancy does not require monitoring of one.

Treatment is reserved for complications, which the guideline describes as rare: rupture, bleeding inside the lesion, a clotting problem seen with very large hemangiomas, or pressure on nearby organs or vessels. For people with cirrhosis or chronic hepatitis B who are already in a liver cancer surveillance program, the guideline recommends imaging every 3 to 6 months for at least a year after a suspected hemangioma is found, because in a diseased liver the stakes of a wrong label are higher.

Focal nodular hyperplasia: a liver lesion that needs no follow-up

Focal nodular hyperplasia, or FNH, is the second most common solid liver lesion. The guideline cites autopsy studies finding it in 0.3 to 3 percent of people, and up to 20 percent of people with FNH also have a hemangioma. It is thought to be a local overgrowth of normal liver cells in response to an unusual blood supply, and it is not a tumor in the sense most people fear.

FNH is found more often in women, which for years led to the belief that hormones drive it. The guideline says that belief has been disproven: there is no link between birth control pills and FNH growth, and FNH does not change in pregnancy. The guideline suggests not routinely stopping birth control pills because of FNH, and says FNH does not need monitoring during pregnancy. Men and women with FNH are evaluated and managed the same way.

The main job with FNH is telling it apart from an adenoma, because the two can look alike on routine scans and are handled very differently. MRI with a liver-specific contrast agent does that with an accuracy the guideline puts at over 90 percent. Once FNH is confidently diagnosed, the guideline recommends no further follow-up. Even if it grows, removal is not recommended, because the chance of cancer is extremely slim. If surgery is ever considered for pain, the guideline cautions that FNH rarely causes symptoms, so the pain may not go away afterward.

Hepatic adenoma: the benign liver lesion that is watched

A hepatocellular adenoma is a benign growth of liver cells, and it is rare. The guideline reports a prevalence of roughly 0.007 to 0.012 percent. Adenomas matter more than their rarity suggests, because unlike hemangiomas and FNH they carry two real risks: bleeding, reported in up to 15 percent, and change into liver cancer, reported in up to 5 percent. Those complications usually involve adenomas larger than 5 centimeters, though smaller ones are not exempt.

Risk factors. The guideline lists birth control pills, anabolic steroids, obesity, polycystic ovary syndrome, and glycogen storage disease. Among women taking birth control pills, it cites an incidence of 3 to 4 per 100,000 users, compared with 0.13 to 1.0 per 100,000 non-users, and notes that modern pills contain far lower hormone doses than the pills of the 1960s. Obesity has emerged as a notable risk factor, likely because fat tissue produces estrogen.

What changes for a person with an adenoma. The guideline recommends stopping birth control pills and hormone-releasing IUDs, and suggests weight loss for people who are overweight. Adenomas have shrunk in many cases after hormones were stopped. These are decisions to make with the physicians managing your care, including whoever prescribes your contraception, not on your own.

How adenomas are followed. The plan depends on sex and size, because men are more likely to have the subtype with the highest cancer risk. The guideline's framework:

• Women with an adenoma under 5 centimeters: contrast MRI after 6 months, then contrast imaging every 6 months for 2 years, then yearly. Growth of about 20 percent or more is a reason to consider removal. After 2 years, ultrasound may be enough for routine checks, with CT or MRI if anything changes.
• Women with an adenoma of 5 centimeters or more: a period of observation after stopping hormones, and losing weight if that applies. If the adenoma is still 5 centimeters or larger after that period, removal is recommended to lower the risk of bleeding or cancer.
• Men with an adenoma of any size: surgical removal or other definitive treatment is recommended, because the guideline reports the risk of cancer change is about ten times higher in men than in women.
• Pregnancy: adenomas can grow during pregnancy, so the guideline describes ultrasound every 6 to 12 weeks as one recommended strategy. Anyone with a known adenoma who is planning a pregnancy should talk with their physicians beforehand.

An adenoma that bleeds can cause sudden, severe abdominal pain and, if bleeding is heavy, lightheadedness or fainting. That is an emergency. Call 911.

Liver cysts: simple, complex, and many

Simple liver cysts are thin-walled sacs of clear fluid that do not connect to the bile ducts. They are more common in women and with age, and the guideline finds no established link to birth control pills or pregnancy. Ultrasound identifies them reliably. The guideline's recommendation is one of its strongest: a simple cyst that causes no symptoms needs no surveillance and no treatment, regardless of its size.

Very large cysts can cause symptoms by pressing on nearby structures: abdominal pain or pressure, shortness of breath, feeling full quickly, or leg swelling. For a cyst that causes symptoms, the guideline suggests either surgery to unroof the cyst, called fenestration, or draining it and injecting a substance that keeps it from refilling, called aspiration with sclerotherapy. Draining alone is not recommended as treatment, because the cyst usually returns. The guideline also notes that a blood test called CA 19-9 is elevated in up to half of people with these cysts and does not reliably separate a harmless cyst from a dangerous one, so a high result on its own is not a diagnosis.

Complex cysts are the ones that get a closer look. The guideline lists the ultrasound features that should prompt CT or MRI: internal walls (septations), calcium in the wall, a thickened or bumpy wall, an uneven appearance, or smaller cysts inside the main one. Those features can point to an infected cyst, an abscess, a parasitic cyst, a cancer that has spread, or a mucinous cystic neoplasm of the liver. For a complex cyst causing no symptoms, the guideline describes review by a multidisciplinary team and repeat imaging in 6 to 12 months.

Mucinous cystic neoplasm of the liver, once called a biliary cystadenoma, is the cystic liver lesion with real cancer potential. It makes up fewer than 5 percent of liver cysts, is about four times more common in women, and usually appears in the 50s or 60s. Recent studies cited in the guideline put the risk of change to cancer at up to 10 percent. Treatment is complete surgical removal. The guideline advises against using a needle sample to decide whether one is benign, because the test misses too much. This is the liver counterpart to the mucin-producing cysts covered in our guide to pancreatic cysts, though the management is different.

Other cysts. Biliary hamartomas are small, usually under 1.5 centimeters, often numerous, and need no specific surveillance. Hydatid cysts are caused by a tapeworm infection acquired in rural sheep-raising regions of South America, Eastern Europe, the Middle East, Central Asia, China, East Africa, and elsewhere, which is one reason your physician asks about travel and where you have lived.

Polycystic liver disease means many cysts, generally more than 10 to 20. It often goes with polycystic kidney disease, in which the guideline reports 60 to 80 percent of people also have liver cysts. A person found to have polycystic liver disease should also have an ultrasound of the kidneys. Because these cysts carry no cancer potential, imaging surveillance is not recommended when there are no symptoms. The guideline suggests stopping estrogen, which can enlarge the cysts. When the cyst burden causes symptoms, treatment ranges from draining or unroofing large cysts to medicines that can shrink liver volume, and in rare severe cases, transplant.

When a liver lesion is more concerning

Two situations change the picture, and both are about the person rather than the spot.

A known cancer, current or past. The guideline says a new liver lesion found during cancer care most likely represents spread from that cancer, because new benign lesions are rare in that setting. MRI with a liver-specific contrast agent is the recommended test. The cancer team typically leads that evaluation.

Cirrhosis or chronic liver disease. The guideline states that any lesion in a person with cirrhosis must be considered liver cancer until proven otherwise, even when it looks like something benign, and it refers readers to the American Association for the Study of Liver Diseases guidance on liver cancer for that population. Liver cancer surveillance in cirrhosis is a separate, planned program rather than an incidental finding, and our page on cirrhosis describes how monitoring fits into ongoing care. People with chronic hepatitis B can need surveillance even without cirrhosis; our guide to chronic hepatitis B and C covers that condition.

When a liver lesion still cannot be identified after proper contrast imaging, the guideline recommends review by a multidisciplinary liver tumor team and consideration of a core needle biopsy. If a biopsy is not possible, repeat imaging is used to watch for changes, generally every 3 to 6 months. Weight loss, fevers, loss of appetite, or yellowing of the skin or eyes alongside a liver lesion are reasons to be seen promptly rather than waiting for a routine slot. Our guide to unexplained weight loss explains why that symptom matters.

Questions to bring about your liver lesion

The visit goes further when you bring the actual reports, and ideally the images, from every scan that showed the liver lesion. Radiologists compare new images with old ones, and a lesion that has not changed in years is read very differently from one with no history. Questions worth asking:

• Does the report describe the lesion as solid or as a cyst, and does it say "simple" or "complex"?
• Was the scan a routine single-phase study, or a multiphase liver protocol study?
• Does my liver look otherwise healthy on the scan, or does it show fat or scarring?
• Is any more imaging needed, and if so, which test and when?
• If this is a type that needs no follow-up, can that be written in my chart so a future scan does not restart the workup?
• Should any of my medicines, such as birth control pills or hormones, change because of this?

Our page on what to expect at your first gastroenterologist visit covers the rest of the appointment, and our guide to when to see a gastroenterologist covers other reasons to come in.

Liver lesion evaluation in Northern Virginia with GC of NoVA

Gastroenterology Center of Northern Virginia sees adults across Arlington, Annandale, and the surrounding communities who have been told they have a liver lesion on a scan done for another reason. Our five gastroenterologists review the reports and images you bring, take the history and blood work that put a lesion in context, decide whether the original scan already answers the question or whether multiphase imaging is needed, and explain which findings need follow-up and which do not. When a lesion calls for a surgical or oncology opinion, we coordinate the referral. Liver care is a core part of our practice, alongside the evaluation of fatty liver, hepatitis, and abnormal liver tests.

We see patients at our Arlington office at 1715 N George Mason Drive, adjacent to VHC Health, and our Annandale office at 3299 Woodburn Road in the Woodburn Medical complex. To schedule a visit, call Arlington at (703) 522-7476 or Annandale at (703) 560-6106, or learn more at gcofnova.com.

This article is for general education and is not medical advice. Talk with a qualified gastroenterologist about your symptoms, diagnosis, and treatment options.