Hepatic Adenoma
A hepatic adenoma is a benign liver tumor made up of abnormally proliferating liver cells, most often arising in association with hormonal factors such as oral contraceptive use, anabolic steroid use, or pregnancy. Hepatic adenomas are less common than other benign liver lesions but carry a small risk of bleeding and, in selected subtypes, a low but real risk of malignant transformation. They are usually discovered incidentally on abdominal imaging or evaluated when liver lesions are detected. MRI with hepatobiliary contrast agents is the central imaging tool for diagnosis, and treatment is individualized based on size, subtype, and patient factors.
What is it?
A hepatic adenoma is a benign tumor of the liver composed of abnormally proliferating hepatocytes (liver cells), often supported by abnormal blood vessels but typically lacking the normal supporting structures of healthy liver tissue, such as bile ducts and portal tracts. Hepatic adenomas are not cancers, but they have distinct features that set them apart from other benign liver lesions: some can grow over time, some can bleed (sometimes severely), and a small subset have the potential to transform into liver cancer (hepatocellular carcinoma). Because of this, hepatic adenomas require careful evaluation and individualized management.
Hormonal influences play a major role in the development of many hepatic adenomas. The most well-recognized association is with long-term use of estrogen-containing oral contraceptives, particularly older high-dose formulations and prolonged use. Anabolic-androgenic steroids—whether prescribed or used illicitly—are another important risk factor, particularly in men. Pregnancy can also influence the size of some hepatic adenomas. Beyond hormonal factors, hepatic adenomas are increasingly recognized in patients with obesity, metabolic syndrome, and steatotic liver disease, and they occur with higher frequency in patients with certain glycogen storage diseases.
Recent advances in pathology and molecular medicine have shown that hepatic adenomas are not a single disease but a group of related tumors with distinct molecular subtypes. The main recognized subtypes include HNF1α-inactivated adenomas (often associated with fatty change and a lower risk of malignant transformation), inflammatory adenomas (the most common subtype, often associated with inflammatory features and a moderate risk of bleeding), β-catenin–activated adenomas (associated with a higher risk of malignant transformation), and unclassified adenomas. Identifying the molecular subtype—through imaging features, biopsy, or surgical pathology—can help guide management decisions, particularly for larger or higher-risk lesions.
Many hepatic adenomas cause no symptoms and are discovered incidentally on abdominal imaging done for other reasons. When symptoms occur, they often include upper right abdominal pain or fullness, particularly with larger lesions. The most concerning complications are bleeding and malignant transformation. Bleeding within the lesion or into the abdominal cavity can occur, particularly in larger adenomas (often greater than 5 centimeters), in pregnancy, or with hormonal influences. Severe hemorrhage can be a surgical emergency. Malignant transformation into hepatocellular carcinoma is uncommon overall but is more frequent in specific subtypes (especially β-catenin–activated adenomas) and in larger lesions, particularly in men.
Diagnosis of a hepatic adenoma requires careful imaging evaluation, ideally with MRI using hepatobiliary contrast agents (such as gadoxetate). MRI can identify characteristic features of different adenoma subtypes—including fat content, inflammatory signal characteristics, and patterns of contrast enhancement—and helps distinguish adenomas from other liver lesions such as focal nodular hyperplasia, hemangiomas, and hepatocellular carcinoma. CT with contrast and ultrasound can provide additional information but are generally less detailed than MRI. Biopsy is used in selected cases when imaging is not conclusive or when molecular subtyping is needed to guide treatment decisions; however, biopsy carries some risk of bleeding and is not routinely required.
Important to Know
Management of a hepatic adenoma is highly individualized and depends on the size, suspected or confirmed molecular subtype, symptoms, sex of the patient, plans for pregnancy, hormonal exposure, and overall health. Care is typically coordinated by hepatologists, hepatobiliary surgeons, gastroenterologists, and—when relevant—radiologists, interventional radiologists, and other specialists.
The first step for most patients is identifying and addressing modifiable factors. Discontinuation of estrogen-containing oral contraceptives and other hormonal therapies, when feasible, often leads to stabilization or regression of hepatic adenomas, particularly smaller ones. Anabolic steroid use should be stopped. Weight loss and metabolic optimization—including treatment of fatty liver disease, diabetes, and metabolic syndrome—may help in patients with obesity-related adenomas. After discontinuation of hormonal exposure and lifestyle changes, periodic imaging is typically performed to assess whether the adenoma stabilizes, regresses, or grows.
Treatment decisions depend on several factors. In general, smaller hepatic adenomas (typically less than 5 centimeters) in women who have stopped hormonal therapy and are not pregnant may often be managed with surveillance imaging. Adenomas that are larger than approximately 5 centimeters, that grow over time, that are symptomatic, that occur in men, that have higher-risk molecular features (such as β-catenin activation), or that have complications such as bleeding are generally considered for definitive treatment.
Treatment options include surgical resection (which can range from local excision to formal liver resection depending on size and location) and transarterial embolization (a catheter-based procedure that can be used both for elective treatment of selected adenomas and for emergency management of bleeding). Less commonly, other approaches such as radiofrequency ablation or, in extreme cases, liver transplantation may be considered. Treatment plans are individualized in coordination with hepatobiliary surgeons and interventional radiologists.
Pregnancy is an important consideration. Adenomas may grow under the hormonal influences of pregnancy, and bleeding can occur. Women with known hepatic adenomas who are pregnant or planning pregnancy benefit from individualized counseling in collaboration with hepatology, hepatobiliary surgery, and obstetrics. The decision about whether to treat the adenoma before pregnancy depends on size, location, and other factors.
Patients with multiple hepatic adenomas (a condition called hepatic adenomatosis), with familial syndromes, with glycogen storage disease, or with other special circumstances may require specialized care in centers with experience managing these conditions.
Care is typically coordinated by primary care clinicians, hepatologists, hepatobiliary surgeons, gastroenterologists, interventional radiologists, and—when relevant—endocrinologists and obstetricians. Imaging findings are interpreted alongside the patient’s symptoms, examination, hormonal history, and broader clinical context rather than in isolation.
Red flag symptoms include sudden severe upper abdominal pain, lightheadedness or fainting, rapid heart rate, cool clammy skin or signs of shock, severe vomiting with abdominal pain, severe jaundice, dark urine, or signs of gastrointestinal bleeding. These warrant immediate emergency evaluation, as they may indicate bleeding or rupture of the adenoma or another serious abdominal condition.