Hepatocellular Adenoma

CLINICAL FEATURES AND NATURAL HISTORYTop

Hepatocellular adenoma is a nonmalignant liver tumor that occurs mainly in women of reproductive age taking long-term oral contraceptives. It is also found in people taking anabolic steroids or androgens. Other risk factors include obesity and components of metabolic syndrome: diabetes, insulin resistance, hypertension, and dyslipidemia. Hepatocellular adenoma generally causes no symptoms and is incidentally detected on imaging. Abdominal pain may occur due to bleeding into the tumor. It may undergo malignant transformation into hepatocellular carcinoma. The presence of >10 tumors is called hepatic adenomatosis.

DIAGNOSISTop

Diagnostic Tests

Imaging:

1) Ultrasonography and computed tomography (CT): see Table 1 in Hepatic Tumors.

2) Magnetic resonance imaging (MRI): Hepatocellular adenoma has no characteristic MRI features that distinguish it from primary liver cancer; using a fat attenuation program or administration of a contrast agent may be helpful.

3) CT angiography shows a well-limited and richly vascularized lesion with possible avascular foci in the setting of tumor hemorrhage.

Diagnostic Criteria

Initial diagnosis is made based on imaging findings. Final diagnosis is only made after tumor resection and histologic examination.

Differential Diagnosis

Focal lesions in the liver: Hepatocellular carcinoma, metastatic tumors, cancer of the intrahepatic bile ducts, focal nodular hyperplasia.

TREATMENTTop

Women with hepatic adenoma should not use oral estrogen-based contraceptive agents, hormone-releasing intrauterine devices, or exogenous estrogen; in the case of adenomas ≥5 cm in diameter, pregnancy is contraindicated. Anabolic steroids should not be used.

Surgery is the treatment of choice due to high risk of malignant transformation of the adenoma (especially in men), risk of hemorrhage (with a lesion diameter ≥5 cm), and lack of certain differentiation between malignant and benign tumors. In the case of high surgical risk, other less invasive methods, such as embolization, can be used.

SPECIAL CONSIDERATIONSTop

Pregnancy and Contraception

Combined oral contraceptive pills should be avoided, as estrogens promote tumor enlargement.

Women of childbearing age with hepatic adenoma should be made aware of the risk of tumor enlargement and rupture during pregnancy. For this reason, in each trimester of pregnancy and up to the third month after delivery, it is reasonable to perform a follow-up ultrasound scan. If the adenoma is <5 cm in diameter, pregnancy is not contraindicated. If it is greater, treatment (liver resection, embolization) should be considered prior to pregnancy.