Focal Nodular Hyperplasia

CLINICAL FEATURES AND NATURAL HISTORYTop

Focal nodular hyperplasia (FNH) is a noncancerous tumor of the liver. It occurs in 0.3% to 1% of adults, 6 to 8 times more often in women. FNH is generally asymptomatic and found incidentally on imaging. In rare cases it presents with abdominal pain. Extremely large tumors can be palpable through the abdominal wall.

DIAGNOSISTop

Diagnostic Tests

Imaging:

1) Computed tomography (CT) and ultrasonography: see Table 1 in Hepatic Tumors.

2) Magnetic resonance imaging (MRI) has greater sensitivity in the case of small lesions than CT.

3) CT angiography or sulfur colloid scan could be used in case of diagnostic uncertainty.

Diagnostic Criteria

Diagnosis is based on imaging findings. If in doubt, perform morphologic assessment of the removed tumor.

Differential Diagnosis

Focal lesions in the liver: Hemangioma, adenoma, cyst, hepatocellular carcinoma, metastatic tumors.

TREATMENTTop

1. The vast majority of lesions do not require specific treatment. Perform ultrasonography every 12 months.

2. Indications for surgical treatment: Intraperitoneal hemorrhage or hemorrhage into the tumor, diagnostic uncertainty, rapid tumor enlargement.

SPECIAL CONSIDERATIONSTop

Pregnancy and Contraception

The use of combined oral contraceptive pills is considered safe. Pregnancy is not contraindicated, and pregnant women do not require special surveillance.