What is the management approach for Focal Nodular Hyperplasia (FNH)?

Management of Focal Nodular Hyperplasia

Conservative management without routine surveillance is the recommended approach for focal nodular hyperplasia (FNH), as this benign liver lesion has an extremely low risk of complications and does not require intervention in the vast majority of cases. 1, 2

Diagnostic Confirmation

• Establish diagnosis through non-invasive imaging alone – contrast-enhanced MRI with liver-specific contrast or gadolinium-enhanced MRI showing characteristic spoke-wheel arterial enhancement pattern is sufficient for diagnosis 2, 3
• Contrast-enhanced ultrasound (CEUS) demonstrating strong hyperperfusion from a large feeding artery in the arterial phase can also confirm the diagnosis 2
• Avoid liver biopsy – it is unnecessary for diagnosis and carries bleeding risk 2
• Diagnostic uncertainty remains the only valid indication for resection, but only after contrast-enhanced MRI has been performed 3

Standard Management Approach

For asymptomatic patients with confirmed FNH:

• No treatment is required regardless of lesion size 1, 2, 4
• Routine imaging surveillance is not recommended 1, 2
• Conservative management is effective in 94.4% of cases 4
• Oral contraceptive use does not need to be discontinued, as the causal relationship between estrogen exposure and FNH development or growth is not established 2

For symptomatic patients:

• Initially manage conservatively, as symptoms often resolve without intervention 4, 5
• In the study by 4, asymptomatic patients remained symptom-free and those with FNH-related pain did not experience worsening during follow-up
• Surgery should be reserved as an exception, similar to hepatic hemangiomas 4

Indications for Intervention (Rare)

Surgical resection, radiofrequency ablation, or arterial embolization should only be considered when 6:

• Persistent, severe pain with no other identifiable cause after conservative management trial
• Large or progressively growing lesions with risk of compressing nearby structures (hepatic vein, stomach, biliary system)
• Diagnostic uncertainty despite optimal imaging with contrast-enhanced MRI 3

Only 5.5% of patients required therapeutic intervention in long-term follow-up studies 4

Special Populations

Pregnancy:

• Pregnancy is not contraindicated in women with FNH 1, 2
• Vaginal delivery is not associated with increased risks 1, 2
• Routine imaging surveillance during pregnancy is not recommended 1, 2
• Unlike hepatocellular adenomas >5 cm that require pre-pregnancy treatment, FNH does not require intervention regardless of size 2
• FNH size typically remains constant or decreases during pregnancy with no FNH-related complications 2

Pediatric patients:

• Conservative management is appropriate even in symptomatic children, as pain often resolves spontaneously 5
• Avoid unnecessary surgery by careful evaluation of symptom severity and stability 5

Critical Safety Considerations

• Risk of rupture is extremely low – only one case of spontaneous hepatic rupture has been reported in the literature, contrasting sharply with hepatic adenomas 2
• FNH may coexist with other vascular hepatic lesions (hemangiomas) in up to 20% of cases 2
• Be aware that FNH may be mistaken for hepatocellular carcinoma on imaging, particularly when the liver appears nodular 2
• FNH is 100-fold more prevalent in patients with hereditary hemorrhagic telangiectasia 2
• In pediatric cancer survivors, FNH/FNH-like lesions are increasingly recognized and should not be mistaken for relapsed malignancy 7

Surgical Outcomes When Intervention Is Necessary

When resection is performed for valid indications, acceptable safety profiles are reported with 14% morbidity and zero mortality 3. However, given that conservative strategies also result in symptom resolution and the benign natural history of FNH, surgery should remain exceptional 4, 6.