Abstract
Focal nodular hyperplasia (FNH) is the second most frequent benign liver tumor in children. It is characterized by hepatocytic nodules separated by fibrous bands.
No malignant transformation has been reported and associated complications are rare. Approximately half of the patients are asympto-matic and their lesions are detected incidentally during routine examination.
The pathogenesis of FNH is unclear. The most widely accepted theory is that FNH is a hyperplastic response of hepatocytes to a localized congenital or acquired vascular anomaly.
Recent reports have described an increased inci-dence of FNH in patients previously treated for malignancy. There is high likelihood of malignancy in liver tumor in children, therefore an accurate diagnosis is essential.
MRI is the most sensitive study for diagnostics of FNH. Conservative management is appropriate only if the patient has no symptoms and malignancy can be confidently ruled out.
Surgical treatment is indicated for symptomatic patients and in case of diagnostic difficulty.