Background: Focal nodular hyperplasia (FNH) is a benign hepatic lesion of unknown etiology. Although uncommon in children, a cumulative incidence is reported in oncologic patients after ending their therapy. Differential diagnosis to other focal liver lesions especially to metastases is often difficult.
Patients and methods: We report on four children (female n=2, male n=2; age at initial diagnosis: 9 months, 20 months, 11.5 and 14 years) with different non-hepatic primary tumors (gastrointestinal stroma-tumor, neuroblastoma (n=2) and nephroblastoma) who developed focal liver lesions 2, 2.5, 3 and 8 years after successful treatment of their primary malignancy, respectively.
Results: Diagnosis of focal nodular hyperplasia was established by sonography, computed tomography and magnetic resonance imaging. In addition percutaneous needle biopsy was performed in two patients. Median interval from the end of chemotherapy to the onset of FNH was 3.9 years (range 2-8 years).
Conclusion: Diagnosis of FNH has to be included in the differential diagnosis of uncertain liver lesions. Biopsy might be avoided by using special imaging techniques like MRI, CT and ultrasound. A wait and see strategy is recommended, specific treatment is not necessary.