Focal fatty liver change in a 12-year-old Japanese boy.

We describe a 12-year-old patient with focal fatty liver change (FFLC). The lesion was incidentally detected by ultrasonography which showed a circumscribed hyperechoic lesion measuring approximately 6 x 4 cm. The lesion was also examined by CT and MRI. Histologically, the lesion corresponded to a focal area of lipid-laden hepatocytes. FFLC has been delineated as a disease entity in adults. As shown by this report, it may also occur in children. There was no associated clinical morbidity and the lesion was incidentally detected by modern imaging techniques. The aetiology and pathogenesis are unknown. The significance of focal fatty lesions is their differentiation from other focal lesions such as hepatic cell carcinomas, metastatic tumours, abscess and benign tumours including lipoma, haemangioma and angiomyolipoma.