Focal nodular hyperplasia: with a focus on contrast enhanced ultrasound

Focal nodular hyperplasia (FNH) is the second most common tumor of the liver after hepatic hemangioma. FNH is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. Therefore, FNH is discovered in most patients incidentally during cross-sectional imaging, angiography, radionuclide liver scanning, or surgery. Although FNH usually has no clinical significance, recognition of its radiologic characteristics is important to avoiding unnecessary surgery, biopsy, and follow-up imaging. Despite advances in imaging techniques, it is still difficult to distinguish between FNH and other focal hepatic lesions. Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in sonography and is being increasingly used to evaluate focal liver lesions. Herein we present a case of FNH of the liver and its characteristic CEUS features.