Large Regenerative Nodules and Focal Nodular Hyperplasia-Like Lesions: Definition, Pathogenesis, and Imaging Findings
Paul E. Nolan MD, Roberta Catania MD, Camila Lopes Vendrami MD, Amir A. Borhani MD, Frank H. Miller MD
Hypervascular liver lesions, when not obviously a hemangioma, often cause concern and diagnostic dilemma. One classic and generally benign type of hypervascular liver lesion to consider is focal nodular hyperplasia-like (FNH-like) nodule. Unlike FNH, which by definition occurs within a normal background liver, FNH-like lesions are seen in the presence of underlying hepatic disease. Although FNH-like lesions are classically described as having an identical radiologic appearance to FNH (with arterial hyperenhancement and central scar), they may have variable imaging appearances. Particularly, the contrast-enhanced appearance of these lesions could be affected by the changes in the global hepatic perfusion (such as in the setting of venous congestion). Recognition of FNH-like lesions is of clinical importance as many patients with diffuse liver disease are also at increased risk for HCC, and misdiagnosis of an FNH-like lesion as HCC can result in unnecessary interventions and therapies. In this article, we describe the pathophysiology and imaging findings of FNH-like lesions, review the common conditions wherein FNH-like lesions can be seen, and discuss the pitfalls and challenges in differentiating these lesions from HCC.
Read Full Article Here: https://doi.org/10.1016/j.rcl.2022.05.004