E1776. Large Regenerative Nodules and FNH-Like Lesions
  1. Paul Nolan; Northwestern University
  2. Amir Borhani; Northwestern University
  3. Roberta Catania; Northwestern University
  4. Camila Vendrami; Northwestern University
  5. Frank Mililer; Northwestern University
Large regenerative nodules (LRNs) and FNH-like nodules are regenerative lesions seen in many diseases, particularly vascular diseases. Although these nodules are of low risk of malignant transformation, their imaging findings can mimic hepatocellular carcinoma (HCC), potentially leading to unnecessary interventions. The purpose of this exhibit is to review the imaging characteristics and natural history of LRNs and FNH-like nodules and provide radiologists with clues to help differentiate these entities from malignancy.

Educational Goals / Teaching Points
The goals of this exhibit are to review the pathology and demographics of LRNs and FNH-like nodules, to discuss the diseases associated with these lesions, to describe their imaging features, and to discuss the natural history of these lesions.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
LRNs and FNH-like nodules are seen in a variety of diffuse liver diseases, most commonly seen in association with vascular diseases such as Budd-Chiari syndrome, chronic congestive hepatopathy (such as in patients with history of Fontan procedure), chronic portal vein thrombosis, autoimmune hepatitis, and congenital portosystemic shunts. As these lesions occur in abnormal livers and often demonstrate arterial enhancement, they can mimic HCC. However, knowledge of the diseases prone to LRNs and FNH-like nodules and typical imaging features on multiphase contrast-enhanced imaging (including hepatobiliary phase) can assist the radiologist in differentiating these lesions from malignancy. Classic and challenging examples will be presented.

LRNs and FNH-like nodules occur in diffuse liver disease and can mimic HCC on imaging. However, recognition of the common liver diseases in which these lesions occur and certain imaging characteristics can help the radiologist suggest these diagnoses and potentially prevent unnecessary interventions.