ACG Clinical Guideline 2024
Dr. Catherine Frenette
Liver
Focal Liver Lesions
Benign lesions, HCC/malignancy diagnosis, LI-RADS, and imaging algorithms — ACG 2024 Guidelines.
Benign Lesions
Hemangioma, FNH, hepatic adenoma
Common Benign Focal Liver Lesions
Most incidentally discovered liver lesions are benign. Accurate characterization prevents unnecessary intervention and patient anxiety.
Hepatic Hemangioma
Most common benign liver tumor (~5% of population)
T2 bright on MRI ("light bulb sign")
Peripheral nodular enhancement with progressive centripetal fill-in
No follow-up needed if classic MRI features + asymptomatic
No malignant potential
Focal Nodular Hyperplasia (FNH)
Second most common benign lesion; young women
Central scar with radiating fibrous septa
Intense homogeneous arterial enhancement; central scar enhances on delayed
NO malignant potential; NO treatment needed
Oral contraceptives: do NOT need to be stopped for FNH
Hepatic Adenoma (HCA)
Rare; associated with OCP use, anabolic steroids, glycogen storage disease
Risk of hemorrhage and malignant transformation (HCC)
Subtypes: β-catenin mutated (highest HCC risk), inflammatory, HNF1α-inactivated
Manage: discontinue OCP/androgens; >5 cm → consider resection
MRI + HCA subtyping guides management
Frenette C et al. ACG Clinical Guideline: Focal Liver Lesions. Am J Gastroenterol. 2024.