Benign hepatocellular nodules: what have we learned using the patho-molecular classification.

Area of Science:

• Hepatology and Oncology
• Gastroenterology
• Tumor Biology

Background:

• Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are common benign liver tumors, primarily affecting females on non-cirrhotic livers.
• Hepatocellular adenomas carry risks of bleeding and malignant transformation into hepatocellular carcinoma (HCC).
• HCA are classified into subgroups (HNF1α mutated, inflammatory HCA, and β-catenin mutated HCA) based on genetic mutations, with β-catenin subtypes strongly linked to HCC transformation.

Purpose of the Study:

• To review the classification and clinical implications of benign hepatocellular tumors, focusing on hepatocellular adenomas.
• To highlight the advancements in diagnosing and managing HCA, including identifying at-risk patient populations.
• To emphasize the limitations of current diagnostic methods and the need for molecular studies in HCA management.

Main Methods:

• Review of current literature on FNH and HCA classification and clinical management.
• Discussion of diagnostic techniques including immunohistochemistry (LFABP, CRP, GS, β-catenin) and imaging (MRI).
• Emphasis on the role of molecular studies in improving HCA diagnosis and prognosis.

Main Results:

• Immunohistochemistry aids in classifying HCA subtypes and identifying patients at risk for HCC transformation.
• Recent advances have expanded the understanding of HCA occurrence in diverse patient groups (males, obese, liver vascular disorders).
• Limitations exist in immunohistochemistry for identifying specific HCA subtypes (e.g., β-catenin mutated HCA), underscoring the need for molecular analysis.

Conclusions:

• HCA classification and phenotype analysis have improved risk stratification for HCC transformation.
• Molecular studies are essential to overcome limitations of immunohistochemistry and enhance HCA diagnosis and prognosis.
• Further research is needed to establish clear clinical practice guidelines for HCA management.