Hepatocellular adenoma: Classification, variants and clinical relevance

Area of Science:

• Hepatology
• Oncology
• Molecular Pathology

Background:

• Hepatocellular adenomas (HCAs) are benign liver tumors with risks of bleeding and malignant transformation.
• Historically associated with oral contraceptive use in women, HCAs are now recognized in diverse populations and linked to various liver diseases.
• Recent advances reveal HCAs are not a single entity but comprise at least three distinct subtypes.

Purpose of the Study:

• To delineate the evolving understanding of hepatocellular adenomas.
• To highlight the morpho-molecular classification of HCAs into distinct subtypes based on genetic mutations.
• To emphasize the importance of subtype identification for assessing malignant transformation risk.

Main Methods:

• Review of current literature on hepatocellular adenoma classification and pathogenesis.
• Analysis of morpho-molecular features and underlying genetic mutations (HNF1A, JAK/STAT pathway, CTNNB1).
• Role of histopathology and immunohistochemistry in subtype identification.

Main Results:

• Identification of at least three distinct hepatocellular adenoma subtypes based on specific gene mutations.
• Association of subtypes with characteristic histopathological features recognizable via immunohistochemistry.
• Recognition of key roles for pathologists and radiologists in subtype diagnosis.

Conclusions:

• The classification of hepatocellular adenomas into subtypes is crucial for risk stratification, particularly for malignant transformation.
• Further molecular research promises deeper insights into HCA natural history and malignant transformation mechanisms.
• Accurate subtype diagnosis impacts patient management and prognosis.