A Limited Immunohistochemical Panel Can Subtype Hepatocellular Adenomas for Routine Practice

Area of Science:

• Hepatobiliary pathology
• Gastrointestinal pathology
• Oncology

Background:

• Hepatocellular adenomas with beta-catenin activation or inflammation have increased malignant transformation risk.
• These subtypes benefit from surgical excision.
• Accurate identification is crucial for patient management.

Purpose of the Study:

• To assess if a limited immunohistochemical panel can identify beta-catenin-activated and inflammatory adenomas.
• To determine the diagnostic accuracy of morphology versus immunohistochemistry for adenoma subclassification.

Main Methods:

• Morphological assessment of 46 adenomas.
• Immunohistochemical staining for beta-catenin, serum amyloid A, and glutamine synthetase.
• Comparison of morphologic diagnosis with final immunohistochemical results.

Main Results:

• Morphology alone yielded inaccurate subclassification in 43% of cases.
• Immunohistochemistry confirmed the diagnosis in 33% and changed it in 43% of cases.
• Final classification included inflammatory adenomas (35%), beta-catenin-activated adenomas (9%), beta-catenin-activated inflammatory adenomas (15%), and other adenomas (41%).

Conclusions:

• Immunohistochemistry effectively identifies inflammatory and beta-catenin-activated adenomas.
• Morphological assessment alone is insufficient for accurate adenoma subclassification.
• A limited panel of widely available immunostains enables accurate diagnosis of these high-risk adenoma subtypes.