Comprehensive Radiopathological and Molecular Review of HCC: Expanding on the WHO, 6th Edition

Area of Science:

• Hepatobiliary pathology
• Gastrointestinal oncology
• Molecular diagnostics

Background:

• Hepatocellular carcinoma (HCC) displays significant heterogeneity.
• The World Health Organization (WHO) Classification of Digestive Tumours (6th ed.) identifies nine HCC subtypes.
• These subtypes, alongside conventional HCC, have distinct morphomolecular and clinical profiles.

Purpose of the Study:

• To review the molecular, pathological, and radiological characteristics of HCC subtypes and patterns.
• To highlight the correlation between imaging features and molecular-pathological traits.
• To emphasize the importance of understanding these features for therapeutic decisions and prognostic assessment.

Main Methods:

• Review of current literature on HCC classification, molecular pathology, and diagnostic imaging.
• Analysis of imaging hallmarks associated with aggressive HCC subtypes.
• Correlation of imaging findings with prognostic implications.

Main Results:

• HCC subtypes are categorized by prognosis: unfavorable (macrotrabecular-massive, sarcomatoid, neutrophil-rich), comparable (steatohepatitic, fibrolamellar, chromophobe), and favorable (lymphocyte-rich, clear cell).
• Scirrhous HCC has variable outcomes; new patterns include vessels encapsulating tumor clusters and CTNNB1-mutated HCC.
• Aggressive subtypes show imaging hallmarks like rim arterial phase hyperenhancement and intratumoral necrosis, predicting clinical outcomes.

Conclusions:

• Imaging features correlate with HCC molecular-pathology and prognosis.
• While challenging, definitive subtype diagnosis via imaging is advancing.
• A comprehensive understanding of HCC subtypes is essential for optimizing patient management and prognosis.