[Tumor grading of the hepatobiliary system]

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Liver, bile duct, and gallbladder tumors exhibit significant heterogeneity.
• Tumor biology and behavior vary considerably across these organs.
• Accurate classification is crucial for diagnosis and treatment planning.

Purpose of the Study:

• To outline the World Health Organization (WHO) grading systems for hepatobiliary and gallbladder cancers.
• To describe the criteria used for grading hepatocellular carcinoma, intrahepatic bile duct carcinoma, and extrahepatic bile duct/gallbladder carcinomas.
• To highlight the importance of recognizing special histological forms beyond standard grading.

Main Methods:

• Review of World Health Organization (WHO) classification guidelines for hepatobiliary and gallbladder tumors.
• Analysis of grading criteria based on tumor architecture, cell/nuclear pleomorphism, and glandular proportion.
• Identification and description of special histological subtypes.

Main Results:

• Hepatocellular carcinoma grading (4-stage) considers tumor size, architecture, and pleomorphism.
• Intrahepatic bile duct carcinoma grading (3-stage) focuses on architectural and cytologic changes.
• Extrahepatic bile duct and gallbladder carcinoma grading (3-stage) is based on glandular proportion in adenocarcinomas.
• Numerous special histological forms exist for all tumor types, requiring separate consideration.

Conclusions:

• Standardized WHO grading systems aid in classifying liver, bile duct, and gallbladder tumors.
• Histological variations and special forms necessitate expert pathological assessment.
• Consistent application of these classifications is vital for patient management and research.