Grading of renal cell carcinoma

Area of Science:

• Uropathology
• Oncology
• Cancer Grading Systems

Background:

• Renal cell carcinoma (RCC) grading has been a prognostic factor for nearly a century.
• Various grading systems have evolved, focusing on cytological and nuclear features.
• The World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading system is now standard for RCC.

Purpose of the Study:

• To review the established WHO/ISUP grading system for renal cell carcinoma.
• To discuss its validation and application in different RCC subtypes.
• To highlight recent advancements in improving RCC outcome prediction through grading.

Main Methods:

• Review of historical and current RCC grading systems.
• Analysis of validation studies for the WHO/ISUP classification.
• Examination of research incorporating tumor necrosis into grading.

Main Results:

• The WHO/ISUP grading system, based on nucleolar prominence and nuclear anaplasia, is validated for clear cell and papillary RCC.
• Grading is not recommended for chromophobe RCC due to lack of outcome correlation.
• Incorporating tumor necrosis into grading has shown improved outcome prediction in recent studies.

Conclusions:

• The WHO/ISUP grading system is crucial for prognostic assessment in specific RCC subtypes.
• Tumor necrosis is a valuable addition for enhancing the predictive accuracy of RCC grading.
• Standardized reporting of RCC grading is essential for clinical decision-making.