Renal tumor pathology has evolved considerably, expanding from two main types of renal malignant tumors to over 20 distinct types. Diagnostic criteria have advanced from purely morphological features to include histochemistry, immunohistochemistry (IHC), and molecular genetics. The World Health Organization (WHO) and the International Society of Urologic Pathology (ISUP) have been instrumental in updating these criteria, resulting in a comprehensive framework essential for accurate diagnosis, effective treatment, and improved patient outcomes.
The field of renal tumor pathology has undergone significant advancements, particularly with the introduction of new molecular data and treatment approaches. The 2022 WHO classification of kidney epithelial tumors reflects these advancements with major updates from the previous 2016 classification. This review outlines the diagnostic updates and major changes in the classification of kidney epithelial tumors, emphasizing the rationale behind these changes.
Despite the rise of molecular techniques, morphological and cytological features remain the cornerstone of renal tumor classification. The 2022 WHO classification reflects this by continuing to prioritize morphological criteria while incorporating molecular genetics for more precise diagnostics. This dual approach ensures both traditional and modern diagnostic methods are utilized, providing a comprehensive understanding of renal tumors.
The 2022 classification reorganizes renal epith.