Subclassification of renal cell neoplasms: an update for the practising pathologist

Area of Science:

• Nephrology
• Oncology
• Pathology

Background:

• The classification of renal cell neoplasms has significantly evolved over the past decade.
• A standardized nomenclature has been adopted, integrating genetic, histological, and immunohistological data.
• Histological features are often sufficient for accurate tumor classification.

Purpose of the Study:

• To summarize the key features of tumors within the current standardized classification system.
• To highlight diagnostic challenges encountered when applying this classification system.
• To review recently characterized renal cell neoplasms not yet incorporated into the standard nomenclature.

Main Methods:

• Literature review of the current classification system for renal cell neoplasms.
• Analysis of diagnostic difficulties based on histological and immunohistological features.
• Inclusion of recently identified and characterized renal cell tumors.

Main Results:

• The review details the essential characteristics of recognized renal cell neoplasms.
• Diagnostic ambiguities and challenges in applying the current system are discussed.
• Several novel renal cell tumor entities are presented.

Conclusions:

• The current classification system for renal cell neoplasms is largely based on histology.
• Awareness of diagnostic challenges and emerging tumor types is crucial for accurate diagnosis.
• Continued research is needed to integrate new entities into the standardized nomenclature.