Sarcomatoid and Rhabdoid Renal Cell Carcinoma: Clinical, Pathologic, and Molecular Genetic Features.

Area of Science:

• Oncology
• Pathology
• Genetics

Background:

• Renal cell carcinoma (RCC) with sarcomatoid and rhabdoid morphologies exhibits aggressive behavior and poor prognosis.
• The 2022 WHO classification views these as transformational changes, not distinct entities.
• Morphologically, sarcomatoid RCC features malignant spindle cells, while rhabdoid RCC has epithelioid cells with characteristic inclusions.

Purpose of the Study:

• To review the clinical, pathologic, and molecular features of sarcomatoid and rhabdoid RCC.
• To emphasize diagnostic recognition and molecular mechanisms of tumorigenesis.
• To discuss advances in treatment, particularly immunotherapy.

Main Methods:

• Review of clinical data.
• Pathologic feature analysis.
• Molecular profiling and genomic alteration studies.

Main Results:

• Sarcomatoid and rhabdoid RCCs possess distinct molecular features and undergo clonal evolution.
• Shared genomic alterations exist between carcinomatous and rhabdoid components, with specific alterations in the sarcomatoid element.
• Immunotherapy targeting PD-1/PD-L1/CTLA-4 has demonstrated significant clinical responses.

Conclusions:

• Sarcomatoid and rhabdoid differentiation in RCC are critical features requiring diagnostic recognition.
• Understanding the molecular pathways is key to targeted therapies.
• Immunotherapy represents a significant advancement in treating these aggressive kidney cancers.