Premalignant lesions in the kidney.

Area of Science:

• Urologic oncology
• Nephropathology

Background:

• Renal cell carcinoma (RCC) is a significant urologic malignancy.
• Potential precursor lesions to RCC, including dysplasia and atypical hyperplasia, have been identified.
• Recent studies detail dysplastic lesions, proposing the term renal intraepithelial neoplasia (RIN) for classification.

Purpose of the Study:

• To define the criteria for premalignant lesions.
• To evaluate renal intraepithelial neoplasia (RIN) as a potential precursor to renal cell carcinoma (RCC).
• To discuss the clinical implications of RIN in RCC management.

Main Methods:

• Analysis of kidneys adjacent to RCC or removed for other reasons.
• Detailed identification and definition of dysplastic lesions.
• Evaluation of criteria for premalignant lesions: morphology, spatial association, progression, frequency, and genetic alterations.

Main Results:

• Renal intraepithelial neoplasia (RIN) exhibits morphological similarity and spatial association with RCC.
• Progression to invasive carcinoma is observed in experimental models and some human tumors.
• Some putative premalignant changes share molecular alterations with RCC.

Conclusions:

• Renal intraepithelial neoplasia (RIN) appears to be a biologic precursor to some renal cell carcinomas (RCCs).
• RIN may persist after partial nephrectomy, potentially leading to local recurrences.
• Further investigation into RIN's biological nature, clinical significance, and management is warranted.