Is perirenal fat an active player in renal cell carcinoma tumorigenesis? A radiologic-pathologic correlation study

Obesity is a significant modifiable risk factor for renal cell carcinoma, yet its involvement in tumor development pathways remains incompletely understood. Perirenal fat tissue has been implicated in various metabolic and oncologic processes. The Mayo Adhesive Probability score is widely used for quantitative and qualitative assessment of perirenal fat tissue. This study aimed to investigate the relationship between perirenal fat tissue evaluated by the Mayo Adhesive Probability score and tumor pathology in patients with renal cell carcinoma.

Patients who underwent surgery for a renal mass between January 2014 and July 2022 with pathology confirming clear cell renal cell carcinoma were included. Retrospective analysis of patient data, pathology findings, and radiological measurements of perirenal fat tissue was performed. Patients with prior surgical interventions potentially affecting perirenal fat evaluation were excluded.

Data from 156 patients were analyzed. A statistically significant positive correlation was observed between posterior perirenal fat thickness and nuclear grade (r=0.186, P=0.022). The Mayo Adhesive Probability score was also positively associated with nuclear grade (r=0.290, P<0.001) and T stage (r=0.272, P<0.001).

To our knowledge, this study is the first to demonstrate a relationship between perirenal fat thickness and nuclear grade, as well as the Mayo Adhesive Probability score and nuclear grade, based on the current grading system. These findings suggest that perirenal fat tissue may contribute to tumorigenesis in clear cell renal cell carcinoma. Further prospective studies are needed to validate and build upon these findings.