Evaluation of the non-neoplastic kidney in tumor nephrectomy specimens and its significance

The pathologic evaluation of tumor nephrectomy specimens focuses on the diagnosis, grading, and staging of the neoplasm. Coincidental non-neoplastic changes are often present in these specimens. Although these conditions may be of prognostic or therapeutic importance, they are commonly neglected. Up to 25% of renal cell carcinoma patients have chronic kidney disease prior to nephrectomy, and those with normal renal function are more likely to develop chronic kidney disease after nephrectomy procedure. Recent studies have highlighted the importance of diagnosing medical kidney diseases in nephrectomy specimens removed for renal neoplasms. These studies have shown that over 60% of tumor nephrectomy specimens have coincidental medical renal diseases, and the presence of diabetic nodular glomerulosclerosis or greater than 20% global glomerulosclerosis is predictive of a significant decline in renal function within 6 months of surgery. Accurate pathologic evaluation of the non-neoplastic renal parenchyma in nephrectomy specimens is important for subsequent patient management.