Pathologic evaluation of non-neoplastic renal parenchyma in partial nephrectomy specimens

Purpose: This study aimed to identify non-neoplastic pathologic changes in partial nephrectomy specimens of patients without a known history of medical comorbidities. Routine analysis of this tissue may allow the clinician to identify subclinical renal disease. Methods: We retrospectively reviewed our database of patients who underwent open partial nephrectomy for a small renal mass. Non-neoplastic tissue of partial nephrectomy specimens of patients without a known history of chronic kidney disease, diabetes mellitus, hypertension, or coronary artery disease was evaluated for glomerular, interstitial, and vascular pathologic changes. Results: A rim of non-neoplastic tissue was adequate for pathologic evaluation in 91.8% of specimens. A total of 45 patients were studied with a median age of 52.0 years. Atherosclerosis was the most commonly identified pathologic finding in 9 (20%) patients, followed by mesangial expansion and interstitial fibrosis, each found in 8 (17.8%) patients. Linear regression found interstitial fibrosis to be the only pathologic lesion associated with preoperative serum creatinine (coefficient = 0.697, P = 0.001). Male gender was also associated with a higher preoperative creatinine (coefficient = 0.270, P = 0.034). Postoperative serum creatinine was not associated with any of the examined lesions. Conclusions: Current surgical techniques provide adequate non-neoplastic tissue for pathologic evaluation. We observed a striking degree of pathologic disease in patients without a known history of medical comorbidities. Routine inspection of the non-neoplastic parenchyma of partial nephrectomy specimens should be performed as it can alert the clinician to presence subclinical renal disease allowing for medical intervention.