Non-neoplastic pathologic findings in nephrectomy specimens; postoperative renal insufficiency and outcomes

Introduction: Incidence of renal masses has increased with increased abdominal imagings. The trend in treatment of renal masses has been toward renal preserving options, including surveillance, ablation and partial nephrectomy. Objectives: To determine the frequency of medical renal disease in patients undergoing surgical intervention for renal neoplasms and to establish whether these pathologic changes predict development of renal insufficiency in the immediate postoperative period. Patients and Methods: This was an Institutional Review Board (IRB)-approved retrospective review of all patients that underwent radical nephrectomy (RN), partial nephrectomy and nephroureterectomy from December 2009 to November 2013. Around 225 patients had complete pathologic and perioperative data for analysis. We compared preoperative and postoperative glomerular filtration rate (GFR), neoplastic findings, tumor characteristics (positive margins and extracapsular extension), and pathology information regarding non- neoplastic findings (tubular atrophy, chronic inflammation and fibrosis). Results: The presence of any pathologic abnormalities in the non-neoplastic renal parenchyma was significantly associated with increased serum creatinine levels postoperatively (P=0.01) and at last follow up visit (P=0.04). Univariate analysis showed that glomerular and vascular abnormalities were each significantly associated with worsening renal function. Conclusion: Our research suggests that abnormalities in non-neoplastic renal parenchyma found in renal specimens after RN should not be ignored as they may predict possible worse outcomes in renal function. This may help make a case for biopsy pre-operatively and a stronger case for nephron sparing surgery. This may also help determine which patients should be followed more closely postoperatively.