Spectrum of nontumoral renal pathologies in tumor nephrectomies: nontumoral renal parenchyma changes

Non-neoplastic changes are not rarely seen in renal parenchyma of nephrectomy specimens removed for primary renal neoplasms. These changes often involve both kidneys, thus causing impairment of renal function, reducing patient's quality of life and sometimes threatening it. Renal tissue accompanying the tumor provides an opportunity in order to evaluate these changes. However, the clinician should make available clinical and laboratory findings involving renal functions of the patient to the pathologist. It is also important that the pathologist must have appropriate knowledge and experience in nephropathology. In this study, we aimed to correlate these changes with the clinical data and make inquiries regarding our experience with nonneoplastic kidney pathology. Consecutive 403 nephrectomy specimens with primary renal neoplasms submitted to our department between 2003 and 2009 were re-examined. Twenty-three nephrectomy materials from 21 patients had non-neoplastic changes, 2 of which were bilateral. Patient follow-up data were obtained from electronic medical records. Of all cases, eight had diabetic nephropathy; 2, amyloidosis; 5, segmental proliferative and/or sclerotic glomerulonephritis; and 6, cystic renal changes. These findings were seen in 5% of nephrectomy specimens diagnosed as clear cell renal cell carcinoma (RCC), chromophobe cell RCC and oncocytoma, whereas this rate was two times higher in nephrectomy specimens with papillary RCC. Most patients with renal failure who were diagnosed with clear cell carcinoma died within the first two years. Despite limited number of cases in our series, prognosis of cases with clear cell RCC were poorer. Consequently, we think that non-neoplastic changes should be reported along with the details regarding the tumor in order to achieve best treatment planning.