Nonneoplastic kidney diseases found in nephrectomy and nephroureterectomy specimens of renal cell carcinoma patients

Abstract

The pathologic evaluation of tumor nephrectomy and nephroureterectomy specimens focuses on the diagnosis of neoplasm, and thus concurrent nonneoplastic diseases are often neglected and omitted in the pathologic reporting. To determine the incidence and clinical significance, we retrospectively examined renal tissues of 93 cases, obtained from nephrectomy or nephroureterectmy for renal cell carcinoma. One paraffin-embedded block sampled from the non-tumorous area was used for histological examination. Hematoxylin-eosin and periodic acid-Schiff staining were performed. Nonneoplastic lesions in each histological compartment of renal parenchyma were evaluated semiquantitatively and quantitatively.Various lesions were observed in nonneoplastic renal parenchyma. Glomerulosclerosis was the most common, but diabetic nephropathy, focal segmental glomerular sclerosis and chronic pyelonephritis were easily found as well. The degree of glomerulosclerosis was correlated with preoperative eGFR and eGFR 5 years after surgery. However, the degree of tubular atrophy, interstitial fibrosis, interstitial inflammation and arterial intimal thickness were not related to preoperative eGFR and eGFR 5 years after surgery. Considering that various clinically important lesions were observed in nonneoplastic renal parenchyma and that pathologic findings correlated with renal function, pathologists should be aware of concurrent nonneoplastic kidney lesions and include them in surgical pathologic reports.