Histopathological features of non-neoplastic areas of clear cell renal cell carcinoma tissues and clinical outcomes of patients

Abstract

This study aimed to investigate the histopathological changes in non-neoplastic areas of clear cell renal cell carcinoma tissue, using H&E and PAS staining, and to evaluate the clinical outcomes of patients. Our findings illustrated several aspects of the histopathological features of non-neoplastic areas of renal cancer tissues. It consisted of mononuclear infiltration, adipocyte deposition, interstitial fibrosis with macrophage infiltration, and fibrinoid necrosis of the interlobar arteries. Nodular glomerulosclerosis along with thickening of glomerular basement membranes was abundant in the non-neoplastic area. The hemorrhagic area was remarkable for containing RBC casts and macrophages containing hemosiderin. Additionally, we found necrosis of the renal tubular epithelium, thyroidization, and inflammatory cells casts in the tubular lumen. Most of our patients were elderly and the neoplasms presented mostly in males. The specimens were mostly found to show chronic pyelonephritis (64.71%) and hemorrhagic areas (88.24%). The patients were observed to have metastatic status (17.65%) and had been diagnosed with chronic pyelonephritis. All 8/17 patients had a comorbidity e g. hypertension (HT), chronic kidney disease (CKD), diabetes mellitus (DM). We noted that ccRCC patients presenting with chronic pyelonephritis and with metastases had cumulative survival rates lower than those patients without chronic pyelonephritis (72% vs. 100%). Hence, evaluation of histopathological changes in non-neoplastic renal parenchyma should be performed for patients with RCC, to improve management and treatment options, that may prevent accelerated function failure of the single remaining kidney, especially in patients with a background of medical diseases, including diabetes or hypertension.