Simple Nephrectomy for Non-Functioning Kidney: An Institutional Experience with Non-Neoplastic and Incidentally Detected Neoplastic Lesions.

Chronic kidney diseases are attributed to a variety of etiologies, including diabetes mellitus, hypertension, vascular diseases, cystic kidney diseases, chronic tubulo-interstitial diseases, chronic pyelonephritis, and glomerular diseases. Simple nephrectomy is indicated when the loss of renal function in a unilateral non-functional kidney is permanent in a persistently symptomatic patient. Uncommonly, a non-functional kidney may develop neoplasm unsuspected pre-operatively and be diagnosed only during histopathological examination of nephrectomy specimen. We examined 275 simple nephrectomies performed between 2019 and 2024 in patients with non-functional kidneys confirmed by DMSA scan. All nephrectomies done for diagnosed or even suspected tumors by pre-operative imaging were excluded from the study. Chronic pyelonephritis (79.3%) was the most common histopathological diagnosis, followed by xanthogranulomatous pyelonephritis (8.7%) and granulomatous pyelonephritis (5.4%). In five (1.8%) patients, microscopy revealed non-specific chronic interstitial inflammation and interstitial fibrosis. One patient (0.4%) was diagnosed with large solitary pyelogenic cyst and renal nocardiosis. Eleven patients (4%) were diagnosed with neoplasms. Clear cell renal cell carcinoma was the most common diagnosis (27.2%), followed by urothelial carcinomas of renal pelvis (18.2%), one patient each of collecting duct carcinoma, squamous cell carcinoma of renal pelvis, and multilocular cystic renal neoplasm of low malignant potential. Three patients had papillary adenomas. Diligent histopathological examination of simple nephrectomy is crucial in establishing the final diagnosis with important further therapeutic implications. This is especially important in neoplastic pathologies developing in non-functional kidneys that may rarely be unsuspected by pre-operative imaging and diagnosed only during histopathological evaluation.