A Retrospective Cross-sectional Analysis of Renal Complications in Association with Cancer: Insights from 120 Autopsies

Abstract

Introduction: Kidney diseases frequently complicate cancer and its treatment, contributing to both morbidity and mortality. Malignancies can give rise to various kidney issues, such as glomerulonephritis and Chronic Kidney Disease (CKD). This association operates bidirectionally, with patients experiencing the development of renal diseases due to cancer, and CKD predisposing to cancer. Furthermore, nephrotoxicity induced by chemotherapy can result in Acute Tubular Injury (ATI) and necrosis, imposing limitations on its application. Aim: To evaluate the spectrum of renal pathology in autopsies of malignancies. Materials and Methods: This was a retrospective crosssectional study of complete autopsies of all cases of malignancies performed in the Department of Pathology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India. The study was carried out over a 5-year period from January 2015 to December 2019. Analysis of cases with respect to demographics, type of primary malignancy, gross and microscopic features, and the final cause of death was conducted. These findings were meticulously tabulated, with frequencies and percentages calculated for each category. Results: A total of 4392 autopsies were conducted throughout the study period, with 120 of them revealing the presence of malignancies. A total of 38 (31.6%) malignancies were diagnosed for the first time at autopsy. The commonest renal findings on gross were scars (superficial and deep) seen in 40 (33.33%), followed by cortical cysts in 25 (20.83%), granular contracted kidney in 15 (12.50%), mass lesions in 7 (5.83%), abscesses in 7 (5.83%), and swollen, oedematous kidneys in 6 (5%) autopsies. The most frequent renal pathology on microscopy were infective lesions seen in 43 (35.83%), Acute Tubular Necrosis (ATN) in 32 (26.66%), ATI in 30 (25%), followed by malignancies- primary and secondary in 11 (9.16%), tubular casts in 6 (5%), etc. Rare findings included membranous glomerulonephritis and Tumour Lysis Syndrome (TLS) (Acute urate nephropathy) in 1 (0.83%) each. The TLS case had classic histomorphological features of TLS, apart from laboratory parameters. Extensive deposits of uric acid crystals were seen obstructing the tubules as well as some of the glomeruli on microscopy. Conclusion: In one-third of the cases, the malignancy was exclusively discovered during the autopsy. The study revealed a diverse array of lesions, encompassing pyelonephritis, ATN, primary and metastatic renal tumours, cast nephropathy, membranous glomerulonephritis, and TLS. One-fifth of the cases had end-stage renal disease (advanced renal disease). A significant number of the cases exhibited tumour masses within the kidneys. One-fifth of the cases had renal pathology contributing to the final cause of death, further highlighting the association between malignancies and renal pathology