Xanthogranulomatous Pyelonephritis in association with Chronic kidney disease: A novel step in early detection of Renal Tuberculosis

Introduction: Xanthogranulomatous pyelonephritis is a chronic renal pathological condition with destructive granulomatous process. It is typically associated with nephrolithiasis followed by sequelae of nonfunctioning kidney. Tuberculosis being a major global infectious disease, the incidence of renal tuberculosis has been increasing in recent years in developing countries like India. Despite recent advances in diagnostic modalities, early and accurate diagnosis of renal tuberculosis has become a challenging task to the Pathologists especially with varied presentations having many differentials on histology. In the present study, we aimed to analyze the incidence of renal tuberculosis associated with Xanthogranulomatous pyelonephritis and correlation with clinical profile thereby aiding in prompt diagnosis & treatment. Materials and Method: The present study involved all age groups. With few exclusion criteria, all the nephrectomy specimen sent to laboratory were subjected to standard histopathological procedure with staining in reference to standard operating procedure. All the histological features on microscopy were documented and correlated with preoperative clinical data and presentation. Results: Total number of twenty nephrectomy specimen with varied preoperative clinical indications were analyzed. Among the cases with diagnosis of calculi without any clinical history and radiological evidence for renal tuberculosis, 18 cases showed renal calculi in association with xanthogranulomatous pyelonephritis. Extensive sampling from these 18 specimens, 10 cases revealed foci of renal tuberculosis associated with xanthogranulomatous pyelonephritis in the adjacent renal parenchyma Conclusion: Renal tuberculosis is an uncommon renal pathology often under diagnosed preoperatively. Hence combination of a nonfunctioning contracted kidney, a central calculus, contracted renal pelvis with association of xanthogranulomatous pyelonephritis, suspicion of renal tuberculosis must always be included in the differential diagnosis by the Pathologist thereby aiding in the post-operative treatment.