Primary kidney squamous cell carcinoma, misdiagnosed as xanthogranulomatous pyelonephritis: A case report.

Squamous cell carcinoma (SCC) of the kidney is a rare malignancy, typically arising in the renal pelvis in association with chronic irritation and infection. Persistent inflammation may lead to squamous metaplasia and progression to carcinoma. Preoperative diagnosis is challenging due to nonspecific clinical and radiologic findings, often mimicking inflammatory conditions. We report a case of renal SCC in a nonfunctional kidney with long-standing pyelonephritis and nephrolithiasis, initially suspected as xanthogranulomatous pyelonephritis. The diagnosis was confirmed histopathologically. This case emphasizes the importance of considering malignancy in chronically diseased kidneys and the critical role of histopathologic evaluation.