MediAI

Executive Clinical Summary A 63-year-old woman presented with persistent gross hematuria for two months. CT urography demonstrated an infiltrative soft-tissue mass centered in the upper portion of the left kidney and extending toward the mid kidney. The lesion contained multiple small calcifications and was closely associated with the left renal pelvis and upper collecting system. It also extended toward the proximal ureter and produced marked obstruction of the left renal pelvis with impaired contrast passage on delayed excretory imaging. The final diagnosis was high-grade papillary urothelial carcinoma . The central radiologic problem in this case is not simply the detection of a renal mass. The more important question is the origin of the tumor . A mass involving the kidney may represent a renal parenchymal neoplasm such as renal cell carcinoma (RCC), or it may represent a urothelial malignancy arising from the renal pelvis or collecting system and secondarily invading the renal par...

  Keywords: Horseshoe kidney, renal cell carcinoma, RCC imaging, CT diagnosis, congenital renal anomaly, hematuria differential diagnosis, kidney cancer CT, abdominal radiology, genitourinary oncology, renal fusion anomaly Abstract Horseshoe kidney is the most common renal fusion anomaly, occurring in approximately 1 in 400 individuals. Although typically asymptomatic, it predisposes patients to multiple complications, including urinary tract infections, urolithiasis, obstruction, trauma susceptibility, and malignancy. Renal cell carcinoma (RCC) arising in a horseshoe kidney presents unique anatomical, surgical, and diagnostic challenges due to aberrant vascular supply and abnormal renal orientation. This comprehensive review integrates radiologic imaging findings, pathophysiology, epidemiology, clinical manifestations, diagnostic strategies, differential diagnosis, therapeutic approaches, and prognosis, based on the most recent high-impact literature. Detailed radiologic inte...