Abstract
Approximately 3% to 4% of all newly diagnosed cancers are kidney tumours, which can develop from either the renal parenchymal tissue or the renal pelvis. Kidney cancer is one of the 13 most prevalent kinds of malignancy worldwide. 85% of all malignant kidney neoplasms are renal cell carcinomas (RCC). We present a rare instance of an RCC that had a thrombus in the ureter and had directly extended into the renal pelvicalyceal system. A thorough diagnostic workup was required because the patient had a number of symptoms, including flank pain, hematuria, and weight loss. Imaging tests identified a renal parenchymal-derived infiltrative tumour with remarkable pelvicalyceal penetration. Neovascularization was found within the tumour as a result of additional search. The discovery of ureteral extension, a peculiar characteristic, raised questions regarding both local and distant metastases. R.E.N.A.L nephrometry score was 11 with high complexity. Multidisciplinary management of the intricate clinical problem was employed. After removing the tumour mass, the ureteral involvement was treated with surgical resection, adjuvant therapy, and CT monitoring over the three-month high-risk follow-up period. With surgery, targeted treatment was employed to stop the cancer from growing. CONCLUSION: The importance of identifying unusual RCC presentations and employing a comprehensive diagnostic and treatment strategy is emphasised by this study. The complex interaction of ureteral extension, neovascularization, and pelvicalyceal penetration highlights the aggressiveness of advanced RCC. Since we are not aware of any literature documented instances including this combination, there are few studies explaining pelvicalyceal system invasion that defies commonly recognised diagnostic and treatment paradigms for renal cell carcinoma.