This case highlights an unusual appearance of a more invasive and infiltrative urothelial carcinoma involving the renal pelvis, resulting in obstruction of the upper pole calyces. The final pathology confirmed “invasive high-grade urothelial carcinoma with positive arterial margin involving the adventitia”. It is important to take the clinical picture into consideration here - the urine was not infected and there is no fever. Additionally, the infiltrative nature in the renal pelvis is unexpected and when you look carefully, it is enhancing and narrowing the vasculature, indicating a neoplastic or infiltrative process rather than infection.