The majority of urothelial carcinomas occur in the lower urinary tract, yet 5-10% originate in the upper urinary tract, including the renal calyces, renal pelvis, and ureters.1 Although upper and lower urinary tract urothelial carcinoma may share similar histology, the natural history differs, and upper tract disease often has a higher incidence of local invasion at diagnosis.2 Risk factors for upper tract urothelial carcinoma are similar to those of the lower tract, but there are some unique risk factors are associated with environmental exposures. For example, Taiwan has an extremely high incidence of upper tract urothelial carcinoma, with a counterintuitive 1:2 male-to-female ratio due to arsenic-contaminated water, termed Blackfoot disease. Additionally, in both Taiwan and the Balkan countries, exposure to the Aristolochic herbs (fangchi and clematis) is carcinogenic, leading to progressive renal fibrosis and upper tract urothelial carcinoma.4, 5