This clinical trial tests how well office based ureteroscopy utilizing a single use digital, flexible ureteroscope works for the assessment of upper tract urothelial carcinoma. Ureteroscopy is a procedure in which a thin camera called a ureteroscope is used to assess patients with a known or suspected diagnosis of upper tract urothelial carcinoma. Ureteroscopy is traditionally performed in an operating room under general anesthesia. In this study, patients undergo ureteroscopy in the doctor's office using an ultra-thin ureteroscope, which is the narrowest instrument of its kind. Because of its small size, researchers believe this procedure can be completed in the office with minimal discomfort and high patient satisfaction, which may eliminate the risks of general anesthesia and reduce delays to diagnosis. Office based ureteroscopy utilizing a single use digital, flexible ureteroscope may be effective for the assessment of upper tract urothelial carcinoma.