Upper tract urothelial cancer.

While urothelial carcinoma is a very common tumor, involvement of the upper tract is relatively uncommon. Consequently, there are no consensus imaging recommendations for upper tract disease. CT urography is the dominant imaging modality for the upper tract, but despite its excellent performance characteristics and being widely accepted as standard of care there is great variability in how CTU exams are performed across practices. MR urography has limited current application, but has the potential to become more mainstream in the future with continued technical advances. Upper tract urothelial carcinoma can manifest as a variety of appearances: a papillary lesion, focal wall thickening, focal enhancement, or as an infiltrative lesion. Pelvicalyceal location is about twice as common as in the ureter. Tumors in the pelvicalyceal location often manifest as an irregular enhancing soft tissue attenuation filling defect, and may be sessile or polypoid in morphology. Within the ureter, 73% are located in the distal segment.