Upper urinary tract urothelial carcinoma and its variants: transition from morphology to personalized molecular characterization in diagnosis, prognosis, and therapy.

Upper tract urothelial carcinoma (UTUC) accounts for 5% of urothelial carcinomas (UCs), the estimated annual incidence being 1-2 cases per 100,000 inhabitants. The aim of this review was to summarize the main morphologic features of UTUC as well as the current status and future role of its molecular characterization in diagnosis, prognosis, and therapy. Areas covered: Several studies on the UTUCs have shown the diagnostic, prognostic, and therapeutic significance of standard pathological features, such as tumor stage, grade, and lymph node metastasis. Investigations have also identified novel factors, in particular, variant histologies, and molecular biomarkers. Based on these, predictive tools have been developed. Expert commentary: The morphology of the UTUC has been considered to be the same as that of Bladder Urothelial carcinoma (BUC). Molecular characterization studies, including genomics, have shown changes in UTUC occurring at differing frequencies in comparison with BUC, the former with unique molecular subtypes and different responses to treatment.