Current methods facilitating diagnosis of upper tract urothelial carcinoma: a comprehensive literature review.

PURPOSE OF REVIEW: Currently, kidney-sparing surgeries are considered the preferred approach in low-risk tumours and in selected high-risk patients. Therefore, accurate diagnosis of UTUC is crucial for further management. The purpose of this review is to summarize available methods facilitating the diagnosis of upper tract urothelial carcinoma (UTUC).

RECENT FINDINGS: Recent articles propose numerous techniques of UTUC diagnosis. In this review, imaging, as well as, urine-based and endoscopic methods have been described and assessed.

SUMMARY: Regarding imaging, computed tomography urography remains a gold standard, while PET is superior in search for small lesions and nodal metastases. However, contrast-enhanced ultrasonography also shows promise. On the contrary, available urine tests, such as urinary cytology, fluorescent in-situ hybridization, Xpert, DNA methylation analysis, urine-based liquid biopsy, p16/Ki-67 dual immunolabelling, ImmunoCyt and NMP22 are either poorly researched, or not accurate enough to use solely. Finally, during ureterorenoscopy, photodynamic diagnosis and narrow-band imaging can facilitate proper visualization of the tumor. Endoluminal ultrasonography and confocal laser endomicroscopy can potentially improve staging and grading of UTUC. Also, the 'form tackle' biopsy should be performed using a basket in papillary lesions and cold-cup biopsy of flat or sessile lesions. Even though cryobiopsy shows promise in UTUC diagnosis, in-vivo studies are necessary before it is introduced into clinical practice.