Editing AUA: Upper Tract Urothelial Carcinoma (2023) (section)

=== Laboratory ===

* '''<span style="color:#ff0000">Selective ipsilateral upper tract urine cytology</span>'''
** '''Provides supplemental histologic data to tumor biopsies'''
***'''High-grade cytology in the setting of low-grade biopsy findings indicates the likely presence of higher-risk features (e.g., high-grade tumor) missed on biopsy sampling.'''
**'''<span style="color:#ff0000">Specimen collection considerations</span>'''
***'''<span style="color:#ff0000">Can be obtained either as barbotage (saline irrigation and aspiration) or by saline irrigation with passive collection (washings)</span>'''
****'''Preferred over a voided urinary specimen''', due to (3) 
****#Improve cellular yield
****#Avoid potential contamination in case of concomitant bladder and/or prostatic urethral disease
****#Avoid theoretical dilution of the specimen from a normal contralateral unit
***'''<span style="color:#ff0000">Should be collected prior to any contrast use to avoid artifactual cellular changes from contrast solutions</span>'''
***'''<span style="color:#ff0000">Collecting selective cytology after tumor biopsy can improve the yield of cells for cytologic analysis.</span>'''
**Urine cytology is reported according to 7 categories (Paris System):
**#Non-diagnostic
**#Negative for high-grade urothelial carcinoma
**#Atypical urothelial cells
**#Suspicious for high-grade urothelial carcinoma
**#High-grade urothelial carcinoma
**#Low-grade urothelial neoplasm
**#Other malignancies
*'''<span style="color:#ff0000">Assessment of renal function</span>'''
**Can help with patient counseling, strategizing treatment sequence (operative approach and administration of systemic therapy), and determination of downstream risks of CKD and potential dialysis.
**'''Recommended test: serum creatinine (to calculate an eGFR)''' 
***For more refined evaluation, split function testing such as with differential renal scan or CT volumetric studies may be considered.
***The two formulas for monitoring eGFR commonly reported in the contemporary literature at this time are the [https://www.mdcalc.com/calc/76/mdrd-gfr-equation Modification of Diet in Renal Disease] and [https://www.mdcalc.com/calc/3939/ckd-epi-equations-glomerular-filtration-rate-gfr CKD – Epidemiology Collaboration (CKD-EPI)] equations.
**'''UTUC with associated hydronephrosis'''
***Implications on assessment of renal function
****Caused by tumor obstruction may falsely under-estimate preoperative renal function and alter decision-making around the use of neoadjuvant chemotherapy (NAC).
****Atrophy of the contralateral (unaffected) renal unit may lead to over-estimates of postoperative renal function in the setting of NU since the kidney with lower differential function will remain in situ
*** '''Renal decompression either by indwelling ureteric stent or a percutaneous nephrostomy tube placed in an uninvolved renal calyx along with oral fluid hydration for 7-14 days before re-checking eGFR will help to establish a more accurate estimation of baseline renal function.'''
****'''Ureteric stenting is the preferred method of drainage'''
*****Percutaneous nephrostomy tubes in the setting of UTUC increases risk of tract seeding and has worse quality of life