Editing Upper Urinary Tract Urothelial Cancer (section)

== Natural history ==

* '''Most occurrences are in a single renal unit'''
** '''Synchronous bilateral UTUC'''
*** '''Rare (<2%)'''
*** Risk of bilateral disease and multifocality increases with the presence of CIS
** Metachronous UTUC occurrences are 80% after bladder cancer and 2-6% after contralateral UTUC
*At the time of diagnosis
** ≈25% will present as localized disease
** >50% will present as regionally advanced cancers
** ≈20% will present as distant disease
*'''UTUC may spread''' in the same ways as bladder tumors do via '''direct invasion into the renal parenchyma or surrounding structures, lymphatic or hematogenous invasion, and epithelial spread by seeding or direct extension.'''
** '''<span style="color:#ff0000">Lymphatic:</span>'''
*** '''<span style="color:#ff0000">Lymphatic spread from the upper urinary tract depends on the location of the tumor:</span>'''
**** '''<span style="color:#ff0000">Renal pelvis and upper ureteral tumors spread initially from hilar to para-aortic and paracaval nodes</span>'''
**** '''<span style="color:#ff0000">Distal ureteral tumors spread to pelvic nodes</span>'''
*** '''Risk of lymphatic spread is directly related to the depth of invasion (stage) of the primary tumor'''
** '''Hematogenous:'''
*** '''Most common sites of hematogenous metastases (3):'''
***#'''Liver'''
***#'''Lung'''
***#'''Bone'''
** '''Epithelial:'''
*** '''Epithelial spreading may occur in both antegrade and retrograde manners.'''
**** Antegrade seeding is more common and thought to be the most likely explanation for the high incidence of recurrence in patients in whom a ureteral stump is left in situ after nephrectomy and incomplete ureterectomy