Editing Kidney Cancer: Pathology (section)

=== <span style="color:#ff0000">Other histologic features</span> ===

* '''<span style="color:#ff0000">Sarcomatoid differentiation</span>'''
** Found in 1-5% of RCCs
** '''Not a distinct histologic subtype of RCC''', '''<span style="color:#ff0000">most commonly in association with ccRCC and chromophobe RCC</span>'''
** '''<span style="color:#ff0000">Associated with worse prognosis;</span> multimodal approaches should be considered'''
* '''Cystic degeneration'''
** Found in 10-25% of RCCs
** '''Associated with better prognosis''' compared with purely solid RCC

* '''Laterality and focality'''
** '''<span style="color:#ff0000">Most sporadic RCCs are unilateral and unifocal</span>'''
** '''<span style="color:#ff0000">Bilateral involvement</span>'''
*** Occurs in 2-4% of sporadic RCCs
**** '''More common in patients with familial forms of RCC ('''e.g'''.''' von Hippel-Lindau disease).
*** Can be synchronous or asynchronous
**** '''<span style="color:#ff0000">If synchronous, likely an independent growth</span>'''
**** '''<span style="color:#ff0000">If asynchronous, likely a metastasis</span>'''
** '''<span style="color:#ff0000">Multifocality'''
*** '''<span style="color:#ff0000">Occurs in 10-20% of cases</span>'''
*** '''<span style="color:#ff0000">More common with papillary histology and familial RCC</span>'''
*** '''<span style="color:#ff0000">Microsatellite analysis suggests a clonal origin for most multifocal RCC</span>'''