Editing CUA: Cystic Renal Lesions (2017) (section)

== Intervention and follow-up ==

=== Bosniak I ===
* '''<span style="color:#ff0000">Follow-up for Bosniak I cysts is not warranted</span>'''
** Majority will grow over time; growth should not necessarily be considered a sign a malignancy
** Transformation into a more complex cyst is rare and has been reported in only a handful of cases
* '''<span style="color:#ff0000">Intervention is only warranted if the cyst becomes symptomatic''' (i.e., bleeding, recurrent infection or pain)
** Treatment options include: percutaneous management (aspiration +/- sclerotherapy) or surgery
** Percutaneous cyst decompression may also be considered prior to offering definitive treatment as a means to confirm that the source of symptoms are cyst-related.

=== Bosniak II ===
* '''<span style="color:#ff0000">Follow-up for Bosniak II cysts is not warranted</span>'''
* '''<span style="color:#ff0000">Intervention is only warranted if the cyst becomes symptomatic</span>'''

=== Bosniak IIF ===
* '''≈15% of these category IIF cysts will progress in complexity (to Bosniak category III or IV)''' over time
* '''<span style="color:#ff0000">Should be followed with a contrast-enhanced CT scan or MRI every 6 months for the first year. Cases without progression should be followed annually for at least 5 years.</span>'''

=== Bosniak III ===
* '''<span style="color:#ff0000">Surgical excision is generally suggested</span>'''
** '''Given the low metastatic potential of cystic RCC, the panel feels that reduced surgical margins and controlled cyst decompression (if required) can be performed with low risk of tumour recurrence.'''
** '''Likewise, due to the same reason, active surveillance and thermal-ablation therapies may also be considered as appropriate treatment alternatives in select cases'''

=== Bosniak IV ===
* '''<span style="color:#ff0000">Surgical excision is generally suggested</span>'''
** '''Most of these malignant cysts are thought to have low metastatic potential and thus, more conservative management may be safely considered in select cases'''