Editing Renal Mass and Localized Renal Cancer (2021) (section)

=== Optional ===
* '''<span style="color:#ff0000">Renal mass biopsy</span>'''
** Generally safe with low risk of significant complications (bleeding) and no reported cases of tumor seeding using contemporary techniques.
** A diagnosis of malignancy or renal cell carcinoma on renal mass biopsy is highly reliable.
*** Pooled sensitivity: 96.7%
*** Pooled positive predictive value: 98.8%
*** Pooled specificity: 94.4%
** '''Potential limitations of RMB include (4):'''
**# '''A benign biopsy must be distinguished from a non-diagnostic biopsy (renal parenchyma or connective tissues) result.'''
**#* Non-diagnostic rate of renal mass biopsy is approximately 14%, which can be substantially reduced with repeat biopsy
**# '''A benign biopsy may not always correlate with benign histology.'''
**#* Pooled negative predictive value: 80.8%
**#*Due to the imperfect nature of renal mass biopsy, patients with benign renal mass biopsy may warrant follow-up.
**# '''Grade concordance from biopsy to surgically resected tissue is imperfect.'''
**# '''Oncocytic neoplasms may represent a diagnostic dilemma.'''
** '''<span style="color:#ff0000">Indications</span>'''
***'''<span style="color:#ff0000">Consider biopsy when a mass is suspected to be hematologic, metastatic, inflammatory, or infectious.</span>'''
*** '''<span style="color:#ff0000">Should be obtained if it will influence management</span>'''
**** '''<span style="color:#ff0000">NOT required for (2):</span>'''
****# '''<span style="color:#ff0000">Young or healthy patients who are unwilling to accept the uncertainties associated with RMB</span>'''
****# '''<span style="color:#ff0000">Older or frail patients who will be managed conservatively independent of RMB findings</span>'''
***'''<span style="color:#ff0000">Biopsy or aspiration of cystic renal masses is generally not recommended, due to (2):</span>'''
***#'''<span style="color:#ff0000">Concerns regarding tumor spillage</span>'''
***#'''<span style="color:#ff0000">High likelihood of obtaining a non-informative result due to sampling error</span>'''
**For biopsy of solid renal mass, multiple core biopsies should be obtained and are preferred over fine needle aspiration.