XXXX Biopsy for Small Renal Masses: A Single-center 13-year Experience.

@entity1 @entity5 @entity703
BACKGROUND: @entity703 biopsy (RTB) for the characterization of small renal masses (SRMs) has not been widely adopted despite reported safety and accuracy. Without pretreatment biopsy, @entity1 with @entity5 are frequently overtreated. OBJECTIVE: To assess the diagnostic rate of RTBs, to determine their concordance with surgical pathology, and to assess their impact on management. DESIGN, SETTING, AND @entity1 : This is a single-institution retrospective study of 529 @entity1 with biopsied solid SRMs  <=4cm in diameter. RTBs were performed to aid in clinical management. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Diagnostic and concordance rates were presented using proportions. Factors that contributed to a diagnostic biopsy were identified using a multivariable logistic regression. RESULTS AND LIMITATIONS: The first biopsy was diagnostic in 90% (n=476) of cases. Of the nondiagnostic biopsies, 24 @entity1 underwent a second biopsy of which 83% were diagnostic. When both were combined, RTBs yielded an overall diagnostic rate of 94%. Following RTB, treatment could have been avoided in at least 26% of cases because the lesion was benign. @entity5 size and exophytic location were significantly associated with biopsy outcome. RTB histology and nuclear grade were highly concordant with final pathology (93% and 94%, respectively). Adverse events were low (8.5%) and were all self-limited with the exception of one. Although excellent concordance between RTB and final pathology was observed, only a subset of @entity1 underwent surgery following biopsy. Thus it is possible that some @entity1 were misdiagnosed. CONCLUSIONS: RTB of SRMs provided a high rate of diagnostic accuracy, and more than a quarter were benign. Routine RTB for SRMs informs treatment decisions and diminishes unnecessary intervention. Our results support its systematic use and suggest that a change in clinical paradigm should be considered. @entity1 SUMMARY: @entity703 biopsy (RTB) for pretreatment identification of the pathology of small renal masses (SRMs) is safe and reliable and decreases unnecessary treatment. Routine RTB should be considered in all @entity1 with an indeterminate SRM for which treatment is being considered.
