Pretreatment Diagnosis of the Small Renal Mass: Status of Renal Biopsy in the United States of America.

Introduction: We surveyed United States of America-based urologists to characterize practice patterns and indications to perform a renal mass biopsy for small renal masses.
Materials and Methods: Members of the American Urological Association who practice in the United States were invited to participate in a 11-question web-based survey that was distributed via SurveyMonkey ^® from December 2016 to January 2017.
Results: There were 1131 respondents. The respondents equally represented all regions of the United States; the majority were in private practice. Overall, 32% of American urologists would "never" perform a biopsy of a renal mass ≤4 cm. Those who saw fewer than five small renal masses per year were more likely to "never" perform a renal biopsy on either a renal mass ≤4 cm or a renal mass 2-3 cm compared with those who saw more than five small renal masses per year (p < 0.001). Urologists who practiced at an academic hospital were more likely to perform a renal biopsy on both a renal mass ≤4 cm and a renal mass 2-3 cm compared with private practice and government-based urologists (p < 0.001 and p = 0.008 respectively). The primary reason for not performing a biopsy, cited by 68% of responding urologists, was that the results of a biopsy "would not change their management of the renal mass." Respondents independently performed only 2% of biopsies; however, almost half stated that they would be interested in learning office-based ultrasound-guided biopsy of a small renal mass.
Conclusions: Among members of the American Urological Association, biopsy of a small renal mass remains an underutilized diagnostic procedure, especially in light of 6000 unnecessary surgeries annually; nonuniversity-based urologists and those who see <5 renal mass cases each year infrequently perform a biopsy. Currently, interventional radiologists perform almost all small renal mass biopsies.