Presentation Authors: Francis Jefferson*, Orange, CA, Egor Parkhomenko, Boston, MA, Zhamshid Okhunov, John Sung, Roshan Patel, Cyrus Lin, Orange, CA, Kei Suzuki, Boston, MA, Ralph Clayman, Jaime Landman, Orange, CA
Introduction: In urology, renal mass biopsy among patients with an image-detected small renal mass (i.e. â‰¤ 4 cm) is currently not the standard of care; instead, most urologists proceed with extirpative therapy despite the knowledge that 20% of these masses are benign. For all other solid, organ-confined masses (e.g. prostate, bladder, lung, breast, etc.), the standard of care mandates a biopsy-established diagnosis prior to treatment. In order to discern why the kidney is an outlier for pre-treatment biopsy, we sought to compare the efficacy and safety of renal mass biopsy to biopsy of a mass in other major solid organ systems.
Methods: We reviewed meta-analyses, systematic reviews, and clinical studies with regard to biopsy of a mass in the following organs: prostate, lung, breast, thyroid, pancreas, and kidney. Rigorous study designs that minimized bias and systematic error were identified; only reports dealing exclusively with needle biopsy were included.
Results: Organ-specific mass biopsy data regarding sensitivity, specificity, diagnostic accuracy, and complication rate were extracted from 10 studies comprising 17,830 breast, 10,383 lung, 4,766 pancreas, 4,746 thyroid, 6,959 prostate, and 2,867 renal masses. The sensitivity and specificity for biopsy of a small renal mass were 99% and 98%, respectively, while the sensitivity and specificity for needle biopsy in the other organs ranged from 48% - 99% and 96% - 100%, respectively (Table 1). The complication rate for renal mass biopsy was 8% (less than 1% of these were Clavien grade â‰¥2), and the diagnostic accuracy (i.e. concordance with surgical pathology) of small renal mass biopsy was 96%, both of which compared favorably to or exceeded biopsy results in the other solid organs.
Conclusions: The safety and efficacy for needle biopsy of a small renal mass provides results equivalent to or better than biopsy of a solid mass in other organ systems. In light of the well-known 20% incidence of a benign diagnosis at the time of small renal mass exploration, the absence of routine preoperative needle biopsy remains an inexplicable urological conundrum.