AUA 2017: Role of Biopsy in the Management of Small Renal Masses

Boston, MA ( The treatment landscape for localized renal cell carcinoma has changed dramatically over the last 30 years, from always performing a radical nephrectomy to now having several treatment options which include partial nephrectomy, thermal ablation and most recently active surveillance. The increase use of cross sectional imaging over the last 20 years has yielded an increase in the incidence of cT1a (≤ 4 cm) masses. Several histopathological reports have shown that small renal masses have a high rate of benign disease or tend to be for the most part low grade in histology. When assessing treatment options for a patient with a small renal mass one must take into account the risk of cancer progression vs. the risk of treatment especially in patients with competing medical comorbidities. Although, several reports have shown the high safety profile of active surveillance of small renal masses, the lack of histological evaluation leads to patient and physician anxiety which may lead to unnecessary treatment.

Renal mass biopsy allows for the histological examination of the renal mass which may aid in treatment allocation. Although renal mass biopsy has been well stablished for well over 10 years hesitations regarding the safety, diagnostic accuracy and potential for tumor seeding remains. The technique of how a renal biopsy should be performed has been well published and recently include in the updated AUA guidelines which include the use of a coaxial sheath, multiple biopsies (≥ 4 cores), and core biopsies vs. fine needle aspiration. The risk of tumor seeding has been for the most part mitigated with the use of a coaxial sheath. The risk of post-biopsy bleeding is low but real with ~ 2-5% of patients in large biopsies series having a clinically significant bleed.

The accuracy of renal mass biopsy has been quoted to be between 80-90% for histological determination. Tumor grade the accuracy remains low at ~ 60%, which is thought to be due to grade heterogeneity within the mass. A recent publication has introduced the use of quadrant biopsies which has been able to more accurately assess the grade of the renal mass.

Dr. Krupski introduces the idea of using process engineering to further improve the accuracy of renal mass biopsy. By using a quality control process the histological diagnosis can be passed to the radiologist which then can discuss with the pathologist and the treating physician about how to improve overall accuracy of the renal mass biopsy process.

In conclusion, renal mass biopsy for renal masses allows for risk stratification of the renal mass which allows for an improved informed decision to be made regarding the treatment options.

Presented By: Tracy, Krupski, MD, MPH

Institution: University of Virginia (UVA) Department of Urology

Written By: Andres F. Correa, MD, Society of Urologic Oncology Fellow, Fox Chase Cancer Center, Philadelphia, PA

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA