Current Management of Small Renal Masses, Including Patient Selection, Renal Tumor Biopsy, Active Surveillance, and Thermal Ablation

Abstract

Renal cancer represents 2% to 3% of all cancers, and its incidence is rising. The increased use of ultrasonography and cross-sectional imaging has resulted in the clinical dilemma of incidentally detected small renal masses (SRMs). SRMs represent a heterogeneous group of tumors that span the full spectrum of metastatic potential, including benign, indolent, and more aggressive tumors. Currently, no composite model or biomarker exists that accurately predicts the diagnosis of kidney cancer before treatment selection, and the use of renal mass biopsy remains controversial. The management of SRMs has changed dramatically over the last two decades as our understanding of tumor biology and competing risks of mortality in this population has improved. In this review, we critically assess published consensus guidelines and recent literature on the diagnosis and management of SRMs, with a focus on patient treatment selection and use of renal mass biopsy, active surveillance, and thermal ablation. Finally, we highlight important opportunities for leveraging recent research discoveries to identify patients with SRMs at high risk for renal cell carcinoma-related mortality and minimize overtreatment and patient morbidity.

Fig 1.

Suggested algorithm for the management of small renal masses (SRMs). Renal mass biopsy (RMB) depicts clinical scenarios in which RMB can be considered. (*) When technically feasible. (†) Benign pathology, chromophobe, papillary type 1, or Fuhrman grade 1 to 2 metastatic renal cell carcinoma (mRCC). AS, active surveillance; CCI, Charlson Comorbidity Index; PN, partial nephrectomy; QOL, quality of life; RCC, renal cell carcinoma; TA, thermal ablation.