Renal biopsies for small renal masses. For whom, when and how.

Objective of this manuscript is to provide an evidence-based analysis of the current status and future perspectives in kidney biopsies in small renal masses (BSRM). A PubMed search has been performed for all relevant urological literature regarding BSRM. A literature research of English, French and Spanish languages was performed using the Pubmed database from 2000 to February 2012 using the terms renal mass biopsy and renal tumor biopsy. Manuscripts providing a highest level of evidence were selected for the review.Clinical experience from author's Institutions is also reflected in the manuscript. Considerable technical advances have been made in imaging over the last decade. The latter allow for a comprehensive sharp diagnosis of small renal masses (SRM). Therapeutic decision for SRM's is supported by objective knowledge of histological features and renal biopsy represents an accurate and safe option to particularize treatment in renal incidentalomas. Furthermore, renal biopsies are incorporated in the application and follow-up of patients undergoing ablative therapies. An important number of clinical reports have been published in the subject but there is lack of technical standardization. The available experience is limited to referral centers and there are still up to 30% of biopsies that fail to provide clear diagnosis. Renal biopsies have significantly improved in its diagnostic accuracy and it is indicated when tissue diagnosis can change the therapeutic approach of SRM's. Meantime, the role of renal biopsies keeps on growing and limitations of the procedure are less when compared to the benefits it provides.