UNASSIGNED: 357 Background: Use of cross-sectional imaging has increased the detection rate for small @entity703 ; more @entity1 now present with early-stage @entity1358 ( @entity1358 ) or benign or indolent renal masses. Histopathology after surgical resection is the definitive method for characterizing @entity703 . Stage migration of renal masses creates uncertainty about the percentage of resected masses that will be benign vs malignant. We sought to better define these proportions through a targeted review of the literature. METHODS: PubMed/select congresses were searched to identify the histologic classification of renal masses in a representative sample from the contemporary literature: [search] incidence AND ( @entity1358 AND benign); incidence AND ( @entity703 AND benign); percentage AND ( @entity1358 AND benign); limit: 2003-2011. RESULTS: Most representative studies included procedures conducted in the mid-1990s to the mid-to-late 2000s. Studies origin was US (n=8), Korea (n=3), China, Japan, Germany, Austria, Australia, and multisite (Israel/France/US; all n=1). Only 8 studies had n>= 500 (range, 70-10,404). The proportion of benign masses are shown (see Table); half of the studies reported values between 16% and 17%. The majority found that @entity5 were more likely to be smaller in size (<4 or <7 cm) than @entity5 . 11 studies reported the @entity1358 subtype (% clear cell range, 46%-83%). CONCLUSIONS: @entity703 occur ~15% of the time and are more prevalent among small masses. Nearly 25% of resected lesions are benign or indolent and may not require surgery. Preoperative discrimination of more aggressive renal masses would be an important clinical advance that could improve clinicians' diagnostic confidence and guide @entity1 management. FUNDING: Wilex AG/IBA Molecular. [Table: see text].

Incidence of benign versus XXXX in selected studies.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity1358 :: ('MESH:D002292', 'Disease') :: ['renal cell carcinoma', 'RCC'] @entity5 :: ('MESH:D009369', 'Disease') :: ['malignant tumors', 'benign tumors'] @entity703 :: ('MESH:D007680', 'Disease') :: ['renal tumor', 'Benign renal tumors', 'renal tumors']
@entity703 :: (MESH:D007680,Disease) :: ['malignant renal tumors']
