title: Incidence of benign lesions according to tumor size in solid renal masses.
abstract: OBJECTIVE
  The incidence of solid renal masses has increased sharply in recent years due to widespread use of abdominal imaging studies. The aim of the present study was to evaluate the incidence of benign lesions in solid renal masses according to tumor size.
  
  
  METHODS
  The authors retrospectively reviewed the records of 305 patients with 328 renal solid masses treated by surgery. Based on a report by one pathologist, the specimen tumor size and the histology of each lesion were tabulated. The frequency of renal cell carcinoma and benign renal lesions was evaluated and a correlation between tumor size and pathological features of the masses was observed.
  
  
  RESULTS
  The frequency of malignant lesions in the 328 renal masses was 83.2%. When lesions were stratified into groups with diameters <or= 3 cm or > 3 cm, the incidence of benign histology was 22.9% and 13.3%, respectively (p = 0.026). The odds ratios for finding a benign lesion in masses <or= 3 cm was 1.93 (IC 95%, 1.07 - 3.46) compared to masses > 3 cm.
  
  
  CONCLUSIONS
  The incidence of benign lesions is significantly higher in renal masses smaller than 3 cm in diameter, which should be taken in account when the treatment of renal solid masses is planned.
authors.affiliation: Division of Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil. srougi@uol.com.br
authors.forename: Victor
authors.initials: V
authors.lastname: Srougi
authors.forename: Raphael B
authors.initials: RB
authors.lastname: Kato
authors.forename: Fernanda A
authors.initials: FA
authors.lastname: Salvatore
authors.forename: Pedro P M
authors.initials: PP
authors.lastname: Ayres
authors.forename: Marcos F
authors.initials: MF
authors.lastname: Dall'Oglio
authors.forename: Miguel
authors.initials: M
authors.lastname: Srougi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000453:epidemiology / Q000473:pathology*; D007680:Kidney Neoplasms / Q000453:epidemiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult