title: Characteristics of image-detected solid renal masses: implication for optimal treatment.
abstract: BACKGROUND
  Solid renal masses are found increasingly. Further analysis of the characteristics of solid renal masses is useful for optimal treatment.
  
  
  METHODS
  A retrospective analysis of all solid renal masses was conducted from December 1998 to May 2003 at the Urology Department, Central University Hospital of Saint-Etienne, France. A total of 162 solid renal masses were treated. The preoperative imaging diagnosis of ultrasound and computed tomography, and final pathological results were reviewed.
  
  
  RESULTS
  One hundred and forty-five tumors were pathologically confirmed to be renal cell carcinomas (RCC); 17 tumors (10.5%) were benign. There were eight renal oncocytomas, eight renal angiomyolipomas and one benign mixed epithelial/stroma tumor. Three oncocytomas and five angiomyolipomas were strongly suspected before surgery. The majority of the benign tumors were < or =4 cm. The percentage of small benign tumors (< or =4 cm) was significantly higher than large benign tumors (>4 cm). Although it is possible to use imaging to detect some benign tumors, the majority of benign tumors cannot be diagnosed definitively by imaging before surgery.
  
  
  CONCLUSIONS
  Malignancy in solid renal masses is tumor-size related. Benign solid renal tumors appear mainly as small-sized tumors. The preoperative differentiation between an RCC and a benign tumor can be difficult. Our data suggest that a biopsy is necessary in selected patients to achieve the maximum accuracy in order to provide optimal treatment.
authors.affiliation: Department of Urology, North Hospital, Central University Hospital of Saint-Etienne, France. grli2001@yahoo.fr
authors.forename: Guorong
authors.initials: G
authors.lastname: Li
authors.forename: Muriel
authors.initials: M
authors.lastname: Cuilleron
authors.forename: Anne
authors.initials: A
authors.lastname: Gentil-Perret
authors.forename: Jacques
authors.initials: J
authors.lastname: Tostain
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology / Q000601:surgery; D000368:Aged; D018206:Angiolipoma / Q000473:pathology / Q000601:surgery; D001707:Biopsy, Needle; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D003937:Diagnosis, Differential; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000379:methods; D011237:Predictive Value of Tests; D011336:Probability; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed