title: Frequency, clinical presentation and evolution of renal oncocytomas: multicentric experience from a European database.
abstract: OBJECTIVE
  To understand the clinical behavior of renal oncocytoma in a retrospective analysis of a European multicentric nephrectomies database.
  
  
  METHODS
  The records of 891 patients who underwent surgical resection of renal neoplasm were reviewed. Relevant clinical and pathological data for each patient were retrieved in a database.
  
  
  RESULTS
  Thirty-two (3.6%) cases of renal oncocytoma were identified. Twenty patients (62.5%) were asymptomatic. No case of lymphatic invasion or metastatic disease, nor any evidence of vascular or fat tissue invasion was found. Thirty-one cases (96%) exhibited low mitotic activity. In one case the presence of renal clear cell carcinoma (diameter: 1.5cm) was found. After a median follow-up of 42 months, 87.5% of patients were alive with no evidence of tumor, while 9.3% of patients had died for non-malignant causes. One patient had not treated the tumor surgically and was disease-free at a 27-month follow-up.
  
  
  CONCLUSIONS
  Renal oncocytoma is a benign neoplasm, characterized by slow growth and excellent prognosis after surgery. Nephron sparing techniques may be adequate for tumor removal.
authors.affiliation: Department of Urology, Medical School of University "Federico II", Naples, Italy. lucacindolo@virgilio.it
authors.forename: Leo
authors.initials: L
authors.lastname: Romis
authors.forename: Luca
authors.initials: L
authors.lastname: Cindolo
authors.forename: Jean Jacques
authors.initials: JJ
authors.lastname: Patard
authors.forename: Giovanni
authors.initials: G
authors.lastname: Messina
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Altieri
authors.forename: Laurent
authors.initials: L
authors.lastname: Salomon
authors.forename: Claude Clement
authors.initials: CC
authors.lastname: Abbou
authors.forename: Dominique
authors.initials: D
authors.lastname: Chopin
authors.forename: Bernard
authors.initials: B
authors.lastname: Lobel
authors.forename: Alexandre
authors.initials: A
authors.lastname: de La Taille
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000453:epidemiology; D018249:Adenoma, Oxyphilic / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery*; D000328:Adult; D000368:Aged; D016208:Databases, Factual; D005060:Europe; D005260:Female; D006801:Humans; D015994:Incidence; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies