title: Incidental neoplasms in renal biopsies.
abstract: BACKGROUND
  Incidental neoplastic lesions are occasionally found in renal biopsy specimens, but there is no evidence to indicate how they should be managed.
  
  
  METHODS
  A retrospective review was made of the management and clinical course of patients in whom an unsuspected neoplasm had been found in a renal biopsy.
  
  
  RESULTS
  In 11 880 biopsies taken over 22 years, there were incidental neoplasms in 25 (0.2%). Twenty-three of the 25 patients were men, and the median age was 59 years (range, 42-83 years). All had chronic renal damage, with a median index of chronic damage of 37% (range, 10-83%; normal=0%). Twenty-two neoplasms were papillary, two were clear cell renal carcinomas and one was in situ carcinoma in a collecting duct. The two clear cell carcinomas, three papillary neoplasms with residual masses after biopsy and the two papillary neoplasms in renal allografts were resected by nephrectomy or partial nephrectomy. Seven patients without resection were imaged with computerized tomography, six with magnetic resonance imaging and three with ultrasound scanning. Two were not imaged. None of the 11 patients who died, nor any of the other 14, had evidence of renal cell carcinoma at death or last follow-up respectively, at median 3.6 years after biopsy (range, 1 month-18.2 years).
  
  
  CONCLUSIONS
  When an incidental neoplasm is found, the pathological type should be defined, and imaging should be performed. Surgery should be considered in patients in whom there is a neoplasm of any type detectable by imaging, and limited resection may be possible. Neoplasms that are undetectable with imaging cannot be resected as the site of the lesion is unknown. We suggest surveillance of these, but whether this is necessary is undetermined. There is no evidence whether neoplasms undetectable with imaging in renal allografts require aggressive treatment.
authors.affiliation: Department of Nephrology, University Hospital Birmingham, Birmingham B15 2TH, UK.
authors.forename: Tanya
authors.initials: T
authors.lastname: Pankhurst
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Howie
authors.forename: Dwomoa
authors.initials: D
authors.lastname: Adu
authors.forename: D Michael A
authors.initials: DM
authors.lastname: Wallace
authors.forename: Graham W
authors.initials: GW
authors.lastname: Lipkin
mesh_terms: D000231:Adenocarcinoma, Papillary / Q000453:epidemiology / Q000473:pathology; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002292:Carcinoma, Renal Cell / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D033162:Incidental Findings; D007680:Kidney Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D018608:Ultrasonography, Doppler; D006113:United Kingdom / Q000453:epidemiology