title: Use of FISH analysis for diagnosis of renal cell carcinoma subtypes.
abstract: BACKGROUND
  Cytogenetic and molecular genetic techniques have been used in demonstrating the chromosomal abnormalities which characterize specific subtypes of renal cell carcinoma (RCC). The aim of this study was to determine the efficiency of fluorescent in situ hybridization (FISH) technique in characterizing various subtypes of RCC based on the presence of specific chromosome abnormalities found in each RCC subtype.
  
  
  METHODS
  FISH was performed on touch imprint smears from eight renal cell carcinomas histologically confirmed by established criteria.
  
  
  RESULTS
  In four tumors with histologic features of chromophobe renal cell carcinoma (ChRCC), interphase FISH was performed using centromeric probes for chromosomes 1, 2, 6, 10, 12, 17 and 21. All four ChRCC tumors showed one FISH signal corresponding to one copy number for each of these chromosomes. Two papillary RCCs included in this study showed trisomy 7 and 17, and loss of chromosome Y, using the corresponding chromosome centromeric probes. Similarly, we tested two clear cell RCCs for chromosome 3 short arm deletion with DNA probe 3p21.3. Both tumors showed loss of 3p21.3 signal.
  
  
  CONCLUSIONS
  We conclude that interphase FISH performed on touch imprint smears is a relatively simple, rapid and reliable method for detecting chromosome abnormalities which are specific for various subtypes of RCC.
authors.affiliation: Departments of Pathology and Laboratory Medicine, and of Biological and Medical Research, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: M A
authors.initials: MA
authors.lastname: Iqbal
authors.forename: M
authors.initials: M
authors.lastname: Akhtar
authors.forename: F
authors.initials: F
authors.lastname: Al Dayel
authors.forename: C
authors.initials: C
authors.lastname: Ulmer
authors.forename: M C
authors.initials: MC
authors.lastname: Paterson