title: Classification of renal neoplasms based on molecular signatures.
abstract: OBJECTIVE
  Gene expression microarray studies have demonstrated distinct molecular signatures for different types of renal neoplasms based on overall gene expression patterns. However, in most of these studies the investigators used renal tumors with defined histology. We analyzed a test set of renal tumors in double-blind fashion using recently established molecular profiles of renal tumors as benchmarks.
  
  
  METHODS
  A total of 16 consecutive nephrectomies performed for neoplasms at a single urological service were subjected to gene expression profiling using cDNA chips containing 21,632 genes. Analysis was clustered with our previously established molecular profiles of 91 histologically defined kidney neoplasms and comparative genomic microarray analysis while blinded to tumor histology and clinical information.
  
  
  RESULTS
  With molecular analysis 9, 4, 2 and 1 tumors were classified as clear cell, papillary RCC, chromophobe RCC, and renal oncocytoma, respectively. Histopathological evaluation was concordant in 14 tumors. One of the 2 tumors with a discrepancy between molecular and pathological diagnoses was composed of oncocytoma and high grade clear cell RCC, and the other was chromophobe RCC that histologically mimicked papillary RCC.
  
  
  CONCLUSIONS
  We report the feasibility of the molecular diagnosis and classification of unknown renal neoplasms. Molecular diagnosis appears to be reliable and comparable to the standard of urological pathology. This molecular method may be a potentially useful test for establishing an accurate diagnosis that can impact clinical management.
authors.affiliation: Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Ximing J
authors.initials: XJ
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Sugimura
authors.forename: Kristian T
authors.initials: KT
authors.lastname: Schafernak
authors.forename: Maria S
authors.initials: MS
authors.lastname: Tretiakova
authors.forename: Misop
authors.initials: M
authors.lastname: Han
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Vogelzang
authors.forename: Kyle
authors.initials: K
authors.lastname: Furge
authors.forename: Bin Tean
authors.initials: BT
authors.lastname: Teh
mesh_terms: D002292:Carcinoma, Renal Cell / Q000145:classification* / Q000235:genetics*; D006801:Humans; D007680:Kidney Neoplasms / Q000145:classification* / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis