title: Rapid evaluation of fresh ex vivo kidney tissue with full-field optical coherence tomography.
abstract: BACKGROUND
  Full-field optical coherence tomography (FFOCT) is a real-time imaging technique that rapidly generates images reminiscent of histology without any tissue processing, warranting its exploration for evaluation of ex vivo kidney tissue.
  
  
  METHODS
  Fresh tissue sections from tumor and adjacent nonneoplastic kidney (n = 25 nephrectomy specimens; clear cell renal cell carcinoma (CCRCC) = 12, papillary RCC (PRCC) = 4, chromophobe RCC (ChRCC) = 4, papillary urothelial carcinoma (PUC) = 1, angiomyolipoma (AML) = 2 and cystic nephroma = 2) were imaged with a commercial FFOCT device. Sections were submitted for routine histopathological diagnosis.
  
  
  RESULTS
  Glomeruli, tubules, interstitium, and blood vessels were identified in nonneoplastic tissue. In tumor sections, the normal architecture was completely replaced by either sheets of cells/trabeculae or papillary structures. The former pattern was seen predominantly in CCRCC/ChRCC and the latter in PRCC/PUC (as confirmed on H&E). Although the cellular details were not very prominent at this resolution, we could identify unique cytoplasmic signatures in some kidney tumors. For example, the hyper-intense punctate signal in the cytoplasm of CRCC represents glycogen/lipid, large cells with abundant hyper-intense cytoplasm representing histiocytes in PRCC, and signal-void large polygonal cell representing adipocytes in AML. According to a blinded analysis was performed by an uropathologist, all nonneoplastic tissues were differentiated from neoplastic tissues. Further, all benign tumors were called benign and malignant were called malignant. A diagnostic accuracy of 80% was obtained in subtyping the tumors.
  
  
  CONCLUSIONS
  The ability of FFOCT to reliably differentiate nonneoplastic from neoplastic tissue and identify some tumor types makes it a valuable tool for rapid evaluation of ex vivo kidney tissue e.g. for intraoperative margin assessment and kidney biopsy adequacy. Recently, higher resolution images were achieved using an experimental FFOCT setup. This setup has the potential to further increase the diagnostic accuracy of FFOCT.
authors.affiliation: Department of Pathology, Weill Cornell Medical College, New York, USA.
authors.forename: Manu
authors.initials: M
authors.lastname: Jain
authors.affiliation: Department of Pathology, Weill Cornell Medical College, New York, USA ; Department of Urology, Weill Cornell Medical College, New York, USA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Robinson
authors.affiliation: Department of Biochemistry, Weill Cornell Medical College, New York, USA.
authors.forename: Bekheit
authors.initials: B
authors.lastname: Salamoon
authors.affiliation: Langevin Institute, at ESPC 1 rue Jussieu, 75005, Paris, France ; LLTech, at Cochin Hospital's Business Incubator, 29 rue du Faubourg Saint-Jacques, 75014 Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Thouvenin
authors.affiliation: Langevin Institute, at ESPC 1 rue Jussieu, 75005, Paris, France ; LLTech, at Cochin Hospital's Business Incubator, 29 rue du Faubourg Saint-Jacques, 75014 Paris, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Boccara
authors.affiliation: Department of Biochemistry, Weill Cornell Medical College, New York, USA.
authors.forename: Sushmita
authors.initials: S
authors.lastname: Mukherjee
keywords: Ex vivo microscopy; full-field optical coherence tomography; histopathology; kidney; tumors