title: Fiber-Optic Confocal Laser Endomicroscopy of Small Renal Masses: Toward Real-Time Optical Diagnostic Biopsy.
abstract: OBJECTIVE
  The incidental detection of small renal masses is increasing. However, not all require aggressive treatments as up to 20% are benign and the majority of malignant tumors harbor indolent features. Improved preoperative diagnostics are needed to differentiate tumors requiring aggressive treatment from those more suitable for surveillance. We evaluated and compared confocal laser endomicroscopy with standard histopathology in ex vivo human kidney tumors as proof of principle towards diagnostic optical biopsy.
  
  
  METHODS
  Patients with a solitary small renal mass scheduled for partial or radical nephrectomy were enrolled in study. Two kidneys were infused with fluorescein via intraoperative intravenous injection and 18 tumors were bathed ex vivo in dilute fluorescein prior to confocal imaging. A 2.6 mm confocal laser endomicroscopy probe was used to image tumors and surrounding parenchyma from external and en face surfaces after specimen bisection. Confocal laser endomicroscopy images were compared to standard hematoxylin and eosin analysis of corresponding areas.
  
  
  RESULTS
  Ex vivo confocal laser endomicroscopy imaging revealed normal renal structures that correlated well with histology findings. Tumor tissue was readily distinguishable from normal parenchyma, demonstrating features unique to benign and malignant tumor subtypes. Topical fluorescein administration provided more consistent confocal laser endomicroscopy imaging than the intravenous route. Additionally, en face tumor imaging was superior to external imaging.
  
  
  CONCLUSIONS
  We report what is to our knowledge the first feasibility study using confocal laser endomicroscopy to evaluate small renal masses ex vivo and provide a preliminary atlas of images from various renal neoplasms with corresponding histology. These findings serve as an initial and promising step toward real-time diagnostic optical biopsy of small renal masses.
authors: Department of Urology, University of Florida College of Medicine, Gainesville, Florida. Electronic address: li-ming.Su@urology.ufl.edu.
authors: Li-Ming
authors: LM
authors: Su
authors: Department of Urology, University of Florida College of Medicine, Gainesville, Florida.
authors: Jennifer
authors: J
authors: Kuo
authors: Department of Surgical Pathology, University of Florida College of Medicine, Gainesville, Florida.
authors: Robert W
authors: RW
authors: Allan
authors: Department of Urology, Stanford University School of Medicine, Stanford, California.
authors: Joseph C
authors: JC
authors: Liao
authors: Department of Urology, University of Florida College of Medicine, Gainesville, Florida.
authors: Kellie L
authors: KL
authors: Ritari
authors: Department of Urology, University of Florida College of Medicine, Gainesville, Florida.
authors: Patrick E
authors: PE
authors: Tomeny
authors: Department of Surgical Pathology, University of Florida College of Medicine, Gainesville, Florida.
authors: Christopher M
authors: CM
authors: Carter
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D005260:Female; D005336:Fiber Optic Technology; D019793:Fluorescein / Q000008:administration & dosage; D006801:Humans; D007275:Injections, Intravenous; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D019793:Fluorescein
keywords: biopsy; carcinoma, renal cell; diagnosis; kidney; microscopy, confocal