Confocal laser endomicroscopy for the diagnosis of urothelial bladder neoplasia: a technology of the future?

Abstract

To evaluate bladder urothelium by confocal laser endomicroscopy (CLE) and correlate microscopic findings with standard histopathology. Fresh bladder urothelium tissue specimens were topically stained with acriflavine for instantaneous microscopic imaging. A single-line laser in a handheld CLE probe delivered an excitation wavelength of 488 nm providing a high resolution of 0.7 µm and an adjustable imaging depth of 0-250 µm. Resection specimens of 18 patients were investigated with 1000-fold magnification and ex vivo findings were compared with targeted histopathology (haematoxylin and eosin staining). Typical tumour growth patterns such as altered nuclear to cytoplasmic ratio, pseudopapillar tissue stratification and neoangiogenesis were readily visible. Nuclear and subnuclear architecture of healthy bladder tissue could be discriminated against neoplastic tissue. In addition to white light cystoscopy, CLE is a promising novel tool for the in vivo microscopic visualization of bladder cancer; first results of the present study show its potential to define microscopic characteristics of bladder cancer tissue. Further in vivo studies are necessary to determine sensitivity and specificity of the technique.