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

What's known on the subject? and What does the study add? Bladder cancer is initially diagnosed by white light cystoscopy followed by histopathological evaluation after transurethral resection of tissue suspicious for cancer. Difficulties may occur especially in the assessment of flat lesions or in discrimination between CIS and inflammatory disease. Confocal endomicroscopy during diagnostic colonoscopy has been a valuable tool for in vivo microscopic visualization and detection of colonic neoplasias and has contributed to optimized detection rates of up to 99%. We evaluated resected bladder urothelium of 18 patients by confocal endomicroscopy and correlated microscopic findings with standard histopathology. Typical tumour growth patterns such as altered nuclear to cytoplasmic ratio, pseudopapillar tissue stratification and neoangiogenesis were readily visible. As nuclear and subnuclear architecture of healthy bladder tissue could be discriminated against neoplastic tissue, confocal endomicroscopy is a promising novel tool for the in vivo microscopic visualization of bladder cancer. OBJECTIVE To evaluate bladder urothelium by confocal laser endomicroscopy (CLE) and correlate microscopic findings with standard histopathology. PATIENTS AND METHODS 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 mu m and an adjustable imaging depth of 0-250 mu m. Resection specimens of 18 patients were investigated with 1000-fold magnification and ex vivo findings were compared with targeted histopathology (haematoxylin and eosin staining). RESULTS 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. CONCLUSIONS 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.