Fluorescencezytology of the urinary bladder

5-aminolevulinic acid induced fluorescence cystoscopy is invaluable for dia gnosing urinary bladder carcinoma and its precursors. Because neoplastic ce lls of the urinary bladder possess striking fluorescent properties due to p rotoporphyrin IX, we initiated a study to evaluate the use of fluorescence microscopy in urinary sediments. In 27 patients suspected of having bladder carcinomas, we instilled 5-aminolevulinic acid into their urinary bladders before transurethral therapy and compared thereafter our studies of standa rd cytological sediments with those made under fluorescence microscopy. The results of fluorescence cystoscopy and those using urinary sediments fo r neoplastic cells under fluorescence microscopy correlated extremely well. In this pilot study using fluorescence microscopy, we found that we could diagnose with precision urinary neoplasms of different grades of differenti ation. Accordingly, we regard fluorescence microscopy as a valuable complem ent for standard urinary cytology, especially since with fluorescence micro scopy we can readily recognize fluorescing cells of highly differentiated u rinary tumors and fiat premalignant dysplasias.