5-ALA-Induced Fluorescent Cytology in the Diagnosis of Bladder Cancer-a Preliminary Report.

5-Aminolevulinic acid (ALA)-induced fluorescence cystoscopy has established itself in the detection of flat and/or small lesions. This is explained by the simple fact that there is increased uptake of ALA, altered activity of certain enzymes, and altered intracellular redistribution and storage of protoporphyrin IX (PPIX) in the malignant cells. Intracellular PPIX allows red fluorescence detection.