[Autofluorescence endoscopy for diagnosing early laryngeal cancer and its precursor lesions].

OBJECTIVE:To assess autofluorescence endoscopy in the diagnosis of early laryngeal cancer and its precancerous lesions. METHODS:Seventy five patients suspected of having precancerous or cancerous lesions were examined with autofluorescence endoscopy (filtered blue light 380460 nm) under microlaryngoscopy. Autofluorescence pictures were taken with high-solution CCD-camera for analysis, diagnosis and storage, to compare with histologic results. RESULTS:Normal laryngeal mucosa with no visible alteration and mild hyperplasia displayed the typical bright green fluorescence signal, and the areas with moderate dysplasia, severe dysplasia or carcinoma in situ, microinvasive carcinoma and infiltrating carcinoma all showed a marked change in fluorescence to red or violet. Thus, autofluorescence enables to distinguish between benign hyperplastic laryngeal lesions (n =30) and precancerous epithelium (n =45) with a sensitivity rate of 97.8%, and specificity rate of 86.7%. False-negative results (n = 1) were caused by extreme hyperkeratosis, and false positive (n = 4) were cases with scarring or inflammation. CONCLUSIONS:Autofluorescence endoscopy is a less invasive method of diagnosing laryngeal cancer and its precursor, which can be manipulated easily and has high sensitivity. But there are considerable false-positive rates.