New trends in endoscopic diagnosis of tumors of the larynx

Early detection and accurate determination of localization and extent of benign growths, particularly precancerous lesions and malignant tumors of larynx have significant therapeutic and prognostic importance. Today, laryngomicroscopy (LMS) is worldwide accepted diagnostic procedure for detection, description and biopsy of laryngeal pathology. In many cases it is a therapeutic procedure. However, detection and accurate description of laryngeal lesion can often be a difficult task, requiring great experience of ENT specialist. Because that attempts to optimize diagnostic procedure for more sensitive detection, and more accurate describing of laryngeal pathology are still challenges for otolaryngologists. Each diagnostic procedure that is able to give accurate information about nature of laryngeal lesion without devastation of tissue has important advantages over standard biopsy. Contact laryngomicroscopy is in vivo microscopic examination of laryngeal mucosa without biopsy. Procedure is performed during laryngomicroscopy by introducing contact endoscope into larynx. Autofluorescent endoscopy is based on ability of flavin mononucleotide (FMN) in normal cells to emit green fluorescence when is exposed to blue light. Neoplastic cells do not have FMN and do not emit green fluorescence. This procedure does not require any substance as a photosenzitizer. Induced fluorescence is based on selective accumulation of protoporphyrine IX (PP IX) in neoplastic tissue that can be detected as a violet fluorescence that emit PP IX. Induction of tumor tissue to fluoresce is achieved with topic or systemic application of 5-aminolevulinic acid (5-ALA). These diagnostic methods have greater sensitivity in detection of tumor than laryngomicroscopy, but have some disadvantages. Combination of laryngomicroscopy and any of these procedures gives more accurate diagnosis than laryngomicroscopy alone.