Laser scanning microscopy of the human larynx mucosa: A preliminary, ex vivo study

Objective. Laser scanning microscopy (LSM) supplies in vivo information from epithelia up to depths between 0.1 to 0.5 mm. The aim of this ex vivo prospective pilot study was to investigate the potential use of LSM for the diagnosis of laryngeal cancer and its precursors. Methods. Forty-three larynx specimens of 26 patients (age 35-61 years, mean age 51.9 +/- 9.5 years; 7 women and 19 men) with laryngeal lesions were investigated with LSM. The LSM findings were compared with histopathologic sections. The following criteria were used for characterization of cancerous lesions: enlarged nuclei, enlarged cells with variable shapes, cluster of cells, increased nucleus/ cytoplasm ratio, irregular cell architecture, and loss of cellular junctions characterized by lack of visualization of the cell membrane. Results. LSM enables the visualization of epithelium up to the basement membrane, Reincke space, the subepithelial vessels, and the fibers of the subepithelial space. In contrast to the squamous epithelium, the respiratory epithelium bears kinocilia. The beat of the cilia and the directed mucous transport can be observed ex vivo. With the use of the presented malignancy criteria, a sensitivity of 72.7% and a specificity of 82.9% for differentiation of dysplasia and benign laryngeal lesions from cancer were reached. Conclusions. LSM in an ex vivo manner supplies microscopic images up to the subepithelial space. LSM could represent a new technology in laryngology to visualize larynx epithelia. In the next step, in vivo LSM will be applied to evaluate laryngeal lesion in vivo.