[In vivo diagnosis of epithelial changes of the oropharynx using confocal microscopy]

Confocal laser scanning microscopy enables the visualization of the anterior regions of the oropharynx mucosa. The specific aim of this investigation was to evaluate whether this in vivo tool supplies essential information for the surgeon prior to operation or not.

The laser scanning microscope HRT II and Rostock Cornea Module were used in this in vivo study. To obtain comparable images, the specifications of this tool used for all investigations were maintained (63 x water immersion objective lens). The investigations were performed on 9 patients with tongue cancer with primary tumor site and stage I (AJCC) and on 12 patients with head and neck cancer who underwent radiochemotherapy (RCT). Data from 21 patients were compared to those of healthy subjects.

The following parameters can be detected using LSM: nuclear density, nuclear size, nucleus/cytoplasm relation, number of nuclei, regularity of cell layers, morphology of cells of a cell layer, and occurrence of cellular junctions. In regard to these parameters, dysplastic and cancerous lesions reveal significant differences compared to healthy tissue of the oropharynx. After RCT several epithelial changes were found, such as keratosis, mild dysplasia, increased vascularization and more cell edema and necrosis.

Consistent differences exist between LSM findings of healthy subjects and those of patients with dysplastic, keratotic and cancerous lesions. Both strong hyperplasia and leukoplakia prevent a visualization of the basement cell layer in the oropharynx. The combination of LSM technology and endoscopy and following further investigations are needed for evaluation of LSM technology in the field of otorhinolaryngology.