Compact endoscopy of the larynx

In order to improve preoperative assessment of suspected precancerous and cancerous lesions of the larynx, we examined 83 patients by compact endoscopy (combination of autofluorescence and contact endoscopy) during microlaryngoscopy in a pilot study. The intraoperative findings were related to histopathologic examination. Cancerous laryngeal mucosa was illuminated during autofluorescence endoscopy by use of blue filtered light (D-light AF system) for optical demarcation of the lesion. After staining the mucosa with methylene blue (1%), we performed contact endoscopy. During autofluorescence examination of the endolaryngeal mucosa, the appearance of precancerous and cancerous lesions varied between opaque light areas and darker reddish areas. By contact endoscopy, it was possible to observe the cells, nuclei, and cytoplasm, as well as different degrees of abnormality. Histopathologic findings of 83 patients revealed laryngeal dysplasia (grade I in 29 patients, grade II in 15, and grade III or carcinoma in situ in 8) and laryngeal cancer (31 patients). In 73 cases (88%), the findings of compact endoscopy corresponded to those of histopathology. In 5 cases, epithelial lesions were overestimated because of inflammation and scarring, and 5 cases were underestimated because of hyperkeratotic thickening of the mucosa covering basal epithelial layers with focal dysplasia of grades II and III, carcinoma in situ, and microinvasive cancer. We conclude that compact endoscopy enables the laryngologist to assess laryngeal cancer and its preceding lesions more accurately during microlaryngoscopy.