Objective: To investigate the value of narrow band imaging (NBI) endoscopy in the detection of laryngeal cancer and its precursor lesions.
Methods: Between December 2008 and July 2009, a total of 122 consecutive patients with suspected precancerous or cancerous lesions of the larynx were enrolled in this study. High performance endoscopic system equipped with the white light mode and NBI mode was introduced in the examination of larynx. Full pharyngeal and laryngeal examination was performed first under white light endoscope and then under NBI. Each lesion was observed by NBI endoscopy and classified according to the detailed morphologic findings of epithelial microvessels. Histological results were then compared to the corresponding white light and NBI images.
Results: Among the 122 patients, a total of 149 lesions were detected by white light and NBI modes. The histological diagnoses of these lesions were as follows: 16 laryngeal polyp, 7 laryngitis, 24 simple hyperplasia, 17 mild dysplasia, 6 moderate dysplasia, 6 severe dysplasia, 9 carcinoma in situ, 64 invasive cancer. The diagnostic accuracy by NBI for the laryngeal lesions was 90.6% (135/149), which was significantly higher than that of white light (75.2%, 112/149, chi² = 12.514, P < 0.001). The sensitivity of NBI and white light to detect laryngeal carcinoma was 93.2% (68/73) and 68.5% (50/73), respectively (chi² = 14.317, P < 0.001).
Conclusions: NBI endoscopy was a promising tool for the differentiation of non-malignant from malignant laryngeal lesions in vivo by detection of the morphology of mucosal capillary vessels. NBI endoscopy was easy to application in the routine pharyngolaryngeal examination with high sensitivity, and facilitated to improve the abilities of preoperative diagnosis and postoperative surveillance.