[Clinicopathological evaluation of intralaryngeal ultrasonography]

We used a miniature ultrasonic probe to study its diagnostic application in the detection of laryngeal lesions. Using the immersion method and an extracted human larynx, we evaluated ultrasonic images, identified the layered structure of vocal folds, and examined clinical cases following the study of diagnostic application. By the immersion method, ultrasonic images revealed that the membranous vocal fold was separated into three layers. We identified the histological structures of these three layers by comparing the ultrasonic images with the corresponding histologies. The first layer (hyperechoic) was the epithelial and the superficial layer of the lamina propria; the second layer (hypoechoic) was the vocal ligament; and the third layer (hyperechoic) was the deep layer of the lamina propria. On the basis of this study, we then evaluated ultrasonographic images of clinical cases. Benign lesions such as vocal nodules or vocal polyps were noted on the layered structure of the mucosa, especially, polyps as hyperechoic images. Furthermore, glottic cancer lesions demonstrated hypoechoic images and sometimes revealed destruction of the layered structures. These results suggest that intralaryngeal ultrasonography can be useful as a clinical application for the detection of tumor involvement in the vocal folds.