Correlation between instability of fundamental voice frequency and malignant infiltration of vocal fold nerve endings

Performing systematically acoustical objective voice analysis in patients with chronic chorditis and glottic cancer we detected a certain number of cases with exceptional acoustical pattern. In 7 of 50 patients with chronic chorditis this acoustical pattern was highly specific demonstrating frequent changes of fundamental frequency in short time interval. In 31 of 50 patients with glottic cancer the same phenomenon was recorded. Histology revealed in 6 of those 7 patients with clinical diagnosis of chronic chorditis invasive cancer of the vocal fold. Detailed and more sophisticated techniques (PAF Halmi for elastic and collagen fibres and neurohistochemical technique S-100 and NSE for nerve elements) demonstrated mainly preserved layer structure of vocal fold lamina propria and infiltrated nerve endings. Such histological findings strongly suggest that cancer infiltration is responsible for rapid changes of fundamental frequency (via mucosal reflexes) although vibratory segments are regular because of preserved layer structure. Such findings could contribute to better understanding of laryngeal control mechanisms and laryngeal mucosal reflexes in human. Also this acoustical sign may be a useful diagnostical parameter for very early diagnosis of glottic cancer. This is possible because of the great sensitivity and complexity of phonatory function.