Laryngeal Epithelial Changes on Effects of Smoking and Drinking

Abstract

The human larynx is essential not only for speech, but also for swallowing and respiration. Its tissues are affected by the presence of alcohol and cigarette smoke. In this report we present our findings on the effects of smoking and drinking on histological changes in laryngeal tissue. The larynges studied were those of autopsy patients: cases with damaged tissue were excluded. We studied the larynges of 84 men (non-smoker and non-drinker, 22 cases; smoker and drinker, 62 cases) and 48 women (non-smoker and non-drinker, 40 cases; smoker and drinker, 8 cases) between the ages of 12 and 88. The squamous metaplasia of laryngeal epithelium was examined using the gross staining method (Pyronin Y) of STELL et al. (J. Laryngeal. Otol. 86: 589-594, 1972). The squamous epithelium is unstained, whereas the respiratory epithelium is a brilliant red. The area of metaplasia in the supraglottic region increased with aging, tobacco and alcohol consumption. Microscopic changes of the laryngeal epithelium were investigated using the hematoxylin-eosin staining method. The thickness of epithelium of the supraglottic region and vocal cord increased with age. There is a significant difference in the thickness of the epithelium of the supraglottic region and vocal cords of smoking and drinking patients, when compared with the same tissues of non-smokers and non-drinkers. Furthermore, there is a significant difference in those tissues of the supraglottic region of heavy smokers, when compared with light smokers, but no significant difference when compared with drinkers. However, there is no significant difference in the thickness of vocal cord tissues when comparing light smokers and drinkers on the one hand, and heavy smokers and drinkers on the other.