Microscopic examination of bronchial epithelium in children.

In an extended study of a large number of adults, including smokers and nonsmokers and subjects with and without lung cancer, the writers have been convinced that persons who are cigarette smokers show changes in the bronchial mucosa which must be considered precancerous and which increase in amount depending upon an increase in the wnsumption of cigarettes. Adult nonsmokers may show a minimal amount of such precancerous changes. It seemed important to study a group of subjects who were nonsmokers and whose tracheobronchial trees had been subjected to a minimal amount of irritation from inhaled contaminants. Accordingly, a group of 35 children less than fifteen years of age were selected, and their tracheobronchial trees were studied. These children had died from various causes with and without pneumonia and bronchial ulceration. It was of special interest to learn whether or not any precancerous changes could be recognized and what had been the effects of pneumonia and bronchial ulceration on the bronchial mucosa.