Simple tumours originating in the bronchi are exceedingly rare. Cancer not infrequently occurs, originating in the mucous glands of the bronchi, although the resulting tumour has rather the characters of cancer of the lung. (See under Cancer of the Lung).

The bronchi are not infrequently involved in tumours growing into the lungs along the connective tissue which accompanies the great vessels and bronchi. This applies more particularly to mediastinal sarcomas, which often incorporate the bronchi in their substance and cause obstruction. Obstruction of bronchi with stagnation of the contents and bronchiectasis are often prominent features in such cases.

The bronchi also take part, often very markedly, in tuberculosis of the lungs.

Foreign bodies in the bronchi give rise to lesions which often affect the lung as a whole and may lead to appearances and symptoms very like those of phthisis pulmonalis. When a foreign body of some size passes down the trachea and lodges in one of the larger bronchi, it becomes a centre of irritation. It irritates the bronchial wall, making for itself a cavity whose internal wall is ulcerated and discharges pus. The discharge stagnates in the cavity and decomposes, and as it is in direct communication with the bronchial tree, it is liable to be insufflated into the finer bronchi and even into the lung alveoli. The whole bronchial mucous membrane is converted into an inflamed and discharging surface, and the discharge is of a highly putrid character. Thus arise some cases of so-called Foetid bronchitis. The inflammation of the bronchial wall renders it less resistant and bronchiectasis often results, the putrid fluid stagnating in the dilated bronchi. There are thus cavities formed which may ulcerate and imitate those of phthisis. In the lung tissue itself there may be developed an acute or a chronic inflammation, the former having the characters of an acute phthisis and the latter more those of a chronic fibroid phthisis. The difference in the result will depend to some extent on the character of the foreign body. If it be a decomposable substance, such as a piece of meat or of bone with meat attached, it is more liable to lead to acute symptoms, while if the body is in itself inert the results may be more chronic.

These remarks are chiefly based on cases observed by the author, who is impressed by the frequency of serious disease of the lungs, resembling phthisis in many cases, brought about by foreign bodies in the bronchial tubes. A fuller account of two such cases is given by the author in his Lectures on Phthisis.

Literature

Biermer, Krankh. d. Bronchien u. d. Lungenparench., Virch. Handb., v., 1854; and on Bronchial asthma, in German Clin. Lect. (Syd.Soc.),1876; Gairdner, On bronchitis, 1850; Greenhow, On bronchitis, 2nd ed., 1878; Peacock, (Fibrinous bronchitis) Path, trans., v. 41, 1853; Salter, ibid., xi., 36,1860; Biegel, Ziemssen's Handb., iv.; Socoleff, Virch. Arch., lxix., 1877; Hamilton, Path, of bronchitis, etc., 1883; Carswell, (Bronchiectasis) Illustrations, 1833-38; Jurgensen, in Ziemssen's Handb., v.; Heller, Deutsch. Arch. f. klin. Med., 1885; Auld, Bronchial affections, Pneumonia, etc., 1891; Leyden, (Charcot's crystals in asthma) Virch. Arch., liv., 1872; Opitz, Fremde Korper in Luftwegen, 1858; Coats, in Gairdner and Coats, Lect. to pract., 1888; Grainger Stewart and Gibson, (Diseases of the Trachea and Bronchial Tubes) in Twentieth Century Practice of Med., vol. vi., 1896; Ewart, in Allbutt's System of Med., vol. v., 1898.