The oesophagus may be directly ruptured by hard or sharp bodies being swallowed with the food. The author observed a case in which a fish-bone cut through the oesophagus and on into the aorta.
A more frequent cause of perforation is disease of the wall. The Traction-diverticulum is, according to Zenker, the commonest cause of perforation. Next to that comes Cancer of the oesophagus, the actual perforation here being often produced by the sound.
Perforating ulcer sometimes occurs in the oesophagus, its causation being similar to that of the stomach (which see). Fig. 387 represents such an ulcer, which perforated into the left main bronchus, causing gangrene of the lung on account of food passing into the bronchi and lung alveoli. There have been cases in which the ulcer has penetrated into the aorta.