The left picture shows a Zenker's diverticula. It s located at the dorsoesophageal wall and is a pseudodiverticula, because it s formed only by mucosa and submucosa. Neurologic coordination disorders of the upper esophagus and anatomical aspects are being discussed as causative. Symptoms at first are a mere global sensation.
Progression is frequent and leads to esophageal compression and dysphagia.
Large diverticula can retain food giving rise to the development of a bezoar. Retained food can also result in regurgitation, thus facilitating aspiration. The right picture shows a Zenker s diverticula with a bezoar. The endoscopist is always in danger of causing a diverticular perforation when inserting the endoscope resulting in a life threatening mediastinitis. Apart from the Zenker s diverticula at the upper entrance of the esophagus, which is of course a pseudodiverticula, there is a second kind called thoracal diverticula.