Lower esophageal diverticulum; Supradiaphragmatic diverticulum
A diverticulum is an outpouching of a hollow organ. Diverticula arising from the esophagus and hypopharynx are usually classified into three types according to anatomical location and pathogenesis. Zenker’s diverticulum (pharyngoesophageal diverticulum) arises from the posterior hypopharynx, just above the upper esophageal sphincter, as a result of increased pressure during swallowing. Middle esophageal diverticula are usually secondary to an inflammatory process in the carinal lymph nodes (e.g., tuberculosis) which exert a traction force over the esophageal wall. Diverticula arising from the distal esophagus, usually within 10 cm of the cardia, are called epiphrenic diverticula.
In terms of pathogenesis, epiphrenic diverticula are generally classified as pulsion diverticula, although there have been reports of cases where a traction form seems to occur. The diverticula are thought to be the result of...