Which type of diverticulum is common in the esophagus -

Hypopharyngeal diverticulum or Zenker's diverticulum or pharyngeal pouch It is a pulsion diverticulum where pharyngeal musoca herniates through the killian's dehiscence, a weak area between two parts of the inferior constrictor. It is the most common esophageal diverticulum. The diverticula arises posteriorly in the midline of neck. The mouth of the diverticula is in the midline but the sac projects laterally (usually left laterally) Zenker's diverticulum is rarely seen below 30 yrs of age, most patients are over 50.