pharyngoesophageal diverticulum

It represents a potentially weak spot where a pharyngoesophageal diverticulum (Zenker's diverticulum) is more likely to occur.

In anatomy, Zenker's diverticulum, also pharyngoesophageal diverticulum, also pharyngeal pouch, also hypopharyngeal diverticulum, is a diverticulum of the mucosa of the pharynx, just above the cricopharyngeal muscle (i.e. above the upper sphincter of the esophagus).