The pyriform sinus (also spelled piriform sinus and also known as the pyriform recess, pyriform fossa, and smuggler's fossa) is the pear-shaped subsite of the hypopharynx located posterolaterally to either side of the laryngeal opening.

Where is the right pyriform sinus?

The pyriform sinus is located in a posterolateral position in relation to the larynx. It is part of the pharynx. Anatomically, its borders are the thyroid cartilage and thyrohyoid membrane laterally, and the cricoid cartilage and aryepiglottic fold medially.

What are the potential dangers of the piriform recess?

The branches of the internal laryngeal and inferior laryngeal nerves (continuation of recurrent laryngeal) lie deep to the mucous membrane of the piriform recess. Fish bones and other foreign bodies may pierce the mucous membrane of the recess and cause injury to the internal laryngeal nerve.