Pyriform Recess

Pear-shaped depression in lateral wall of laryngopharynx, one on each side of the laryngeal inlet.

Location

Within laryngopharynx (extends from upper border of epiglottis to lower border of cricoid cartilage anteriorly / lower border of C6 vertebra posteriorly)
Communicates anteriorly with laryngeal cavity through laryngeal inlet; inferiorly with oesophagus at pharyngoesophageal junction

Boundaries

Medial: Aryepiglottic fold (+ laryngeal inlet)
Lateral: Thyroid cartilage + thyrohyoid membrane

Beneath mucosa: internal laryngeal nerve (branch of superior laryngeal nerve → branch of vagus)
Provides sensory innervation to supraglottic larynx (above vocal folds)

Applied Anatomy

Foreign body lodgement — fish bones, safety pins commonly lodge here; careless removal → internal laryngeal nerve injury → anaesthesia of supraglottic larynx → loss of protective cough reflex
“Smuggler’s fossa” — artificially deepened using lead balls to conceal diamonds
Endoscopic perforation risk — dangerous site for perforation during upper aerodigestive tract instrumentation
Silent hypopharyngeal carcinoma — tumour grows in pyriform fossa without symptoms → patient presents late with metastatic cervical lymphadenopathy

The pyriform recess (piriform fossa) is a pear-shaped depression in the lateral wall of the laryngopharynx, one on each side of the inlet of the larynx.

Location

The pyriform fossa lies within the laryngopharynx — the lowest part of the pharynx, which extends from the upper border of the epiglottis to the lower border of the cricoid cartilage anteriorly (and to the lower border of the C6 vertebra posteriorly), communicating anteriorly with the laryngeal cavity through the laryngeal inlet and inferiorly with the oesophagus at the pharyngoesophageal junction.

Boundaries

Medial: The aryepiglottic fold (and laryngeal inlet).
Lateral: The thyroid cartilage and the thyrohyoid membrane.

Beneath the mucosa of the pyriform fossa lies the internal laryngeal nerve (a branch of the superior laryngeal nerve, itself a branch of the vagus). This nerve provides sensory innervation to the supraglottic part of the larynx (above the vocal folds) and is closely related to the floor of the fossa.

Clinical Correlation

Foreign Body Lodgement: Ingested foreign bodies (e.g., fish bones, safety pins) frequently lodge in the pyriform fossa. If care is not taken during removal, the internal laryngeal nerve may be damaged, resulting in anaesthesia of the supraglottic larynx and consequent loss of the protective cough reflex.

“Smuggler’s Fossa”: The pyriform fossa is sometimes artificially deepened by smugglers using lead balls to conceal precious materials such as diamonds — hence it is also referred to as the “smuggler’s fossa.”

Endoscopic Perforation Risk: The pyriform fossae are dangerous sites for perforation by an endoscope during instrumentation of the upper aerodigestive tract.

Silent Hypopharyngeal Carcinoma: A malignant tumour of the laryngopharynx (hypopharynx) may grow within the space provided by the pyriform fossa without producing symptoms, until the patient presents late with metastatic cervical lymphadenopathy.