What Is the Piriform Sinus?

In the laryngo-pharynx, between the sides of the larynx and the inner surface of the thyroid cartilage, the deep recesses formed by the subsidence of the mucosa are called pear-shaped crypts, which are often the sites where foreign bodies tend to invade.

Chinese name: Pear-shaped crypt
Foreign name: piriform recess

Features: Foreign objects are likely to entrap and stay
Place: Laryngo-pharynx

Clinical Anatomy of Piriform Crypt

Piriform crypt sinus

Occasionally, a sinus tract leads to the thyroid from the piriform crypt, which is a potential cause of thyroiditis. This sinus develops from the remnants of the thyroglossal canal connected to the laryngo-pharynx at the developmental stage (Moore and Persaud, 1998). The thyroid gland develops from the lower end of the thyroglossal canal. Because the pear-shaped recess is located deep on the upper end of the thyroid, this sinus tract needs to be removed during partial thyroidectomy (Scher and Richtsmeier, 1994).

Foreign objects remaining in the pharynx are called pharynx foreign bodies, which can occur at any age. According to remaining in different parts, it can be divided into nasopharyngeal foreign body, oropharyngeal foreign body and laryngo-pharyngeal foreign body.

Essentials of Pear Crypt Diagnosis

(1) Due to accidental eating, there is a history of swallowing foreign bodies (mostly fishbone).

(B) Foreign bodies in the nasopharynx are rare, and food or other foreign objects can enter the nasopharyngeal cavity during vomiting. The foreign bodies and secretions above the soft palate are bloody, and odorous pus appears in the long-term. In addition, there are nasal congestion, local pain and discomfort.

(3) Most of the foreign bodies in the oropharynx are accidentally fed into the tonsil, the root of the tongue, the side of the pharynx, or epiglottis due to accidental eating, and often feel sore throat, foreign body sensation and swallowing. Tingling.

(4) Throat and pharynx foreign bodies are swallowed by fishbone, meat and bones, buttons, coins, needles, nails or dentures, etc., and stay in the piriform fossa. They have difficulty swallowing, pain, cough and salivation. Large foreign bodies can cause breathing difficulties.

(5) Oropharyngeal and posterior nasal or indirect laryngoscopy, foreign bodies can be found in different parts.

Piriform crypt treatment

(1) Spray 2% of decaine in the pharynx, remove the foreign body under anesthesia of the mucous membrane, and use different instruments for different parts of the foreign body. Take care to prevent the foreign body from falling into the lower respiratory tract or swallowing by mistake.

(2) Use systemic antibiotics or compound sodium borate solution for gargle to keep the mouth clean and prevent infection.

(3) Anti-infective treatment should be given to those who have had a pharyngeal infection.

Essentials of Pear Crypt Diagnosis

1. There is a history of mistaken swallowing foreign bodies.

2. There is often foreign body sensation and tingling sensation in the throat. Symptoms are noticeable when swallowed, and the site is mostly fixed and persistent.

3. Sharp foreign matter, pierce the mucous membrane, a small amount of bleeding can be seen.

4. Larger foreign bodies remain in the pharynx, which can cause parapharyngeal space emphysema or even mediastinal emphysema, which can cause difficulty in swallowing and breathing.

5. Nasopharyngeal foreign bodies can cause nasal congestion, and often have a foul odor if left too long.

6. Most of the foreign bodies in the oropharynx and laryngo-pharynx remain in the tonsils, tongue base, epiglottis valley, and piriform fossa. Generally, foreign bodies in the oropharynx and laryngo-pharynx can be found during oropharyngeal inspection or examination with indirect laryngoscope, fiber laryngoscope or dynamic laryngoscope.

7. Nasopharyngeal foreign body is rare, and nasopharyngeal foreign body can be found by nasopharyngoscope or nasal endoscopy.

8. A small number of steel needles and metal foreign bodies may enter the retropharyngeal space or parapharyngeal space, which can be confirmed by X-ray or CT examination.

Pear-shaped crypt treatment

1. Oropharyngeal foreign bodies, such as tonsil fishbone, can be clamped out with forceps.

2. The foreign body located at the base of the tongue, the epiglottis valley, the piriform fossa, etc., after anesthesia on the mucosal surface, remove it with a laryngoscope under an indirect or direct laryngoscope.

3. Penetrating the pharyngeal wall and post-pharyngeal or parapharyngeal abscesses, incision or drainage of the pus through the mouth or neck, remove the foreign body.