Estimated prevalence at 1.8/100,000. Laryngeal cysts are classified into supraglottic, glottic and subglottic cysts.

Two etiopathogenic mechanisms are distinguished:

-        ductal or retentional type cysts are the most common (75 %). They result from obstruction of the mucous gland ducts by inflammation or following a trauma. Their wall is covered with the same epithelium as the excretory canal of these glands.

-        saccular cysts develop in the supraglottic area (between the true and the false vocal cords), in the region of the laryngeal saccule. They are due to an atresia of the ventricular orifice, are more voluminous and their wall is lined with a respiratory type epithelium. They are filled with mucus.

Subglottic cysts may be congenital or, more frequently, acquired, especially in the former premature infant who has been intubated.

Epiglottic (10.1 %) and valecular (10.5 %) cysts are usually retentional. Chronic inflammation, leading to obstruction of the mucus glands, is the main cause. However, a congenital origin is also possible as some epiglottic cysts have been described in newborns as young as 6 weeks old.

vallecular cyst

  punction of an epiglottic cyst

In children, cysts may be revealed by inspiratory stridor (biphasic in case of subglottic localization, positional if the cyst is pedunculated), or by respiratory distress. Because of its anatomical location, the vallecular cyst is a rare but classic cause of upper airway obstruction and death in the newborn. Rarely they can become obstructive and responsible for dyspnea or even acute asphyxia. This occurs mainly during episodes of superinfection. Dysphagia and pain rarely accompany these cysts.

Awake fibroscopic examination of the upper airway establishes the diagnosis. The definitive diagnosis and treatment are, then, made by laryngeal endoscopy under general anesthesia.

Treatments:

In case of significant dyspnea or difficulty in exposing the glottis, it may be useful to first empty the cyst by direct puncture using a large bore needle.  In children, the first-line procedure is performed endoscopically: simple incision of the cyst with aspiration of its contents or marsupialization (scalpel or CO2 laser) which may be repeated in case of recurrence. In the absence of satisfactory results, an external cervical surgical approach is performed.

Differential diagnosis of subglottic cysts: subglottic stenosis, subglottic angioma (hemangiomas elsewhere, especially in the beard area: in this case, treatment with oral propranolol is preferred).

Anesthetic implications:

frequently associated laryngomalacia; it the patient is often an ex-premature ; if the cyst is subglottic, plan for difficult mask ventilation (valve effect, obstruction) and difficult intubation (retromolar approach, fiberscope, avoid using a laryngeal mask if the cyst is supraglottic); a nasopharyngeal airway (spontaneous ventilation) is very useful; lingual traction may be useful during laryngoscopy. Beware of a positional effect (supine, head rotation) that can lead to complete obstruction.

References:        

-        Halimi C, Nevoux J, Denoyelle F, Garabedian E-N, Leboulanger N.
Acquired subglottic cysts : management and long term outcome.
Int J Pediatr Otorhinolaryngol 2012 ; 76 : 589-92.

-        Prowse S, Knoght L.
Congenital cysts of the infant larynx.
Int J Pediatr Otorhinolaryngol 2012 ; 76 : 708-11.

-        Chen KS, Ng J-M, Li H-Y, Haartigan PM.
Vallecular cyst and laryngomalacia in infants : report of six cases and airway management.
Anesth Analg 2002 ; 95 :1248-50

-        Wrong CM, Ghazal EA, Dyleski RA, Applegate R.
Management of near-complete airway obstruction caused by a vallecular cyst in an infant using a tongue tip traction suture.
A&A Case Reports 2016 ; 6 :31-5.

-        Last SP, Patterson HI, Hauser N, et al.
Congenital subglottic cyst: a rare cause for sudden airway compromise in a newborn. 
BMJ Case Rep 2023;16:e253750. doi:10.1136/bcr-2022-253750

Updated: May 2023