Laryngopyocele: a rare neck mass and an uncommon excision
Microlaryngoscopic (MLN) examination of the larynx prior to surgery confirmed a midline/left submucosal swelling of the infrahyoid laryngeal surface of the epiglottis. Curative resection of the lesion via an external approach was performed. Access to the capsule of the laryngocele was achieved after division of the strap muscles. Dissection to the base of the cyst continued, where a tract was identified passing through the thyrohyoid membrane but not adherent to it (Fig. 2). The tract was traced to the submucosa and the lesion was everted and extracted without the need for a laryngofissure (Fig. 3). The post‐operative period was uneventful with normal findings on a follow‐up laryngoscopic examination.
Laryngoceles are rare anomalous diverticulum arising from the laryngeal saccule within the ventricle of Morgagni.1 They consist of a membranous sac located between the false vocal cord and thyroid cartilage. Laryngoceles, a passé term, are now classified under the nomenclature of saccular cysts. A saccular cyst may be mucous‐filled, air‐filled because of communication with the larynx (laryngocele) or purulent (laryngopyocele).2 To date, only several hundred laryngeal saccular cysts have been reported, while a mere 40 cases of laryngopyoceles have been described in the literature.3 The aetiology remains unclear but has been hypothesized to be atavistic remnants from apes, congenital (large saccules or weak laryngeal tissue), or acquired because of conditions giving rise to increased intra‐glottic pressure.1
Three forms of laryngeal saccular cysts have been described in relation to the thyrohyoid membrane. An internal cyst is confined to the paraglottic space, while an external extends and dissects superiorly through the thyrohyoid membrane.5 The combined type is the more commonly reported form (44%) in the English literature.3
Saccular cysts may range in presentation from being asymptomatic to causing acute airway respiratory obstruction, thereby being fatal.6 Hoarseness, dyspnoea and cough are common symptoms. Pain, fever and, occasionally, stridor are associated with laryngopyoceles. The swelling becomes more prominent on Valsalva maneuver.6 CT remains the primary modality for radiological diagnosis.6 Several cases have reported the coexistence of saccular cysts and laryngeal carcinoma or amyloidosis, potentially as the causative agent. It is hypothesized that an increase in intraluminal pressure by obstruction of upper airways, speech effort, excessive coughing and/or local mechanical conditions is the underlying pathology.9 A thorough investigation including an MLN examination prior to excision, particularly with a previous smoking history,10 to exclude occult squamous cell carcinoma in the ventricle causing the laryngocele is imperative. It is also important to note that laryngeal tuberculosis or syphilis can cause prolapse of the ventricle and saccule into the airway causing obstruction.8 One needs to consider brachial cyst, neck abscess, paraganglioma, schwannoma and thyroglossal duct cysts as the differential diagnoses.