Abstract

Background

Neck swelling associated with positive pressure such as glass blowing or playing musical instruments may be as a result of a pharyngocele or laryngocele. Both are incredibly rare and differentiating between the two can be difficult. Despite being well described, pharyngoceles are often underdiagnosed or misdiagnosed as laryngoceles. While differences can often be subtle, correct diagnosis can be made confidently with targeted investigation and a high index of suspicion.

We present a case of bilateral neck swelling and discuss the differentiating features, investigations and treatment options of both laryngoceles and pharyngoceles.

Case presentation

A 20-year-old male trumpet player was referred to our tertiary ear, nose and throat clinic with a 5-year history of bilateral neck swelling. This was only associated with playing the trumpet, with complete resolution between episodes. He was otherwise fit and well with no difficulty breathing, dysphagia or dysphonia. Previous investigations, including imaging at the referring clinic had revealed no cause for the swelling. The patient was asked to attend clinic with the trumpet in order to reproduce the symptoms.

At rest, head and neck examination was grossly normal with no visible or palpable neck lumps or swellings. Interestingly, blowing the trumpet produced significant bilateral external neck swelling (figure 1). Videostobolaryngoscopy during trumpet blowing showed marked expansion of both piriform fossa confirming the diagnosis of a pharyngocele (figure 2). The remaining supraglottic structures were unremarkable with normal movement of the vocal cords bilaterally.

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Figure 1

Inspection of the patient’s neck (A) at rest (B) during trumpet playing.

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Figure 2

Fibreoptic examination of the supraglottic structures (A) at rest and (B) during trumpet playing revealing the grossly enlarged piriform fossa.

A CT scan was requested while trumpet playing to enable estimation of the size of the defect and to allow for surveillance and future comparison. This was initially reported as ‘large bilateral gas filled laryngoceles’ (figure 3), however following further review and identification of the grossly enlarged piriform fossa seen in figure 3B this was amended to a diagnosis of a pharyngocele.

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Figure 3

(A) Axial slice from CT neck demonstrates large bilateral air spaces during trumpet playing, (B) Reformatted coronal slice from CT revealing extent of the pharyngocele.

Barium swallow performed subsequently (without positive pressure as it will be impossible to blow and swallow at the same time) to look for pockets or pouches of the hypophayrnx was normal (figure 4).

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Figure 4

Still image from barium swallow revealing normal hypopharynx.

Given the absence of symptoms, the patient was managed conservatively and advised regarding healthy oral hygiene and the use of scarf tying while playing.

Discussion

A laryngocele can be defined as an ‘abnormal dilation or herniation of the laryngeal saccule’¹ which according to Holinger can be diagnosed if the sac is (1) symptomatic, (2) palpable, (3) observed internally or (4) observed through imaging or surgery.² Laryngoceles can be congenital or acquired, though the majority fall into the latter category. They occur as a result of increased intralaryngeal pressure such as that in excessive coughing, playing blowing instruments or due to obstructing lesions within the larynx.³ They are described according to their relation to the parapharyngeal space as internal (confined within the parapharyngeal space), external (saccule herniation through the thyrohyoid membrane) or mixed and can be both unilateral or bilateral.

Laryngoceles are usually asymptomatic and detected incidentally on imaging. However, they may present with symptoms ranging from simple neck swelling, hoarseness of voice to airway obstruction. Management options include conservative measures such as scarf wearing during times of high pressure to surgical excision of the saccule itself through a cervical approach. Novel treatment options involving transoral robotic surgery and endoscopic repair have been described, eliminating the need for the cervical incisions.⁴

In contrast, a pharyngocele is a bulging of the lateral pharyngeal wall frequently arising from two areas of weakness; a superior area between the middle and superior constrictor muscle and the most common site; inferiorly between the middle and inferior constrictor muscle and the thyrohyoid membrane within the base of the piriform fossa.⁵ Figure 5 highlights the anatomical difference between the two entities.

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Figure 5

Diagram showing the difference between a pharyngocele (2) and a laryngocele (5); and (1) hyoid, (2) pharyngocele, (3) thyroid, (4) cricoid, (5) external laryngocele, (6) thyrohyoid membrane, (7) vestibular folds and (8) vocal folds.¹¹

True lateral pharyngeal diverticula (pharyngoceles) that penetrate through the thyrohyoid membrane are very rare with fewer than 60 cases reported in the literature over the past 126 years.^{6 7} Pharyngoceles are frequently misdiagnosed as laryngoceles and of all reported cases with neck swelling in woodwind or brass musicians pharyngoceles seem to be more common particularly in the younger age group.⁸ Like laryngoceles, pharyngoceles can either be congenital or more commonly acquired with the main risk factor being raised intrapharyngeal pressure. Congenital cases are thought to be due to a remnant of the brachial cleft. When symptomatic these may present with nocturnal coughing, regurgitation of food, pain and dysphagia.

Recommended diagnostic tools include fibreoptic laryngoscopy, as well as imaging, in particular CT neck and barium swallow during valsalva. CT reveals laryngoceles to be arising from the dilated laryngeal ventricle whereas in pharyngoceles imaging can clearly demonstrate the communication with the pouch and the piriform sinus (figure 3).⁹

Ideally such CT imaging should be performed while performing the valsalva to fully demarcate the size of the defect. Although the CT was performed with the patient supine, this did not affect the size of the pharyngocele significantly during trumpet blowing. This is because either way (supine or erect) the player has to create the same pressure to blow his trumpet. However, it is important to consider that the player may get exhausted quicker if playing in a position he is not used to for a prolonged time.

The presence of a normal barium swallow may be thought to make the diagnosis of laryngocele more likely however it is important that such a procedure is performed during valsalva or trumpet blowing to enable full assessment of the size of the defect and help in confirming diagnosis. This is highlighted in our case where the patient had multiple previous scans performed at rest which did not identify the cause of his symptoms.

The treatment options for both conditions depend on the associated symptoms. In asymptomatic patients, as in our case, conservative management is appropriate. The use of a truss or scarf has been documented in the literature to provide excellent symptomatic control of pharyngoceles and as such was advised for our patient while playing.¹⁰ Importance is also placed on good oral hygiene and healthy dietary habits to avoid bacterial overgrowth. Other conservative measures include adapting correct expiration techniques and posture and review by speech and language therapists for tailored exercises.⁸

Footnotes

References