Laryngeal lymphangioma as a cause of respiratory distress in an adult with Down’s syndrome: an extremely rare presentation

Abstract

A 32-year-old man with Down’s syndrome was referred to the ear, nose and throat (ENT) department in view of failed attempts at extubation, and subsequently, at decannulation of tracheotomy tube. He had previously required ventilatory support and had history of intubation for 1 week. A flexible fibre-optic laryngoscopy showed a smooth mass covering the laryngeal inlet which moved with respiration. Direct laryngoscopy under general anaesthesia revealed a smooth mucosa covered fleshy mass arising from the left aryepiglottic fold and arytenoid, obstructing the laryngeal inlet. The mass was removed using controlled plasma ablation, and histopathological examination of the same was consistent with lymphangioma. Endoscopic examinations during the regular follow-up visits revealed well-healed supraglottic area with adequate glottic chink and the patient could be successfully decannulated.

Background

Down’s syndrome or Trisomy 21 affects 1 in 600–800 live births and is the most common chromosomal anomaly.¹ There has been tremendous improvement in life expectancy of babies with Down’s syndrome owing to the milestones made in the management of cardiac and other abnormalities early in life.²

Laryngo-tracheo-bronchial abnormalities are more common in children with Trisomy 21 in comparison to the general population, of which symptomatic subglottic stenosis and tracheobronchomalacia are the most common. The most common presentations are stridor and problems associated with extubation.³

Isolated laryngeal lymphangioma is a very rare entity and mimics symptoms of other conditions causing upper respiratory obstruction. It is even rarer for lymphangioma to present beyond 2 years of age.⁴

We report a case of isolated laryngeal lymphangioma in an adult with Down’s syndrome. Even though the presentation of difficulty in extubation is not unexpected in Trisomy 21, the cause of it being lymphangioma, especially in a 32 years old, well beyond the usually expected age, makes it a rare differential diagnosis to be kept in mind.

CASE PRESENTATION

A 32-year-old man with Down’s syndrome was referred to the ear, nose and throat (ENT) department in view of inability to decannulate him off tracheotomy tube. He was previously managed in an intensive care unit for community-acquired pneumonia subsequently developing respiratory distress for which he was intubated and kept on ventilatory support for a week. The patient was tracheotomised following a failed extubation trial and was gradually weaned off the ventilatory support. An attempt at tracheotomy tube removal was made which was not successful. The patient was asymptomatic at the time of presentation to the department. A flexible fibre-optic laryngoscopy revealed a smooth mass obstructing the larynx. A diagnostic direct laryngoscopic examination under general anaesthesia was then planned for deciding the further line of management.

Investigations

A flexible fibre-optic laryngoscopy under local anaesthesia revealed a smooth mucosa covered swelling obscuring the endolaryngeal inlet. The swelling was found to move with attempted respiration after occluding the tracheotomy tube opening.

A direct laryngoscopic examination (figures 1 and 2) was performed under general anaesthesia. It revealed prominent palatine and lingual tonsils and a 4×2×1 cm smooth, mucosa covered, fleshy mass arising from the left aryepiglottic fold and arytenoid, obscuring the laryngeal inlet. The mass could be displaced off the laryngeal inlet, which revealed normal false vocal cords, true vocal cords and glottic chink. There was no evidence of subglottic stenosis.

Figure 1.

Laryngeal lymphangioma involving the left aryepiglottic fold and arytenoid. Note the palatine tonsils and normal epiglottis.

Figure 2.

Site of attachment of lymphangioma to the left arytenoid.

The histopathological examination of the mass, after its excision, revealed intact epithelium with hyperplastic-stratified squamous lining. Subepithelium contained many dilated vascular channels with variable thickened walls, which were lined by flattened cells. Surrounding stroma showed reactive lymphoid cell inflammation with formation of lymphoid follicles. The features were consistent with that of a lymphangioma.

Treatment

The patient underwent transoral endoscopic removal of the mass using plasma ablation (Smith & Nephew, Andover, Massachusetts, USA) under general anaesthesia (figure 3). The mass was excised completely with negligible blood loss. The immediate postoperative period was uneventful. The tracheotomy tube was downsized and observed during the stay and the patient was discharged on postoperative day 4, in a stable condition.

Figure 3.

Endolarynx after excision of lymphangioma.

Outcome and follow-up

The 4-week follow-up endoscopy revealed a well-healed supraglottis and a normal glottis with no evidence of subglottic stenosis. The patient could thereby be successfully decannulated. Long-term follow-up showed no recurrences and the patient could go about his daily routine without any difficulty.

Discussion

Lymphangiomas are rare lesions of the lymphatic system, mainly involving head and neck areas. It is commonly seen in the posterior triangle of neck. Depending on the size of the cavity of the lesion, they are usually divided into capillary, cavernous and cystic hygroma. It is rarely detected beyond 2 years of age, with more than 90% being diagnosed before it.⁴

Isolated laryngeal lymphangiomas are the rarest manifestation by site. Laryngeal involvement usually happens by direct extension of extensive congenital lymphangiomas.⁵ An extensive review of paediatric lymphangioma by Cohen and Thompson showed 14%–22% involvement due to the extension of head and neck lesions.⁶ Of the laryngeal subsites, supraglottic lymphangioma is the most common. It is hypothesised that supraglottic larynx undergoes repeated friction due to the passage of food particles and this might be the reason for it being the site of origin of isolated lymphangioma.⁵ In adults, fibrosis and lymphatic obstruction caused by inflammation, trauma or post radiotherapy also have been suggested as the possible causes.⁷

The symptoms of laryngeal lymphangiomas are not different from any of the similar condition causing upper airway obstruction. This makes a clinical diagnosis based on just the clinical features virtually impossible. The features are usually that of airway obstruction and voice change.⁷ Smaller ones can usually be asymptomatic too. The symptoms are usually progressively worsening while the congenital laryngeal lymphangiomas can present as stridor and thus an emergency, given the narrow airway in neonates. Sudden worsening of symptoms may also be due to infection and in children might present with symptoms similar to that of epiglottitis.⁷ In our case, the trauma caused by intubation and the low-grade infection associated with the stay in the intensive care unit might have led to hitherto smaller and asymptomatic lesion to grow in size and present itself as it did.

The diagnosis is usually made based on clinical history, endoscopic findings and radiology.⁸ The final diagnosis, however, would be based on histopathological examination of the excised lesion. In the laryngeal and hypopharyngeal sites, the radiological differential diagnoses would be a retention cyst, dermoid cyst, thyroglossal duct cyst and haemangioma.⁹ An MRI is the preferred modality, especially in extensive lesions, as it helps to delineate the soft tissue attachments, thus helping to plan the excision.⁸ A CT or ultrasound could also be used to identify the presence of the lesion, but are suboptimal in identifying the soft tissue planes as an MRI. In our case, we did not get an imaging done as the attachments could be made out from the endoscopic examination itself and because of the logistical difficulties associated with getting an MRI done as the patient was claustrophobic.

Even though not extensively studied or conclusively proven, chromosomal abnormalities, especially trisomies, are associated with defects in lymphangiogenesis. Increased nuchal thickness between 10 and 14 weeks in ultrasonogram (USG) is a sensitive method for screening chromosomal abnormalities, Down’s syndrome in particular. Disturbance in lymphangiogensis of the jugular lymphatic system is a proposed mechanism.¹⁰ The fact that our patient too had Down’s syndrome should be seen in this light. In one of the earliest case reports of isolated laryngeal lymphangioma, Claros et al too described it in a 16-year-old girl with Down’s syndrome.¹¹

Even though multiple modes of management have been described for various head and neck lymphangioma, laryngeal lymphangioma calls for surgical excision in view of the airway emergency it poses.⁸ Tracheotomy is almost always needed. Cohen and Thompson used cryosurgery, Light Amplification by Stimulated Emission of Radiation (LASER) surgery, steroids, incision and drainage, as well as needle aspiration in 10 children with lymphangioma. They emphasised that LASER surgery was the only valuable therapeutic modality within the larynx.⁶ It had the advantage of providing precise ablation. Virk et al, however, had shown that plasma ablation is equally effective in laryngeal procedures using it for endoscopic management of tracheal stenosis.¹² It is easier to use, cheaper and beneficial in resource-limited situations where setup of LASER is available only at limited centres.

Thus laryngeal lymphangiomas, though rare, could present as life-threatening respiratory distress even in adults and have to be differentiated from a bunch of other conditions presenting with similar symptoms.

Learning points.

• Isolated laryngeal lymphangiomas are rare but life threatening and hence early diagnosis could be potentially lifesaving.

• Laryngeal lymphangiomas mimic subglottic stenosis or obstructive sleep apnoea and hence are difficult to diagnose.

• Plasma ablation is an effective alternative tool for LASER surgery in terms of cheaper cost, reduced set-up time, negligible heat transfer and minimal collateral thermal damage in laryngeal procedures.