Neurenteric cyst presenting with stridor and dysphagia: case report and literature review

Introduction

Spinal neurenteric cysts are rare benign lesions that represent 16% of cysts in the central nervous system and 0.3–0.5% of spinal tumours.^1,2 Neurenteric cysts can either be intramedullary or extrameduallary in location. Most published cases document patients presenting with pain and focal neurological signs. We report the first ever case of a neurenteric cyst presenting with symptoms involving the upper aerodigestive tract.

Case report

A 48-year-old man presented with a 10-month history of an enlarging left neck swelling and a 2-month history of dyspnoea, dysphagia to solids and restricted neck movements. He had no other ear, nose and throat (ENT) symptoms. Past medical history was significant for hypothyroidism for which he was on thyroxine. He was a smoker and consumed a moderate amount of alcohol. Clinically the patient was noted to have a mild degree of stridor, and neck examination revealed a large cystic lesion (approximately 8 cm) extending from level 2 to level 4 on the left side. The rest of the examination including flexible nasendoscopy was unremarkable.

Investigations

The patient underwent an ultrasound-guided aspiration of the cyst which revealed mucinous contents. Computed tomography (CT) imaging of the neck and chest (Figure 1) revealed a large cystic structure centred within the lower neck and extending down into the upper mediastinum measuring 10 × 8 cm. It was overlying the vertebral bodies C2 to C7. Compression of the trachea was noted. The mass itself was also seen extending into the prevertebral space through a gap in vertebral body C2 and appeared to be in continuity with the spinal canal. An MRI scan of the neck (Figure 2) apart from this large cystic lesion further identified a small 1-cm cyst immediately anterior to the vertebral body extending through the defect in C2 vertebra. Whilst this small cystic lesion demonstrated cerebrospinal fluid (CSF) signal intensity consistent with a meningocele, the large 10-cm mass had a predominantly fluid signal. OPEN IN VIEWER

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Figure 2.

T2-weighted MRI coronal slice showing hyperintense cystic mass.

Differential diagnosis

A diagnosis of neuroenteric cyst was made based on the imaging. Differential diagnosis of a large cervical cyst causing airway compromise includes lesions arising within the thyroid, branchial cyst or a cervical lymph node.

Treatment options

Due to the presence of airway compromise, the most appropriate management plan was excision of the cyst under general anaesthesia.

Surgical technique

A left transcervical incision was made. Subplatysmal flaps were raised and the sternomastoid retracted laterally. Dissection was close to the cyst and the cyst was freed from the prevertebral fasica. The neck of the cyst was identified, ligated and excised in total. A drain was placed postoperatively and the patient discharged home two days later.

Recovery and follow-up

The patient was discharged home two days later and follow-up at 6 months revealed no evidence of recurrence. Patient remains under close follow-up.

Discussion

Spinal neurentic cysts are rare congenital lesions that are usually present in the second and third decades of life with a slight male preponderance. They are commonly seen in the cervicothoracic region. ³ They occur due to incomplete separation of the embryonic notochodal plate and endoderm during the third week of embryogenesis. The nomenclature of these lesions has evolved from their first description by Kubie and Fulton in 1928 ⁴ as teratomatous cysts later modified by Puusepp in 1934 ⁵ as intestinomas to the now widely accepted neurenteric cyst by Holcomb and Matson in 1954. ⁶

Histologically Wilkins and Odom classified neurenteric cyst into three variants. ⁷ Type A cysts comprise ciliated or nonciliated cuboidal/columnar cells resting on basement membrane composed of type-4 collagen. Type-B cysts consist of all the elements of type-A cysts along with bone, fat, cartilage and/or lymphatic tissue. Type-C cysts in addition to type-A contents contain ependymal or glial tissue. Another classification system based on clinical and prognostic features was proposed by Gimeno ⁸ (Table 1).

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Table 1.

Classification of spinal neurenteric cysts.

Type of cyst	Pathology	Prognosis
Congenital dorsal enteric fistula	Fistulous communication between gut and skin in midline traversing the spinal column and cord	Poor prognosis, often incompatible with life
Congenital dorsal enteric diverticulum	Persistence of ventral part of neurenteric canal	Asymptomatic
Congenital dorsal enteric cyst (a) Prevertebral (b) Postvertebral	Ventral and dorsal portion of canal obliterate with remnant tissue forming a cyst Associated with vertebral anomalies	Intraspinal and postvertebral types are often symptomatic The prevertebral type can extend into the mediastinum
Congenital dorsal enteric sinus	Ventral portion of canal obliterates with persistence of only the dorsal portion	Can cause spinal compression and meningitis

To our knowledge, this is the first reported case of a neurenteric cyst presenting with stridor and dysphagia. Clinical symptoms are usually secondary to meningeal irritation and include pain, and motor or sensory deficits depending on the level involved. Myelopathic symptoms are usually seen with lesions involving the cervicothoracic region, while radicular symptoms are seen in lesions affecting the cervical and lumbar region. Newborns and infants can also present with signs of meningitis, incontinence, chronic pyrexia and paraplegia.^9,10 Our patient did not have neurological signs.

Neurenteric cysts have also been reported with other malformations such as spinal dysraphism, spina bifida and Kippel–Fiel syndrome. ¹¹ There are also reported associations with gastrointestinal, renal, cardiac and cutaneous abnormalities. ¹²

Cross-sectional imaging is paramount in the workup of these patients. CT and MRI imaging are complementary. CT imaging is useful to identify bony abnormalities that are associated with these lesions, whereas MRI is superior in studying neural anatomy. Typical features of neurenteric cyst on imaging are a lobulated homogenous mass without an associated mural nodule. ¹³ Like our case, the classic MRI feature is isointensity on T-1 weighted imaging and hyperintensity on T-2 weighted images. However these radiological findings are not entirely specific. Muzumdar et al. described a cyst with a granulomatous-type presentation with peripheral enhancement whilst in a study of 18 patients, ¹⁴ Kimura et al. in their study of 18 patients reported only two cases showing the typical isointensity on T-1 and hyperintensity on T-2 weighted images. ¹⁵

Complete surgical excision with avoidance of neurovascular injury is the treatment of choice for neurenteric cysts within the spinal canal. Various approaches described in the literature include anterior, posterior and lateral techniques. The posterior approach is favoured as it is associated with fewer complications. Although complete excision is the norm, this may not be possible in all cases. Factors contributing to difficult excision include limited access, bony abnormalities, adhesions to the spinal cord or intramedullary cysts.^15,16 An attempt at complete resection of intramedullary neurenteric cysts carries a risk of permanent neurological injury. Hence in such cases, a planned subtotal excision may be appropriate as documented in some case series.^1,17,18

Cyst recurrence is a recognised complication and ranges between 0% and 37%. Chavda et al. in the longest follow-up period at 30 years report a 37% recurrence rate (two patients) among eight patients. ¹⁹ Unsurprisingly, recurrences were observed in patients who underwent partial excision. In the largest series of 23 patients, Garg et al. reported recurrence in five patients (21%). ¹⁶ Other modalities of treatment include simple aspiration, fenestration of the cyst and/or marsupialisation. Although these methods may bring about symptomatic relief, these are temporary measures. Certainly our patient demonstrated an improvement in stridor following needle aspiration.

Conclusion

Neurenteric cysts are rare lesions and usually present with focal neurological signs.