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CASE REPORTS
Neurenteric Cyst
Dharmendra Singh, Sangram Singh, Ravi Kiran, SS Bhagwat
Neurenteric cysts (NC) are rare foregut duplication cysts that also have connections to the dura, and at times with the spinal canal. We recently encountered a rare case of neurenteric cyst, which was diagnosed antenatally and presented to us at day 5 of life with mild respiratory distress. Patient underwent thoracotomy and successful surgical excision of the cyst. We have discussed the embryology, presentation and management of neurenteric cyst with review of pertinent literature.
INTRODUCTION
Neurenteric cyst is a type of foregut duplication cyst.1 Foregut duplication cysts have been classified1 clinically and pathologically into 1) enteric duplications and cysts (lined by intestinal epithelium), 2) bronchogenic cysts (lined by respiratory epithelium), 3) neurenteric cysts (associated with vertebral anomalies or have a connection with the nervous system). NC commonly presents as intrathoracic mass, but they can also present as an intraspinal mass. We present a case of NC who had an associated vertebral anomaly and an intraspinal connection.
CASE REPORT
A first born, day 5 old, full term, normal vaginally delivered, male child, was referred to us from the obstetric department. The patient was diagnosed on antenatal ultrasonography to be having a posterior mediastinal cyst, done at 34 weeks of gestation. Patient at the time of admission had mild tachypnoea (respiratory rate - 64/minute), but there was no respiratory distress (intercostal, subcostal, or suprasternal indrawing and ala nasi flaring), nor there was any cyanosis. On auscultation there was diminished air entry on the right side, and on percussion there was dull note over upper and the middle zone on right side of the chest. Laboratory investigations revealed that haemogram, arterial blood gas analysis, liver function tests, serum electrolytes and bleeding profile were within the normal limits. X-ray chest revealed multiple cervical hemivertebrae along with radio opacity in right upper and the middle zone. MRI of the chest and abdomen (Fig. 1) was done which revealed a large cystic fluid filled mass in the right posterior mediastinum and right hemithorax in contiguity with and displacing the mediastinal structure to the left. The cervical spine showed a dorsal cleft. The C7 and T1 vertebral bodies showed an oblique right paramedian defect through which the right half of the spinal cord was communicating with the cyst and some neural elements were seen extending into the cystic lesion in the right hemithorax. A provisional diagnosis of NC was made.
On 7th day of life patient underwent right posterolateral thoracotomy, through 4th intercostal space. There was a large bilobed tense cyst which was occupying almost the entire right thoracic cavity and was pushing the right lung anteromedially and inferiorly. The pleura overlying the cyst was incised and separated. The tense cyst was aspirated to ease the dissection. Cyst was dissected from all around, except the apex, where it had an intraspinal connection. Inferior lobe of the cyst was excised, whereas the superior lobe of the cyst was opened and neural structures were seen entering the cyst. The neural structures were separated from the cyst wall and then reposited back into the spinal canal and the redundant sac was excised. Water tight closure of the dura was done with 4-0 silk sutures. Chest was closed after placing an intercostal tube drain, which was connected to underwent seal drainage bottle.
Postoperative course of the patient was uneventful. Chest drain was removed on 3rd postoperative day and patient was discharged on 7th postoperative day. Post chest drain removal X-ray chest demonstrated good expansion of the right lung. Histopathological examination revealed that the cyst was lined by stratified squamous epithelium and had a muscle wall, which was consistent with foregut duplication cyst.
DISCUSSION
Neurenteric cysts are thought to form early in the course of development, when notochord and foregut are in apposition, either because of failure of complete separation or because of herniation of foregut endoderm into the dorsal ectoderm.2,3 Histologically, NC has alimentary tract mucosa, well developed muscle wall and have no serosa.1 Almost all patients have vertebral anomalies, as was also seen in our case, and the central nervous system may be involved.4,5 Respiratory distress due to air way compression is the most common presentation in young children, whereas older children present with heartburn or melaena, because of the occasional presence of gastric mucosa which undergoes inflammation or ulceration.6 MRI or CT-myelogram is suggested when a posterior mediastinal mass is associated with vertebral anomalies.1 Treatment is excision of the cyst, but simultaneous laminectomy may be required in select cases.7,8,9
Hence to conclude the coexistence of a cystic posterior mediastinal mass with adjacent hemivertebrae should raise the suspicion of NC as well as anterior meningocoele.
REFERENCES
1. Arvin IP, Diana LF. Mediastinal cysts and tumours. Pediatric Surgery 1998; 5 : 839-51.
2. Kropp J, Emons D, Winkler C. Neurenteric cyst diagnosed by technetium-99m pertechnetate sequential scintigraphy. J Nucl Med 1987; 28 : 1218.
3. Piramoon AM, Abbasioun K. Mediastinal enterogenic cyst with I cord compression. J Pediatr Surg 1974; 9 : 543.
4. Superina RA, Ein SH, Humphreys RP. Cystic duplication of the esophagus and neurentric cysts. J Pediatr Surg 1984; 19 : 527.
5. Wolf YG. Thoraco-abdominal enteric duplication with meningocele, skeletal anomalies and dextrocardia. Eur J Pediatr 1990; 149 : 786.
6. Holcomb GW III, Gheissari A, O’Neill JA. Surgical management of alimentary tract duplications. Ann Surg 1989; 209 : 167.
7. Beardmore HE, Wigglesworth FW. Vertebral anomaly and alimentary tract duplication. Pediatr Clin North Am 1958; 5 : 457.
8. Bilik R, Ginzberg H, Superina RA. Unconventional treatment of neurenteric cyst. J Pediatr Surg 1995; 30 : 115.
9. Fallon M, Gordon ARG, Lendrum AD. Mediastinal cysts of foregut origin associated with vertebral anomalies. Br J Surg 1954; 41 : 520.
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