neurenteric cysts are congenital malformations arising during the embryonic phase and are therefore not true neoplasms. Many different synonyms exist (enterogenic, teratomatous- archenteric cyst, intestinoma…). The endothelium of the cyst wall resembles that of the gastrointestinal or, more rarely, the respiratory tract. This pathology is mostly found in the thoracic spinal region, less commonly intracranially. The cysts develop at 3 weeks of gestation during embryogenesis due to a local breach at the bottom of the notochordal canal.
Epidemiology
Neurenteric cysts are extremely rare and account for only about 0.01% of all brain and 0.3-1.3% of all spinal tumors. Most frequent localizations intracranially are: Cerebellopontine angle, anterior to the brainstem, and cisterna magna. In the spinal canal, cysts are usually located anteriorly. Most commonly, patients become clinically symptomatic in the first decade of life (neonates, children). However, these cysts may not manifest clinically until young adulthood.
Radiological findings
In MR imaging, neurenteric cysts show no KM-enhancement. They are iso- hyperintense compared to CSF. In the spinal region (40% thoracic localization), cysts are mostly intradural extramedullary (80-90%) and ventral to the myelon. The size of the cysts vary widely (<1cm to several cm).
Differential diagnoses
Metastase zerebral oder spinal, (Epi) Dermoid, Rathke Zyste, Colloid Zyste, Kraniopharyngeom
Special / to be noted
Concomitant anomalies
If localization is in the spine, associated developmental anomalies may also be present in terms of fistulous or connective tissue connections to the gastrointestinal tract. Vertebral anomalies such as Klippel-Feil syndrome, hemivertebae, or spina bifida have been described in association with neurenteric cysts.
Indication for surgery
In symptomatic patients, an “in toto” resection is indicated. The cyst wall should be removed as well, due to the increased risk of recurrence with parts left in situ. Marsupialization techniques have been described for adherent cyst wall portions in the brainstem region. With intracranially located neurenteric cysts and subsequent resection, VP shunt may be required postoperatively.
Author(s) of the article
- Dr. med. D. Schöni, Facharzt für Neurochirurgie, executive MBA HSG
References
- Goel A. Comment on Lin J, et al.: Ventral brainstem enterogenous cyst: an unusual location. Acta Neurochir (Wien). 2004; 146