Spinal neurenteric cyst

Spinal neurenteric cysts are a rare type of foregut duplication cyst, accounting for ~1% of all spinal cord tumors. They are usually classified as spinal or intracranial and are associated with vertebral or CNS abnormalities respectively. 

Pathology

Neurenteric cysts result from incomplete resorption of the neurenteric canal. 

Location

The intraspinal cysts are usually intradural extramedullary (80-90%) ⁴ and ventral in location ⁵. They most commonly occur in the thoracic region (~40%).

Associations

• vertebral anomalies like Klippel-Feil syndrome, hemivertebra, butterfly vertebra, scoliosis, split cord and spina bifida ^5,6

Radiographic features

CT

The cyst is seen as a well-defined hypoattenuating lesion which may show soft-tissue attenuation. 

On CT myelography, the cyst does not opacify with intrathecal contrast. However, larger cysts may cause obstruction to the CSF flow; in such cases, intrathecal contrast material forms meniscus shape (meniscus sign) ⁵.

MRI

It is the investigation of choice and the appearance depends on the variable protein content:

• T1: variable signal intensity
• T2: variable signal intensity

Treatment and prognosis

These lesions can recur and hence MRI is also used for follow up.