脊椎および脳神経外科ジャーナル

Rare Neural Tube Defect: Type I Split Cord Malformation and Spinal Neurenteric Cyst in an Adult

Francesca Granata, Concetta Alafaci, Daniele Cafarella, Antonio Collufio, Valeria Barresi, Marcello Longo, Enricomaria Mormina1 and Francesco Maria Salpietro

Rare Neural Tube Defect: Type I Split Cord Malformation and Spinal Neurenteric Cyst in an Adult

Objective: Split cord malformation (SCM) is a rare form of closed neural tube defect characterized by a sagittal splitting of the spinal cord. Pang’s classification distinguishes a type I SCM (diastematomyelia with septum) and a type II SCM (true diplomyelia). SCM typically presents in childhood and, rarely, in aduls. Neurenteric cysts are composed of heterotopic endodermal tissue. They usually have an intradural extramedullary location, ventrally or ventrolaterally to the spinal cord. Less frequently, the cyst may be located posteriorly to the spinal cord, within the cord, or within the cleft of a diastematomyelia.

Methods: We reported a 56-year-old woman with a 4-month history of severe back pain and paresthesia on the right flank. MRI revealed, at T9-T11 level, the coexistence of a type 1 SCM and an intradural extramedullary neurenteric cyst. The patient underwent surgery.

Results: Following a T9-T11 laminectomy, a posterior median incision of the dura was performed to expose the cystic thin-walled translucent membrane. The wall was opened with drainage of a whitish fluid and the cyst membrane was totally removed “en-bloc”. After the operation, the patient referred complete disappearance of the dorsolumbar pain. There was no deterioration of neurological status. The patient was discharged on 7th day post-operatively.

Conclusion: The association between diastematomyelia and neurenteric cyst represents a very rare condition, especially in adulthood, in spite of their possible common embryological origin. The symptoms are usually related to the spinal cord compression caused by the cyst; therefore, the surgical excision of the cyst is effective.