Symptomatic Extra-Dural Arachnoid Cyst

Abstract

Objective: The aim of this study is to report a case of arachnoid cyst due to mass effect on the thoracic marrow. Observation: A 15-year-old patient was admitted to our institution and complaining of high back pain. Three months before he developed progressive and occasional back pain with thoracic irradiation in hemi-belt, increased by the dorsal decubitus. Neurological examination revealed a spasmodic paraplegia. The muscular strength was quoted as 2 to the left and 3 to the right on a scale of 5. Magnetic resonance imaging (MRI) revealed and extradural cyst located to the dorsal spinal cord. The ablation of a voluminous translucent cyst was achieved after a vast decompressive laminectomy from the sixth to the eighth thoracic vertebra. The dural communication with the cyst was stitched. After surgery, the pain has disappeared and the neurological recovery was progressive over a period of 21 days. The diagnosis of arachnoid cyst was confirmed by histological examination. Conclusion: The extradural thoracic arachnoid cyst is a rare affection of good forecast. In the symptomatic form, the surgery as soon as possible remains the solution. The MRI keeps all its interest for the diagnostic orientation and the therapeutic strategy.