This is a case of a 25 year old male who manifested with a 5-month history of slowly progressive difficulty in ambulation with urinary retention requiring catheterization on the day of admission. Neurologic examination revealed hypoesthesia at the level of T10 with mild spastic gait, with paraparesis and hyperactive reflexes of the lower extremities with bilateral Babinski.

On contrast-enhanced spinal Magnetic Resonance Imaging (MRI), presence of syringomyelia, at the T7 to T11 levels, with an extramedullary, intradural dorsal arachnoid cyst at T1 to upper T7 levels. The arachnoid cyst caused anterior cord displacement and mild compression of the spinal cord. Neurosurgery performed a decompressive laminectomy at T2-T3 levels, with drainage of arachnoid cyst, and laminectomy at T8-T9 levels with insertion of syringosubarachnoid shunt. Post-operatively, there was improvement in symptomatology.

The coexistence of syringomyelia and spinal arachnoid cyst is uncommon and was first reported in 1973, followed by another 31 other cases until now. Excluding the cases at the craniocervical junction, the thoracic region is the most common location where spinal arachnoid cysts are found. A Pubmed/Medline literature review yielded 90 articles.

We present an unreported case and discuss the current hypotheses on the pathomechanism, surgical management, and evaluation of the features of the 31 previously published cases.