T10-L3 Cystic Lesion of the Ventriculus Terminalis Presenting as Conus Medullaris Syndrome

Background: Intramedullary spinal cord cysts are benign, rare, fluid-filled lesions that can present anywhere along the craniospinal axis. However, when present at the level of the ventriculus terminalis, conus medullaris syndrome may occur. Radical resection of the cyst wall and evacuation of the cyst content are the 2 surgical procedures of choice. Case Description: We present the case of a 54-year-old woman with a long-lasting history of left lower-extremity weakness and recent onset of bladder dysfunction. On further assessment, magnetic resonance imaging of the thoracic and lumbar spine showed a T10-L3 intramedullary cystic lesion. Surgical fenestration of the cyst was rendered, but no biopsy was taken due to the highly functional tissue along the full extension of lesion. Conclusions: Cystic lesions of the ventriculus terminalis are rare entities with a common presentation of severe, progressive neurologic impairment. Our case matches the classic presentation of conus medullaris syndrome. We describe and demonstrate through an operative video novel surgical techniques used to achieve successful fenestration of the cyst wall with remarkable neurologic symptom improvement. Moreover, the present case does not correlate with the classic radiographic characteristics available in current literature, such as involvement of 5 spinal segments.