Spinal extradural arachnoid cyst in cervicothoracic junction.

Only 3% of all SEACs are observed in the cervical spine. They are the most common in young men and present with compressive symptoms. SEACs have potential to enlarge. As they are surgically removable lesions, early and definite diagnosis is important in preventing clinical deterioration. MRI is recommended for the diagnosis and preoperative planning.