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Synovial Cyst of Dens Axis

Synovial cyst of dens axis is a rare pathology accounting for 0.5%-1% of all cases of spinal synovial cysts. The lesion is normally found in the final part of the lumbar tract. The etiopathogenesis is uncertain and many theories abound Clinical inspection is important and the symptoms are caused by compression of posterior roots of spinal nerves and by spinal canal stenosis. Differential diagnosis is with disc herniation or tumours, but the diagnosis can only be established after CT and MRI examination. We describe the case of an 83-year-old man who underwent radiological exmaination after ten years of symptoms. The pathology was diagnosed only after the CT and MRI investigation.