Foramen magnum meningioma originating from the dentate ligament

The authors report a woman with a foramen magnum meningioma originating from the dentate ligament. A 72 year-old woman developed posterior neck pain and a tingling sensation in the left arm. Magnetic resonance imaging showed a well defined and homogenously enhancing mass at the foramen magnum with no dural attachment. Angiography did not demonstrate a blood supply to the tumour via the posterior meningeal branches of the vertebral artery. The mass was totally removed via a midline suboccipital approach. Intraoperatively, the mass was found to adhere to the dentate ligament without a dural attachment. Histopathology findings were consistent with the diagnosis of meningioma. This case is the first report of a meningioma originating from the dentate ligament and the tumour may have originated from the pia-arachnoidal extension of the spinal cord to the dura.