[Three cases of cystic neurinoma arising from the upper cervical nerve roots and extending into the posterior cranial fossa (author's transl)].

Three cases of cystic neurinoma arising from the upper cervical spinal nerve roots and extending to the posterior cranial fossa through the foramen magnum were reported. Case 1 was a 52-year-old female presenting marked bilateral papilledema, hyperactive right knee jerk, left positive Gordon reflex and trunkal ataxia. The mass was mostly cystic and arose from the left 1st cervical nerve root. It extended to the posterior fossa, occupied the cerebello-medullary cistern and displaced the left cerebellar hemisphere posteriorly and superiorly. Case 2 was a 39-year-old male presenting marked bilateral papilledema, neck stiffness, dysfunction of the right 7, 9, 10 and 11th cranial nerves, gaze nystagmus, Horner's syndrome, right limb ataxia, and ataxic gait. The mass was totally cystic containing yellowish fluid and was growing from the right 2nd cervical spinal nerve root. The mass extended to the posterior cranial fossa up to the right cerebello-pontine angle and compressed the medulla oblongata, upper cervical cord and 7th through 11th cranial nerves on the right side. Case 3 was a 66-year-old male presenting marked bilateral papilledema, gaze nystagmus, left hemiparesis, bilateral hyperactive deep tendon reflexes, numbness of the left fingers and ataxic gait. CT scanning revealed in the midline of the posterior cranial fossa a low density mass which was enhanced in a ring-like fashion. Vertebral angiograms showed an avascular mass displacing the PICAs upwards and elongating its cranial loops antero-posteriorly. The mass was totally cystic, arose from the left 2nd cervical spinal nerve root, extended to the posterior cranial fossa and occupied the cisterna magna and vallecula. Foramen magnum syndrome was discussed and the symptoms and signs presented in these three cases were compared with those presented by foramen magnum meningioma in other reports.