Benign extramedullary tumors in the foramen magnum region.

We present 16 cases of benign extramedullary tumors of the foramen magnum region who were operated on between the years 1984 and 1992. On admission, no case was neurologically intact and over 50% had had symptoms for more than 1 year. Nine patients had erroneous diagnoses initially. CT myelography and magnetic resonance (MR) imaging were the most appropriate diagnostic tools in visualizing tumors of this region. All operations except one, were performed by the posterior approach without surgical mortality. Histopathological examination revealed 8 meningiomas, 6 neurinomas, one tuberculous abscess and one neurenteric cyst which has not been reported at this location before. Patients with minor to moderate disability on admission showed good functional results without any recurrences during follow-up.