Ossified anterior foramen magnum meningioma: report of long-term surgical outcome.

BACKGROUND: Technical surgery-related issues for large ossified/calcified meningioma that encased one or both vertebral arteries located anterior to brainstem in the region of foramen magnum are discussed. Relatively long-term outcome of successful surgery is reported. CASE DESCRIPTION: Three women were operated on for symptoms of progressive quadriparesis. Investigations revealed ossified meningioma located anterior to the brainstem. One or both vertebral arteries were encased within the confines of the tumor. Large size, bone-hard consistency, location anterior to the brainstem, and intimate vascular relationship made the surgery a formidable surgical problem. A midline posterior suboccipital approach was used to resect these tumors. Radical tumor resection was achieved in all cases successfully. Tumor drilling or heavy tumor breaking instruments were not necessary to debulk the tumor. Histologic examination in all 3 cases revealed psammomatous meningioma. During the follow-up period that ranged from 2 to 12 years, all 3 patients were leading a normal life, and there has been no documented recurrence in any case. CONCLUSIONS: Successful resection of "ossified" meningioma is associated with satisfactory long-term clinical outcome.