Spinal cord meningioma accompanied by ossification is considered to be rare. Ossification was noted in 3 of the 7 patients with spinal cord meningioma encountered at our department during the past 20 year. All lesions were of the psammomatous type and showed plate-like ossification of 4×2, 7×5, 15×10mm. The lesion of ossification was adhered to the meningeal side of the tumor in all 3 cases but was located in the tumor parenchyma in 1. However, no ossification caused directly by fusion of psammomatous lesion was observed. The lesion could be visualized by CT (direct tumor sign) only in the case in which ossification extended over more then 10 mm. Direct tumor sign are considered to contribute to the diagnosis of meningioma and determination of its site. Ossification was suspected to have been caused by metaplasia due to stimulation of the meninges by the tumor.
