Spinal extradural meningiomas.

Spinal meningiomas may be primarily extradural, leading to errors in diagnosis and management. Myelographic findings and the microscopic examination of fresh tissue at the time of operation often lead to the conclusion that the tumor is metastatic. Three patients with this type of meningioma have been encountered. Although extensive removal of the tumor was accomplished in each case, the correct diagnosis was difficult to establish at the time of the operation. A second operation was necessary in one patient because the true nature of the tumor was not recognized initially.