[Spinal epidural meningioma--a case report with special reference to neuroradiological findings]

Spinal meningiomas are common as intradural-extramedullary neoplasm, but solitaly epidural spinal meningiomas are extremely rare. They may often be misdiagnosed as malignant neoplasms which are much more common in this location. Furthermore, at the time of operation, it is often difficult to distinguish the epidural meningioma from malignant tumors, even by the microscopic examination of the fresh frozen section. We present a case of spinal epidural meningioma, and emphasize the importance of preoperative neuroradiological examinations. A 26-year-old woman was referred to us from a neurologist of another hospital under the diagnosis of thoracic spinal tumor. She noticed sensory numbness in the lower extremities and thermal hypesthesia below the breasts about one year previously, and progressive gait disturbance about half a year prior to admission. Neurological examination revealed spastic paraparesis with hypesthesia of all modalities below T3. Plain films of the thoracic spine showed scalloping of the posterior margine of the T3 vertebral body. Metrizamide myelography showed a complete block at T3/4, and metrizamide CT revealed marked dural compression by an epidural mass which occupied the left side of the spinal canal from T2 to T4. The subarachnoid space all around the spinal cord was preserved comparatively well. The tumor was homogeneously enhanced by intravenous contrast enhanced CT scan, and the extracanalicular extension was not revealed. MRI [SE (400/25)] showed an iso-intensity signal tumor. Neither extracanalicular nor intrathecal extension of the tumor was showed. In addition to the possibility of the malignant tumors, we considered the possibility of spinal epidural meningioma. At operation, of highly vascularized, moderately firm epidural tumor was found invading the surrounding epidural fat.(ABSTRACT TRUNCATED AT 250 WORDS)