A Case of Cervical Extradural Meningioma Mimicking Hematoma in Preoperative Images

Extradural spinal meningiomas (EDSMs) are extremely rare, and most literature on these lesions have been case reports and short case series. We report a case of cervical EDSM in a 76-year-old woman with right hemiparesis due to a previous cerebral infarction. She had fallen and sustained a Th12 vertebral compression fracture 2 months before admission and had since been bedridden. Around the same time, she became aware of weakness in her left upper and lower limbs, but magnetic resonance imaging (MRI) did not reveal any new structural lesions in the brain. Although she had continued rehabilitation for 3 months, her weakness gradually worsened. Eventually, she developed tetraplegia following severe neck pain approximately a month before admission. On admission, she was nearly completely tetraplegic and had severe pain across the neck that radiated to the left upper limb. She complained of numbness below Th1 ; her pinprick and light touch sensations had reduced to 2—3/10 in the left lower extremity. Her neurosurgical cervical spine score was 1 : 1 : 1 : A, and the Japanese Orthopaedic Association cervical score was 2. MRI revealed a left-dominant extradural mass extending from the C3 to C5 vertebral level and compressing the spinal cord anterolaterally. Computed tomography at C4 showed an enlargement near the left neural foramen, which was overlooked preoperatively. Based on the provisional diagnosis of an extradural hematoma, laminectomy was performed from C3 to C5. The surface of the dura was found to be covered by a sheet-like yellowish-white mass that adhered around the left C3/4 intervertebral foramen. Histopathological examination revealed meningothelial meningioma. The postoperative course was uneventful, but the neurological symptoms did not change after the procedure. EDSMs are thought to arise from the nerve root sheath ; it has been reported that recurrence and regrowth are likely due to difficulties with removing the tumor completely. EDSM radiologic findings also overlap with those of several other types of common extradural spinal masses, including metastatic tumors and schwannomas. In this case, the urgent need for decompression necessitates treatment without sufficient preoperative information, which can happen in an emergency. Therefore, in describing this rare case, we also wish to highlight the pitfalls in the differential diagnosis of EDSM.