Totally extradural spinal en plaque meningiomas - Diagnostic dilemmas and treatment strategies

Abstract

Background:Meningiomas are the second most common intraspinal tumors, constituting ~25% of all intraspinal tumors; however, in the context of extradural spinal lesions, the diagnosis of meningioma is an uncommon one. Purely extradural spinal meningiomas, especially of the en plaque variety, frequently mimic metastatic disease and may result in inadequate therapy.Case Description:We report two cases of totally extradural en-plaque meningiomas of the spine, one each in the cervical and dorsal spine. We present the significant diagnostic dilemmas posed by these cases and discuss the pathogenesis, treatment strategies, and long-term behavior of these uncommon lesions.Conclusion:Attention needs to be drawn to this dangerous preoperative and intraoperative misinterpretation. Intraoperative histopathology support for correct identification, gross total resection at surgery, inclusion of a durotomy to rule out intradural extension, and long-term follow-up are cornerstones for successful management of totally extradural en plaque spinal meningiomas.

Spinal extradural meningioma en plaque with nerve root attachment and extracanal (intrathoracic) extension

“…The presence of a "sole" extradural spine meningioma is entirely rare [2]. Common tumours located in the spinal extradural space are metastatic spinal tumour and lymphoma, hence the dilemma in preoperative diagnosis which was also emphasis by Saryedekar et al in the two cases reported by them [7].…”

“…An entirely spinal extradural meningioma especially of the 'en plaque; variety poses a dilemma in pre-operative diagnosis [2,7]. In this index case, a pre-operative diagnosis of C4-T1 schwannoma of the spine in view of its location and C7 nerve root attachment.…”

“…However, the thoracic extension was left in-situ. Saryedekar et al in their work shows the importance of intraoperative frozen section with near total resection of spinal extradural meningioma en plaque [7]. This strategy will give the best postoperative outcome, as prognosis depends on the extent of tumour resection [8],…”

“…It may be necessary to only peeled off the tumour from the dura. Saryadekar et al in the two cases reported shows that the tumour was stripped off the dura with no durotomy done [7]. Though there is essentially no consensus on whether the dura should be excised or not, However, it is necessary that the dura be opened to rule out intradural extension of the meningioma which is seen in literature to account for about 10% of cases [2].…”

Extradural spinal meningioma: Revisiting a rare entity

“…Hence, intraoperative pathological examination using either frozen section examination or squash cytology is very important. [ 12 ]…”