Key Clinical Findings & Highlights
- Documents a rare WHO Grade II clear cell meningioma presenting as an extradural lumbosacral mass.
- Clarifies key immunohistochemical distinctions between clear cell meningioma (EMA+) and schwannoma (S-100+).
- Demonstrates complete gross total resection with nerve root preservation and excellent functional recovery.
Abstract
Introduction & Background
Clear cell meningiomas account for less than 0.2% of all meningiomas. Unlike classical benign meningiomas (WHO Grade I), clear cell meningiomas exhibit aggressive local invasion, high recurrence rates, and younger age predilection. When arising in the lumbar or sacral spinal canal without obvious dural attachment, their encapsulated, lobulated appearance closely mimics that of a giant spinal schwannoma on contrast-enhanced MRI.
Clinical Case Presentation & Diagnosis
A 32-year-old male presented with a 6-month history of severe, progressive low back pain radiating down the left L5 and S1 dermatomes, accompanied by numbness in the lateral foot and mild weakness during plantar flexion. Magnetic resonance imaging demonstrated a massive (5.4 cm x 3.2 cm) well-circumscribed, homogenously enhancing extradural mass occupying the left lumbosacral neural foramen and expanding into the retroperitoneal paraspinal space, eroding the adjacent vertebral body and sacral ala. Preoperative radiological impression was a giant benign schwannoma.
Surgical Technique & Management
A posterior midline lumbosacral approach was performed with multilevel hemilaminectomy and facet-sparing technique. The encapsulated extradural tumor was separated microsurgically from the exiting L5 and S1 nerve roots under continuous intraoperative neurological monitoring. Complete gross total resection (Simpson Grade I equivalent) was accomplished without compromising spinal biomechanical stability.
Discussion & Literature Context
Histopathological analysis revealed sheets of polygonal cells with abundant clear, glycogen-rich cytoplasm (positive on Periodic acid-Schiff stain and diastase-sensitive) surrounded by dense hyalinized collagen bands. Immunohistochemistry confirmed strong positivity for Epithelial Membrane Antigen (EMA) and Vimentin, while S-100 and SOX10 were negative, confirming clear cell meningioma rather than schwannoma. Because of the aggressive nature of WHO Grade II tumors, close long-term clinical and MRI follow-up is critical.
Conclusion
Spine surgeons must maintain clear cell meningioma in the differential diagnosis of giant lumbosacral paraspinal lesions. Complete gross total microsurgical resection is the primary determinant of recurrence-free survival.
How to Cite This Research
Dr. Surendra K. Gupta, N. Nayak, C. Gandhoke, R. Gupta, A. Sharma, P. Singh, R. Sharma (2021). "A giant nondural-based lumbosacral clear cell meningioma mimicking schwannoma: A case report and review of the literature". Asian Journal of Neurosurgery, Volume 16, Issue 1, Pages 44-50.
