Huge Spinal Extradural Meningeal Cyst in the Thoracolumbar Spine: A Case Report of a Rare Cause of Low Back Pain

Symptomatic intraspinal extradural meningeal cysts are rare. We present the case of a 17-year-old female with low back pain, progressive numbness, and radiation pain to the flank and lower limbs. Magnetic resonance imaging and computed tomographic myelography revealed a huge intraspinal extradural meningeal cyst extending from T12 to L3 with cord and dural sac compression. The patient underwent surgery to open the cyst and close the connecting dural defect. Pathologic examination of the cyst disclosed non-specific fibrous connective tissue without an inner arachnoid single-cell lining. She achieved complete recovery after the operation. There was no recurrence of the cyst at a 2-year follow-up.