Imaging of thoracic and lumbar spinal extradural arachnoid cysts: report of two cases

Abstract

Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal which may communicate with the subarachnoid space. Usually in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report cases of thoracic and lumbar arachnoid cysts studied by cystography, myelography, CT and MRI. These techniques showed extradural cystic lesions containing cerebrospinal fluid, with variable communication with the subarachnoid space, causing anterior displacement and flattening of the spinal cord.

Spinal extradural meningeal cyst with spinal stenosis

“…Myelography can be helpful in detecting spinal compression but sometimes fails to show the filling of the cyst. 10 In this case, delayed CT-myelography can be helpful. Our diagnostic tool of choice is the MRI, which has great sensitivity and specificity for cerebrospinal fluid containing lesions.…”

“…With the MRI cord, atrophy and extent of myelomalacia can be assessed. 10 Differential diagnosis to extradural arachnoid cysts are intradural arachnoid cysts, neurenteric cysts, perineural cysts, synovial cysts, meningocele, cystic neoplasms, congenital and traumatic epidermoid, dermoid, inflammatory cysts and cysticerosis. 9 For patients with symptomatic arachnoid cysts, surgery is the treatment of choice.…”

Dural Repair for Intraspinal Extradural Meningeal Cyst -Case Report-

“…The differential diagnosis includes extradural arachnoid cyst following discectomy, laminectomy, vertebral injury, or repeated lumbar punctures, but the neck of these lesions is usually wide, the postoperative changes are obvious, and the history indicates the correct diagnosis. 17,18) The diagnosis is usually established by myelography, and cystography, which demonstrates an extradural defect with smooth displacement of the margin of the dural sac. The correct diagnosis can be made with confidence only if the cyst is filled by contrast medium.…”

“…The neck of the arachnoid diverticulum may be so narrow that even water-soluble contrast medium may not enter the cyst during myelography and delayed CT myelography may be required to demonstrate filling of the cyst. 9, 13,17) CT myelography and CT following cystography can show the communication between the spinal subarachnoid space and the cyst cavity, and delayed CT can provide information about the nature of the communication between the cyst and the subarachnoid space. CT myelography in the present case showed the findings that contrast medium infiltrated into extra-spinal canal.…”

Spinal Extradural Arachnoid Cyst. Case Report.

“…[2][3][4][5][6][7][8][9] The patients were eight males and two females, aged from 11 to 49 years. Four patients were teenagers and four were in the forties.…”