Ventral "spinal epidural meningeal cysts"--not epidural and not cysts? Case series and review of the literature.

BACKGROUND

Ventral spinal epidural meningeal cysts are rare entities for which the pathogenesis is poorly understood.

OBJECTIVE

We present the clinical, radiographic, surgical, and pathologic findings of 4 patients with extensive ventral spinal epidural meningeal cysts and review the relevant literature. In addition, we discuss a suspected mechanism for pathogenesis.

METHODS

Four patients with anterior spinal epidural meningeal cysts are retrospectively reviewed.

RESULTS

Ventral spinal epidural meningeal cysts are often large, extending on average from C2 to L1 in our series. Patients typically present with a prolonged course of symptoms and signs, including segmental muscle weakness and atrophy, subtle myelopathy, mild to moderate spinal pain, and headache. Histopathologic analysis of the cyst wall demonstrates collagenous tissue consistent with dura but without arachnoid features. Dynamic computed tomographic myelography is the study of choice for localization of the primary dural defect. Patient symptoms and neurological deficits routinely improve after appropriate surgical intervention.

CONCLUSION

Diverse signs and symptoms herald the presentation of ventral spinal meningoceles. Intraoperative, radiographic, and pathological findings are all suggestive of an intradural dissection as the etiology. Hence, they may be more appropriately named "ventral spinal intradural dissecting meningoceles." Definitive treatment involves identification and obliteration of the dural defect.