Spinal clear cell meningioma:clinical study with long-term follow-up in 12 patients.

BACKGROUND: Clear cell meningioma (CCM) is a rare histologic subtype of meningioma, and the features of CCMs are commonly based on the intracranial cases. However, CCMs in spinal cord are even rarer, and the natural history, management and prognosis of them remain ill defined.

METHODS: From January 2006 to January 2018, twelve patients with spinal CCM were treated in our hospital. The clinical features, radiologic findings, diagnosis, treatment, and outcome of these patients were analyzed retrospectively. Additionally, a literature review of spinal CCMs was performed.

RESULTS: CCMs accounted for 2.8% of all the spinal meningiomas treated in our hospital. The most common localization of this disease was the lumbar region (7/12). The mean age at diagnosis was significantly younger than that of patients with spinal meningiomas (28.8±13.4 versus 54.0±14.4 years). During the follow-up period, five patients (41.7%) suffered from tumor recurrence. Kaplan-Meier analysis showed that patients with younger age had significantly shorter progression-free survival (PFS) time than elder patients. Literature review showed 55 cases with spinal CCMs had been reported. Nineteen patients (38.0%) suffered from local recurrence with a 5-year PFS rate of 33.3%.

CONCLUSIONS: Spinal CCMs are extremely rare tumors with a predilection to affect younger patients and a high recurrence rate. Although gross total resection (GTR) is considered to be the optimal treatment, radiotherapy might be considered to patients underwent subtotal resection (STR), or those younger patients regardless of the extent of removal. Close follow-up of the entire neuraxis for years is crucial.