Sporadic meningioangiomatosis with and without meningioma: analysis of clinical differences and risk factors for poor seizure outcomes.

Background: Meningioangiomatosis (MA) is a rare cerebral lesion. Sporadic MA occasionally combines with meningioma (MA-M). The aim of the present study was to clarify whether MA-M and pure MA have clinical differences and to determine risk factors for unsatisfactory seizure outcomes in sporadic MA.

Methods: We reported 14 sporadic MA cases in our center and conducted a literature review. We compared the demographic, clinical, imaging, electrophysiological and pathological features and surgical outcomes. Logistic regression analysis was performed to evaluate the risk factors for poor seizure outcomes.

Results: MA-M cases showed a more prominent male predilection (4.2 times vs. 1.6 times, p = 0.04), a shorter duration of symptoms (2.8 ± 0.8 years vs. 5.2 ± 0.6 years, p = 0.02), and a lower seizure incidence (53.6 % vs. 89.3 %, p < 0.001) as compared to pure MA. A gyriform alteration on imaging was exclusively associated with pure MA. The Ki-67 was higher in the meningioma component than in the MA component in MA-M (1.2 ± 0.3 % vs. 6.1 ± 1.1 %, p < 0.001). Lesions located in the temporal lobe predicted poor seizure outcomes (p = 0.02, OR = 4.4, 95 % confidence interval, 1.24-15.89).

Conclusion: Clinical differences may be caused by the different biological natures. MA-M seems to be a neoplastic lesion, while pure MA seems to be a non-neoplastic lesion. Long-term follow-up is required for MA-M. Because the coexistence of hippocampal sclerosis may explain the poor seizure outcomes of MA located in the temporal lobe, it is important to identify underlying hippocampal sclerosis and to perform complete resection.