On the other hand, grade 2 lesions correspond to 5%-17% in the international literature [24], and our study reported 1%; these results are different from what has been reported in the literature; we suggest that the delay in diagnosis and the lack of resources to identify genetic mutations, such as mutations of the Telomerase reverse transcriptase (TERT) promoter, in developing countries like ours are involved in malignant progression and misdiagnosis of a grade 2 meningioma [18] Grade 3 lesions constitute 1-3% of all meningiomas [25]; in our series, we found 10% of these lesions. Here, TERT is linked to meningioma.