Meningioma originating from the oculomotor nerve without dural attachment in a child.

Meningioma originating from the oculomotor nerve without dural attachment in children has been rarely reported. A 6-year-old patient presented ptosis of the right eye for 5 years. MRI indicated an occupying lesion in the right cavernous sinus. A tumor originating from the oculomotor nerve without dural attachment was found during subsequent surgery and confirmed as meningioma by pathology. Subsequently, the tumor was removed completely, and the oculomotor nerve was reconstructed using the sural nerve. The patient's symptoms were relieved partially after 3 months. The findings of this case suggested that the mechanisms underlying meningioma involve ectopic arachnoid cap cells within the nerve sheath. Thus, the tumor should be removed completely; also, nerve reconstruction is suggested.