Primary papillary meningioma of the optic nerve sheath: a case of unique location and benign pathology.

I report here a case of primary papillary meningioma of the optic nerve sheath which developed in the left eye of a 54-year-old woman over a period of 20 years. A review of 123 primary papillary meningiomas, including the current instance, disclosed that they tended to occur in young patients of both sexes at an average age of 35 years, with one-fourth of them occurring in the first two decades of life, and with a female/male ratio of 3:2. These meningiomas were most frequent in the supratentorial compartment of the cranial cavity, especially on the cerebral convexity and in the parasagittal region. They were uncommon subtentorially, intraspinally, and outside the central nervous system. Most reported papillary meningiomas were claimed to be malignant, but the tumor of this particular woman was benign pathologically and clinically.