Orbital schwannoma

Neurilemmoma is a benign tumor that occurs in axon sheath cells, and is more common in the brain and peripheral nerve roots, limbs, and head and neck. Sheath cells are also called Schwann's cells. Schwannoma was once called Schwannoma. The orbital is rich in nerve tissue, including sensory branches of the ophthalmic nerves from motor nerves, sympathetic nerves, parasympathetic nerves and trigeminal nerves that supply extraocular muscles, and a few branches of the maxillary nerve, so schwannomas are also common. Most orbital peripheral nerve tumors originate from sensory nerves. Patients often feel pain, but the movement of extraocular muscles and other non-sensory nerve functions are normal after tumor removal. The optic nerve belongs to the central nerve and does not contain sheath cells. Schwannomas do not occur in the optic nerve fibers. However, the meninges surrounding the optic nerve, which contain ophthalmic and sympathetic nerve components, can cause nerve tumors, but it is rare. Intraorbital schwannomas mostly occur in the sensory nerve trunk and its small branches. Schwannomas account for about 3% of orbital tumors. Orbital schwannomas mostly occur alone, with a small number of patients with neurofibromatosis. Most tumors occur above and outside the orbit.